[Minimally invasive mini-midvastus approach as standard in total knee arthroplasty]

Different minimally invasive techniques have been introduced for total knee arthroplasty. With the mini-midvastus incision technique, all deformities and patients can basically be treated. As the surgeon gains experience, this technique can be applied as part of day-to-day clinical routine. Surgery is done in front of the patient. All important landmarks are visible. Most patients benefit from the new surgical technique. Mobilisation and rehabilitation are possible sooner than after an open procedure. The risk of component malalignment and the overall complication rate do not appear to be any higher. In a prospective study 100 consecutive patients with the mean age of 67 (54 to 83) years were treated using the mini-midvastus incision technique. Mean Knee Society Scores (KSS) increased from 55/62 preoperatively to 82/65 (Knee/Function) after 7-10 days, to 92/86 after 6 weeks and to 93/92 after 12 months. Preoperative mean flexion was 106 degrees (75-140 degrees ), 92 degrees (75-140 degrees ) on day 7-10 after surgery, 113 degrees (90-140 degrees ) after 6 weeks and 128 degrees (90-140 degrees ) after 12 months. The average skin incision was 10.5 (7-13.5) cm long. The mean surgical time of 98 (70-145) min is 20 min longer than required for our conventional technique. Long-standing radiographs in all patients showed an overall alignment of +/-3 degrees in 93%. The complication rate was 5%, which is comparable to that with an open procedure.