[An open wedge tibial head osteotomy using continuous callus distraction. An alternative method for the treatment of of varus arthrosis].

High tibial osteotomy is an accepted method for treatment of medial osteoarthritis. An alternative technique is an open-wedge osteotomy and consecutive callotasis (CO) using an external fixator. The purpose of this study was to evaluate the clinical and radiological results and the efficiency of this technique for precise correction. This prospective study included 41 patients (44 knees) evaluated by the HSS score, radiological stage of osteoarthritis, bone healing, and complications after a follow-up period of 49 (36-61) months. The HSS score increased from median 67 preoperatively to 82 points at the time of follow-up (p<0.001). Of 44 knees, excellent/good results were found in 70.5% and fair/poor in 29.5%. The median preoperative femorotibial anatomical angle was 3.6 degrees varus and 9.4 degrees valgus at the latest follow-up examination. The total time in external fixation was median 80 (61-125) days. We observed one early collapse of the new bone wedge, one complete corticotomy, and pin tract infections in ten cases. Furthermore, two hematomas required revision surgery. Hemicallotasis with external fixators allows constant manipulation of alignment during the healing process to optimize alignment. The disadvantage of the external fixation is the risk of pin track infection. Therefore, CO may constitute an important contribution to our algorithm in the treatment of varus gonarthrosis.