Quantitative analysis of tissue injury after minimally invasive total hip arthroplasty.

BACKGROUND: We intended to clarify the hypothesis that minimally invasive total hip arthroplasty (MI-THA) leads to less tissue damage and inflammatory response than does conventional total hip arthroplasty (C-THA). METHODS: We performed 30 cases of THA between September 2005 and May 2006 and evaluated these cases prospectively. We chose 15 MI-THA cases for the study group and another 15 C-THA cases for the control group. We checked skeletal muscle marker enzymes, such as serum creatinine kinase and aldolase, the pro-inflammatory cytokines, interleukin (IL)-6 and 8, and the anti-inflammatory cytokines, IL-10 and IL-1 receptor antagonist (ra) the day before surgery and at postoperative days 1, 7, and 14. RESULTS: On postoperative days 1 and 3, the study group showed significantly lower serum creatinine kinase, IL-6, IL-10, and IL-1ra values than those in the control group. Additionally, IL-8 was significantly lower on day 7 after surgery. CONCLUSIONS: These data show that MI-THA decreased the release of muscle marker enzymes due to tissue damage immediately after surgery and minimized the inflammatory response related to the surgery during the early postoperative period.