Clinical Application And Therapeutic Effectiveness Of Large Diameter Heads Metal-on-metal Total Hip Replacement

Objective To explore the key operation techniques, postoperative early rehabilitation, indications and short-term results of total hip replacement(THR) using large diameter heads(LDH)in metal-on-metal(MOM)articulation. We try to find the result in different age groups by this approach.Methods:A consecutive series of 32 patients(32 hips)who underwent THR using ASR LDH in MOM articulation from March 2009 to May 2009 were studied. There were 20 men and 12 women with a mean age of 57 years(range,31-78years). The 32 patients were divided into two groups:the first group was consist of 14 patients(14 hips), and the other of 18 patients(18 hips).Results:No intraoperative complications such as intraoperative fracture, nerve palsy, or vascular injury was observed. There was no dislocation or deep vein thrombosis postoperatively. In all patients, leg length discrepancy was within 10mm difference. The average Harris hip score at the last follow-up was significantly improved compared with the preoperative (89.4 points versus 39.5 points). The average range of motion(ROM)of hips at the last follow-up was significantly improved compared with the preoperative values. Statistically significant differences were not found between the two groups.Conclusion:The short-term results of LDH in MOM total hip replacement on ANFH, osteoarthritis, rheumatoid arthritis, femur neck fracture, osteoarthritis secondary to dysplastic hips, ankylosing arthritis are excellent.