Acute total hip arthroplasty for selected displaced acetabular fractures: two to twelve-year results.

BACKGROUND: We assessed the role of acute total hip arthroplasty in a selected group of patients with a displaced acetabular fracture and complicating features that greatly diminished the likelihood of a favorable outcome after open reduction and internal fixation.

METHODS: Between 1985 and 1997, fifty-seven patients underwent an acute total hip arthroplasty for a displaced acetabular fracture. Patients were followed for a mean of 8.1 years (range, two to twelve years). The mean time from the injury to the arthroplasty was six days (range, one to twenty days). The mean age of the patients at the time of the arthroplasty was sixty-nine years (range, twenty-six to eighty-nine years). Indications for the acute arthroplasty included intra-articular comminution as well as full-thickness abrasive loss of the articular cartilage, impaction of the femoral head, and impaction of the acetabulum that involved >40% of the joint surface and included the weight-bearing region.

RESULTS: At the time of the latest follow-up, the mean Harris hip score was 89 points (range, 69 to 100 points); forty-five patients (79%) had an excellent or good outcome. There were six cases of heterotopic bone formation, including one of symptomatic grade-IV ossification. During the initial six postoperative weeks, the acetabular cups subsided an average of 3 mm medially and 2 mm vertically. All of the cups then stabilized, and none were loose at the latest follow-up evaluation. Six patients had excessive medialization of the cup, but none had late loosening or osteolysis. Nine cups (16%) had notable polyethylene wear, but none were revised. No cup or stem had late clinical or radiographic evidence of loosening. There were three late procedures: one for revision of a malaligned cup because of recurrent dislocations, one for removal of hardware from the greater trochanter, and one for excision of heterotopic bone.

CONCLUSIONS: In selected patients with a displaced acetabular fracture that has a low likelihood of a favorable outcome after fracture treatment, an acute total hip arthroplasty may provide an alternative means with which to achieve a painless, mobile hip. These complex procedures are best undertaken by a surgical team with substantial experience with both acetabular trauma and hip arthroplasty.