For up to 26 years, doctors in Japan examined patients with surgically repaired hip dysplasia. Each patient received the same total joint replacement. The implant was cemented in place and extra bone was grafted to form a proper socket. The results are reported in this study.
Developmental hip dysplasia is a condition some people are born with. The hip socket is too shallow to provide a “rooftop” or cover for the head of the femur (the thighbone). In previous studies, the results of this operation varied quite a bit. The authors of this study set out to find factors that affect the results of hip joint replacement for developmental dysplasia.
All patients were examined every year. Hip pain, walking distance, and range of motion were measured each time. They found that the two most important factors are patient age and graft size. A cemented hip implant with added bone graft to cover the head of the femur work best in older patients (more than 50 years old).
Success is also greater if the bone graft makes up less than 50 percent of the cover for the femoral head. If more is needed, the socket is moved. Long-term results are good when these two guidelines are followed. None of the patients reported pain and further surgery wasn’t needed.
The authors conclude that younger patients should have surgery to save the original joint. They also need instruction about safe activity levels. A total hip replacement for developmental hip dysplasia is usually reserved for older patients.