Hip dysplasia is a condition where the head of the femur (thigh bone) does not fit properly into the acetabelum (the cup-like area of the pelvis where the femur sits). For several years, a procedure called the Ganz (Bernese) periacetabular osteotomy was used in adults who had hip dysplasia, but recently, surgeons have been using this procedure on teens. However, there is not much research on how effective the procedure is on teens over the short term, nor is there any reliable information regarding the gait and functional outcome in this age group.
Other procedures have been tried to treat hip dysplasia. The Wagner spherical osteotomy corrected the problem, but at a cost. The surgery would put the blood supply in the acetabelum at risk, putting the hip in jeopardy. The Steel triple innominate osteotomy has been fairly successful but not so for the more severe dysplasias.
The Ganz procedure is popular because of its technical advantages. The authors of this article analyzed the short-term outcomes of teens who underwent the Ganz procedure for adolescent hip dysplasia to see how this surgery can help this age group.
Researchers studied 21 patients (18 female) who had a total of 24 hips that required correction. They were, on average, 16.1 years old at the time their hip disorder was diagnosed and 16.2 years when they had their surgery. About 38 percent of the patients had had previous hip surgery. Most of the hips were considered to be moderate-to-severe hip dysplasia. Preoperative assessments of the patients included range of motion of both hips, checking for pain with flexion (bending), adduction (moving away from the body), and internal rotation of the hip. X-rays of the hips were taken before surgery and again at six months after surgery and one year after surgery. The gait of each patient was analyzed in the same time period.
The researchers found that there was a significant improvement in all measurements among the teens who had the surgery. The hip angles and weight-bearing zones improved, as did their strength, flexion power, and gait. Interestingly, the abductor strength actually declined at six months, but was above pre-operative levels by one year. The authors of the article were surprised by this finding, particularly because there were exercises to strengthen these muscles not long after the surgery was completed.
Home physiotherapy plays a large role in post-surgery progress. After hip arthroplasties (replacements), it has been shown that three times daily physiotherapy effectively strengthens the hip muscles. However, compliance when it comes to teens is not always possible. In this study, the patients did have a short course of in-patient physiotherapy to show them how to do exercises. After six weeks, the physiotherapy program increased to full weight-bearing and more intense strengthening exercises. Not all patients complied with the program, which could have resulted in the delays seen by the researchers.
The authors concluded that the Ganz procedure is effective in teens, but work needs to be done on strengthening the muscles after surgery, which may require different strategies than with adults.