Minimally invasive anterolateral surgical approach for total hip arthroplasty: early clinical results

The purpose of this study is to describe our early experience in the development and use of a minimally invasive, anterolateral approach to the hip joint for total hip arthroplasty (THA). This approach uses a specific intraoperative protocol involving leg positioning to maximise exposure and hip joint visualisation. Between October, 2004 and December, 2004, we operated on 18 male and 29 female patients without selection and in consecutive order. The average patient age at surgery was 66 years (range 28 to 86 yrs) with an average body mass index (BMI) of 26 (range 18 36) and with a majority of patients presenting with osteoarthritis as the primary indication for surgery. The average length of the skin incision was 8 cm and the average incision-to-suture time was 45 minutes. The preoperative average Harris Hip Score was 38 and improved to 70 at 10 days postoperatively, and 92 at three and six months. Similarly, the HHS average pain component score increased from 12.6 preoperatively to 39 at 10 days postoperatively, and 40 at three and six months. An exact neutral implantation of the stem was found in 48% of the patients, between one to three degrees out of neutral in 40% and greater than four degrees of varus in 12%. The average inclination angle of the cup was measured at 44 degrees. No intraoperative or perioperative complications of any kind occurred in this series of 47 consecutive patients. From our experience, the MIS AL approach for THA with patients in the lateral position can be applied without restrictions for patient indication. Improved results can be observed when using the MIS AL approach, especially in the ear-ly postoperative phase. Since the abductors can be completely spared during the surgery, improved long-term results may be expected. Moreover and when necessary, an operative expansion is always possible without difficulties. Overall, the approach yields promising results.