MEDIUM-TERM RESULTS OF METASUL ARTICULATION AND CEMENTED WEBER CUP IN TOTAL HIP JOINT REPLACEMENT

Abstract

Introduction: There has been a renewed interest in metal-on-metal articulation in hip joint Arthroplasty. The reason for having metal-on-metal articulation is to reduce the volume of wear particles that are produced with THR. The outcome of reduced particle formation will hopefully be reduced osteolysis.

Methods: We reviewed the results of 139 primary hip arthroplasties (130 patients) performed using Metasul articulation and cemented Weber cup. Six patients were lost to follow-up leaving 133 hips (124 patients) for review with at least 5-year follow-up. The acetabular socket was the cemented Weber cup and Bone grafting of the acetabulum and application of a reinforcement ring was done where necessary. Cemented CF-30 femoral stem was used in all patients but one (PFMR). The study was conducted retrospectively based on the information collected from hospital notes and Orthocom database. Immediate post-operative films were seen to measure the cup and stem inclination and quality of cementing using the Barracks grading system.

Results: There were 102 females and 22 males in the cohort. Mean age was 73 years (SD-7.46, range 58–86). Left to right hip ratio was 52:81. Most common Pre-operative diagnosis was Osteoarthritis (103) followed by Intracapsular fracture neck of femur (20). The average follow-up was 7.23 years (range 5–10.9). Mean pre-operative Harris hip score was 42.09 and mean post-operative hip scores were 90.01, 86.84, 87.42 and 84.63 at 1-year, 3-year, 5-year and final follow-up with the corresponding pain scores were 42.9, 41.84, 41.56 and 41.56 respectively. Only two hips were revised for aseptic loosening of the cup with a 93.4% implant survivorship at 12 years. There was no case of aseptic stem loosening. No untoward systemic effects were noted in the cohort.

Discussion: We believe that in our study Metasul metal-on-metal articulation has shown satisfactory results with regards to aseptic loosening and reduction in osteolysis in medium-term.