Radiographic changes after resection of the distal ulna in rheumatoid arthritis.

Progressive ulnar translocation of the carpus and problems with the ulnar stump have been reported after resection of the distal ulna in rheumatoid arthritis (RA). However this has only occasionally been quantitatively assessed. In this study 24 wrists in 21 patients with RA were followed up for an average of 100 months after resection of the distal ulna. An additional 24 wrists in 14 non-operated RA patients were followed up for 92 months. In a retrospective radiographic analysis we demonstrate similar increases in ulnar translocation and ulnar-carpal distances in both groups.

Preliminary results of total wrist arthroplasty using the RWS Prosthesis.

Twenty-nine wrist prostheses were implanted and followed-up for a mean of 4 (range, 2-8) years. Twenty-four of these patients had rheumatoid arthritis. Pain and range of motion improved significantly. Sixteen patients were graded as excellent, six as good, two as fair and three as poor according to Meuli's wrist score. There were three frank radiological failures and one revision in this study. Eleven prostheses showed signs of possible loosening without progression or clinical instability. The management of the distal ulna during this procedure and the long-term fixation of the carpal component were problematic.

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.

Risk factors for dislocation during the first 3 months after primary total hip replacement.

The prevalence of dislocation of a total hip replacement during the first 3 postoperative months was determined for a series of 315 patients who underwent a unilateral primary total hip operation. All operations were performed by 1 surgeon using a standardized posterior approach with a complete capsulectomy. All of the patients had a femoral component made by 1 manufacturer that had the same 28-mm modular head, the same femoral neck diameter, and the same offset for each size implant. One cementless acetabular component was used for all patients. All of the patients followed the same postoperative rehabilitation program. Of 315 patients, 14 sustained a dislocation, resulting in a prevalence of 4%. There were 13 posterior dislocations and 1 anterior dislocation. Because the surgeon, the surgical approach, the femoral component design, and the rehabilitation protocol were identical for all of these patients, the only variables that could affect the risk of dislocation were the size of the acetabular component and the femoral neck length, the type of fixation of the femoral component, the orientation of the acetabular component, and the characteristics of each patient. The patient characteristics that were studied included age; gender; height; weight; preoperative diagnosis; and a category termed cerebral dysfunction, which included a state of confusion during the hospital stay, a prior history of excessive alcohol consumption, or both of these conditions. Statistical analysis demonstrated 1 variable that was associated with a higher dislocation rate, the presence of cerebral dysfunction. There was a trend toward increased age as a risk factor. None of the other patient or component variables were found to be significant risk factors.