Oxford Handbook of Paediatrics (2 edn)
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Clinical assessment 732
The limping child 734
The limping child: differential diagnosis 736
Infections: septic arthritis 738
Infections: osteomyelitis 740
Spinal disorders 742
Spine: kyphosis 744
Spine: scoliosis 746
Hip disorders: developmental dysplasia of the hip 748
Hip disorders: Perthes’ disease 750
Hip disorders: slipped upper femoral epiphysis 752
Knee disorders 754
Orthopaedic trauma 758
Osteochondroses 760
Osteogenesis imperfecta 762
Osteopetrosis 764
Cleidocranial dysplasia 765
Skeletal dysplasias 766
Juvenile idiopathic arthritis 768
Juvenile idiopathic arthritis: clinical principles and management 770
Systemic arthritis 772
Oligoarticular juvenile idiopathic arthritis 773
Rheumatoid factor-positive polyarthritis 774
Rheumatoid factor-negative polyarthritis 776
Psoriatic arthritis 777
Enthesitis-related arthritis 778
Systemic lupus erythematosus 780
Juvenile dermatomyositis 782
Mixed connective tissue disease—overlap syndromes 784
Scleroderma 786
Henoch–Schönlein purpura 788
Polyarteritis nodosa 789
Wegener’s granulomatosis 790
Takayasu’s arteritis (pulseless disease) 791
Clinical assessment
History
This should focus on the following:
Presenting complaint:
pain—site, severity, onset, nature, duration/chronicity, exacerbating/relieving factors, rest pain, radiation;
if child presents with knee pain, always ask about and examine the hips;
swelling—site, size, onset, duration, exacerbating/relieving factors;
limp—refusing to weight bear 9 history of trauma or injury;
morning stiffness/start-up pain;
deformity—static/worsening or improving condition.
Associated systemic symptoms:
infection (rigors, night sweats, flu-like symptoms);
loss of appetite/weight.
Antenatal and birth history—important with congenital conditions.
Neurodevelopmental milestones (see 
p.557).
Past medical history—previous trauma, surgery, medical illnesses.
Sports and activities.
Drug history—glucocorticoid usage, allergies.
Family history—hereditary conditions.
Neurological screening:—important in syndromic children.
Examination
Inspection
Observe the child walking and at play (don’t forget to watch as they walk into the consulting room).
General:.
height, weight, proportion (long limbs, short trunk);
skin (scars, lesions, colour, discharge)—soft tissue (swelling, muscle wasting, contractures), skeletal (alignment, rotation, limb length);
limb—amelia (absence), hemimelia (absence of distal half), phocomelia (hand/foot attached directly to trunk), syndactyly (fused digits), polydactyly (additional digits);
Skeletal alignment:
Spine—normally there is a flexible kyphosis of the thoracic spine, a lordosis at the cervical and lumbar spine (not noticeable in neonates). look also for plagiocephaly, torticollis, scoliosis;
lower limb—check rotational profile, symmetric range of movement, varus/valgus deformity; always examine the hips;
feet—babies have ‘flat’ feet. The medial longitudinal arch develops during childhood. Look at the shoes!
elbows—there is a mild valgus deformity when in extension especially in females.
Mobility and gait: toddlers have a wide stepping jerky gait. As the child matures (by the age of 7yrs), the gait becomes more ‘adult-like’ with the heel strike, stance phase (whole of foot to the ground), push off phase, and arm swing. The cadence decreases and the step length increases.
antalgic (painful) gait—short stance phase (child does not want to put weight on affected limb);
high stepping gait—usually due to foot drop (child lifts foot higher off the ground to avoid tripping over);
Trendelenberg gait—look at pelvis. When weight is loaded on the ipsilateral side, the contralateral hemipelvis tilts downwards (due to weak abductors or neurological, muscular, or hip joint causes in the weight-bearing ipsilateral limb). The upper body is then used to counter-balance;
Trendelenburg test: stand facing the child with your hands out, palms facing upwards. Ask the child to rest their hands (palms down) on your hands. Then ask the child to lift one leg. If the pelvis tilts downwards on the non-weight-bearing side (you will feel the downward pressure on your hand of this side) the test is positive.
Gower’s sign: child should be able to independently stand from a sitting position without using their upper limbs. With weak lower limb muscles, the child may ‘crawl’ hands up thighs in order to stand up, e.g. in muscular dystrophy.
Neurodevelopmental assessment: see p.557.
Can the child hop on either foot?
Can the child climb on to the examination couch?
Feel
Tenderness, warmth, swelling (firmness, fluctuant), leg length discrepancy (true leg length: measure from the anterior superior iliac spine to the medial malleolus), pulses.
Move
General: muscle tone, symmetric full joint range of movement, hyperlaxity/stiffness, contractures (are they fixed or can they be overcome?).
Spine: fixed/correctable deformity?
Hip: Ortolani and Barlow tests ( p.748).
Knee: patella instability, anterior drawer/Lachman test (ACL integrity).
The limping child
Exclude trauma and infection before considering other disorders.
Examination
Lower limbs, back, and abdomen need to be examined. Observe the following:
Limb position of least pain (e.g. in hip septic arthritis, the hip is held in flexion and external rotation).
Gait ( p.34).
Movement and mobility:
ability to weight bear passively and actively;
ability to move the joints and limbs freely;
palpate for tenderness, heat, and swelling around the joint; palpate the entire length of the extremity, the abdomen, and spine;
leg length difference: anterior superior iliac spine (ASIS) to medial malleoli. to determine if discrepancy is in femur, or tibia perform galeazzi test (flex knees and hips and examine from the side);
range of movement (ROM): in individual joint and compare with other side;
neurological and vascular status : abdominal examination.
Beware of referred pain from joint above or from the abdomen (consider appendicitis, inguinal hernia, UTI with hip pain). Always assess the joint above and below. Hip pathology may present as knee pain.
Investigations
Temperature.
Bloods: FBC, ESR (may be normal), CRP, blood cultures, blood film, rheumatoid factor (RF), antinuclear antibody (ANA), anti-streptolysin (ASO) titre, Lyme titre, HLA-B27.
Urine: dipstick + MSU.
X-rays: antero-posterior (AP), lateral plain X-ray of entire bone involved including joint above and below (e.g. if hip: AP pelvis and frog leg lateral views).
US scan: of muscle and bone.
MRI: very sensitive and specific—good for soft tissues and bone pathology.
Three phase bone scan: when pain not easily localizable; sensitive, but not specific. Radiation exposure.
The limping child: differential diagnosis
| Back | Hip | Femur | Knee | Foot & ankle |
|---|---|---|---|---|
Age 0–5yrs | ||||
Discitis | Developmental dysplasia of hip, transient synovitis, septic arthritis | Osteomyelitis* | Septic arthritis | |
Age 5–10yrs | ||||
Discitis | Transient synovitis, Perthes’ disease, septic arthritis | Osteomyelitis* | Discoid meniscus, septic arthritis | Kohler’s disease, Freiberg’s disease, tarsal coalition, verruca |
Age 10–15yrs | ||||
Discitis | Slipped upper femoral epiphysis, septic arthritis | Osteomyelitis* | Osgood–Schlatter’s disease, osteochondritis dessicans, patellofemoral pain syndrome, chondromalacia patella | Sever’s disease, tarsal coalition, verruca, in growing toenails |
| Back | Hip | Femur | Knee | Foot & ankle |
|---|---|---|---|---|
Age 0–5yrs | ||||
Discitis | Developmental dysplasia of hip, transient synovitis, septic arthritis | Osteomyelitis* | Septic arthritis | |
Age 5–10yrs | ||||
Discitis | Transient synovitis, Perthes’ disease, septic arthritis | Osteomyelitis* | Discoid meniscus, septic arthritis | Kohler’s disease, Freiberg’s disease, tarsal coalition, verruca |
Age 10–15yrs | ||||
Discitis | Slipped upper femoral epiphysis, septic arthritis | Osteomyelitis* | Osgood–Schlatter’s disease, osteochondritis dessicans, patellofemoral pain syndrome, chondromalacia patella | Sever’s disease, tarsal coalition, verruca, in growing toenails |
Consider with septic joint.
Causes of limp
Tumour
Benign tumour
Osteoid osteoma (age 5–15yrs).
Haematological causes (all ages)
Infection (all ages)
Neurological causes (all ages)
Rheumatological causes (all ages) Juvenile idiopathic arthritis (JIA; p.768).
Trauma (all ages)
Non-accidental injury (NAI).
Trauma (open/closed fractures).
Sprains/contusions.
Ill-fitting shoes.
Congenital causes (all ages)
Congenital limb deficiency/shortening.
Infections: septic arthritis
An infectious arthritis of a synovial joint. The frequency is highest in young children with half of all cases presenting in the first 2yrs. Males > female (2:1).
Pathogenesis
Septic arthritis can develop from osteomyelitis especially in neonates where infection spreads from the metaphysis via transepiphyseal vessels. It may also arise due to haematogenous spread of infection or by direct inoculation.
Aetiology
Age <12mths old: Staphylococcus aureus, Group B streptococcus, Gram −ve bacilli, Candida albicans.
Age 1–5yrs: Staph. aureus, Haemophilus influenza (rarely in immunized children), Group A streptococcus (pyogenes), Streptococcus pneumonia, Kingella kingae, Neisseria gonorrheae (child abuse).
Age 5–12yrs: Staph. aureus, Group A streptococcus.
Age 12–18yrs: Staph. aureus, Neisseria gonorrhoeae (sexually active).
Community acquired MRSA (CA-MRSA) is increasing worldwide.
Common joints affected
Most (75%) are in lower limb. Knee > hip > ankle. Other 25% are in upper limbs.
Differential diagnosis
This depends on age and joint involved:
Hip: transient synovitis, Perthes, slipped capital femoral epiphysis, psoas abscess, proximal femoral or vertebral osteomyelitis, discitis.
Knee: distal femoral or proximal tibial osteomyelitis. Pain often referred from the hip.
General: cellulitis, pyomyositis, other infectious arthritis (viral, mycoplasmal, mycobacterial, fungal, Lyme disease), sickle cell, haemophilia, trauma, collagen vascular disease, Henoch–Schönlein purpura, reactive arthritis from GI infections or GU infections, streptococcal pharyngitis, viral hepatitis, salmonella, or post-viral (HIV, CMV).
>1 joint involved: pauciarticular arthritis, rheumatic fever, serum sickness, HSP, collagen vascular disease, sickle cell disease, chronic recurrent multifocal osteomyelitis (CRMO).
Haemophilia: increased risk of septic arthritis due to haemarthrosis (predisposes to infection: pneumococci).
Symptoms and signs
Infants characteristically do not appear ill. 50% do not have fever. In the older child—acute onset; decreased range of movements or pseudoparalysis; pain on passive motion; hot, warm, swollen joint; inability to weight bear; systemic symptoms of infection. In <10% of cases more than one joint affected (except gonococcal infections). The clinical picture may be less acute if the child has received antibiotics.
Investigations
Blood: FBC, ESR, CRP, blood cultures; Lyme titres if exposure.
X-ray of joint: usually normal initially (widened joint space suggests an effusion). Subluxation/dislocation, joint space narrowing and erosive changes are later signs.
Joint aspiration: most useful diagnostic investigation. Send aspirate for microscopy and culture. PCR may be useful if already on antibiotics.
US: to detect effusion and guide aspiration.
MRI: if diagnosis in doubt to exclude osteomyelitis, (do not delay treatment while waiting for MRI).
CT: to imaging sternocalvicular and sacroiliac joints. Psoas abscess.
Bone scan: if multiple sites and child too unwell to localize pain.
Lumbar puncture: if a septic joint with Haemophilus influenzae (increased incidence of meningitis).
Treatment
Medical: IV antibiotics, after aspirate taken, for up to 3wks (until inflammatory markers normalize), followed by oral antibiotics for a total of 4–6wks. Outcome of treatment is time dependent.
Surgical: early referral to orthopaedic team as there is a low threshold for irrigation and debridement of the affected joint (+ drainage of any associated osteomyelitis).
Splintage: In the acute setting a brief period of splintage improves pain and allows inflammation to settle. Splint in position of function.
Physiotherapy: to avoid joint stiffness.
Prognosis
Usually good unless the diagnosis is delayed. Recurrence of disease and development of chronic infection occur in <10%. Long-term follow-up is needed as growth-related sequelae may not become apparent for months or years. Hip joint infection has the worst prognosis for anatomical and functional impairment.
Complications
Chondrolysis, ongoing infection and bone destruction, joint incongruity/stiffness, and growth disturbance. Avascular necrosis of the femoral head can occur.
Infections: osteomyelitis
Infection of bone. The frequency of osteomyelitis is greatest in infants, with 33% of all cases in the first 2yrs, and 50% occurring by 5yrs. Male > female (2:1).
Pathogenesis
Infection usually seen in the metaphyseal region of bones. Most infections are spread via the haematogenous route from a p site of entry (e.g. respiratory, GI, ENT, or skin sites). Infection may also occur by direct inoculation (open fractures, penetrating wounds) or local extension from adjacent sites. In the infant, transphyseal vessels are patent and infection may spread to the adjacent joint causing a septic arthritis. In adolescents infection tends to spread through the medullary canal.
Types of osteomyelitis
Acute
Subacute (2–3wks duration)
Chronic: may develop ‘sequestrum’ (dead bone) and ‘involucrum’ (new bone).
Bone abscesses may become surrounded by thick, fibrous tissue and sclerotic bone (Brodie’s abscess).
Aetiology
The yield for bacterial growth from synovial fluid and bone aspirate is small; therefore organisms are not always isolated. Staphylococcus aureus is most common in children in all age groups. Other organisms seen include the following:
Neonates: group B streptococcus and Gram −ve enteric bacilli.
<2yrs: Haemophilus influenzae (rare).
>2yrs: Gram +ve cocci, Pseudomonas aeruginosa.
Adolescents: Neisseria gonorrhoeae.
Consider salmonella in SCD. Tuberculosis is rare.
Symptoms and signs
Neonates characteristically do not appear ill and may not have fever.
Older children have pain, limping, refusal to walk/weight bear, fever, malaise, flu-like symptoms. Overlying bone may be tender (+ warm), with/without swelling. Long bones principally affected: Tibia > femur > humerus.
Differential diagnosis
Investigations
Blood: FBC, ESR, CRP, blood cultures (positive in 50%).
X-ray of bone: early stages may be normal; soft tissue oedema may be visible. Late stages reveal metaphyseal rarefaction. Destructive changes in bone appear after 10 days.
US-guided aspiration: for microscopy and culture.
MRI: soft tissue assessment—bone marrow involvement; abscess formation, joint effusion, subperiosteal extension.
Bone scans: good for acute osteomyelitis; can identify up to 90% of joint involvement (seen as hot spots) and differentiate joint from bone involvement; good for infections of pelvis, proximal femur, and spine.
Open biopsy may be necessary.
Consider immunological evaluation if atypical organism.
Treatment
Medical: IV antibiotics for a minimum of 2wks, followed by oral antibiotics for 4wks. Early liaison with microbiologist required.
Surgical: drainage and debridement if there is frank pus on aspiration or a sequestered abscess or collection (not accessible to antibiotics).
Prognosis
Usually excellent if treated early. Disease recurrence/progression to chronic infection is seen in <10%.
Complications
Systemic: may include septicaemia.
Local: pathological fracture, sequestration, growth disturbance.
Spinal disorders
General management
History
Pain, onset of deformity, loss of weight, night sweats, family history, disability, other disorders.
Examination
Inspection: asymmetry, scapular prominence, skin lesions (especially midline pits and haemangiomas), café au lait spots (associated with neurofibromatosis), foot deformity, leg atrophy.
Feel: spinal tenderness.
Move: forward flexion, hamstring tightness.
General: neurological examination.
Investigations: radiographs, CT, MRI, bone scan.
General spinal disorders
Back pain
Take it seriously! More likely to be caused by significant pathology than in adult (e.g. osteoid osteoma, eosinophilic granuloma). Beware of the following, especially in young children—several weeks of symptoms; night pain; increasing symptoms; abnormal neurology; recent onset of scoliosis; night sweats. Pain may be referred from intra-abdominal or intrathoracic process. Investigate thoroughly, but remember 50% of children experience back pain by 15yrs of age.
Discitis
Inflammation (probably infection) of the disc space:
Age group: any age (infants and children rather than adolescents).
Symptoms: fever; irritability; unwilling to walk; back pain, abdominal pain. Symptoms may be vague.
Investigations: bloods (↑ CRP and ESR); MRI; bone scan.
Treatment: antibiotics (according to local policy), at least until inflammatory markers return to normal.
Outcome: usually do well.
Congenital anomalies
Diastematomyelia: spinal cord is split by a central cartilaginous/bony prominence.
Signs: other abnormalities are common (e.g. scoliosis, clubfoot, cavus foot); cutaneous lesions seen in most children; positive neurology seen in 50%.
Management: consider resection of spur if neurology appears/is progressive.
Spina bifida.
Regional spinal disorders
Cervical spine: torticollis
Thoracic spine
See Scheuermann’s disease ( p.744).
Lumbar spine: spondylolysis and spondylolisthesis
Definition: defect of pars interarticularis (spondylolysis). If bilateral and at the same level may result in anterior displacement of one vertebra upon another (spondylolisthesis). Usually due to a stress fracture through a congenitally dysplastic pars.
Incidence: uncommon, associated with spina bifida, metabolic (e.g. osteopetrosis), connective tissue (e.g. Marfan’s), hyperextension sports (e.g. gymnastics).
Symptoms/signs: sudden/insidious onset of pain exacerbated by activity. Decreased forward flexion and straight leg raise.
Investigations: X-rays—lateral and oblique spinal views. Look for ‘Scotty dog’s collar’. Bone scan/SPECT for occult fractures and evidence of healing.
Management: non-operative usually. Rest and change of activities; consider short-term bracing, analgesia, hamstring stretches, and core strengthening. Operative intervention seldom required for stabilization.
Sacral spine: sacral agenesis
Definition: hypoplastic/absent sacrum; most common in infants of diabetic mothers.
Signs: abnormal pelvic ring affecting lower limbs with associated neurology.
Management: tailor towards severity of agenesis and neurology.
Spine: kyphosis
Definition: from Greek Kyphos, a hump. Increased curvature of the spine in the sagittal plane, visible from the side. Normally there is a 20–40° curvature of the thoracic spine.
History: site, age of onset, rate of progression, associated scoliosis/pain/neurological symptoms, family history.
Examination
Assess:
Flexibility: stand, bend forwards, bend backwards (hyperextension).
Ability to lie flat: associated lumbar lordosis (more prominent with greater severity of kyphosis).
Hips for tight hamstrings: limited straight leg raising.
Full respiratory (pulmonary function) and neurological examination.
Investigation
PA and lateral standing X-rays of entire spine.
Diagnosis
Three major causes are identified by answers to:
Is it flexible?
Is it painful?
When did it start?
Postural kyphosis (most common)
Flexible, usually painless, onset <10yrs old.
Other findings: tall; girls > boys; poor physical development; flat-footed; poor at games.
Investigations: supine hyperextension lateral radiograph confirms complete correction.
Treatment: physiotherapy to improve posture and provide exercises for dorsal spine, education, occasionally brace.
Outcome: corrects spontaneously by end of adolescence.
Congenital kyphosis
Rigid, occasionally painful, onset <10yrs old.
Other findings: severe deformities recognized at birth, associated with congenital spinal abnormality, e.g. spina bifida.
Cause: may be secondary to failure of vertebral formation +/− segmentation during the first trimester.
Treatment: brace, if progression fusion to prevent paraplegia.
Outcome: can progress rapidly and lead to paraplegia.
Scheuermann’s disease
Rigid, aching pain between shoulder blades; onset 10–15yrs (previously normal spine).
Incidence: unknown (up to 7–8% of population in cadaveric studies).
Aetiology: osteochondritis.
Investigations
AP and lateral spine X-rays: >45° kyphosis with >5° anterior wedging at three sequential vertebrae = radiographical definition of Scheuermann’s disease.
May have vertebral body end-plate changes (Schmorl’s nodes—vertical herniations of the intervertebral discs into the vertebral end-plate), spondylolysis (30–50%), scoliosis (33%).
Treatment
Physiotherapy (extension exercises): bracing may be considered.
Medical: NSAIDs.
Surgical correction: with severe kyphosis (>70°), the patient is skeletally mature, with severe pain or evidence of cord involvement.
Outcome
Little evidence that patients with kyphosis <70° experience late progression, disabling pain, or neurological compromise.
Spine: scoliosis
Idiopathic scoliosis
Lateral curvature (>10°) +/− rotation deformity of the spine without an identifiable cause. Description of curvature based on direction of apical convexity. There are 3 types.
Infantile (<3yrs old): left > right side; males > females; associated plagiocephaly (skull flattening), hip dysplasia, and other congenital defects. May be s to underlying spinal abnormality.
Juvenile (3–10yr olds): may be s to underlying spinal abnormality; high risk of curve progression (70% require treatment with 50% needing brace and 50% surgery).
Adolescent: most common in 11–16-yr-olds. Females > male.
Incidence
Curves >10°, 2% incidence.
Curves >30°, 0.2% incidence.
Right thoracic curves > double major (right thoracic and left lumbar) > left lumbar > right lumbar.
Risk factors
Positive family history; daughters of affected mothers more likely to be affected, Marfans, neurofibromatosis.
Disease progression
Risk factors for curve progression: age <12yrs; skeletal immaturity; female; curve magnitude >20°; spine at greatest risk of curve progression during puberty. Natural history after skeletal maturity is curves < 30° unlikely to progress, if >50° 2/3 will progress. Severe curves (Cobb angle >100°) associated with pulmonary dysfunction, early mortality, pain, poor self-image.
Symptoms
Onset of symptoms, rate of progression, Is it painful? (inflammatory or neoplastic.) Ask about respiratory and neurological symptoms.
Signs
Inspect child standing.
Describe scoliosis as the side to which the spine is convex (shoulder on convex side is elevated).
Inspect: pelvic height—limb length difference; waistline asymmetry; trunk shift; spinal deformity; rib rotational deformity (rib hump).
Bend—touch toes. Is it fixed?
Adam’s forward test: asymmetry of the posterior chest wall on forward bending. If scoliosis disappears: postural (80% of scoliosis).
Full neurological examination including abdominal reflexes.
Lower limb examination (other causes of postural scoliosis: unilateral muscle spasm; unequal leg length).
True idiopathic scoliosis
Painless, convex to the right in the thoracic spine, not associated with any neurological changes.
Investigations
Standing PA and lateral X-rays full spine.
MRI if pain, neurological changes, rapidly progressive curve, excessive kyphosis, left thoracic/thoracolumbar curves, considering surgery.
Treatment
Based on maturity of patient, magnitude of deformity, and curve progression. The aim is to prevent further progression.
Non-operative
Close observation (6-monthly X-rays for curves <25°).
Bracing is controversial. May slow/halt curve progression—the more it’s worn, the more effective it is. Consider for children with curves <40°.
Manipulation and casting for young children with more severe curves
Operative
Anterior/posterior spinal fusion with instrumentation for severe deformities (>45°).
Posterior instrumentation without fusion
Vertebral expanding prosthetic titanium rib
Congenital scoliosis
Most common congenital spinal disorder.
Aetiology
Abnormal vertebral development in the first trimester.
Associations
Can be isolated deformity or associated with other congenital abnormalities: Spinal (40%)> genitourinary (20%) > heart disease (10–15%), also associated with syndromes, e.g. VACTERL ( p.848).
Disease progression
Risk of progression dependent on morphology and growth potential of vertebrae. Greatest risk during periods of rapid growth (<2yrs and >10yrs old).
Treatment
Early diagnosis; often need surgery.
Scoliosis secondary to neuromuscular disorders
Symptoms and signs
Progresses more rapidly and may continue after maturity; longer curves involving more vertebrae and less likely to have compensatory curves.
Associations
Skeletal: pelvic obliquity, bony deformities, cervical involvement.
Pulmonary: more frequent, ↓ lung function and pneumonia.
Neurological: brainstem, proprioception, Klippel–Feil syndrome.
Upper motor neuron disease: cerebral palsy, spina bifida, spinocerebellar degeneration, syringomyelia, spinal cord tumour/trauma, tethered cord, diastematomyelia.
Lower motor neuron disease: poliomyelitis, spinal muscular atrophy, (myopathic: DMD).
Syndromes: neurofibromatosis, Marfan’s.
Hip disorders: developmental dysplasia of the hip
Previously known as ‘congenital dislocation of the hip’. Disorder of hip joint development resulting in hip instability/subluxation/dislocation 9 acetabular dysplasia.
Incidence: 2:1000 (but up to 20:1000 newborn hips are unstable; 90% spontaneously stabilize by 9wks).
Risk factors: family history (1:5), female > male (5:1), Left > right (1.5:1), racial predilection, breech presentation.
Aetiology: capsular laxity (increased type III collagen, maternal oestrogens), decreased intrauterine volume (breech position, first born, oligohydramnios).
Associations: other ‘packaging’ disorders: torticollis (20%), metatarsus adductus (10%), talipes calcaneovalgus, teratologic dislocation, Down’s syndrome.
Teratologic dislocation: a distinct form of hip dislocation associated with neuromuscular syndromes (e.g. myelodysplasia, arthrogryposis, chromosomal abnormalities, lumbosacral agenesis, diastrophic dwarfism). The hip is dislocated before birth. It is more difficult to treat.
Disease progression
Capsular laxity + shallow acetabulum → instability/subluxation/dislocation → muscle contracture → progressive acetabular dysplasia with a fibrofatty substance filling the acetabulum (pulvinar); femoral head becomes hypoplastic.
History
Usually uneventful pregnancy; parents may notice delayed walking, painless limp, prone to falls. DDH may be incidental finding.
Examination
All newborn infants should be screened for DDH before discharge and then again at 6wks. High-risk infants are selected for ultrasound screening. Still controversy over selective v universal screening program.
Neonate
Is hip dislocated? If so, is it reducible? Ortolani’s test (O for out). Gently elevate (anteriorly) and abduct the dislocated hip to reduce it (clunk of reduction).
If not dislocated, can I dislocate it (i.e. dislocatable)? Barlow’s test. Gently adduct and depress (posteriorly) femur; vulnerable hip dislocates.
These 2 provocation manoeuvres become unreliable after age 6–8wks.
Infant: asymmetric gluteal folds, limited abduction, leg length discrepancy. Galeazzi sign—flex knees with feet together; +ve sign = affected femur appears short due to dislocated hip joint. (Note. Also +ve if femur is congenitally short; −ve with bilateral DDH).
Older child: may walk with limp; positive Trendelenburg test. With bilateral dislocations, the only sign may be an exaggerated lumbar lordosis and limited hip abduction.
Investigations
Age <6mths: hip US (before ossification; operator-dependent).
>6mths: AP pelvis radiograph. A shallow acetabulum with increased acetabular index, and hypoplastic femoral head in superolateral position is demonstrated. Shenton’s line broken.
Treatment
Depends on age of child (see Box 20.1). An urgent referral to a paediatric orthopaedic surgeon is needed in order to start treatment as soon as possible. The aim is to achieve and maintain concentric hip reduction to encourage early acetabular development to reduce the risk of future degenerative joint disease.
Pavlik harness (maintain hip in flexed position with some hip abduction)
Manipulation and closed reduction (+/− adductor tenotomy) + hip spica plaster cast
Open reduction (medial approach if <12mths old; anterior approach if >12mths old) + hip spica plaster cast
Trial of closed reduction
Open reduction (anterior approach) +/− pelvic osteotomy + hip spica plaster cast
Open reduction (anterior approach) +/− femoral shortening +/− pelvic osteotomy + hip spica plaster cast
Complications
Early: inadequate reduction and redislocation.
Intermediate: residual acetabular dysplasia; avascular necrosis.
Late: early osteoarthritic changes.
Prognosis
Any residual acetabular dysplasia may be treated with a pelvic osteotomy as a secondary procedure. Long-term acetabular dysplasia is likely to lead to early degenerative changes in the hip.
Hip disorders: Perthes’ disease
Also known as Legg–Calve–Perthes disease. It is due to an idiopathic osteonecrosis (avascular necrosis) of the femoral head of unknown aetiology. Incidence: 1:10,000
Risk factors
Boys > girls (4:1); age 4–10yrs. <20% bilateral (usually staged + asymmetric), 10% family history, low birth weight, 4% children with transient synovitis, delayed skeletal maturity.
Aetiology
Unknown, although several risk factors lead to avascular necrosis: trauma, endocrine (e.g. hypothyroidism, renal disease, steroids), metabolic, coagulability (blood dyscrasia, protein C or S deficiency, thrombophilia).
Differential diagnosis
Pathological stages
Avascular: hip appears sclerotic with minimal loss of epiphyseal heightt
Fragmentation: initially fissures appear in epiphysis, followed by more severe fragmentation and loss of height.
Remodelling: regeneration, new bone formation, and head remodelling
Healed: no avascular bone visible on radiograph
Symptoms
Mild/intermittent anterior thigh/groin/referred knee pain with limp; classical ‘painless limp’. Note: Knee pain: beware hip pathology.
Special signs
Investigations
AP and lateral pelvic X-rays: many different classifications, but most useful is lateral pillar classification. The femoral head is divided into thirds. Group A no loss of height of lateral 1/3, B up to 50% loss of height, group C >50% loss of height.
MRI may help diagnosis especially in the early stages.
Technetium 99 bone scan: decreased uptake in femoral epiphysis due to poor vascular supply.
Dynamic arthrography to delineate hip joint and plan surgery.
Prognosis
This is a local self-healing disorder. Prognosis depends on bone age and X-ray appearances. Poor prognostic indicators are:
Clinical: heavy child; ↓ range of movement; adduction contracture; flexion into abduction, female and older age at presentation (> 6yrs).
Radiological: Gage’s sign; lateral subluxation of femoral head with lateral calcification; whole head involvement; metaphyseal cysts; lateral pillar group C hips.
Treatment is controversial
The aims are to relieve symptoms and signs by eliminating hip irritability and maintaining hip range of movements. This is achieved by:
Maintaining sphericity of femoral head.
Containing femoral head in acetabulum whilst remodelling occurs.
Preventing epiphyseal collapse and secondary osteoarthritis.
Non-operative treatment
Observation and activity modification, including bed rest and walking aids. NSAIDs, physiotherapy. Bracing is controversial.
Operative treatment
Femoral/pelvic osteotomies to contain femoral head in acetabulum.
Hip disorders: slipped upper femoral epiphysis
Displacement of the upper femoral epiphysis on the metaphysis through the hypertrophic zone of the growth plate. The femoral neck displaces anteriorly and the head remains in the acetabulum.
Incidence: the most common adolescent hip disorder (3:100 000); 25–60% bilateral.
Risk factors: African American, >50% obese (weight >95th percentile), positive family history, puberty, boys (12–16yrs) > girls (10–14yrs).
Aetiology: unknown, but associated with the following:
Endocrine—hypothyroidism, hypogonadism, renal osteodystrophy;
Mechanical—retroversion of femoral neck or vertical growth plate;
Other—Down syndrome, radiotherapy/chemotherapy.
Symptoms and signs
Groin, thigh, or knee pain. Antalgic gait, limited hip flexion and abduction, flexion into external rotation, and thigh atrophy.
Always consider hip pathology in a child presenting with knee pain.
Presentation
Characterized by 2 broad types of children.
Obese hypogonadal (low circulating sex hormones): delayed skeletal maturation bone age.
Tall thin, often boys, post growth spurt (younger age in girls): overabundance of growth hormones.
Diagnostic classification
This is based on duration of symptoms.
Preslip: wide epiphysis; mild discomfort, but normal examination; often seen on contralateral hip.
Acute slip: mild symptoms <3wks, then sudden slippage usually without trauma; pain so severe child unable to weight bear; usually unstable.
Acute on chronic: acute slip on pre-existing chronic slip; usually have previous symptoms (pain, limp, out toe gait) for several months; unable to weight bear; usually unstable.
Chronic: most common type; history for several months; symptoms worsen as slip progresses; child able to walk with mildly antalgic externally rotated gait. Usually stable.
Slips may be further sub-classified into stable or unstable (Loder): in an unstable slip’ child unable to weight bear, even with crutches, and cannot do straight leg raise actively. These have increased risk of AVN.
Investigations
X-Ray: AP pelvis and frog lateral hips. Widening of physis, Klein’s line intersects lateral capital epiphysis on AP.
MRI: useful in pre-slip diagnosis, and evidence of AVN.
Endocrine tests: if appropriate, e.g. thyroid function.
Treatment
The aim is to prevent further ‘slippage’ and to minimize complications.
Operative
Usually pin in situ (to encourage the proximal femoral epiphysis to close, hence preventing further slippage); usually not reduced as manipulation may increase the incidence of avascular necrosis. Prophylactic pinning of opposite hip is controversial. It is recommended in younger children and those with endocrinopathy.
Complications
Chondrolysis (degeneration of the articular cartilage of the hip with narrowed joint space, pain, decreased motion): associated with more severe slips; occurs more frequently among African American children and females; associated with pins protruding out of the femoral head.
Osteonecrosis/avascular necrosis (higher incidence in unstable hips): due to injury to retinacular vessels (at time of slip or manipulation) or compression from intracapsular haematoma. Commonly leads to degenerative joint disease. Avascular necrosis uncommon in stable slips.
Knee disorders
Anterior knee pain
Common in the growing child and is usually due to overuse. Pain is worse with load-bearing, going downstairs, and prolonged sitting with knee flexed.
Common causes include the following:
Osteochondroses: Osgood–Schlatter’s disease (see p.761).
Sinding–Larsen–Johansson disease: see p.761.
Bipartite patellae: usually bilateral and a normal variant of ossification. There is a risk of developing an avulsion fracture; thus the child should rest, stop sports, and the knee should be splinted. NSAIDs may help. Once resolved, a gradual return to activities is possible.
Patella maltracking: several causes including dysplasia of the femoral condyles, malalignment of the quadriceps mechanism with relatively weak vastus medialis, genu valgum, tibial torsion, increased laxity. Presents with vague anterior knee pain, instability, +/− episodes of patella dislocation. Treatment is physiotherapy, but some may need surgery.
Chondromalacia patellae: softening of the articular cartilage, which may progress to osteoarthritis (X-rays may be normal) Treatment physio strengthening and stretches.
Genu recurvatum
Congenital hyperextension
Commonest in breech presentations.
Associated with arthrogryposis, spina bifida, DDH, talipes equinovarus.
Severity varies from mild hyperextension to dislocation. Management: look for other abnormalities (e.g. DDH).
Gentle stretching, serial casting, quadriceps lengthening at 1–3mths if necessary.
Acquired recurvatum
Physiological ‘curved’ knee occurring in girls due to joint laxity. May be familial and predispose to sprains or patella instability.
Consider neurological causes if not bilateral.
Clinical features include a hyperextended knee, generalized lax joints.
May be caused by trauma to the proximal anterior tibial physis causing a progressive deformity with growth.
Genu valgum (knock knees)
Defined by position of knees such that, when standing with knees together, the medial malleoli are not touching (therefore it is a frontal plane deformity). Commonly observed between ages 2 and 7yrs.
Causes
Bilateral
Physiological: most common.
Metabolic: renal osteodystrophy, rickets, hypophosphataemia.
Skeletal dysplasia: Kniest’s syndrome, congenital dislocation of patella.
Haematological: myelodyplasia.
Unilateral
Asymmetric growth—trauma/infection/tumour/epiphyseal dysplasia to tibia or femur.
Presentation
Child is noticed to walk knock-kneed. Establish rate of progression, diet, and family history.
Examination
General: height and body proportions. May be overweight or have dysmorphic features. Full lower limb examination (standing and lying); often accompanied by flat feet (pes planus); measure knee angle and intermalleolar distance.
Specific signs. Tibiofemoral angle assessment. The angle at which the long axis of tibia bisects the long axis of femur can be measured clinically and radiologically. Widened intermalleolar distance (distance between medial malleoli of ankles).
Investigations
No X-ray required until >18mths age; then AP and lateral standing full leg length views.
Treatment
Non-operative: mainstay for physiological genu valgum.
Operative: reversible epiphysiodesis (physeal stapling or eight plate) of medial side tibia. If skeletally mature corrective osteotomy
Prognosis
95% physiological valgus resolves with growth achieving normal adult alignment by 7–8yrs.
Genu varum (bowed knees)
Bowing of the knees if patient stands with ankles together. Normally genu varum (15°) at birth progresses to physiological genu valgum by 4–5yrs. Genu varum is common in children <3yrs (especially obese children who start walking <1yrs old)
Causes
Physiological: in utero (curled up) foetal position results in a bowed appearance due to:
a tight posterior hip capsule which causes external rotation of the hips;
internal tibial torsion.
Structural: osteogenesis imperfecta ( p.762).
Skeletal dysplasia: metaphyseal dysplasia, achondroplasia, enchondromatosis ( p.766).
Local asymmetric growth: Blount’s disease (abnormal growth of medial aspect of proximal tibial epiphysis), osteochondromas, physeal injury (e.g. trauma, infection), dysplasia.
History
Parents notice child is walking bowlegged/in toeing of feet. Establish developmental milestones and rate of progression, family history, diet, social history, etc.
Examination
General examination including height and weight; full lower limb examination including rotational profile, widened intercondylar distance (distance between medial femoral condyles).
Investigations
Weight-bearing AP and lateral lower leg views
Symmetrical physiological bowing, flaring of tibia and femur. Can also measure tibiofemoral angle, metataphyseal–diaphyseal angles.
Treatment
Severe physiological genu varum may be treated by guided growth (reversible epiphysiodesis) using staples or eight plates. Blounts disease may require corrective osteotomes. Refer to orthopaedic paediatric surgeon
Prognosis
95% of cases of physiological varus resolve with age.
Osteochondritis dissecans of the knee
Occurs when an area of subchondral bone becomes avascular and fragments and separates from the underlying bone. May involve the overlying cartilage, leading to mechanical problems (e.g. loose bodies) and joint incongruity. Most commonly involves the lateral aspect of the medial femoral condyle. It may progress to early degenerative osteoarthritis.
Risk factors: adolescents (10–15yrs). Boys > girls. Often secondary to trauma, ischaemia, abnormal epiphyseal ossification.
Clinical features: non-specific knee pain, +/− locking and +/− stiffness. Knee swelling after activities, but no history of acute trauma or injury. May be tender over affected articular cartilage of medial femoral condyle if knee is fully flexed.
Disease progression: the overlying articular cartilage is usually intact in younger children and the bone heals as revascularization occurs. The risk of articular fracture with separation and loose body formation increases with increasing age, larger lesions, and a weight-bearing location.
Investigations
X-rays of knee in AP, lateral, and notch views to assess femoral condyles. MRI may be useful for determining integrity of articular cartilage and defining whether synovial fluid is behind the lesion.
Treatment
Depends on patient age, size, and stability of fragment. Usually a short treatment with rest, anti-inflammatory drugs, and splintage will suffice. However, it may require surgery:
Non-operative: as above, including observation with periodic X-rays and MRIs to assess degree of healing. Bracing and restricted weight-bearing/activities if significant growth remaining.
Operative: adolescent with minimal growth left/loose lesion—arthroscopic assessment with possible debridement and microfracture through subchondral plate to promote revascularization and healing. Fixation of large fragments.
Prognosis
Worse with large lesions in lateral femoral condyle in older children.
Note: Osteochondritis dessicans may occur in other major joints including the elbow (capitellum) and less often the lateral condyle of the patella.
Orthopaedic trauma
Trauma is the most common cause of childhood deaths. It is often due to falls especially in the home environment (home> sports > school > road traffic accident).
Fractures
Generally boys > girls with a peak incidence at 12yrs of age, although specific injuries peak at different ages, e.g. NAI at 1yr, femoral fractures at 3yrs, pedestrian vs car at 6yrs, lateral condyle/supracondylar fractures at 7yrs, physeal injury at 11–12yrs. 4% are multiple fractures. Children’s fractures usually are more frequent in summer than in winter.
Principles of management
Stabilize according to resuscitation principles (see Chapter 4).
Full history (including nature of injury, left/right handedness) and examination.
Is the fracture open/closed?
Is the limb neurovascularly intact? Is there a compartment syndrome?
Is the associated joint dislocated?
Splint limb for comfort; analgesia; elevate.
X-ray affected bone +/− joint above and below.
Liaise with orthopaedic team.
Complications
Early
Neurovascular problems: e.g. median nerve paraesthesia with distal radius fractures, median/ulnar nerve paraesthesia with supracondylar fractures, radial nerve in humeral shaft fractures, common peroneal nerve with proximal fibula fractures.
Compartment syndrome: especially associated with closed low energy mid-shaft tibia fractures.
Intermediate
Joint stiffness: especially fractures around the elbow.
Malunion: usually well tolerated if malunion is within plane of motion; may be compensated in younger children with remodelling.
Late
Overgrowth: occurs in long bones due to physeal stimulation (from hyperaemia). Femoral fractures in children may overgrow by 1–3cm.
Deformity: if epiphysis is damaged, child may develop progressive deformity several months later. Require long-term follow-up
Non-union: rarely shaft of tibia/ulna.
Common fracture patterns
The most common fracture pattern is a complete fracture of both cortices (e.g. spiral, transverse, oblique, multifragmentary). However, the following fractures are specific to children.
Buckle/torus fractures: children <10yrs. Usually caused by a fall on an outstretched hand (causing compression of one cortex resulting in ‘buckle’ on the X-ray) resulting in a metaphyseal distal radius fracture. Inherently stable. Treatment immobilize in plaster of Paris/backslab; fracture clinic follow-up within 2–3 days. Remove plaster in 3–4wks and mobilize.
Plastic deformation or bend fractures: traumatic bending/bowing of bone, but insufficient energy to produce a fracture. No fracture seen on X-ray (limb may appear ‘bent’). Commonly ulna (look out for radial head dislocation); occasionally fibula. Treat as for torus fracture. If severe bowing or dislocation require manipulation under anaesthetic.
Greenstick fractures: like bending a young twig, the cortex will break on the tension side and bend on the compression side. The energy is insufficient to result in complete bicortical fracture. It may require manipulation under anaesthesia.
Salter–Harris fractures (physeal injuries): 20% of all children’s fractures involve the physis (most commonly the distal radius). It is usually extra-articular, but fractures in the proximal femur/humerus, radial neck, distal fibula may be intra-articular.
Osteochondroses
A spectrum of conditions primarily affecting the epiphyses , but may also involve cartilage and bone. Despite the term ‘osteochondritis’, the condition is not always due to inflammation and may be due to trauma or over-usage, vascular irregularities, or may be a normal variation. The affected devascularized bony region undergoes spontaneous healing with revascularization, resorption, and re-ossification. Symptoms are usually worse with activity and relieved with rest. It is usually a self-limiting condition with clinical outcomes ranging from normal to serious disability. Investigations include radiographs of the affected region, which may demonstrate fragmentation/collapsed sclerotic bone. An MRI scan will confirm the diagnosis. The conditions can be classified anatomically.
‘Physeal’ (growth plate) osteochondroses
Often require treatment.
Madelung deformity (distal radius): defect in the volar and ulna side of the distal radial physis resulting in a shortened tilted distal radius and a prominent ulna. Occurs in teenage girls and features include pain, decreased range of movement, and abnormal wrist joint. Treated with analgesia and surgery.
Scheuermann’s disease (vertebra): see p.744.
Blount disease: tibial physis.
Articular osteochondroses
Great potential for disability.
Freiberg disease: infarction of the second metatarsal head or epiphysis in teenagers (females > males), presenting with pain on running and dancing. Joint tenderness with decreased range of movement, and pain on tip-toe standing. Managed with change of activities, analgesia, orthotics, intra-articular corticosteroids+/− surgery.
Perthes’ disease: see p.750.
Panner’s disease (osteonecrosis of the capitellum): children <10yrs. No history trauma. Mild flexion contracture diffuse synovitis. X-ray shows irregular areas with sclerosis. MRI/CT/USS may aid diagnosis. Treatment NSAIDs, splint, occasionally arthroscopy. Prognosis good.
Osteochondritis of capitellum: occurs in older children. May be due to overloading of the elbow (e.g. overhand throwing/batting) with accentuation of any valgus deformity. Clinical findings include mechanical block +/− flexion contracture, general lateral elbow pain, and swelling. AP X-ray with elbow flexed 45° may demonstrate irregular joint surface. CT/MRI/USS have also been used. Treatment: rest with avoidance of exacerbating factors; anti-inflammatories; arthroscopic removal of loose bodies, drilling, or fixation of unstable lesions.
Radial head: similar to osteochondritis capitellum, except the radial head is affected. Child is prone to developing overgrowth and joint incongruity.
Non-articular osteochondroses
At tendon attachments
Osgood–Schlatter’s disease (tibial tubercle traction apophysitis): failure of the tibia tubercle apophysis due to repetitive traction stress from the extensor mechanism in boys (aged 12–14yrs) > girls (aged 10–12yrs). Usually a self-limiting condition with complete resolution through physiological healing (physeal closure) of tibia tubercle within 12–24mths. Presents with painful swelling over a prominent tibial tubercle (usually unilateral), associated with running/jumping. An irregular fragmented tibial tubercle may be seen on X-ray. Treatment includes non-operative (activity modification, rest +/− ice +/− knee brace), physiotherapy (isometric hamstring and quadriceps exercises), medication (NSAIDs), and operative (occasionally excision of separate ossicles may improve symptoms after skeletal maturity).
Sinding–Larsen–Johansson syndrome: related condition arising at distal end of the patella.
At ligament attachments
Adam’s disease (medial epicondyle)
Repetitive injury to the elbow following throwing/serving sports (e.g. racquet sports). Results in medial epicondylar fragmentation or avulsion and delayed closure of the growth plate. May have ulnar nerve involvement and point tenderness over the medial epicondyle.
Treated with rest/change of activities, splintage, analgesia (NSAIDs). Gradual return to activities once symptoms have settled. May need surgery to excise loose bodies.
At impact sites
Kohler’s disease: infarction of the navicular bone presenting as medial midfoot pain and a limp in young children (males > females) especially with load-bearing sports. Treated with rest from load-bearing sport, in soles/casts. If symptoms are severe, child may need to be non-weight-bearing with gradual return to activities depending on symptoms.
Sever’s disease: calcaneal apophysitis. Caused by repeated microfracture (with subsequent inflammation and healing) of the fibrocartilaginous insertion of the tendo-Achilles to the calcaneum during the pubertal growth spurt. Symptoms vary depending on the level of activity and it improves with skeletal maturation. There may be a bony prominence at the tendon insertion due to overgrowth during healing response. Treatment symptomatic NSAIDs, heel cord stretching.
Osteogenesis imperfecta
See also pp.763, 838. An inherited condition affecting collagen maturation and organization. The incidence is around 1/20 000. Osteogenesis imperfecta (OI) is due to a mutation in type I collagen gene that predisposes to fracture formation. Following a fracture, initial bone healing is normal, but there is no subsequent remodelling and the bone heals with deformity. 10% are clinically asymptomatic.
Clinical features
Bones:.
low birth weight/length for gestational age;
short stature;
50% scoliosis.
Joints: ligamentous laxity resulting in hyperextensible joints.
Specific signs and X-ray features (see Table 20.2).
| IU fractures | Eyes (sclera) | Bones | X-ray features: thin cortices; osteopenia |
|---|---|---|---|
Type I Mild; AD (60–80%). Presenile hearing loss in 30–60%, often with aortic valve regurgitation * | |||
No | Blue | Frequency of recurrent fractures decreases after puberty; diaphyseal > metaphyseal fractures; usually ambulatory | Wormian bones on SXR (occipital) |
Type II Perinatal. Lethal (stillborn/death within first year); AD | |||
Yes | Blue | Relative macrocephaly, large fontanelles, micromelia, triangular facies with beaked nose, bowed limbs, legs abducted 90° | ‘Beaded’ ribs—respiratory insufficiency |
Type III Progressive and deforming (most severe non-lethal type) AR | |||
Yes | White | Pectal deformity, triangular facies, relative macrocephaly, abnormal teeth, easy bruising, severe osteoporosis (fractures), progressive shortening, deformity | ‘Popcorn’ metaphyses, flared lower ribs, vertebral compression |
Type IV Moderately severe, AD. Usually able to attain community ambulation skills * | |||
Yes | White | Bowed long bones, relatively infrequent fractures (frequency decreases after puberty). Moderately short stature | Osteoporotic, metaphyseal flaring, vertebral compression |
Type V Moderately deforming; AD | |||
No | White | Mild/moderate; short stature | IO calcification; hyperplastic calus |
Type VI Moderately/severely deforming | |||
No | White | Short stature, scoliosis | ‘Fish scale’ bone lamellation |
Type VII Moderately deforming; AR | |||
No | White | Short stature; short proximal limbs | |
| IU fractures | Eyes (sclera) | Bones | X-ray features: thin cortices; osteopenia |
|---|---|---|---|
Type I Mild; AD (60–80%). Presenile hearing loss in 30–60%, often with aortic valve regurgitation * | |||
No | Blue | Frequency of recurrent fractures decreases after puberty; diaphyseal > metaphyseal fractures; usually ambulatory | Wormian bones on SXR (occipital) |
Type II Perinatal. Lethal (stillborn/death within first year); AD | |||
Yes | Blue | Relative macrocephaly, large fontanelles, micromelia, triangular facies with beaked nose, bowed limbs, legs abducted 90° | ‘Beaded’ ribs—respiratory insufficiency |
Type III Progressive and deforming (most severe non-lethal type) AR | |||
Yes | White | Pectal deformity, triangular facies, relative macrocephaly, abnormal teeth, easy bruising, severe osteoporosis (fractures), progressive shortening, deformity | ‘Popcorn’ metaphyses, flared lower ribs, vertebral compression |
Type IV Moderately severe, AD. Usually able to attain community ambulation skills * | |||
Yes | White | Bowed long bones, relatively infrequent fractures (frequency decreases after puberty). Moderately short stature | Osteoporotic, metaphyseal flaring, vertebral compression |
Type V Moderately deforming; AD | |||
No | White | Mild/moderate; short stature | IO calcification; hyperplastic calus |
Type VI Moderately/severely deforming | |||
No | White | Short stature, scoliosis | ‘Fish scale’ bone lamellation |
Type VII Moderately deforming; AR | |||
No | White | Short stature; short proximal limbs | |
IU, Intrauterine; AD, autosomal dominant; AR, autosomal recessive.
Type A, no teeth involvement; type B, dentinogenesis imperfecta present.
Investigations and diagnosis
Prenatal US scan may detect severe forms in foetus.
Molecular genetic testing (pre- or postnatal).
Biochemistry: normal/increased alkaline phosphatase (ALP).
Skin biopsy: assess collagen in cultured fibroblasts.
Bone biopsy: histology—increased Haversian canal + osteocyte lacunae diameters, increased cell numbers.
Treatment
No curative treatment. Aim to prevent and manage fractures with long-term rehabilitation.
Prevention
Strategies to decrease fracture frequency include:
oral calcium supplements;
bisphosphonates;
synthetic calcitonin.
Surgical interventions
Intramedullary rods (fixed length/telescoping) to prevent bowing of long bones, especially for fractures in children >2yrs old. Corrective surgery for scoliosis deformities >50°.
Prognosis
In severe OI a good predictor of future walking is being able to sit by 10mths. May develop cardiopulmonary or neurological complications. Usually develop progressive shortening and deformity caused by multiple fractures, e.g. ‘sabre’ tibia, ‘accordion’ femora.
Osteopetrosis
Also known as marble bone disease or Albers–Schönberg disease. This is a rare chromosomal condition defined by failure of osteoclastic bone resorption and hence failure of remodelling.
Classification
Malignant/infantile type: AR. Severe skeletal deformity presenting at birth or shortly after. Poor prognosis. Bone marrow transplantation may help in some cases.
Benign type: AD. Later childhood/adulthood benign presentation. Prone to frequent fractures.
Clinical features
Face: macrocephaly, hydrocephalus, ‘abnormal eyes’ (optic atrophy, partial oculomotor nerve paralysis), compression of other cranial nerves resulting in deafness, facial nerve palsy.
Teeth: late eruption; early caries, osteomyelitis, and necrosis of mandible.
Limbs: generalized osteosclerosis, fragile bones (due to failure to form lamellated bone in stress areas) with fractures that are difficult to fix and prone to delayed union, dwarfism.
Haematological: encroached marrow cavities leading to anaemia, pancytopenia, spontaneous bleeding/bruises. Spleen (extra medullary haemopoiesis leading to hepatosplenomegaly).
Kidneys: causes distal renal tubular acidosis (type 1 RTA).
Investigations
Blood: pancytopenia and leucoerythroblastic picture (increased primitive cells in blood film). Dry bone marrow tap.
X-rays: dense ‘marble’ bone (generalized increased density with loss of normal trabecular pattern).
Skull: underdeveloped mastoid air cells and paranasal sinuses.
Long bones: widened ends (‘Erlenmeyer flask’ proximal humerus/distal femur).
phalanges—dense transverse band in metaphysis close to epiphyseal line, condensed bone proximal and distal ends of phalanges;
metacarpals—‘bone within a bone’ appearance—sclerotic cortex separated from central bone by area of normal calcification;
vertebral bones—‘sandwich/rugger jersey’ appearance—relative sclerotic upper and lower plates;
bone scan—increased uptake in epiphyseal ends of long bones; normal elsewhere.
Treatment
Depends on severity of disease and is mainly supportive. Medical therapy includes glucocorticoids. Bone marrow transplant may help. Treatment of fractures is difficult due to dense bone quality.
Prognosis
Malignant type—usually terminal within first 10yrs of life. Benign form—lifespan unaffected.
Cleidocranial dysplasia
Also known as cleidocranial dysostosis. Characterized by deficient ossification of the clavicle (cleido) and bones of skull (cranial). It is a rare congenital autosomal dominant condition.
Clinical features
General: proportionate mild short stature. No mental retardation.
Cranium: large skull, frontal and parietal bossing, delayed imperfect ossification of sutures and fontanelles.
Face: underdeveloped/deficient facial bones leading to prominent forehead, pseudoexophthalmos, and hypertelorism (due to small wide nasal bridge and widely spaced shallow orbits); protruding mandible.
Dental: high arched/cleft palate, late loss of deciduous teeth with slow disordered eruption of secondary teeth (= extra/absent teeth).
Ears: hearing loss +/− frequent ear infections.
Upper limb: mobile drooping shoulders; completely absent/partially absent clavicle (especially lateral part, usually unilateral); recurrent dislocation shoulder/elbow; short middle and distal phalanges; long second metacarpal.
Torso: narrow thorax and pelvis.
Spine: delayed vertebral ossification; scoliosis/lordosis; kyphosis; prominent cervical transverse processes.
Lower limbs: tubular phalanges of feet.
Investigations
Skull: multiple imperfect ossification centres (wormian bones); large open anterior fontanelle; absent/delayed development of sinuses; hypoplastic maxilla.
Clavicle: total absence/partial absence of lateral aspect clavicle (commonest) or bipartite clavicle.
Shoulder: subluxation of humeral heads.
Pelvis: delayed ossification pelvic bones with widened symphysis pubis; coxa vara of hips.
Spine: failure of union of neural arches. Association with syringomelia
Renal tract: association with Wilm’s tumour requires imaging kidneys.
Treatment
Usually abnormalities cause little functional disability. Lateral part of clavicle may cause brachial plexus problems (if so, for excision). Recurrent dislocations of the shoulder may require stabilization. Dental anomalies should be treated by maxillofacial surgeons. Coxa vara may require valgus osteotomy.
Prognosis
Normal lifespan.
Skeletal dysplasias
This is a heterogeneous group of conditions characterized by abnormal growth of bones. They can be classified according to the region of bone involved or by their genotype (see Table 20.3).
| Region | Example of | |
|---|---|---|
| Hypoplasia (‘failure of’) | ||
Epiphysis | ||
Articular cartilage | Spondyloepiphyseal dysplasia | |
Ossification centre | Multiple epiphyseal dysplasia | |
Physis | ||
Proliferating cartilage | Achondroplasia | |
Hypertrophic cartilage | Metaphyseal chondrodysplasia (Schmid, McKusick, Jansen) | |
Type 2 collagen | Diastrophic dysplasia | |
Proteoglycan metabolism | Kneist syndrome | |
Metaphysis | ||
Intramembranous bones | Cleidocranial dysostosis | |
Formation of primary spongiosa | Hypophosphatasia | |
Absorption of primary spongiosa | Osteopetrosis (functionally deficient osteoclasts) | |
Diaphysis | ||
Diaphyseal aclasia | ||
Periosteal bone formation | ||
Endosteal bone formation | ||
| Region | Example of | |
|---|---|---|
| Hypoplasia (‘failure of’) | ||
Epiphysis | ||
Articular cartilage | Spondyloepiphyseal dysplasia | |
Ossification centre | Multiple epiphyseal dysplasia | |
Physis | ||
Proliferating cartilage | Achondroplasia | |
Hypertrophic cartilage | Metaphyseal chondrodysplasia (Schmid, McKusick, Jansen) | |
Type 2 collagen | Diastrophic dysplasia | |
Proteoglycan metabolism | Kneist syndrome | |
Metaphysis | ||
Intramembranous bones | Cleidocranial dysostosis | |
Formation of primary spongiosa | Hypophosphatasia | |
Absorption of primary spongiosa | Osteopetrosis (functionally deficient osteoclasts) | |
Diaphysis | ||
Diaphyseal aclasia | ||
Periosteal bone formation | ||
Endosteal bone formation | ||
Radial dysplasia
An absent or hypoplastic radius that causes abnormal radial deviation of the hand. This is the most common form of longitudinal upper limb deficiency and is often accompanied by a congenitally absent thumb. Anomalies of other systems may also be associated.
TAR.
FA.
Holt–Oram syndrome: AD; cardiac anomalies, and radial dysplasia.
VACTERL (vertebral anomalies, anal atresia, cardiac malformations, tracheo-oesophageal fistula, renal and limb anomalies).
Management
Serial castings/splinting.
Surgery is usually required to place the hand in position to maximize function. If a thumb is absent, pollicization of the index finger could improve function. The index finger is reconstructed and radially positioned to form a functional ‘thumb’.
Juvenile idiopathic arthritis
JIA is a common chronic childhood disorder (UK prevalence 1/1000; incidence: 1/10 000). It is a diagnosis of exclusion in children <16yrs old with a history of at least 6wks of persistent arthritis. JIA is divided into 7 subsets for research purposes.1 These are not diagnostic categories, but are useful clinical groups. As a child’s symptoms evolve with time (e.g. the appearance of a psoriatic rash), they may change subtype.
Classification of JIA1
Systemic arthritis: relative frequency,10–13%. See p.772.
Oligoarthritis (persistent or extended): relative frequency, 40%. See p.773.
Polyarthritis (rheumatoid factor +ve): relative frequency, 3%. See p.774.
Polyarthritis (rheumatoid factor −ve): relative frequency, 27%. See p.776.
Psoriatic arthritis: relative frequency, 2–15%. See p.777.
Enthesitis-related arthritis: relative frequency, 1–7%. See p.778.
Undifferentiated arthritis: relative frequency, 2–15%.
Differential diagnoses of childhood arthritis
Reference
Juvenile idiopathic arthritis: clinical principles and management
Before labelling child with diagnosis of JIA it is imperative to exclude the differential diagnoses, the most important of which are sepsis, malignancy, and trauma (see p.736).
History from carer and child
Limp, stiffness and loss of function, pain, or malaise.
Onset usually gradual. Beware of misleading history of trauma as young children frequently fall without significant injury.
History of non-use, or change in use.
Child may not complain of pain. Infant may be ‘irritable’.
Inflammatory symptoms: worse after rest or inactivity.
Stiffness is rarely volunteered. Parents sometimes describe child as ‘like a little old person in the mornings’. Toddler’s behaviour may be perceived as being difficult and uncooperative (e.g. refusing to move in the morning, then running in the afternoon).
History of associated rash, fever, weight loss.
History of sore throat, URTI, antecedent infections, and travel.
Family history of arthritis, psoriasis, colitis, rheumatic fever, or acute iritis.
Examination
Observe the child before they become self-conscious.
Watch them playing and walking.
Examine all the joints and spine for swelling, warmth, pain on movement, or limited movement.
Measure for leg length inequality and pelvic tilt.
Examine muscle bulk around affected joints.
Assess general muscle strength.
Examine the skin, hair and nails for rashes, psoriasis.
General examination: vital signs, height, weight, and BP.
Examine mouth and palate for ulcers, dentition; fauces for asymptomatic tonsillitis; heart for murmurs; abdomen for hepatosplenomegaly.
Investigations
FBC may show mild anaemia and thrombocytosis.
Neutrophilia suggests sepsis or systemic JIA.
Severe anaemia or thrombocytopenia: consider leukaemia.
ESR/CRP usually normal or mildly elevated. Very high levels suggest infection or malignancy. High ESR plus thrombocytopenia suggests leukaemia.
Infection screen: throat swab, urinalysis, blood for ASOT, viral serology (CMV, EBV, parvovirus B19, hepatitis) and culture.
Rheumatoid factor: non-specific test, but significant in polyarthritis (>5 joints). Exclusion criterion for oligoarticular JIA.
ANA: non-specific (5% children ANA +ve). In oligoarticular JIA limited prognostic determinant for iritis.
Muscle enzymes (CK, LDH, aldolase) raised in dermatomyositis, but can be normal. Very high LDH suggests malignancy.
Imaging:.
radiographs—exclude fracture or tumour; early JIA—soft tissue swelling, and juxta-articular osteopenia; later—joint space narrowing and erosions;
US—helpful for confirming synovitis and joint effusion;
MRI—useful for atypical monoarthritis; gadolinium-enhanced MRI is gold standard for diagnosis of synovitis, but does not differentiate from sepsis.
Synovial fluid aspirate: culture for sepsis. Microscopy rarely helpful.
Management
General
Establish diagnosis and counsel child and parents.
Start treatment as soon as possible.
Most children will need regular hospital review to look for presence or reappearance of thickened synovium or effusions.
Exercise: regular, daily aerobic and ‘range of motion’ exercises.
Psychological support for children and carers: education and support groups (e.g. Arthritis Research Campaign).
Ask about school performance and support at school.
Adolescents may need counselling about contraception and alcohol if taking MTX.
Amyloidosis: rare complication of severe disease.
Joints
Minimize pain and stiffness using NSAIDs:
ibuprofen (30–40mg/kg);
diclofenac (1.5–2.5mg/kg bd);
naproxen (5–15mg/kg bd);
piroxicam (5–20mg daily according to weight).
Prevent deformity: regular daily exercises; night splints; intra-articular steroid injections (triamcinolone) may settle inflammation for years.
Control disease activity: MTX oral or SC in resistant cases.
Etanercept: anti- tumour necrosis factor (TNF) if unresponsive to NSAIDs and SC MTX.
Eye screen for uveitis
Must have regular screening, initially 3-monthly, by experienced ophthalmologist. Treat with topical steroids and midriatics. Course is independent of joint disease severity. Potentially blinding.
Growth
Measure growth velocity; nutritional status; muscular atrophy.
Dentition
Watch for caries.
Once the diagnosis is established the child should be looked after by a paediatric rheumatologist for specialist drugs and co-ordinating multidisciplinary support.
Systemic arthritis
Multisystem disease is often diagnosed late as joint involvement is often late. Peak age 2–3yrs; 10–20% JIA; equal male:female.
Clinical features
Fever is essential, typically quotidian up to 39°C, returning to normal between attacks.
Rash: salmon pink, macular/urticarial on chest, trunk, and intertrigones. Present when warm and disappears within minutes.
Myalgia, arthralgia, and arthritis. Arthritis often appears after first 6mths of illness and can be oligo- or polyarthritis.
Generalized lymphadenopathy and hepatosplenomegaly.
Polyserositis with pericarditis, pleuritis, and sterile peritonitis. Silent pericardial effusions (15%). Myocarditis + tachycardia, cardiomegaly, and congestive cardiac failure is rare.
Growth retardation s to disease, steroids, or joint damage.
Late complications: amyloidosis (difficult to treat).
MAS: rare, life-threatening; precipitated by infection or NSAIDs. Haemophagocytic bone marrow with falling WBC, platelets, and ESR, and very high ferritin.
Investigations
FBC (normocytic or hypochromic anaemia; leucocytosis; thrombocytosis).
ESR/CRP can be high: use to monitor disease during treatment.
Hypoalbuminaemia: multifactorial—poor diet, general ill health with catabolism, possibly proteinuria secondary to renal amyloid.
ANA and RF usually −ve.
Viral titres and blood cultures.
Malignancy screen: CXR, US abdomen.
ECG and echocardiogram.
Management
NSAIDs for initial management of pain, fever, and serositis. Indomethacin often used for pericarditis.
Pulsed IV corticosteroids if no improvement after 1wk of NSAIDs.
Oral steroids at 1mg/kg in divided doses until fever settled and inflammatory markers normal. Taper dose to reduce side-effects. Use alternate day doses and add steroid-sparing agent.
MTX is used, but is not as effective as in other JIA subsets.
Intra-articular corticosteroid for flares of single joints.
Biological therapy: anti-TNF and anti-IL6 in resistant cases.
Prognosis
Three groups—monocyclic (11%); recurrent or polycyclic (34%); and persistent (55%). Monocyclic patients do well. More than 33% of the others will have permanent disability with active disease in adult life. Death from infection, MAS, or amylodosis.
Oligoarticular juvenile idiopathic arthritis
Commonest subtype (previously known as pauciarticular JCA/JRA). 40% of patients.
Two subsets are recognized: persistent and extended. If the number of joints increases to more than 4 within the first 6mths of illness, it is termed extended oligoarticular JIA.
Children may develop silent, blinding iritis (anterior uvertis). It is usually ANA-positive patients (40–75% of this form of illness) who are at risk of developing iritis.
Clinical features
Diagnosis of exclusion; rule out infection.
Milder symptoms than reactive arthritis; no constitutional symptoms.
Often present with joint swelling or limping rather than pain.
2/3 single joint; 1/3 only 2 joints; often asymmetrical; knees, ankles, elbows, wrists common, but any joint possible.
Careful examination may reveal more extensive disease as the child may be too young to express pain.
Elbows and knees may lack full extension, but not be painful.
Affected leg may overgrow; measure leg lengths and check pelvis is level.
Observe gait for circumduction to compensate for limb overgrowth.
Investigations
FBC; CRP (usually normal); ANA (prognostic value for uveitis).
X-ray: exclude fracture, tumour; look for overgrowth and damage.
Management
Regular review to assess joints, eyes, and general growth.
NSAIDs for pain and stiffness: full dose for 8wks (ibuprofen, diclofenac, naproxen, or piroxicam).
Intra-articular steroid injections: may settle inflammation for years.
If not controlled with oral NSAIDs and intra-articular steroids, MTX oral or SC is used in resistant cases.
Rarely etanercept (anti-TNF therapy) is needed.
Screen for uveitis: initially 3-monthly, by ophthalmologist.
Disease course and prognosis
80% normal at 15yrs. ‘Extended’ subset have worse prognosis.
Uveitis is most important extra-articular complication.
Rheumatoid factor-positive polyarthritis
A chronic symmetrical inflammatory polyarthritis (>5 joints) with positive RF on two occasions at least 3mths apart. Typically affects teenage girls, though any age possible. Similar to adult rheumatoid arthritis, but generally a more aggressive disease.
Morning stiffness: >1hr at peak illness
Arthritis in at least 3 joints: witnessed by a physician
Hand arthritis: wrists, MCPs, or PIPs
Symmetrical arthritis
Rheumatoid nodules
Rheumatoid factor-positive
Erosions on X-ray
All symptoms need to be present for at least 6wks. Four or more criteria need to be fulfilled for diagnosis of rheumatoid arthritis (RA). These are primarily classification criteria (90% sensitivity and specificity).
Clinical features
History of early morning and immobility stiffness.
Symmetrical arthritis affecting large and small joints associated with rheumatoid nodules. Wrists and PIPs affected early. Hip involvement can be aggressive and lead to early hip replacement.
Tenosynovitis common around fingers and ankles.
Systemic features: low grade fever (differential diagnosis systemic JIA); hepatosplenomegaly; lymphadenopathy; serositis (pericarditis and pleurisy).
Eyes: uveitis rare; dry eyes relatively common (10–35%); episcleritis can lead to a painful red eye.
Investigations
FBC; CRP; LFTs; RF; ANA.
Renal function and urinalysis.
X-rays of affected joints and CXR.
Management
Monitor disease activity and aim for good control of arthritis.
Regular meticulous assessment for tender and swollen joints, muscle wasting, joint damage, and loss of joint function.
Monitor growth development and nutritional status.
Exercise: range of joint motion and aerobic activity.
Psychosocial development can be severely affected and needs addressing.
Treatment
Start treatment as soon as possible.
NSAIDs provide relief from pain, stiffness, and swelling.
All children will need disease-modifying antirheumatic drug (DMARDs): MTX is the least toxic and most well established—orally or SC. Others include hydroxychloroquine, sulfasalazine, azathioprine, ciclosporin, and gold. These have been used in combination with MTX or alone.
Steroids: intra-articular steroids to settle synovitis in individual joints; oral steroids as adjunct to DMARDs; pulsed IV steroids for flare of disease. Aim to minimize total steroid load.
Biologic agents: Anti-TNF agents (etenercept, infliximab, adalimimab) have been shown to reduce joint erosions and may prevent progression to secondary arthritis
Prognosis
Most children survive into adulthood though with poor functional outcome because of aggressive, unremitting disease, early erosions, and high incidence of joint replacement. The use of aggressive, early systemic MTX and biological therapies may have improved this outcome.
Reference
Rheumatoid factor-negative polyarthritis
30% of JIA cases. Previously known as polyarticular onset JCA. Characterized by 5 or more affected joints within first 6mths.
Clinical features
Diagnosis of exclusion: IgM RF-negative 3mths apart.
Systemic features: low grade fever and transient rashes possible, but mild.
Asymmetrical joint involvement of any joint including jaw, cervical spine, wrists and fingers, and subtalar joints.
Joint swelling leads to limited mobility and muscle wasting.
Chronic hyperaemia leads to accelerated bone growth and premature cartilage fusion. Common sites: carpus, subtalar, jaw (micrognathia, dental malocclusion); cervical spine (C3–5 apophyseal joint fusion with instability above and below).
Tenosynovitis and bursitis around fingers and feet.
Flexion contractures at elbows, knees, and hips.
Investigations
Blood: FBC, CRP, ANA.
X-ray: affected joints.
Treatments
Start treatment as soon as possible.
NSAIDs for 8wks in adequate dose, plus intra-articular steroids to target joints.
Start DMARDs early to try and induce remission with oral or SC MTX (use sulfasalazine or azathioprine if intolerant to MTX; see p.775).
Remission: continue NSAID for 6mths and DMARD for 1yr.
Persistent arthritis: intra-articular steroids into target joints + combination DMARDs.
Etanercept: anti-TNF therapy if intolerant or unresponsive to MTX.
Prognosis
Heterogeneous group of conditions with variable prognosis. Prognosis has dramatically improved in recent years with the aggressive use of MTX and anti-TNF therapy. However, up to a third will have persistent deformity, disability, and disease activity into adult life.
Psoriatic arthritis
Recently recognized, underdiagnosed subset of JIA; 2–15% of children with JIA; unknown aetiology on a background of strong genetic predisposition (up to 50%).
ILAR criteria for diagnosis of psoriatic arthritis1
Inflammatory arthritis in presence of psoriasis, or inflammatory arthritis with dactylitis or psoriatic nail changes plus a first-degree relative with psoriasis.
Exclusions: RF +ve; HLA-B27 +ve in male >6yrs; any enthesitis-related arthritis or uveitis in first-degree relative; systemic arthritis.
Clinical features
Arthritis and rash rarely present simultaneously. Rash usually precedes arthritis.
Arthritis: commonest is asymmetrical large joint (knees or ankles). Small joint polyarthritis of fingers and toes (metacarpal phalangeal (MCP), proximal interphalangeal (PIP), and distal interphalangeal (DIP) joints) and dactylitis are also common. Some children have tendonitis or tenosynovitis, especially around the ankles.
Skin: predominantly plaque psoriasis (examine extensor surfaces of elbows and knees, hairline, behind the ears, around the umbilicus, groin, and natal cleft; see p.810).
Nails: pitting, ridging, onycholysis, subungual hyperkeratosis.
Uveitis: needs regular screening as can potentially blind.
Psoriasis affects up to 3% of normal population; the association with inflammatory arthritis may be coincidental.
Investigations
No specific tests: need exclusion bloods (see p.734).
Often evidence of chronic inflammation: raised CRP; thrombocytosis; and low grade normocytic anaemia.
Radiographs
Periarticular osteopenia and soft tissue swelling.
Periosteal new bone formation, particularly in dactylitis.
Treatment
Important to diagnosis dactylitis. NSAIDs are the mainstay of treatment. Intra-articular steroid injections often help settle inflammation. Methotrexate and ant-TNF agents are effective for persistent disease.
Prognosis
Arthritis can be episodic and continue into adult life. A few patients have a very destructive course with arthritis mutilans.
Reference
Enthesitis-related arthritis
Recently introduced ILAR terminology and category.1 Previously known as juvenile ankylosing spondylitis or seronegative spondyarthropathy. Characterized by arthritis with enthesitis (inflammation in any tendinous, ligamentous, or muscular insertion on to bone) or arthritis alone or enthesitis alone with 2 of the following features:
sacroiliac joint tenderness;
inflammatory spinal pain;
HLA B27 +ve;
first degree relative family history of uveitis;
age of onset 6 >yrs.
Exclude RF +ve; systemic arthritis; psoriasis in patient or first degree relative.
Clinical features
Commonly adolescent or pre-adolescent boys (M:F, 10:1).
Oligo- or polyarthritis predominantly in lower limbs.
Enthesitis especially around the foot (heel pain). Children can present with isolated heel pain many years before spinal symptoms.
Spinal pain may not be present at onset.
Progresses to sacroiliac joint tenderness, inflammatory spinal pain, or buttock pain (worse at night plus early morning stiffness).
Systemic features: low grade fever, weight loss, and fatigue.
Acute anterior uveitis (10–15%): acutely painful red, photophobic eye—different from uveitis seen with other JIA.
Associated IBD and reactive arthritis.
Examination
Examine affected joints: for synovitis, effusions, associated muscle wasting, and range of movement.
Spine examination: is essential. Test for cervical rotation, thoracic rotation, lateral flexion, and document the Schober test (mark 10cm above and 5cm below the ‘dimples of Venus’ and note the increase gained by forward flexion). Normal is at least 21cm—varies little with age and gender. Look for loss of normal lumbar lordosis.
Chest expansion: may be reduced in advanced disease.
Examine commonly affected enthesitis sites around the heel: Achilles insertion and calcaneum.
Investigations
FBC (normochromic anaemia, mild leucocytosis, and thrombocytosis).
If microcytic anaemia think of occult IBD.
CRP may be raised.
RF and ANA negative.
HLA B27 +ve 90%, but also +ve in 8–10% of normal population.
Radiology
X-ray changes lag behind clinical symptoms by up to 10yrs. MRI is the gold standard in adults. Interpretation is difficult in children. Lateral views may show Romanus lesions (small erosions of the corners of the vertebral bodies).
X-rays
Affected joints: soft tissue swelling, periarticular osteopenia, erosions, joint space narrowing, bony ankylosis.
Heel may show calcaneal spur or fluffy exostoses on Achilles.
Sacroiliac joints may show erosions, sclerosis, and fusion.
Thoracolumbar junction may show bony overgrowth syndesmophytes.
Reference
Systemic lupus erythematosus
Complex, multisystem autoimmune disorder affecting adolescents (rare in younger children; female:male ratio 20:1). Commoner and more severe in Afro-Caribbean, Hispanic, and Far Eastern girls.
The ARA criteria are helpful (90% sensitivity 97% specificity), but less reliable in early disease.1 One of the ‘great mimics’ of other conditions.
SLE is diagnosed if 4 of the 11 features present simultaneously or serially:
Malar rash
Discoid rash
Photosensitivity
Mouth ulcers
Arthritis (non-erosive)
Serositis: pleurisy or pericarditis
Renal disease: persistent proteinuria >0.5g/24hr or cellular casts
Neurological disorder: psychosis or seizures in absence of known precipitants
Haematological abnormality: haemolytic anaemia or leucopenia <4.0 x 109/L on 2 or more occasions or thrombocytopenia <100 x 109/L
Immunological: raised anti DNA binding antibody, anti-Smith antibody, and/or +ve antiphospholipid antibodies
Antinuclear antibody
Clinical features
The presenting complaint may affect any organ system.
Non-specific constitutional symptoms common: low grade fever, weight loss, fatigue, anorexia, and lymphadenopathy.
Mucocutaneous problems: hair loss (scarring and non-scarring alopecia); mouth ulcers; photosensitivity (50%); Raynaud’s phenomenon (90%); malar ‘butterfly’ rash over bridge of nose and sparing nasolabial folds; discoid lesions; livido reticularis; urticarial rashes; purpuric rashes; digital vasculitis.
Musculoskeletal (90%): polyarthritis resembling rheumatoid arthritis (non-erosive); tendonitis; arthralgia; myalgia; myositis (5%); aseptic necrosis.
Cardiovascular: pericarditis (silent or rapidly constrictive); myositis, valvulitis with endocarditis (Libman–Sachs).
Pulmonary: pleurisy; pleural effusions; haemoptysis from pulmonary vasculitis; interstitial fibrosis; pneumonitis.
Renal: hypertension; proteinuria; nephritis; nephrotic syndrome; renal failure.
Haematological: anaemia (normochromic normocytic, Coombs +ve haemolytic, renal failure, drug-related); leucopenia and lymphopenia common (80%); thrombocytopenia (20%) chronic, rarely aggressive.
Neurological: migraine (40%); mood disorders (anxiety, depression, emotional liability (70%)); psychoses (rare); seizures (rare); peripheral neuropathies (10%).
Careful drug history: especially tetracyclines for acne (+ve antihistone antibodies).
Investigations
FBC, LFTs; renal function; BP measurement; urinalysis; ANA (99%), dsDNA (40% , but specific for SLE); RF; coagulation screen; anticardiolipin and antiphospholipid antibodies. ESR may be raised; CRP low unless serositis or infection; C3, C4 low in active disease.
Management: in specialist clinic
General: avoid sun exposure and use sun-screen; treat hypertension; and minimize long-term cardiovascular risks. Use ACE inhibitors for nephroprotection for proteinuria.
Target and treat aggressively affected organs.
NSAIDs for musculoskeletal symptoms.
Hydroxychloroquine for fatigue, rashes, and arthritis.
Prednisolone and steroid-sparing drugs (azathioprine (AZA), MTX, mycophenolate mofetil (MMF)) for other severe manifestations.
Prednisolone and cyclophosphamide for active nephritis; then AZA or MMF.
Experimental treatments for refractory cases: rituximab; autologous stem cell replacement.
Prognosis
Very variable between ethnic groups. Overall 5-yr survival 90% with death from unremitting active disease or immunosuppression.
Prognosis worse for those with nephritis (60% after 15yrs).
Bimodal survival curve with long-term increased risk of cardiovascular disease.
Reference
Juvenile dermatomyositis
Autoimmune inflammatory disease of skin and muscles. Rare (incidence 2–3 per million) and occurs between ages of 10 and 14yrs. Cause unknown; infectious and environmental triggers are likely.
Erythematous rash plus two other criteria:
Symmetrical weakness of proximal muscles
Periorbital oedema with heliotrope discoloration; scaly rash over MTPs and PIPs (Grottron’s papules)
Elevation of one or more muscles enzymes: CK, AST, LDH, aldolase
EMG changes of myopathy and denervation
Muscle biopsy evidence of necrosis and inflammation
MRI (has largely superseded EMG and muscle biopsy in children)
*Modified from Bohan A, Peter JB. (1975). Polymyositis and dermatomyositis. N Engl J Med 292: 403–7.
Clinical features
Onset usually insidious, rash may precede muscle weakness.
Rash: periorbital oedema with heliotrope discolouration of upper lids; facial rash includes nasolabial folds (unlike SLE); erythematous maculopapular rash over extensor surfaces of MCP, PIPs, elbows, and knees (Grottron’s papules); nail-fold vasculitis.
Muscles: typically symmetrical proximal muscle weakness with fatiguability of arms and legs; truncal weakness (unable to sit from lying); ‘Gower’s sign’ ( p.733); palatal and respiratory muscles affected in severe cases with nasal speech, poor swallowing, decreased lung volume.
Arthritis (60%): 2/3 oligoarthritis; 1/3 polyarthritis.
Lung disease (uncommon): interstitial fibrosis; pulmonary vasculitis.
Diagnosis
is usually made by typical rash, proximal muscle weakness, raised muscle enzymes, and typical MRI changes.
Differential diagnosis
Infectious myositis (usually viral); overlap with autoimmune disorder (SLE and mixed connective tissue disease (MCTD)); systemic arthritis JIA.
Late complications
Calcinosis: linked with active myositis; occurs in skin, fascia, subcutaneous fat and muscle. Superficial lesions may be painful, erupt, and discharge. Sheets of calcification may prevent movement and usually resolve with time. Tumoural deposits may be surgically removed.
Lipodystrophy: generalized or partial; painless; generalized form associated with insulin resistance, diabetes, liver disease, and short stature.
Investigations
Muscle enzymes: CK; LDH; aldolase; AST; ALT.
ANA (6–60%): may be raised; Myositis-specific antibodies rarely present in children.
ESR and CRP: variable.
MRI (STIR or T2 fat suppressed): diffuse white signal throughout affected muscles.
EMG: low amplitude, short-duration polyphasic potentials with early recruitment, fibrillations, and repetitive discharges.
Muscle biopsy can show histological evidence of necrosis and inflammation.
Monitoring
Regular examination: muscle strength testing and muscle enzymes.
Aim to maintain function, normalize muscle enzymes, and limit steroid effects on growth.
Course and treatment
The condition may be uniphasic, polyphasic, or continuous. Corticosteroids are the mainstay of treatment. Methotrexate is used in more severe and persistent severe cases as a steroid-sparing drug. Cyclophosphamide is used in some centres for vasculitis. Treat for 18mths after remission induced. Some evidence that aggressive treatment may minimize calcinosis.
Mixed connective tissue disease—overlap syndromes
Combined features of SLE, progressive systemic sclerosis, and dermatomyostis with positive ribonucleoprotein (RNP) antibody.
Prognosis and management similar to that of SLE , but more benign prognosis because renal and CNS involvement are rare.
Clinical features
Raynaud’s phenomenon (common).
Swollen hands and fingers (common).
Polyarthritis: symmetrical peripheral.
Rashes: similar to SLE or JDM rash; tight non-elastic skin of hands. See also p.839.
Muscle weakness and myositis.
Restrictive lung disease and pulmonary hypertension (rare).
Differential diagnosis
Investigations
Characteristic anti-RNP antibody.
Other autoantibodies: ANA +ve (90%); RF +ve (often).
FBC: leucopenia; thrombocytopenia.
CXR.
Renal function.
Echocardiogram: screen for right ventricular hypertrophy secondary to pulmonary hypertension in established disease
Scleroderma
Hard, tight, inelastic skin and subcutaneous tissue. Female to male ratio is 2:1. Two distinct syndromes.
Localized scleroderma (morphoea, linear scleroderma)
Lesions confined to the skin are termed morphoea.
Lesions that involve the underlying tissues, sometimes down to bone, are termed linear scleroderma (LS).
In both types there is an initial inflammatory phase with single or multiple flesh-coloured or erythematous plaques. These evolve into firm, waxy, yellow-white shiny lesions with violaceous borders.
Growth of the region under LS is arrested and this can result in severe growth and cosmetic deformities.
Linear lesions across the forehead to the nose are termed ‘en coup de sabre’. These lesions may extend down to the brain and be associated with epilepsy.
Oligoarthritis (10%) can precede skin changes.
Oesophageal involvement not infrequent, but no other systemic changes.
Systemic sclerosis (SSC or progressive systemic sclerosis PSS)
Raynaud’s phenomenon is universal (often the presenting symptom); severe attacks can result in digital ischaemia, ulceration, and bony resorption.
Skin changes follow with oedema and inflammation. Symmetrical involvement of the metacarpal phalangeal (MCP) joint and metatarsal phalangeal (MTP) joints.
Finger oedema lasts for several weeks and is replaced by taut, waxy, shiny, thickened skin that eventually becomes atrophic. Finger tip skin may crack (‘mechanics’s hands’).
Facial involvement: pinched nose, expressionless façade, and decreased gape.
Nail folds are ragged with telangiectasia.
Joints: stiff from overlying scleroderma. Occasional oligoarthritis.
Dysmotility and bowel wall thickening can occur throughout the bowel leading to malabsorption, wasting, bloating, abdominal cramps, diarrhoea, or severe constipation.
Pulmonary fibrosis and pulmonary hypertension are initially asymptomatic. When more severe they lead to dyspnoea, syncope, and death.
Myocarditis, pericarditis, and arrhythymias reported.
Renal disease with crisis used to be commonest cause of death.
Investigations
FBC, ESR; LFTs, renal function including BP; ANA, anti-centromere, and anti-topoisomerase antibodies.
CXR; ECG; echocardiogram to screen for pulmonary hypertension.
LFTs and CT scan if fibrosis or pulmonary hypertension.
Treatment and management
No treatment is consistently effective in slowing or preventing fibrosis and sclerosis in severe progressive cases. MTX, mycophenolate, ciclosporin, and low dose steroids have been used in the inflammatory phase. Steroids and ciclosporin may precipitate scleroderma renal crisis (check for hypertension and treat with ACE inhibitors).
Symptomatic treatment depending on organ involvement:
Raynaud’s: hand warmers; double gloves; oral or topical vasodilators; prostacyclin for severe attacks and digital gangrene;
GI tract: avoid NSAIDs. Metoclopramide aids gut motility; proton pump inhibitors for acid secretion; pancreatic supplements.
Prognosis
Localized scleroderma: generally good prognosis. Cosmetic deformities may occur if bone involvement with linear scleroderma.
SSC/PSS: poor prognosis. 5yrs survival 34–73%. Death from pulmonary hypertension and renal crisis.
Henoch–Schönlein purpura
Small vessel vasculitis associated with IgA immune complexes. A triad of arthritis, colicky abdominal pain, and palpable, papular, purpuric rash. Characteristically affects prepubertal boys.
Clinical features
Skin rash: palpable purpura over buttocks and lower legs. Severe skin vasculitis can lead to oedema (dorsum hand, scrotum, and periorbital).
Arthritis: typically short-lived affecting large joints (knees, ankles, or elbows).
Gastrointestinal: colicky abdominal pain (commonest), malaena, haematemesis, intussusception, perforation, appendicitis.
Renal: dipstick haematuria and proteinuria present (50%). Glomerulonephritis and nephrotic syndrome rare.
Investigations
FBC, renal function, dipstick urinalysis, and full renal investigation with biopsy if evidence of renal involvement (crescentic IgA glomerulonephritis).
Skin biopsy rarely necessary: leucocytoclastic vasculitis.
Abdominal investigations as per symptoms.
Treatment and prognosis
Most cases have a benign course with complete resolution of symptoms within 6wks. NSAIDs help arthritis symptoms. Corticosteroids for abdominal pain and arthritis may hasten symptom resolution. Test for haematuria because nephritis and nephritic syndrome carry worse prognosis for hypertension and decreased renal function.
Polyarteritis nodosa
Rare, medium-vessel necrotizing vasculitis with aneurysm formation. Male:female ratio 2:1.
Clinical
Antecedent systemic illness with unexplained fevers, abdominal pains, and arthralgia of up to 1yr.
Testicular pain in males (often mistaken for torsion).
Vasculitis or purpuric skin rash.
Arthritis (30%) large joints: exquisite bony tenderness from peripheral vasculitis and periosteal new bone formation.
Renal: hypertension; haematuria, proteinuria; renal failure; intrarenal aneurysms.
GI involvement (50%): abdominal pain; pancreatitis; bowel infarction.
CNS: mononeuritis multiplex; peripheral neuropathy; fits; hemiplegia.
Investigations
FBC; LFTs may be elevated.
Renal function urinalysis for active sediment.
MRI; MR angiography to reveal multiple aneurysms.
Histology: panarteritis with fibrinoid necrosis, thrombosis, infarction, weakening of artery walls, and aneurysms. Segmental lesions at bifurcations of small- and medium-vessel walls.
Course and treatment
Without treatment may be fatal. Often under recognized and undertreated in children. If treated promptly, with pulsed cyclophosphamide and high dose steroids, prognosis improved.
Wegener’s granulomatosis
Triad of ANCA positive small vessel vasculitis, respiratory tract granulomata, renal disease. Rare. Usually diagnosed in adolescents (male = female). Staphylococcus aureus may have role in pathogenesis since 3 times greater carriage in Wegener’s granulomatosis (WG).
Clinical features
Subacute disease can be present for years. Transformation into systemic disease (malaise, fever, weight loss, vasculitis) occurs.
ENT (90%): nasal crusting, obstruction, and ulceration; serous otitis media; sinusitis. Nasal septum and sinus wall destruction (saddle nose deformity).
Pulmonary (80%): subglottic stenosis (stridor); haemoptysis (25%); lower bronchial obstruction with atelectasis and pneumonia; pulmonary haemorrhage; asymptomatic nodules.
Renal (90%): varies from mild asymptomatic (commoner microscopic haematuria; mild renal impairment) to fulminant diffuse necrotizing crescentic glomerulonephritis and renal failure.
Arthritis (50%): non-erosive polyarthritis; muscle and joint pains common (60%).
Skin (40%): palpable purpura of leucocytoclastic vasculitis; livido reticularis; pyoderma gangrenosum.
CNS (30%): mononeuritis multiplex and sensorimotor peripheral neuropathy.
Eye lesions: episcleritis; uveitis; orbital pseudotumour.
Investigations
Blood:
FBC (normocytic, normochromic anaemia, leucocytosis, thrombocytosis). ESR and CRP raised (differential diagnosis: infection);
renal screen with BP measurement and urinalysis at each visit. Renal biopsy if active sediment and declining renal function;
CANCA (proteinase 3) positive in 90% patients with generalized WG. High specificity.
Lungs:
CXR, sputum culture, and cytology; CT lungs; bronchoscopy and biopsy if indicated.
CT sinuses +/− nasendoscopy and biopsy.
Histology: necrotizing, giant cell, granulomatous, medium vessel vasculitis in respiratory tract.
Course and treatment
Systemic disease: treated with pulsed IV cyclophosphamide and steroids to induce remission. Remission maintenance with MTX or AZA. Minimize total steroid load. Only stop after min. 12mths disease-free.
Subacute and limited disease: have variable (milder) course; may respond to MTX alone or with low dose steroids. Long-term co-trimoxazole in remission reduces pulmonary infection and relapse rates. 10yr survival 75%; morbidity considerable.
Takayasu’s arteritis (pulseless disease)
Rare chronic granulomatous panarteritis affecting aorta and large arteries. Adolescent Asian (Japanese) girls and young women most susceptible.
Clinical features
Subclinical prepulseless phase may last years: anorexia, fatigue, poor growth, unexplained fevers, and episodic arthritis (50%).
Pulseless phase: diagnoses often made incidentally.
diminished peripheral pulses and aortic dilatation on CXR or hypertension and renal artery stenosis;
dramatic presentation with severe hypertensive encephalopathy and seizures; congestive cardiac failure; aortic valvulitis and aortic regurgitation; pulmonary stenosis;
syncope s to paroxysmal hypertension or paroxysmal tachycardias with facial flushing headaches, chest pain, dyspnoea, and palpitations. May be triggered by changes in posture or micturition (i.e. baroreceptor hypersensitivity).
Investigations
FBC (normochromic normocytic anaemia, thrombocytosis); ESR and gamma globulins very elevated even in the prepulseless phase.
Imaging: high resolution carotid US, angiography, or MR angiography show characteristic arterial dilatation, post-stenotic dilatation, aneurysm, thrombosis, and occlusion of the proximal branches of the aorta.
Treatment
Manage hypertension: β-blockers and ACE inhibitors. Avoid vasodilators.
Treat vasculitis: initially high dose steroids (prednisolone 1mg/kg/day or equivalent) with MTX or AZA as steroid-sparing drugs. Cyclophosphamide for severe or resistant cases.
Surgery: range from angioplasty to bypass grafting.
Prognosis
10yr survival 90%, although the majority (75%) have some impairment of daily living, and 50% are disabled. Prognosis depends on hypertension and aortic incompetence. Successful planned pregnancy is possible.
