Background: Femoro-acetabular impingement has been associated with
acetabular labral and/or articular cartilage damage that may ultimately result
in osteoarthritis of the hip. Surgical treatment of femoro-acetabular
impingement is directed at restoring a more normal femoral head-neck offset to
alleviate femoral abutment against the acetabular rim and treating associated
labral and articular cartilage damage.
Methods: Thirty hips with femoro-acetabular impingement (in
twenty-nine patients) underwent débridement through a greater
trochanteric flip osteotomy and anterior dislocation of the femoral head.
There were sixteen male patients and thirteen female patients with a mean age
of thirty-one years. Cam (femoral based) impingement was noted in fourteen
hips; pincer (acetabular based) impingement, in one hip; and combined cam and
pincer impingement, in fifteen hips. The mean duration of clinical and
radiographic follow-up was thirty-two months. All patients were followed
according to a prospective protocol, with Harris hip scores and plain
radiographs obtained preoperatively and at six months, one year, and annually
for a minimum of two years.
Results: The mean Harris hip score improved from 70 points
preoperatively to 87 points at the time of final follow-up (p < 0.0001).
Osteonecrosis did not develop in any hip, and there were no trochanteric
nonunions. In eighteen hips, severe damage of the acetabular articular
cartilage that had not been appreciated on preoperative plain radiographs or
magnetic resonance arthrography was noted on arthrotomy. Eight of these
eighteen hips subsequently had radiographic evidence of progression of the
osteoarthritis, and four of the eight hips required or were expected to soon
require conversion to a total hip arthroplasty to treat progressive pain.
Conclusions: At the time of early follow-up, we found that surgical
dislocation and débridement of the hip for the treatment of
femoro-acetabular impingement in hips without substantial damage to the
articular cartilage can reduce pain and improve function. This procedure has a
low rate of complications. Radiographic signs of progression of osteoarthritis
and clinical failure requiring conversion to a total hip arthroplasty were
seen only in patients with severe damage to the acetabular articular
cartilage, a finding that emphasizes the need for better imaging methods to
assess the extent of damage to the acetabular articular cartilage in patients
with this disorder.
Level of Evidence: Therapeutic Level IV. See Instructions
to Authors for a complete description of levels of evidence.