Hip dysplasia is a condition characterized by a shallow hip socket. The hip socket is called the acetabulum. With hip dysplasia, the cup-shaped curve forming a roof over the femoral head is shortened. The femoral head can slip out of the socket and dislocate.
Uneven joint load from hip dysplasia can result in severe osteoarthritis (OA). The joint space narrows. Bone spurs form around the joint. X-rays show places where bone density changes occur around the joint. The patient experiences pain and loss of function.
Surgery to repair the hip socket is called rotational acetabular osteotomy. The surgeon removes a wedge of bone and uses it to re-angle the joint. A small piece of bone is also used to improve the roof angle.
In this study, 43 patients with hip dysplasia and osteoarthritis had the osteotomy. Patients were followed from two up to 16 years. Mid- to long-term results were reported based on decrease in pain and increase in walking ability.
Most of the patients had improved joint angle and increased joint space. Ten patients had X-ray changes showing that their arthritis was worse. A 10-year survival rate was predicted for the surgery in 72 per cent of the patients.
The authors conclude a rotational acetabular osteotomy can benefit some patients with advanced OA caused by hip dysplasia. They do not recommend this surgery for anyone with end-stage OA. With end-stage OA, there is no remaining joint surface. Changing the angle of the hip will not improve the width of the joint surface.