Abstract
Objective: Large-diameter metal-on-metal total hip arthroplasty (LDMOM-THA) has been proposed to reduce wear and postoperative dislocation. This study assesses the clinical effectiveness and complications of LDMOM-THA.
Methods: We performed cementless LDMOM-THA in 14 patients (15 hips). The mean age of patients at the time of surgery was 65.3 years (range 39-86 years). Adaptation of LDMOM-THA was done for elderly patients who had high risk for postoperative dislocation and for high-activity patients who required a large range of hip joint motion. All procedures were performed using a posterolateral approach and general anesthesia. The mean diameter of the head of the femoral component was 45.5 mm (range 40-50 mm). Average follow-up was 4.5 months. Preoperative and postoperative Japanese Orthopaedic Association (JOA) hip scores were recorded for all patients.
Results: The average preoperative JOA score was 45.8, contrasted against 86.7 at the last follow-up. The average preoperative range of motion of the hip joint was 60.5 in flexion, -10.2 in extension, 10.5 in abduction, and 5.4 in adduction, contrasted against 98.2, 4.5, 20.4, and 10.3 at the last follow-up. Four patients were able to squat on their heels. One superficial wound infection occurred, but no intraoperative fracture, dislocation, deep infection, deep-vein thrombosis, or pulmonary embolism occurred.
Conclusion: Our findings suggest that LDMOM-THA can produce satisfactory results in the short term. For elderly patients, LDMOM-THA was useful, especially for those with weak muscles and reduced cognitive function; the procedure was also useful for patients who required a large range of hip joint motion postoperatively.
