Abstract
Aim: To determine feasibility and short-term outcome following total hip arthroplasty using a minimally invasive modified direct lateral approach.
Methods: 97 unilateral total hip arthroplasties (THA) in 97 patients were performed in 2003 with use of a mini-incision inferior or equal to 10 cm and consecutively included in this prospectively study. Selection criteria for mini-incision were based on preoperative diagnose (rheumatoid arthritis and post traumatic osteoarthritis were excluded). The study group was compared with a population of 88 hips performed through a standard incision in 2002. The control group was retrospectively matched using the same selection criteria as the study group; no statistically significant differences between the two study arms were found with respect to age, gender, body mass index, pre-operative Merle d ‘Aubigné score, aetiology, or preoperative haemoglobin level. No patients in either group were lost to follow up. On patients placed in the lateral position minimal dissection and preservation of the soft tissue surrounding the hip was achieved through a slide osteotomy of the lateral facet of the great trochanter.
Results: Average time for surgery was 62 minutes for the study group and 63 minutes for the control group (p = .51). Postoperative haemoglobin [day-1] was 11.8 g/l for the study group and 11.6 g/l for the control group (p=. 42). However , fewer patients were auto transfused with the hemocare device (16% vs. 47%, p=. 00) and less allogenic transfusions were required in the study group. No complications relating to the procedure were seen. In both groups, stem position was neutral in 95% of the patients. Cup inclination was between 30° and 48° in all cases. Hospitalisation time was 8.3 postoperative days for the study group and 9.6 postoperative days for the control group (p=. 00). One year postoperatively, the Merle d ‘Aubigné score was 17.3 for the study group and 17.1 for the control group (p=. 42).
Conclusions: Because of the consistently reported high success rate of conventional THA it is imperative to critically appraise any changes of surgical technique. In a selected patient population the modified direct lateral minimal invasive approach was found to be as safe as the standard approach. Other than obvious cosmetic advantages, the MIS approach had the advantage of a quicker patient recovery.
Theses abstracts were prepared by Professor Roger Lemaire. Correspondence should be addressed to EFORT Central Office, Freihofstrasse 22, CH-8700 Küsnacht, Switzerland.
