Abstract
Total hip arthroplasty through minimally invasive procedures potentially reduces operative trauma, which is expected to result in improved recovery and rehabilitation. We presently perform total hip arthroplasty using minimally invasive techniques via an anterolateral modification of the Watson-Jones approach. This approach is performed in the supine position and requires sterile draping of both legs. It also involves a modified operative technique which preserves the pelvitrochanteric muscles and extends the release of the hip capsule. In order to employ a proven implant system (BICON-PLUS threaded cup, SL-PLUS stem), it was necessary to modify the stem rasps and use manipulation rasps as trial stems. In this report, we compare 50 conventional total hip replacements with 50 procedures performed using the minimally invasive procedure in terms of blood loss and the duration of the operation. The length of the skin incision varied between 7 and 12 cm with the minimally invasive technique, compared to 15 to 22 cm with the conventional procedure. Both groups were virtually identical with respect to average blood loss (haemoglobin on 10th post-operative day: minimally invasive group, 108.0 g/L; conventional group, 112.0 g/L) and the duration of the procedure (minimally invasive group, 60 minutes; conventional group, 58 minutes). The position of the implanted components correlated with the pre-operative planning with regard to medial head offset, centre of rotation of the hip, and leg length, and was as satisfactory as that observed with the conventional procedure. The complication rate was low (2.9%). Shaft fissures occurred in the first months of use of the minimally invasive procedure before adaptation of the shaft rasps. Dislocations were attributable to improper patient behaviour. Minimally invasive surgery via the anterolateral approach in the supine position was equivalent to the conventional procedure, had a low rate of complications, and did not adversely impact the technical success of the procedure.