Abstract
Recently, the benefits of converting an ankylosed or arthrodesed hip to total hip arthroplasty have been well documented; however, there are few reports showing the results of minimally invasive total hip arthroplasty (MIS-THA) for ankylosed hip. In this study, we report a case of arthrodesed hip treated by MIS-THA using the anterolateral-supine approach (ALSA). A 37-year-old man with arthrodesed hip presented to our hospital with chronic low back pain in November 2010. At presentation, the right hip was fused at 5° of flexion, 10° of adduction, and 15° of external rotation. The right lower limb was 2 cm shorter than the left. The patient's body mass index was 22.2. The preoperative Japanese Orthopaedic Association (JOA) hip score was 67. Examination and radiographs of the lumbar sacral region were normal. The patient underwent MIS-THA utilizing ALSA in June, 2011. The surgical time was 107 min and the estimated blood loss during surgery was 587 ml. At present, 4 months postoperatively, he is pain-free and is able to walk, run, and squat. The range of motion of the right hip are flexion 100°, extension 10°, abduction 45°, and adduction 30°. The postoperative JOA hip score was 96. Converting MIS-THA for hip ankylosis is technically difficult; however, with careful planning, successful outcomes can be expected. Utilizing MIS-THA for ankylosed hip avoids damage of the abductor muscle, leading to better muscle and hip function. It is our belief that in the hands of an experienced surgeon, MIS-THA using ALSA can be safely performed for takedown of ankylosed hip with good functional outcomes.
