13.6 Management of the child with total body involvement

This group includes children with severe motor disability that affects control and posture of all four limbs, the trunk, and the head. The majority of children are non-ambulant or therapeutic/household walkers (Gross Motor Function Classification System (GMFCS) IV or V). As a result of the severity of their neurological condition and their limited mobility most develop a variety of secondary musculoskeletal deformities but deformity in itself is not an indication for orthopaedic treatment. Management of the child with total body involvement cerebral palsy (TBI CP) should have well-defined aims and targets. Parents/carers as well as a multidisciplinary team of health professionals involved in the care of the child should take part in the decision-making process (see Chapter 13.3, Figure 13.3.5). Orthopaedic interventions are indicated to relieve or prevent pain, to improve quality of life, and to maintain or improve function.

Prevention of musculoskeletal deformity is an essential part of the management of these children. The treatment modalities that are used have been discussed in the preceding chapters and include physiotherapy, postural management, orthotics, casts, and botulinum toxin injections. The use of intrathecal baclofen treatment may also have a place in the management of intractable spasticity that affects the lower body predominantly. Dorsal rhizotomy is usually restricted to those children with spastic diplegia.

The most common musculoskeletal deformities requiring orthopaedic treatment in the TBI CP child are scoliosis and hip displacement (subluxation or dislocation). Indications for other orthopaedic interventions are less common and require careful, individual consideration.

Hip displacement in CP is a common problem, particularly in non-ambulant patients. Depending on age and severity of involvement, the incidence of hip displacement varies from 10–70%. Lack of weight-bearing stimulation to the femoral head and acetabulum, muscle spasticity, and asymmetrical posture may explain the higher incidence of displacement in the non-ambulant children. The displacement is gradual and secondary changes occur on both sides of the joint. The femoral head becomes oval-shaped while acetabular dysplasia develops gradually with the formation of a groove-shaped deficiency. In the majority of patients, the direction of displacement is superoposterior. Posterior acetabular defects are more often seen in patients who progress to subluxation, while global defects are more common in patients with fully dislocated hips.

Both the Reimers migration percentage and the acetabular index can be used to quantify the severity of the displacement but problems with the reliability of both measurements have been reported (Figure 13.6.1). Three-dimensional imaging, particularly as part of preoperative planning may be appropriate in determining the direction of instability and the site of acetabular deficiency.

Indications for treatment of hip displacement in CP include pain during the displacement process and prevention of pain from the secondary degenerative changes that develop with chronic, established displacement. Correction of posture and improvement in the range of hip movement facilitate better sitting as well as easier care and hygiene.

There are several areas of controversy in the management of hip displacement in TBI CP that will hopefully become clearer over years to come with a better understanding of the outcome of intervention in various subgroups of CP.

The indications for early screening and any preventative interventions are unclear.

The acetabular index represents the single most important predictor of hip dislocation in children with CP. A normal index at the age of 3 years predicts normal hip development, provided that the clinical examination remains normal and that no scoliosis develops. Similarly, it has been suggested that the migration percentage is the best guide for hip surveillance. A population study has recommended that all children with bilateral CP should undergo a standardised position AP pelvic radiograph at the age of 30 months, in order to predict the risk of dislocation. Another population-based study in southern Sweden claimed that, with adequate screening and early intervention, the incidence of dislocation dropped significantly, when compared with historical controls. The screening was based on a register of children with CP and relied on this for its validity.

Overall the existing literature suggests that all children with bilateral CP should undergo an anteroposterior (AP) pelvic radiograph around the age of 2–3 years in order to assess the risk of hip dislocation (Box 13.6.1). The presence of an abnormal acetabular index (> 30 degrees) or an abnormal migration percentage (>15%) would indicate a significant risk of dislocation (Figure 13.6.2). A normal radiograph at this age would be reassuring but ongoing clinical surveillance is still essential. There is consensus in the literature that non-ambulant children (GMFCS IV and V) are at higher risk and should be screened regularly.

Hip displacement in CP is a slow process that allows secondary structural changes in the femoral head and the acetabulum to develop. These secondary changes occur early and, in some cases, before the evolution of hip instability.

Poor sitting balance as well as prevention of windswept posture and the resulting pain have been suggested as indications for treatment of the displaced hip in CP. Loss of mobility in ambulant children as well as decubitus ulceration and secondary deformity of the spine in the non-ambulant patients have also been suggested as indications. However, a comparison between quadriplegic children with scoliosis and hip displacement and similar children with spinal deformity but no hip displacement showed no effect of hip displacement on the progression of the spinal curvature, despite the higher incidence of pelvic obliquity in the group with hip displacement (Box 13.6.2).

Pain in the non-ambulant child and loss of mobility in the ambulant one are suggested as the main indications for treatment. Posture, care, and hygiene are secondary indications.

The role of soft tissue surgery around the hips in the prevention of hip displacement in children with bilateral disease is controversial. Some have suggested that such surgery can result in long-term radiographic stability in previously displaced hips in approximately 65% of treated patients but the effectiveness of adductor tenotomy alone in comparison with more extensive releases and obturator neurectomy is unclear. There is agreement that a preoperative migration percentage of less than 40% predicts a successful outcome and early surgery, before the age of 6 years, with postoperative bracing leads to good results. Approximately two-thirds of patients maintain hip stability at 8–10 years from surgery.

An American Academy of Cerebral Palsy and Developmental Medicine (AACPDM) evidence report concluded that the published evidence on the effects of adductor surgery in CP should be ‘regarded as preliminary at best’. The lack of long-term studies and comparison with controls was highlighted, as was the need to study the reliability and validity of the radiographic methods used.

In a Swedish population-based study, it was shown that the introduction of preventative measures to treat spasticity or dystonia reduced the incidence of hip dislocation compared with historical controls. Preventative measures included selective dorsal rhizotomy, continuous intrathecal baclofen infusion, botulinum toxin injections, and non-surgical treatment of contractures.

Surgical correction of hip displacement in CP may include a combination of femoral and/or pelvic procedures. The choice of surgical procedure to treat displacement or to salvage the painful chronically dislocated hip remains controversial. Furthermore, there is also the question of whether or not to treat the contralateral hip.

Femoral varus/derotation osteotomy used in isolation for the treatment of the displaced hip in CP is associated with a relatively high risk (10–40%) of redislocation, particularly if acetabular dysplasia is already present when treatment is undertaken (Figure 13.6.2 and Figure 13.6.3).

A variety of procedures have been suggested to treat the acetabular deformity and deficiency. The Salter and Pemberton osteotomies, designed for the treatment of developmental dysplasia, offer improved anterolateral cover that may not be appropriate in CP hip displacement. Results with the Chiari osteotomy have also been unsatisfactory. The triple pelvic osteotomy offers good stability but adds significantly to the complexity of the surgical procedure.

The Dega osteotomy and its modifications address posterolateral instability and may carry advantages over conventional pelvic osteotomies performed for developmental hip dysplasia. The common principle of these procedures is that they leave the medial cortex of the ilium intact and centre the osteotomy on the triradiate cartilage. The claim is that they reduce the volume of the acetabulum and provide posterolateral articular cartilage cover whilst maintaining some stability by preserving the medial wall of the ilium. Such an acetabular procedure, in combination with femoral varus shortening derotation osteotomy, provides more consistent satisfactory results in the treatment of CP hip displacement with improvement in pain, hip mobility, and sitting balance (Figure 13.6.3). Additional soft tissue releases may be required. Satisfactory clinical and radiographic results in over 90% of patients at 5–10 years of follow-up have been reported from retrospective reviews.

In children with TBI CP, by definition, both hips are at risk of displacement and dislocation. In two retrospective studies, unilateral surgery to treat hip displacement in non-ambulant CP patients was shown to be associated with progressive deformity and displacement of the contralateral non-operated hip in over 50% of cases. Bilateral pelvic and femoral osteotomies were shown to carry similar perioperative risks as unilateral or staged surgery.

Patients with TBI CP may demonstrate significant asymmetry and develop a windswept posture with one hip lying abducted and the other adducted. This posture is frequently associated with pelvic obliquity. The pseudo-Galeazzi sign identifies apparent shortening of the thigh; due more to a fixed abduction of one hip and an associated pelvic tilt rather than a true discrepancy in femoral length. The abducted hip may benefit from release of the gluteus maximus and tensor fascia lata with or without preventative bony surgery as discussed earlier. If there is clinical subluxation with a femoral head palpable in the groin, a hip reconstruction including a varus/derotational femoral osteotomy and acetabuloplasty is indicated (Figure 13.6.4).

The established hip displacement in CP may develop secondary degenerative changes and pain, which may result in further functional compromise affecting the patient and carer’s quality of life (see Figure 13.6.4). Hip reconstruction can still be considered if there is a reasonable chance of creating an acetabulum to contain the femoral head which is often deformed and degenerate but the recovery period is prolonged and the outcome variable. Hip replacement surgery, excision/interposition arthroplasty with or without valgus femoral osteotomy and hip arthrodesis have all been suggested as treatment methods. However, the existing literature reports a limited follow-up on small numbers of patients with no control group. If an excision arthroplasty is considered this should be performed as a proximal femoral excision below the lesser trochanter with a repair of the soft tissues over the acetabulum (Figure 13.6.5).

Non-ambulant patients with CP often suffer with reflux, absent gag reflex, epilepsy, and respiratory problems. Therefore there is a small but significant mortality rate and they are more at risk of perioperative complications, particularly respiratory problems. It has been suggested that 25% of CP patients undergoing hip osteotomies suffer at least one complication. Surgical complications of hip reconstruction include infection, skin sores, metalwork failure, heterotopic ossification, femoral head osteonecrosis, redislocation, persistent pain, and loss of ambulation. Some studies suggest that many of these complications are more frequent in patients who were casted following surgery compared to those who were not.

Whilst most CP hips displace in a posterolateral direction, some hips lie in abduction, extension, and external rotation and are at risk of anterior subluxation or dislocation. This may result in painful restriction of hip flexion which has a significant effect on sitting ability and thus quality of life (Figure 13.6.6).

An early soft tissue release (as mentioned previously for the abducted side in windswept hips), often combined with femoral shortening varus derotation osteotomy may help in maintaining a balanced sitting posture. Treatment of the established anterior dislocation is difficult and salvage with proximal femoral resection may become necessary.

A large number of patients with TBI CP develop a scoliosis and once it has developed it does tend to progress. The curve pattern is classically a long ‘C’-shaped curve. The pelvis frequently becomes part of the curve and the subsequent pelvic obliquity leads to an unstable sitting base which may cause more functional problems than the curve itself. Children with low-toned CP develop a thoracic kyphosis (Figure 13.6.7).

Severe curves may lead to back pain and respiratory compromise but the main problems are associated with an unstable sitting posture which often limits upper-limb function if one arm is needed to support the body position. Abdominal discomfort secondary to chest wall impingement on the pelvis is common.

There is no good evidence that spinal deformity can be prevented but care with seating and posture is considered good practice. Seating with adequate trunk and pelvic control may delay the onset of scoliosis. Deformity often becomes clinically apparent between the ages of 5–10 years and once progression has been documented, brace wear should be considered. Spinal braces are often poorly tolerated particularly in these children with multiple other problems and who are ‘peg fed’ in which case reliance on adapted seating with a tilt-in-space facility and good lateral supports may be more appropriate. The aim of bracing is to delay the progression of deformity rather than to halt it: allowing surgical correction to be delayed until sufficient spinal growth has taken place.

Untreated curves do tend to progress throughout adulthood and may leave the patient in a position where they are unable to sit and must be cared for in bed. Thus, once the curve has reached a Cobb angle of approximately 50 degrees, surgical correction should be considered and a full explanation of the risks and benefits of the procedure given to the parents.

Spinal fusion is usually undertaken posteriorly from T2–pelvis using a segmental instrumentation system. It is important to correct pelvic obliquity and to recreate a normal lumbar lordosis (see Figure 13.6.7). A failure to do so may exacerbate rather then relieve seating problems. As the spinal fixation is usually secure, prompt mobilization is possible. In these children, there are frequently associated hip problems and postoperative rehabilitation may be hampered initially by increased stiffness and discomfort at hip level, particularly if the pelvic position and effective hamstring length have been altered.

Preoperative assessment must pay close attention to the patient’s nutritional status as well as to respiratory compromise. A poor swallowing reflex combined with the supine position and potential ileus postoperatively mean that oral feeding should be delayed until the patient is able to be in a more upright position and swallow safely.

The ability to perform a weight-bearing transfer is a significant factor in maintaining quality of life and a degree of independence. Patients who can perform such transfers or have the potential to achieve this may be candidates for correction of knee contractures over 15–20 degrees. Hamstring lengthening should provide enough correction for this purpose (Box 13.6.5) and supracondylar femoral extension osteotomies are rarely indicated. Lengthening of the hamstrings may also improve sitting posture by reducing posterior pelvic tilt.

Foot deformities may also require correction to aid standing transfers or simply to accommodate the feet more comfortably on the foot-plates of the wheelchair. Severe foot deformities may also merit treatment if they risk skin ulceration over prominent bones or due to external pressure. In addition, severe upper or lower limb contractures may require treatment to facilitate care and hygiene. Any upper limb interventions should be carefully considered to avoid compromise of existing function, such as the use of an electric wheelchair control (the ‘joystick’), computer keyboards or communication devices.