Prospective matched-pair analysis of hydroxyapatite-coated and uncoated femoral stems in total hip arthroplasty. A concise follow-up of a previous report.

This prospective study was performed to examine the results of total hip arthroplasty with a tapered uncemented femoral component with and without hydroxyapatite coating in a matched-pair group of patients. Since our original publication in 1996, no femoral component was revised in either group. After a mean clinical and radiographic follow-up of 9.8 years, all femoral components were stable, with no evidence of progressive radiolucency or osteolysis. Ten acetabular components were revised because of aseptic loosening and wear. Our study demonstrated no clinical or radiographic advantage, during the first decade after implantation, to the use of hydroxyapatite on this design of femoral component in primary total hip arthroplasty.

Surgical treatment of limb-length discrepancy following total hip arthroplasty.

BACKGROUND: Although most patients with limb-length discrepancy following total hip arthroplasty have manageable symptoms, others may be disabled as a result of pain or functional impairment. In these patients, reoperation may be indicated to equalize the limb lengths. There is a paucity of published data regarding the outcome of surgical intervention to treat this problem. The purpose of the present study was to evaluate the results of revision hip surgery for the treatment of symptomatic limb-length discrepancy. METHODS: We retrospectively reviewed the clinical and radiographic records of patients who had undergone revision hip surgery at our institution for the treatment of a symptomatic limb-length discrepancy following a previous total hip arthroplasty. We identified twenty-one patients (twenty-one hips) who had an average age of sixty-six years at the time of revision hip arthroplasty. The average duration of follow-up was 2.8 years, and no patient was lost to follow-up. The indications for revision hip arthroplasty were severe hip and/or back pain for eleven patients, instability of the hip for eight, hip pain and ipsilateral limb paresthesia for one, and hip pain and ipsilateral foot drop for one. RESULTS: Revision arthroplasty was performed at a mean of eight months (range, six days to six years) after primary total hip replacement. The mean limb-length discrepancy at the time of the revision was 4 cm (range, 2 to 7 cm). Following revision arthroplasty, which involved revision of a malpositioned acetabular and/or femoral component, equalization of the limb lengths was achieved in fifteen patients. In the remaining six patients, the mean discrepancy had decreased to 1 cm. The mean Harris hip score improved significantly, from 56.5 points before the revision to 83.2 points at the time of the latest follow-up (p < 0.005). All but two patients were satisfied with the outcome of the revision surgery. CONCLUSIONS: Limb-length discrepancy following hip arthroplasty can be associated with pain, paresthesia, and hip instability. In these patients, careful evaluation of the position and orientation of the components may reveal the cause of the discrepancy. Revision arthroplasty may be indicated when a surgically correctable cause of limb-length discrepancy can be identified.

Complications associated with reimplantation after girdlestone arthroplasty.

Complications associated with reimplantation of a total hip arthroplasty after resection or Girdlestone arthroplasty for treatment of an infected hip are not well-documented. Forty-four hips in 44 patients with a minimum 2-year followup (range, 2-9 years) from the time of reimplantation total hip arthroplasty were evaluated retrospectively. The average Harris hip score changed from 40 preoperatively to 78 at the latest followup. One patient had persistent infection requiring rerevision surgery, and another patient had rerevision surgery for recurrent dislocation. Complications related to the prosthesis consisted of dislocations in five patients (11.4%), recurrent infection in one patient (2.3%), trochanteric nonunion in four patients (9.1%), hematoma in one patient, heterotopic ossification in one patient, and postoperative wound drainage in one patient. Resection arthroplasty of the hip is highly effective in eradicating infection. In the current series, 97.7% of patients were free of infection at the latest followup. However, with an 11.4% dislocation rate and 39% of patients having a persistent limp, alternative approaches need to be evaluated which might reduce these complications.

Ten to fifteen-year follow-up after total hip arthroplasty with a tapered cobalt-chromium femoral component (tri-lock) inserted without cement.

BACKGROUND: Fixation of the femoral component of a total hip arthroplasty without cement has had variable results. While tapered stems appear to have consistently good results, the duration of follow-up in many series has been relatively short. The purpose of this study was to present a longer-term (ten to fifteen-year) follow-up after total hip arthroplasty with insertion of a tapered femoral component without cement. METHODS: Sixty-seven total hip arthroplasties were performed with insertion of a tapered, cobalt-chromium femoral component without cement in fifty-eight patients from 1983 to 1986. Thirteen patients (fifteen hips) died prior to the fifteen-year follow-up examination, and three patients (three hips) were lost to follow-up after ten years, leaving forty-two patients (forty-nine hips) who were followed clinically for a mean of fifteen years. Thirty-seven of the forty-nine hips were followed radiographically for fifteen years, and the remaining twelve were followed for a minimum of ten years. RESULTS: The mean preoperative Charnley score was 3.0 points for pain, 2.7 points for function, and 3.2 points for motion. At the time of the final follow-up, the mean scores were 5.6, 5.6, and 5.2 points, respectively. Although no preoperative Harris hip scores were available, the mean score at the time of the latest follow-up was 92 points (range, 78 to 100 points). There were no revisions because of isolated aseptic loosening of the femoral component (although revision because of aseptic loosening of the acetabular component led to femoral component revision in seven hips). Two femoral components showed radiographic evidence of instability. At fifteen years, the prevalence of thigh pain was 2%. No femoral component that was thought to be stable, with bone ingrowth at two years, lost fixation. CONCLUSIONS: The design features of this cobalt-chromium femoral component (i.e., the collarless, tapered, wedge fit with circumferential porous coating) are thought to be crucial to the achievement of the good-to-excellent results seen in this study.