A new long-term study that has evaluated the outcomes of the traditional Charnley total hip replacement (THR) prosthesis has shown that most are still viable 35 years after the initial surgery.
The prosthesis, named after the British surgeon who pioneered the THR procedure over fifty years ago, is made up of a polyethylene acetabular socket and a metal femoral head.
Out of 69 THR patients (93 hip replacements) who participated in the 25-year follow-up assessment, 32 were still alive (44 per cent) and 30 were available for an evaluation. Out of the original 93 hip replacements, 28 required revision surgery. The 30 patients with viable hip components were assessed through quality of life and hip scores, and activity measurements, including six-minute walk and pedometer monitoring.
Although 63.5 per cent of the original hip replacements were functioning at the latest follow-up examination or at the time of patient death, a significant decrease in activity level, as measured by functional scores, was seen over time. However, age and health related factors, as opposed to implant failure, limited activity in the participants at the long-term follow up.
According to the study authors, the results reflect the durability of cemented hip replacements, and provide a benchmark comparison for THR performed in younger patients with other designs, materials and techniques.
The study entitled "Assessment of Durability and Function at Minimum 35-Year Follow up of THR Patients 50 and Under” was presented at the 2014 Annual Meeting of the American Academy of Orthopaedic Surgeons (AAOS).