The anterolateral approach in supine position for minimally invasive implantation of hip endoprostheses

Abstract: Since September 2004 patients with primary THR are operated minimally invasive at our department. 350 implantations were carried out using the modified anterolateral Watson-Jones approach in supine position till now. For this method it is necessary to cover both legs sterilely and to use an OR table where it is possible to tilt the legs down, to perform adduction, external rotation and hyperextension during the preparation of the shaft. Besides theminimization of the surgical approach (skin incision between 7 and 12 cm) the main criterion of the minimal invasiveness is the preservation of the gluteal minimus and medius tendon insertions. Patient positioning and the surgical procedure with modified shaft rasps with double offset and use of the manipulation rasps as trial prostheses are presented. The complication rate was 2.9% (4 shaft fissures, 4 postoperative dislocations, one early infect, one post-traumatic trochanter fracture). Intraoperative trochanter fracture was not stated. When comparing both methods no differences arose regarding the postoperative hematocrit and haemoglobin level or the need for blood substitution, no further difference in the positioning of cups and stems, the postoperative leg length, the offset and the rotation centre of the hip. Tips and tricks from the experiences made till now are discussed. Patients with minimally invasive surgery on the 2nd hip and a conventional operation in earlier years were asked for their opinion using a standardized questionnaire and results were evaluated. Questions were asked about the postoperative pain, support needed during the first postoperative days, the use of crutches and walking up stairs, the skin incision and an overall assessment of the preferred operation method. In all respects a clearly increased patient satisfaction has been noticed for the minimally invasive procedure, with especially remarkable results for getting out of the bed on the 1st postoperative day, faster walking without crutches and easier walking up and down stairs.