No abstract

No abstract

Introduction Currently there is a tendency of increasing the proportion of knee joint organ-preserving surgery. High tibial osteotomy (HTO) was recommended as a method of knee joint varus deformity treating in cases with extraarticular deformity. The question of necessary angle correction remains controversial, which does not harm biomechanics of knee and adjacent joints. And the issue of preventing excessive hypercorrection as a complication of osteotomy. Methods The clinical case of the 59-year-old patient who underwent primary HTO and revision HTO is analyzed in this article. The patient had a varus deformity of a left lower limb with isolated medial knee osteoarthritis. The patient complained only at pain and range of motion limitation in the knee joint. According to arthroscopy and magnetic resonance imaging (MRI) data, there was cartilage damage classified as Outerbridge 4 stage of the medial compartment. There were no signs of lateral compartment cartilage damage and patellofemoral joint arthritis. The patient's body mass index (BMI) was 28kg / m2. Varus deformity of the knee joint 10˚. Results The patient underwent a medial high tibial open wedge osteotomy. During preoperative planning topograms of the lower limb with a weight bearing were used. A clinical result before the operation according to the scales was: Knee injury and Osteoarthritis Outcome Score (KOOS) 46 points, Visual Analogue Scale (VAS) 7 cm., American Orthopaedic Foot and Ankle Society (AOFAS) 92 points. After 6 months from initial surgery: knee joint VAS 1 cm., ankle joint VAS 5 cm., KOOS 88 points, AOFAS 63 points. During clinical examination and according to instrumental studies, excessive valgus hypercorrection of the 11,2˚ noted. Also, tibial plafond inclination (TPI) and talar inclination (TI) significantly increased. 1,5 years after the primary osteotomy, a revision closed wedge osteotomy was performed. Valgus deformity of the knee joint became 3˚, axis of the ankle joint changed to normal values. Clinical and functional results after 6 months after revision osteotomy: KOOS 92 points, AOFAS 99 points, pain in the knee and ankle joint on the VAS scale 1 cm. Conclusions The case showed: careful preoperative planning before the operation and using of additional methods for monitoring intraoperative correction were important. Excessive valgus hypercorrection promotes good regeneration of the medial compartment cartilage, however it overloads a lateral compartment and adversely affects the ankle joint and foot.