Outcome of total hip arthroplasty in small-proportioned patients.

In a prospective, consecutive series, 41 total hip arthroplasties were performed in 27 small-proportioned patients with small femoral dimensions. The 17 female and 10 male patients averaged 23.6 years (range, 14-47 years), and the mean height and weight were 157 cm (range, 132-183 cm) and 53.5 kg (range, 36-84 kg). The most common preoperative diagnosis was juvenile rheumatoid arthritis in 18 patients (28 hips). Most patients were severely disabled in their daily activity, and 68% of the patients were classified as Charnley functional class C. The femoral implants consisted primarily of the proximally porous-coated miniature Anatomic Medullary Locking femoral component (AML/CDH, Depuy, Warsaw, IN) in 33 hips in 22 patients (average stem diameter, 9.5 mm; range, 8-12.0 mm). A porous ingrowth acetabular cup fixed with screws was used in all procedures. At an average follow-up of 51 months, Harris Hip Scores improved significantly from 34 points (range, 0-65 points) preoperatively to 85 points (range, 33-100 points) after arthroplasty. There were no intraoperative complications. There was 1 revision because of femoral implant loosening. Three cementless femoral components showed evidence of nonprogressive subsidence. One patient had significant bilateral acetabular component polyethylene wear and underwent revision. All other femoral and acetabular components were radiographically stable. The relief of pain and improvement of function were dramatic. The miniature AML/CDH femoral component, combined with an uncemented acetabular cup, provides a promising, off-the-shelf alternative in small-proportioned patients.