Goals of surgery and factors to consider
It must be remembered that children with CP do not have deformities at birth, their deformities are secondary to the failure of muscle growth and to abnormal development within the bones.
From a surgical perspective the aim of treatment is to try and restore a normal biomechanical environment to allow these children to maximise their potential.
If orthopaedic surgery to correct these deformities is performed at a young age, there is a very high risk that the deformities will recur and that repeat operations will be required. These involve an increased risk of muscle weakness and poor outcome. By leaving the surgery until maturity, however, the problems become very complex and difficult to correct. In addition, with older parents, rehabilitation is more difficult.
It is essential to be careful about treatment because these children have very limited functional reserves and any detrimental intervention can produce quite profound or devastating effects.
Therefore, the aim of treatment should always be to have defined goals of what is to be achieved for each individual child and what barriers will need to be overcome.
The goals for surgery in CP should be to:
- improve function - generally in gait and upper limbs
- improve posture - hip and spine surgery
- relieve and prevent pain
- improve cosmesis
There may be relatively little scope for improving function in hemiplegia.
Strategies to achieve these goals include measures to:
- remove deformity
- stabilise unstable joints
- balance / normalise dynamic abnormalities
- deal with secondary effects of the condition
Procedures are performed typically on the lower limbs, particularly for gait abnormalities, hips, spine and upper limbs, with rhizotomy being considered in appropriate cases.
Factors to consider before surgery
It is essential to consider several factors before deciding whether to perform any orthopaedic surgery:
- consider the child as a complex system
- evaluate the value added
- consider the possible long-term effect - might a procedure weaken a child in the future?
- identify good and bad results, looking for causality
- quantify the quality of the package of care delivered by services rather than individual procedures (for example, is a child walking better?)
- aim for convergence of services and measurement systems
There are several measures which may be used to assess the outcome of surgery in children with CP:
- static measurement: whereby the range of motion is measured; eg the use of X-rays
- dynamic measurement: gait analysis EMG and oxygen consumption
- functional scales: Gross Motor Function Measure is starting to become more widely used
- goal fulfilment: setting goals prior to treatment and seeing if outcome matches the goals identified
- subjective measures: assessed by the young person, parents and carers, including measures such as pain