BACKGROUND: Cotyloplasty is a technique that involves making a perforation of the medial wall of a shallow acetabulum and then inserting an acetabular cup with the medial aspect of its dome beyond the Kohler line. The purpose of this study was to evaluate the results of cementless total hip arthroplasty (THA) using cotyloplasty with focusing on the amount of medial cup protrusion. METHODS: Sixteen hips with insufficient acetabulum in sixteen patients were treated by cementless THA using cotyloplasty. The average patient age was 47 years. The diagnoses included dysplastic hip (12) and infection sequelae (4). All the patients were followed up for at least 2 years. Clinically, the Harris hip scores were assessed and radiologically, the amount of cup protrusion, the hip center movement and cup fixation were evaluated. RESULTS: The average Harris hip score improved from 57 to 94 postoperatively. The average proportion of cup surface beyond the Kohler line was 44.1% and the hip centers were medialized by an average of 23 mm. Stable fixation of the acetabular cup was achieved in all the cases except one. In this one case, migration of the cup was detected 2 weeks postoperatively and a reoperation was performed. CONCLUSIONS: Using cotyloplasty, good coverage of the acetabular cup was obtained without a block bone graft, and the hip joint centers were medialized. However, the safety margin for the amount of protrusion should be established.
Acetabulum/*pathology/radiography/*surgery ; Adult ; Arthritis, Infectious/complications/pathology ; *Arthroplasty, Replacement, Hip ; Female ; Hip Dislocation, Congenital/pathology/surgery ; Hip Joint/radiography ; *Hip Prosthesis ; Humans ; Male ; Middle Aged

PURPOSE: The purpose of this study was to evaluate the clinical and radiological results of total hip arthroplasty using a proximal modular femoral stem in patients who had secondary coxarthrosis associated with a dysplastic hip. MATERIALS AND METHODS: Forty-two patients (45 hips) with secondary coxarthrosis were evaluated after undergoing primary total hip arthroplasty using an S-ROM proximal modular femoral stem. The average follow-up was 80 months (range: 60 to 96 months). Clinical and radiological assessments were performed based on the Harris hip score and the radiological changes around the prosthesis. RESULTS: The average Harris hip score improved from 52.2 points to 88.5 points. All femoral stems showed stable fixation; there were 37 cases by bony ingrowth and 8 cases by stable fibrous ingrowth. Neither osteolysis nor progressive radiolucent lines around the femoral stem were found at the last follow-up. Forty-one hips (91.9%) revealed excellent or good clinical results at the most recent follow-up. CONCLUSION: For advanced secondary coxarthrosis, total hip arthroplasty with the use of the proximal modular femoral stem yielded good mid-term results with respect to the clinical and radiological criteria.
Adult ; Aged ; Arthroplasty, Replacement, Hip/adverse effects/*methods ; Female ; Femur/*pathology ; Hip Dislocation, Congenital/complications/pathology/*surgery ; *Hip Prosthesis ; Humans ; Joint Deformities, Acquired/complications/pathology/*surgery ; Male ; Middle Aged ; Osteoarthritis, Hip/etiology/surgery ; Postoperative Complications/pathology