13.23 Sports injuries and syndromes

As a truly multidisciplinary specialty, sports medicine crosses traditional medical boundaries. The focus of this chapter is on sports-related injuries, rather than injuries from accidents but the epidemiological data for such injuries are sparse for some disciplines and studies use varying definitions and methodology. Nonetheless, it is clear that the majority of children and adolescents aged 5–17 years participate in organized sport in both the United Kingdom and United States of America that accounts for a significant proportion of injuries in this age group. For most sports, the knee is the most common site of injury. Increased participation in competitive sport is reflected in a 15% increase in reported knee injuries in the under 17-year age group between 1996 and 2001 despite increased injury prevention programmes.

Injuries in children secondary to sports trauma are modulated by the unique properties of the growing musculoskeletal system with vulnerable epiphyseal and apophyseal cartilage plates but with greater capacity for healing and remodelling than in adults.

If discoid menisci and other congenital malformations are excluded, meniscal injuries in the immature athlete are uncommon, particularly under the age of 10 years. Their incidence is on the increase, however, with greater and more vigorous sports participation. The menisci are similar in structure and function to those in the adult but differ critically in their increased vascularity and thus improved potential for healing. Magnetic resonance imaging (MRI) is less accurate in the diagnosis of meniscal tears in children compared to adults so reliance on clinical evaluation and a lower threshold for repair over excision are the key differences in management of childhood meniscal injury.

The anxious child or apparently indifferent adolescent may not recall a twisting injury or varus/valgus strain and decreasing age and increasing time from the relevant injury further diminish the value of direct questioning. Key features in the clinical examination are the presence of focal joint line tenderness and the presence of an effusion. In the acute setting, this indicates a likely haemarthrosis (Box 13.23.1).

There is a high rate of concomitant meniscal and anterior cruciate ligament (ACL) injury in children with haemarthrosis, especially adolescents. With chronic tears, intermittent locking, clicking, or ‘popping’ and the presence of an effusion and quadriceps wasting are common findings.

Despite reports of improved specificity and sensitivity in the diagnosis of meniscal tears using contemporary MRI sequences, this modality is less accurate in children, especially those aged less than 12 years, in part because of differing patterns of vascularity. The presence of joint line tenderness and a modified McMurray’s test in the clinic is at least as accurate for diagnosis as MRI, with arthroscopic evaluation the gold standard for assessment of tear morphology. The majority are vertical longitudinal (‘bucket-handle’) type; oblique, radial, and degenerative tear patterns are seen less commonly than in adults. Standard plain orthogonal radiographs form part of the diagnostic work-up to exclude occult pathology such as infection or bone tumour as a cause for symptoms. Additional skyline patella and tunnel or notch views are helpful to search for osteochondral defects or patellofemoral incongruity.

Short (<10mm) longitudinal tears that are stable when probed can be left to heal. A hinged knee brace permitting 0–60 degrees of flexion restricts activity for 4–6 weeks. All other unstable and arthroscopically reducible tears should undergo repair, particularly if anterior cruciate ligament reconstruction is also required. A combined repair is associated with improved healing rates, most likely reflecting an enhanced vascular response. Similarly, in chronic tears, local preparation of the tear site with an arthroscopic shaver or rasp is advisable to promote vascular ingress. Early meniscal resection causes increased joint contact stresses which are associated with osteoarthritis. Adult guidelines for repair versus excision, based on tear location in relation to centrally decreasing zones of vascularity, are less relevant in children with greater healing capacity, except perhaps for very central tears which can be debrided back to a stable rim.

Arthroscopic techniques for meniscal repair include placement of ‘inside-out’ or ‘outside-in’ sutures, employing posteromedial or posterolateral incisions to protect the saphenous and peroneal nerves for posterior horn tears. The latest generation of ‘all-inside’ suture passing kits with an appropriate tissue-guard and straight and curved needle tips are increasingly favoured over the ‘inside-out’ technique for most tears. Exceptions include anterior horn tears which are difficult to access and are an indication for ‘outside-in’ suture placement. Similarly, concerns about the ‘all-inside’ needle damaging structures behind the capsule in a small knee mean the ‘inside-out’ technique is preferred with posterior horn tears in younger children. A hinged knee brace restricted to 60 degrees of flexion should be worn for 6 weeks after meniscal repair, followed by a gradual return to sport once a full range of knee motion has been restored. Larger and more chronic tears may benefit from a period of partial weight bearing postoperatively but clear guidance regarding rehabilitation is lacking.

ACL injuries in the skeletally immature knee are currently a focus for debate. It is increasingly clear that ACL deficiency in this age group is associated with high rates of symptomatic instability and secondary osteochondral and meniscal damage. Techniques for anatomical placement of a tunnelled, intra-articular graft reconstruction have been refined in the last 20 years for adult injuries. In children and adolescents, the open physes around the knee account for two-thirds of lower limb growth. Damaging either risks limb length discrepancy or angular deformity that may be difficult to manage. With an increasing incidence of immature ACL injury, especially in female adolescents, interest has focused on whether, when and by what means tunnels can be placed safely around the immature knee. Similarly, older techniques such as non-anatomical reconstruction and primary repair have been revisited.

Below the age of 12 years, ACL failure by tibial spine fracture is much more common than intrasubstance rupture: after this the relative likelihood of these injury patterns is reversed. Meniscal tear is the commonest associated injury but physeal fracture, patellar dislocation, and posterior cruciate ligament injury are also reported.

The hallmark clinical features in the history of a ‘pop’ at the time of injury (sustained during a sudden deceleration, pivoting movement or awkward landing) followed by an immediate haemarthrosis, inability to complete the game, and subsequent instability with a return to cutting sports are much harder to elicit in this younger age group. The Lachman and anterior drawer tests should be performed but the pivot shift test is the best predictor of symptomatic ACL insufficiency although it requires optimal relaxation in the conscious child. Signs of an effusion or meniscal injury should be sought. As mentioned previously, standard radiographs with additional tunnel/notch and skyline patella views may be required to exclude bony injury such as tibial spine avulsion and associated osteochondral lesions. MRI may delineate primary, high signal and/or ligament discontinuity, and secondary, bone bruising, signs of ACL injury. Overall, this modality is less accurate in children and is considered an adjunct to clinical diagnosis determining the presence of associated injuries.

ACL injury in the immature athlete does not require urgent operative intervention in the absence of an associated tibial spine fracture or incarcerated meniscus. A phased non-operative programme of rest followed by restoration of range of movement and strengthening exercises and finally sports rehabilitation is indicated. Recurrent instability with ongoing risk of cumulative damage to the knee should prompt consideration of surgical intervention (Box 13.23.2).

The physeal-sparing iliotibial band technique is well described for preadolescent children (Tanner Stage 2 or less) with ACL rupture. The iliotibial band is detached proximally but left attached at Gerdy’s tubercle and brought into the knee through the ‘over the top’ position of the femur. It then passes out under the intermeniscal ligament and is secured in a groove in the anteromedial aspect of the proximal tibial epiphysis. Non-anatomical reconstructions such as this are unlikely to be isometric throughout the range of knee motion, predisposing to graft failure and suboptimal function. Furthermore, iatrogenic injury to the perichondrial ring of the distal femoral physis, which is in close proximity to the over-the-top position, predisposes to growth arrest with angular deformity.

Technically challenging, ‘all epiphyseal’ reconstructions involve the placement of short tunnels within the confines of the epiphysis. The undulating femoral physis provides resistance to shear but the projections into the epiphysis increase the risk of damage.

The literature in adult knee ACL reconstruction emphasizes the importance of anatomical tunnel placement to ensure isometric graft function. Animal studies indicate a low risk of growth arrest with violation of up to 7% of the total cross-sectional area of a physis. Six to nine-mm centrally placed tunnels, in the femur or tibia, damage less than 5% of the physis. They have not been associated with angular deformity or limb length discrepancy except when material other than a soft tissue graft is placed across the defect. Hence the consensus recommendation for ACL rupture in the skeletally immature is increasingly for adult-type surgery using soft tissue graft fixation techniques that avoid bone plugs or screws across the physis. Nonetheless this remains an area of controversy. Historically, direct repair has been associated with poor outcomes although there are obvious advantages to this procedure in the immature knee. Interest is now centred on attempts to produce a biological scaffold to augment the repair.

Any consideration of surgical reconstruction requires a careful assessment of skeletal age and development. Growth rate peaks during puberty between 13–15 years bone age in boys and 11–13 years in girls; after this lower limb growth is virtually complete with remaining growth occurring simply through the spine. Chronological age is generally a good guide to skeletal age, but this generalization cannot be applied to individual cases (Box 13.23.3).

The Gruelich–Pyle atlas method for determining skeletal maturity derives from old population data which may no longer be applicable and bone age determinations for the hand do not always coincide with growth remaining at the knee. Secondary sexual characteristics are staged in the Tanner classification and provide a guide to skeletal growth remaining but these milestones are not familiar to most orthopaedic surgeons and are rarely used. The Sauvegrain or simplified olecranon method of assessment is perhaps the most useful (Figure 13.23.1). At the beginning of puberty, there are two olecranon centres of ossification visible on a lateral elbow radiograph marking the start of the accelerating phase of pubertal growth. Two years later, the olecranon apophysis appears fused and growth decelerates. During the intervening period, morphology of the olecranon ossification centre(s) is a reliable staging guide to the accelerating phase of growth with closure of the triradiate cartilage occurring half way through this phase.

Therefore in adolescents approaching skeletal maturity with a fused olecranon and bone age greater than 15 in boys and greater than 13 in girls, adult-type ACL reconstructive surgery is to be preferred when indicated. The same recommendation can be applied to younger adolescents providing the physeal tunnels are no greater than 9mm in diameter and bridged by soft tissue graft only. Although tunnelled ACL reconstruction is reported in prepubertal children without secondary growth arrest, this remains controversial and non-anatomical reconstruction avoiding physeal graft placement should be considered even if only as a temporizing measure.

This injury pattern is seen mainly in 8–14-year-olds whose ACL is attached to the chondroepiphyses of the distal femur and proximal tibia. These attachments are relatively weak compared to the adult fibrocartilaginous insertions into bone and so, in this age group, ‘the bone ‘fails’ before the (midsubstance) ligament’. Femoral fractures are rare; most are an avulsion of the tibial spine (also known as the tibial eminence).

The mechanism of injury is commonly a valgus force to the knee with rotation or forced flexion. The patient presents with a tense haemarthrosis, reluctance to weight bear, and restricted motion. Anteroposterior and lateral radiographs are indicated (Figure 13.23.2A). Computed tomography (CT) scans are reserved for evaluation of fracture displacement either at presentation or after manipulation. The fractures are classified as a guide to treatment (Table 13.23.1).

Casting after closed reduction is recommended: the cast position of hyperextension, extension, or flexion 20 degrees does not affect outcome. Entrapment of meniscus or the intermeniscal ligament may block closed reduction. A range of open (mini-arthrotomy) and arthroscopic reduction and fixation methods are reported. There are case reports of anterior physeal arrest with screw fixation across the physis; hence cannulated all-epiphyseal screws are to be preferred (Figure 13.23.2B). Fixation techniques using smooth wires or heavy sutures, which can be passed across the physis via cannulae, are also described.

Slight reduction in motion, with loss of hyperextension and deep flexion, is common but rarely symptomatic: arthrofibrosis is rare. During the original injury, it is postulated that the ligament substance stretches prior to the bone failing and this may be the cause of subsequent knee laxity after the fracture has healed. A study comparing treated tibial spine fractures with ACL deficient and reconstructed knees indicated that reduction with fixation restored both adequate stability and proprioception to the knee after fracture.

This Latin name describes the tendency of articular cartilage to separate from subchondral bone. The aetiology is unknown but currently the theory of a primary, ischaemic defect of subchondral bone secondary to repetitive microtrauma is popular. The bone then offers inadequate support to the overlying cartilage which subsequently accrues damage.

Presentation is with activity related knee pain and ache postexercise. Local palpation may indicate the site of the lesion. An effusion may indicate an unstable lesion and mechanical symptoms of locking or giving way, the presence of a loose body.

Healing of these lesions is unpredictable. Children with open physes around the knee have much greater potential for spontaneous healing but larger defects are more likely to fail non-operative treatment. Plain radiographs, including notch and skyline views, will show the majority of significant lesions. The lateral aspect of the medial femoral condyle is the commonest location which is well visualized on the notch view. Additional imaging modalities such as MRI are often used to diagnose and stage the lesion and to predict the likelihood of healing or the requirement for surgical intervention. A breach in the overlying cartilage and high signal behind the lesion on MRI are the most reliable indicators of a poor prognosis (Box 13.23.4).

Given the good prognosis for children with open physes, initial management for early stage lesions should be non-operative. A short period of restricted weight bearing in a slightly flexed cylinder cast, or a knee brace is followed by physiotherapy to restore motion. Once symptoms have resolved, a graduated return to sports begins: the timing may be influenced by further imaging.

Operative management should be considered for larger lesions in older children that fail to heal following non-operative management and with MRI signs of ongoing bone oedema or a break in the articular cartilage. Drilling with K-wires is appropriate for early lesions with intact overlying cartilage or early separation. This can be done arthroscopically in a retrograde fashion. Alternatively a marker wire can be placed percutaneously under image intensifier guidance into the centre of the lesion: the position is confirmed arthroscopically and then multiple passes of a second wire parallel and circumferential to the first are made. These passes abut but do not cross the articular surface allowing containment of the reparative haematoma.

Larger, unstable lesions can be pinned in situ by a variety of techniques with favourable outcomes. These techniques include the use of variable pitch cannulated screws or bioabsorbable implants.

Techniques to reconstruct full thickness cartilage defects, either from unhealed Stage IV osteochondritis dissecans (OCD) or previous osteochondral fracture (see below), include the techniques of mosaicplasty and autologous chondrocyte implantation and are mainly described for adults. Good results have been reported in younger patients (see Chapter 13.20).

Acute patellar dislocation is the most common acute knee disorder in children and adolescents with a peak age incidence of 15 years. The mechanism of injury for the first episode can be identical to that for an ACL rupture. In changing direction whilst running or pivoting the femur rotates internally relative to the tibia which is fixed by a planted foot. This in association with quadriceps contraction causes lateral patella dislocation. Thus, ACL injury and the less common diagnosis of a ruptured extensor mechanism (quadriceps insertion or patella tendon) are included in the differential diagnosis of an acute haemarthrosis with this history.

Relocation often occurs spontaneously on the sports field making the diagnosis less obvious in the Emergency Department. Examination demonstrates tenderness over the ruptured medial patellofemoral ligament (MPFL) or retinaculum and a haemarthrosis, confirmed on aspiration. There is often considerable apprehension to lateral displacement of the patella. There may also be tenderness palpable over the lateral femoral condyle or the medial patella facet which are the common sites for an associated osteochondral fracture. As an osteochondral fracture may be present in 25–50% cases, skyline patella and notch view radiographs in addition to standard films are essential. If an osteochondral fracture is suspected, an MRI is indicated to characterize the fragment: large fragments with sufficient subchondral bone to facilitate reattachment should be repaired, smaller fragments or those with only a sliver of bone should be removed arthroscopically. Arthroscopic reattachment is difficult in the patellofemoral joint and a mini-arthrotomy is usually required.

The rate of recurrent patellar instability after acute dislocation may be as high as 60% in children and adolescents and immediate repair of the ruptured medial restraints to dislocation has been advocated. However, in the acute setting, it can be difficult to delineate the MPFL clearly and to repair it in a durable fashion. A recent study showed that, compared to non-operative management, MPFL repair did not reduce the redislocation rate and therefore in the absence of a significant osteochondral fracture, conservative management with a period of immobilization followed by restoration of motion and quadriceps strength remains the treatment of choice. This rationale accepts a high rate of recurrent instability and the need for a secondary stabilizing procedure in some cases (see Chapter 13.20).

The relatively high incidence of this injury in adolescents reflects the transition period from the juvenile joint, in which the chondral surface is anchored to the underlying bone by interdigitations of cartilage, and the adult joint in which the bond is formed orthogonally to this at the calcified cartilage layer (cement line or tidemark). During this period, the knee is at risk of osteochondral fractures. The commonest locations are the medial patella facet and the lateral femoral condyle, reflecting a strong association with acute patella dislocation. For these and other anatomical areas of involvement, the injury is often a direct blow or a twisting mechanism about a fixed foot.

Diagnostic work-up is similar to that for acute patella dislocation, with a low threshold for additional MRI studies. The false negative rate for osteochondral fracture may be over a third with plain radiographs alone. Large fragments should be reattached if possible, particularly when from a weight-bearing area of cartilage. The detached fragment may imbibe joint fluid and swell considerably, particularly if fixation is delayed, such that it must be trimmed to fit back into the defect. Smaller defects with a thin cortical fragment should be removed. Microfracture is indicated for the remaining defect if it is significant and involves a weight-bearing region (Box 13.23.5).

Osgood-Schlatter disease and Sinding-Larsen Johansson syndrome are typical overuse injuries causing apophysitis of the anterior tibial tubercle and inferior pole of the patella respectively. They are common in active adolescents and associated with local tenderness and palpable swelling (see Chapter 13.20).

Avulsion fractures around the pelvis are common injuries in football, gymnastics, and track and field. They are usually visible on a plain radiograph and are caused by the sudden contraction of powerful muscles against an apophysis. If presentation is delayed, radiographs may demonstrate a large ossified area and clinical examination may reveal an obvious ‘lump’. The possibility of a tumour must be considered but the classic history usually ensures that the avulsion fracture is correctly diagnosed (Figure 13.23.3 and Box 13.23.6).

The vast majority can be managed non-operatively with rest until symptoms subside. Repair may occasionally be indicated in high-demand athletes with symptomatic weakness or pain. Ruptures at the musculotendinous junction of the same muscle groups, particularly the quadriceps, are associated with weakness during kicking and visible bunching of the muscle belly on resisted motion. Repair may be attempted even after delayed presentation, with MRI or ultrasound useful to confirm the diagnosis and location of the rupture.

A ‘popping’ or ‘snapping’ hip, often reported by the patient or family as one which goes in and out of joint, should provoke consideration of an ‘internal’ snapping psoas tendon or ‘external’ snapping iliotibial band at the lesser and greater trochanters respectively. The Ganz test of snapped adduction in hip flexion can help differentiate these from a labral tear: injection of contrast into the joint for magnetic resonance arthrogram (MRA) is uncomfortable and best avoided. Physiotherapy is the mainstay of treatment, with injection of local anaesthetic and steroid for refractory cases. Surgical release should only be performed as a last resort: results are often disappointing.

Any child complaining of groin, thigh, or knee pain should undergo thorough clinical examination, in particular to assess range of hip rotation in flexion. There should be a low threshold for anteroposterior and cross table lateral views of the hip. Slipped capital femoral epiphysis can present with a sports injury and may be misdiagnosed as a ‘groin strain’: the consequences of missing this diagnosis or making a late diagnosis can be significant. See Chapter 13.19.

Osteochondral lesions of the talus are uncommon but can be a cause of persistent ankle pain in children. In an adult study, lesions of the talar dome were slightly more common on the medial side with lateral lesions occurring more anteriorly and more commonly associated with trauma (see Chapter 14.11) (Figure 13.23.4). The staging system of Berndt and Harty is a useful guide to prognosis and treatment (Table 13.23.2). Lesions up to Stage 3 can be managed non-operatively with a period of immobilization and a good result expected with open physes. Stage 4 lesions and symptomatic Stage 2/3 lesions that fail to respond to non-operative management can be considered for arthroscopic debridement, drilling, or microfracture. ACI and mosaicplasty is also described but is rarely indicated in the paediatric sports-injured population.

Inversion injuries to the ankle are very common. In the paediatric population this can result in injuries to the lateral ligament complex, in particular the anterior talofibular ligament (ATFL), local bony avulsions, and fibular fractures including Salter–Harris injuries of the distal fibular physis. Diagnosis of a soft tissue sprain can be made by eliciting localized tenderness over the ATFL without bony or physeal tenderness. All are managed non-operatively and the vast majority have no persistent symptoms. Chronic pain may be related to instability or non-union of small fracture fragments. Examination may demonstrate a positive anterior drawer sign, indicative of ATFL incompetence, and varus stress radiographs may uncover talar tilt. Again, initial management should be with intensive physiotherapy to restore stability. Good results have been reported with a variety of procedures to repair, reconstruct or otherwise advance the capsular condensations which form the lateral ligament complex in children and adolescents with persistent and symptomatic ankle instability.

Most upper limb sports injuries are subacute and related to overuse. Their increased incidence reflects the earlier and more intensive sports training now seen in the paediatric population. The predominant mechanism is the repetitive overhead motion of the throwing action. This is best characterized for the sport of baseball; however, the biomechanical science is applicable to other disciplines such as tennis and swimming. Gymnastic sports have a particular range of injuries as the upper limbs are required to weight bear for many activities.

The throwing action can be divided into distinct phases; wind-up, early and late cocking, acceleration, deceleration, and follow-through. Most injuries are related to the late cocking and acceleration phases due to the extreme range of motion and forces generated in these actions. The late cocking phase places the shoulder in abduction and maximal external rotation generating large shear forces across the rotator cuff muscles and anterior structures. In the acceleration phase the forward force is generated by shoulder internal rotation and adduction combined with rapid elbow extension. This results in a valgus force across the elbow with tension across the medial compartment and compression in the radiocapitellar joint. Forceful triceps contraction in elbow extension generates tensile stress at the triceps insertion.

Repetitive microtrauma, secondary to rotational torque forces with overhead activity and throwing, can lead to epiphysiolysis of the proximal humeral physis. This is most common in the 11–13-year age group and is often associated with poor technique. The athlete presents with diffuse shoulder pain, exacerbated by the throwing action and often with characteristic radiographic features. MRI may demonstrate signal change in both the proximal humeral metaphysis and the epiphysis.

Treatment is with rest from throwing (which should be prolonged if radiographic changes exist—Box 13.23.7) followed by action modification and a gradual return to sport.

Anterior glenohumeral instability following acute traumatic dislocation is by far the commonest form of shoulder instability seen in the paediatric athlete. Reported recurrent instability approaches a rate of 100% in children with open physes, but in a 25-year prospective series it was only 50% in the 12–16-year age group. Initial management is typically non-operative. Surgery, in the form of an open or arthroscopic repair of the anteroinferior glenoid labrum (Bankart repair), is reserved for those with ongoing instability and the desire to continue with a sport that causes symptoms. There is good evidence of a reduced recurrence risk in young adults immobilized in external rotation for 3 weeks after the primary dislocation but, to date, there is little enthusiasm for this management. Otherwise there is no evidence to recommend immobilization beyond that limited by pain. A good randomized controlled trial of arthroscopic Bankart repair versus arthroscopic lavage alone performed in young adults (under age 30 years) after primary anterior dislocation, demonstrated a 76% reduction in risk of recurrent instability after immediate Bankart repair with better function, satisfaction and rate of return to competitive sports. Despite these results, the authors did not recommend primary operative stabilization for all first time dislocations in this age group because of the risk of over-treatment. However, the primary surgical management of choice would be an arthroscopic Bankart repair.

Multidirectional instability is typically seen in adolescents with underlying generalized hyperlaxity, compounded by an acute traumatic event or repetitive microtrauma. Physical examination of the glenohumeral joint will show increased translation in many planes; however, determining the direction of symptomatic subluxation is crucial as an athlete may display mulitdirectional laxity without instability. The diagnosis is clinical. Management is with intensive physiotherapy to address altered scapulothoracic biomechanics and dynamic glenohumeral stabilization. Occasionally, MRI or arthroscopy may be helpful to assess cuff or labral damage and to demonstrate redundant capsule.

The immature shoulder may undergo adaptive changes with repetitive overhead activity. Repeated maximal external rotation, particularly in late cocking, causes microtrauma to the anterior capsule and ligament complex creating anterior laxity. This is often associated with posterior capsular hypertrophy and contraction leading to a glenohumeral internal rotation deficit (GIRD). Secondary anterior instability and translation may follow together with internal impingement of the rotator cuff tendon at the posterosuperior rim on the glenoid. The presence of GIRD and anterior hyperlaxity is associated with a significantly increased risk of injury and with secondary adaptive bony changes such as a retroverted glenoid.

Rotator cuff impingement in the subacromial space, generally a degenerative condition of early middle age, can occur in the young throwing athlete. Altered scapulothoracic biomechanics lead to a laterally placed, downwardly rotated, and protracted scapula secondary to repetitive overhead activity. The imbalanced scapulothoracic musculature fatigues easily and is often painful. This position of the scapula, particularly in association with GIRD, predisposes to rotator cuff impingement in the subacromial space. Management is with rest and anti-inflammatory medication followed by physiotherapy to address scapulothoracic biomechanics and modification of overhead throwing technique. Subacromial decompression is seldom if ever required in the paediatric athlete.

Some 18–69% of players in the United States of America report some degree of elbow pain, most commonly in pitchers aged 8–16 years. The term ‘Little Leaguers’ elbow’ initially described an avulsion fracture of the medial epicondyle but now encompasses a combination of elbow complaints that occur due to repeated rapid extension in the acceleration phase of throwing leading to valgus strain across the elbow joint. This strain causes tension in the medial structures and compression in the lateral joint. Forceful extension in the acceleration phase and locked extension in the deceleration and follow-through place significant stress on the triceps insertion and olecranon apophysis (Box 13.23.8).

Initial symptoms of pain and reduced elbow function relate to inflammation of the common flexor mass or medial apophysitis, progressing to irregular ossification and enlargement of the medial apophysis which may separate and eventually fragment. Younger players tend to develop apophysitis whereas similar valgus stresses in an adolescent may result in complete or partial avulsion of the medial epicondyle. On the lateral side, repetitive compression leads to radial head hypertrophy or OCD of the capitellum. In the posterior compartment, repetitive extension may lead to the development of olecranon apophysitis, ulna hypertrophy, and traction spur formation. After treatment with rest, anti-inflammatory medication and physiotherapy a cautious return to sport may require specific limitation in the number of throws or pitches per session.

Repetitive compression within the radiocapitellar joint causes articular cartilage to separate from subchondral bone secondary to ischaemic micro-trauma resulting in an OCD lesion (Table 13.23.3). This is distinct from the condition of Panner’s disease that has a presumed temporary avascular aetiology similar to that of Perthes disease of the hip. Panner’s disease has a defined clinical course: revascularization is to be expected with return of normal appearance and function to the radiocapitellar joint. (This differs from Perthes disease, presumably because the hip is a weight-bearing joint.) (Table 13.23.4).

OCD usually develops in adolescence with well-demarcated areas of cartilage damage that may progress to osteochondral fragmentation and loose body formation (Figure 13.23.5). Pain may be marked, particularly with ongoing sports participation, and mechanical locking may occur if loose bodies are present. As for the knee, treatment depends upon the size, stability, and articular continuity of the lesion and the state of the physis. Stable, continuous lesions may be managed non-operatively and loose bodies may be amenable to arthroscopic removal. Unstable, discontinuous lesions that restrict elbow motion, in the presence of a closed physis, may be suitable for subchondral drilling, open fragment fixation or osteochrondral plug grafting. These procedures are technically difficult to perform arthroscopically and a mini-arthrotomy through a posterolateral approach with the elbow flexed is often useful.

Wrist pain can affect up to 80% of elite gymnasts in whom wrist loads may regularly exceed twice body weight and peak to 16 times this level. Repetitive compressive forces at the distal radial physis cause a stress reaction (Box 13.23.7) (Figure 13.23.6) that can culminate in premature closure of the distal radial physis and positive ulna variance. Avascular necrosis of the lunate (Keinbock’s disease) has been noted in some athletes (Figure 13.23.7). Secondary overload of the ulna side of the carpus and wrist joint is a cause of degenerative changes and potentially long-term disability. The weight bearing upper limb position also places the elbow under valgus stress which can lead to a similar pattern of injury to that seen in the overhead athlete. Radiographic follow-up is required in children and adolescents with a pattern of physeal stress injury because of the risk of premature physeal closure.

This term has been applied to almost any type of lower leg pain that results from overuse in the teenage athlete, most commonly after running or hiking. The pain is usually felt on the posteromedial border of the tibia and may correspond with the medial origin of the soleus muscle. Pain may be exacerbated by resisted plantar flexion or toe raises. The differential diagnosis should include a stress fracture and an exercise-induced compartment syndrome whilst the possibility of infection or a benign or malignant bone tumour must also be considered.

An exercise-induced compartment syndrome should be confirmed with pressure studies both at rest and after exercise. The compartments most frequently affected are the deep posterior and the anterior compartments: numbness in the sole or on the dorsum of the foot may be part of the clinical picture. A careful surgical fasciotomy is the treatment of choice. The procedure can be performed through limited skin incisions to improve the cosmetic appearance.

Stress fractures are increasingly common in those children and adolescents participating in sports involving running. True stress fractures (defined as abnormal stresses applied to normal bone) are rare in children who are active but not involved in training programmes. Training, particularly after a period of inactivity such as after an injury or a long vacation, leads to a stimulation of both osteoblastic activity and osteoclastic activity and perhaps an increased tendency to fracture. In adolescents, the combination of ligamentous laxity, muscle tightness, and relative muscle weakness are relative risk factors for a stress fracture and the risk may be increased if the athlete is tall and heavy and involved in a sport which requires bursts of explosive activity.

Fractures are often diagnosed on careful history taking and examination. Radiographic features may take some time to develop and imaging techniques such as MR and bone scans are often useful.

Treatment will depend on the age of the child, the site of injury and the severity of the symptoms but usually involves relative rest from the sporting activity and the use of a brace, orthotics, or a cast until symptoms resolve. Surgical treatment is sometimes required for fractures affecting the femoral neck and the medial malleolus (Box 13.23.9).

Sports participation in children and adolescents is on the increase and is to be encouraged for the control of body weight, development of peak bone mass, and instilling the virtues of teamwork and discipline. Ongoing analysis of the environment and specific sports situations in which critical injuries occur will lead to better information for the development of injury prevention programmes for paediatric athletes. Greater recognition of particular injury patterns through ever-improving imaging techniques and better data collection with a denominator of hours and type of sports played will occur. The development of increasingly sophisticated techniques and instruments for arthroscopic management of osteochondral and meniscal injuries may improve outcomes and there is the potential for stem cell manipulation to aid reconstruction of damaged tissue.