Radiological study of THA after mini-incision technique

Mini-incision procedures reduce perioperative blood loss, postoperative pain, time of the postoperative recovery, length of the surgical scar, and hospitalisation time. Implant malposition and poor stability are potential risks for compromising long-term results. Between September 2000 and February 2002 (18 months), 120 cemented primary total hip arthroplasties for primary osteoarthritis were performed at the authors' institutions. In 60 of these cases selected at random, a posterolateral mini-incision up to 10 cm was used. Sixty other THAs were implanted through a standard posterolateral approach. The radiological measurements of the inclination and anteversion of the cup and stem position were performed and statistically evaluated by use of Mann-Whitney U and Bartlett tests. In the mini-incision group the average inclination angle was 42.3° (range 36° to 52°) and the anteversion angle 13.6° (range 6° to 21°). The femoral component coronal alignment was within 3° of neutral position in 54 cases (90.0 %). In the standard implanted group the average cup inclination angle was 42.4° (range 35° to 50°) and anteversion angle 13.6° (range 8° to 24°). Fifty-three stems (88,3 %) were implanted correctly. Statistical analysis found no significant difference in component position between the two groups.

There are therefore no potential risks of compromising long-term results after the mini-incision procedure. The authors are encouraged to continue this technique.