There is a lot of controversy about hip surgery in CP.
Firstly, there is very little agreement on the incidence of pain from dislocated hips. Pain is reported in 20 to 80% of cases.
Most children with CP can communicate if they are feeling hip pain, if they are asked appropriately.
Windsweeping is a major problem for seating, but there is no accepted measure for judging the extent or outcome. It is important to look at the overall position of the child in relation to what is happening in the hip.
Another factor for considering hip surgery is the role of hip asymmetry in the pathogenesis of scoliosis and pelvis obliquity, although this is controversial. It is debatable whether those with hip asymmetry are more likely to suffer scoliosis and vice versa. Correcting the hips may help the scoliosis, but there is no clear evidence for this.
Hip surgery for subluxation may be useful in young children, where there is a lot of potential for remodelling. Adductor release is successful in reducing uncovering. Five published trials in this area have claimed success, but they were uncontrolled studies.
However, if uncovering is greater than 40% there is a high risk of failure. Obturator neurectomy carries a risk of abductor contracture, although no figures on this are available. In older children, it is necessary to address bony deformity, with procedures such as pelvic / femoral osteotomy. However, femoral osteotomy increases adductor contracture.
Hips at risk of subluxation should be identifiable, with the indication for surgery being progression of subluxation (such as more than 25% uncovered). Whether pain should be a prerequisite for surgery is contestable, as a lot of centres would operate without this. There should be a surveillance protocol monitoring the hips of all children with bilateral CP.
Hip surgery for dislocation is generally much less successful than for subluxation. If dislocation is established, the hip is likely to be incongruous so may be difficult to get back in position, and, once there, kept in position.
Other issues include whether the procedure will be pain-free and whether the leg position may deteriorate. Most surgons agree that in established dislocation, with deformity of the femoral head, surgical restoration should not be attempted.
If symptomatic, palliative procedures such as valgus osteotomy or femoral head resection should be considered. However, if dislocation is recent with little associated femoral head deformity, some authorities would recommend surgical relocation, whereas others would disagree with this view.
The panel felt that dislocation of the hip was a disaster, which should be avoided at all costs.
In children with profound problems, often with a relatively short lifespan, and whose hips are at a greater risk of dislocation, their lives could be made more difficult by extensive surgery.
It is important to check hips regularly and act quickly where problems develop. Evidence shows that correcting hip problems before the age of about five years can result in much better outcome. The ability to remodel hips diminishes rapidly after this age. Children with bilateral CP should have their hips checked regularly by a specialist with expertise in this area.