Surgery effective for femoro-acetabular hip impingement

Radiographic follow-up at a mean 26 months postop showed no osteoarthritis progression for 19 of 30 patients.

Surgical dislocation and debridement appears effective for treating femoro-acetabular impingement, according to the early results of a small study.

In femoro-acetabular impingement (FAI), the anterofemoral head-neck junction abuts against the anterior acetabular rim or the labrum.

“This is predominantly a femoral-based problem where the femoral head is characterized as being out-of-round or has an anterolateral bump on the proximal femur. This anterolateral bump cams into the acetabulum, theoretically producing labral damage and hyaline cartilage damage,” said Christopher L. Peters, MD, a surgeon at the University of Utah Orthopaedic Center in Salt Lake City.

“Initially, the condition was described in relationship to some periacetabular osteotomies that were overcorrected. Then it was extrapolated that this process could be occurring in other conditions that present with a relative lack of femoral head-neck offset, such as Perthes Disease and slipped capital femoral epiphysis,” he said.

Peters and colleagues at the center reviewed their experience surgically correcting FAI in 30 patients treated over three years. Peters presented their results in a poster at the 118th Annual Meeting of the American Orthopaedic Association in Huntington Beach, Calif.

“Our interest in this procedure and this diagnosis came about from our experience with dysplastic patients and periacetabular osteotomy. We started doing surgical dislocation procedures for femoral acetabular impingement in 2000,” he said.

The study included 16 men and 14 women with a mean age of 30 years. Preoperatively, 18 patients exhibited purely cam-type periacetabular impingements, one patient had a pure pincer-type impingement and 11 patients had mixed cam and pincer impingements. Surgeons performed all procedures through a trochanteric osteotomy and with the femoral head anteriorly dislocated. “This gives a clear 360° view of the femoral head and a good view of the acetabulum. It is a powerful way to address intra-articular pathology,” Peters said.

Postoperative protocol was similar to that of periacetabular osteotomies. Patients remained in the hospital for about three days, followed by partial weight-bearing for six to 12 weeks.

Follow-up averaged 26 months. At final follow-up, the mean Harris Hip Score had improved to 88 points from 70 points preoperatively, Peters said. Additionally, no patients experienced major complications such as avascular necrosis, trochanteric nonunion or femoral neck fracture, he noted.

“We had three hips that we converted to total hip replacements. All three of these were females over the age of 40 years, and at the time of surgery they all had severe hyaline cartilage delamination,” Peters said. “I think today, with improvements in MRI technology, we would have picked these up and not operated on these people.”

One other younger patient needed a revision ORIF of the femoral neck osteotomy, he added.

Radiography showed no progression of osteoarthritis for 19 of the 30 patients. Nine patients showed one grade of progression and two patients showed two grades.

For more information:
Peters CL, Erickson JA, Hines J. Surgical dislocation and debridement for femoro-acetabular impingement: Early clinical results. #AR3. Presented at the 118th Annual Meeting of the American Orthopaedic Association. June 22-25, 2005. Huntington Beach, CA.