Osteotomy for Hip Dysplasia
Hip dysplasia is a condition where the hip socket is not deep enough to allow proper function of the hip joint. It is sometimes referred to as developmental dysplasia of the hip (DDH) or congenital dysplasia of the hip (CDH). Often it appears bilaterally. In the worst cases the hip may be dislocated from the socket. Dysplasia is often diagnosed when a child has difficulty walking or is very slow to begin walking. In less severe forms the condition can go undiagnosed until adulthood, when the patient begins to have pain and show signs of early osteoarthritis due to the poor mechanics of the joint. Dysplasia is more commonly found in females and in those born by breech birth, especially the first-born. It can be a genetic trait, so if you have this condition, you should have your children checked for it at a very young age. At less than 6 months of age, it can be detected by ultrasound and with an X-ray after that.
If dysplasia is caught soon enough the child can be treated non-surgically. Before 6 months of age, the child can be placed in a special harness, known as a Pavlik harness. This places pressure on the pelvis while the bone is still relatively soft and is developing, and the sockets will respond by expanding. The harness is used for 6-12 weeks.If the patient does not respond to the Pavlik harness or the dysplasia is not caught soon enough, the child may need to have a Spica cast. This is a hard cast which keeps the legs in a spread position and pressure on the pelvis to expand the sockets. Unfortunately a Spica cast does not allow for walking or weightbearing. The Spica cast is usually required for 12 weeks, with a re-casting at the 6-week mark to allow for adjustment of angles and growth.
In an osteotomy, fully named periacetabular osteotomy (PAO), the pelvis is cut in two or more places and rebuilt with a wider opening in the hip socket. The surgery is sometimes known as a Ganz osteotomy, after the Swiss surgeon, Reinhold Ganz who devised the procedure in the mid-1980s. The rebuilding will require the use of screws and possibly plates and/or bone grafting. Compared to total hip replacement this procedure is more conservative in that it preserves the original bone and cartilage. Because of the extent of the work that must be done and healing that must occur to restore the pelvis to full strength, the patient may be on limited weight bearing for about 8-10 weeks. A second surgery may be performed after the pelvis has healed to remove some of the surgical hardware. Recovery to walking without aidsis typically longer than with the total hip replacement, about 4-6 months.