HARD BEARING HYBRID TOTAL HIP REPLACEMENTS IN MIDDLE-AGED FEMALE PATIENTS: SHORT TO MID-TERM RESULTS OF METAL-ON-METAL AND CERAMIC-ON-CERAMIC BEARINGS FROM A SINGLE SURGEON'S PRACTICE

Middle-aged female patients with painful hip arthritis often have high expectations, are physically active and are more likely to have underlying anatomical abnormalities such as DDH. Large hard bearing total hip replacement (THR) offer the possibilities of reduced wear and risk of dislocation. The patients in this series all had surgery in the private sector and were operated on by one surgeon. They were selected for a hard bearing THR on the basis of age, health and expectations. Large bearing metal-on-metal (MOM) THR became possible in 2003, with ceramic-on-ceramic (COC) bearings used in patients with allergies to metal. There were 90 patients in the MOM group and 92 patients in the COC group. The mean age was 60 and the commonest diagnosis was osteoarthritis in both groups. In the MOM group there were 8 complications: 2 deep infections, 1 death from PE, and 5 severe soft tissue reactions (pseudotumour). In the COC group there were 2 complications: 1 deep infection and 1 patient with intermittent squeaking. The patients in this study were closely matched in terms of age and lifestyles. All of them were operated on by a single high volume specialist hip surgeon. The results suggest a high risk of failure in female patients who have had MOM THR. Most of the failures had described discomfort in the hip for many months before revision surgery. All of the failures were associated with a cemented CPT stem. The surgeon no longer uses MOM bearings in female patients because of the unacceptably high failure rate compared to COC bearings. COC bearings appear to offer the active middle-aged female patient consistently good results and a low risk of failure at least in the short to medium term.