COMPARISON OF CONSECUTIVE HIP RESURFACING AND METAL ON METAL LARGE HEAD TOTAL HIP REPLACEMENT

Abstract

Introduction: We hypothesised that a stemmed hybrid total hip replacement with a large metal head, (LMOM), with the same bearing technology, would give early functional results as good as hip resurfacing (HR) with fewer contraindications and reduced morbidity due to a less invasive approach.

Methods: We performed a 12 month observational study of consecutive patients undergoing LMOM (n=40) and HR (n=60). Patients’ age, sex, blood loss, hospital stay and early complications were compared as well as pre and post-op Oxford scores and range of movement.

Results: The HR group was younger with more normal hip morphology. Mean age 54years HR/ 59years LMOM, BMI 28 and 29 respectively. Diagnosis of primary osteoarthritis 77% HR compared to 47% in LMOM group. Operation time, blood loss and haemoglobin drop were similar in both groups. The LMOM group achieved an earlier discharge of 5.5 days compared to 6.3 (p< 0.12). Complications included 2 aseptic wound leakages in the LMOM group. In the HR group an aseptic wound leakage, superficial infection and a sciatic nerve palsy was observed. At 6 week and 3 month follow up, the range of moment of both groups was very similar. Mean Oxford hip scores were 44 preoperatively and 22 postoperatively in the HR group and 45 falling to 24 in the LMOM group.

Discussion: LMOM compared to HR is preferable in respect to hospital stay and reduced perioperative complications despite an older cohort with a wider variety of arthritic pathologies. However longer follow up is required to conclude further.