COMPARISON OF PRIMARY TOTAL HIP REPLACEMENTS PERFORMED WITH A STANDARD POSTERIOR INCISION OR A POSTERIOR MINI-INCISION.

Abstract

Purpose: The objective of this study was to compare the results of a single mini-incision posterior approach with those of a standard posterior incision total hip arthroplasty.

Patients & methods: During the year 2005 52 patients were randomized to undergo total hip arthroplasty (THA) surgery through a short incision of 10 cm (or less) or a standard incision of 16 cm. 27 pts (20 females – 7 males) underwent THA through a posterior standard approach whereas 25 pts (19 females – 6 males) underwent THA through a posterior minimal invasive technique. Surgical indication was primary degenerative osteoarthritis in all patients. A single experienced surgeon performed all operations. In all patients the same cementless acetabulum and femoral component was used. The anaesthetic, analgesic, and postoperative physiotherapy protocols were standardized in both groups. The patients were compared with respect to the preoperative ASA score, incision length, hospital stay, intraoperative blood loss, postoperative blood transfusion, early mobilisation and satisfaction evaluated by the Harris Hip Score(HHS) and the visual analoque scale (VAS) for pain.

Results: The two groups were matched for age, grade according to the system of the American Society of Anesthesiologists and the preoperative Harris Hip Score. No significant difference was detected with respect to average surgical time, postoperative hematocrit, blood transfusion requirements, pain scores, or analgesic use. Additionally, we found no difference in early walking ability or length of hospital stay and no difference in component placement or functional outcome scores at the latest follow-up 6 – 12 months (mean 8 months) after surgery.

Conclusions: In arthroplasty the term ‘minimal invasive’ not only refers to the length of the skin incision but more so to its soft tissue protecting features and thereby to a better outcome. There was no evidence that the mini-incision technique resulted in less bleeding or less trauma to the soft tissues of the hip. Even more, it offers no significant benefit in the early postoperative or late period compared with a standard incision of 16 cm.