Koinzidenz und Therapie von Beinachsdeviationen bei degenerativen Knorpelschäden des Kniegelenks. Ergebnisse aus dem Deutschen KnorpelRegister DGOU

<b>Purpose</b> This multicenter study was aimed to evaluate the coincidence of degenerative knee cartilage lesions with a varus or valgus dysalignment. Furthermore, the frequency of the combined surgery of cartilage treatments and corrective osteotomies are determined. <b>Material and Methods</b> A total of 1778 patients were included in the German CartilageRegistry (deadline 01.08.2016). In 90.6% of patients, the surgeon calculated the alignment by clinical observation. Varus or valgus conditions were measured radiologically in only 56.0%. This study describes patients who underwent treatment of degenerative cartilage lesions with a complete (clinical and radiological) determination of the alignment. <b>Results</b> The mean mechanical tibia-femur angle (Paley) (mTFA) in clinically neutral extremities was 0.2° (SD 0.6; 0 - 5), in varus cases 5,0° (SD 3.2; 0 - 15), and - 4.7° (SD - 4.0; - 15 - 0) in valgus cases. Varus dysalignment was significantly associated with cartilage lesions in the medial compartment. Valgus dysalignment more frequently occurred in knees with lateral cartilage lesions. Independently of the surgeon's choice of the method of cartilage surgery, in 72.4% of all valgus deformities a corrective osteotomy was performed. Valgus dysalignment was corrected in 50%. <b>Conclusions</b> In about a quarter of all cases, cartilage lesions are associated with a varus (18.9%) or valgus (4.2%) dysalignment. In a number of cases, the treatment of cartilage lesions should include the addressing of these axial deviations. Still the efficacy of this procedure regarding prognosis and clinical outcome is unclear.