In this study, bilateral simultaneous high tibial osteotomy (HTO) was compared with staged bilateral HTO in terms of complications. We did not use any grafts to support the osteotomy line and the patients were mobilized immediately with a full load on a postoperative day 1. And our hypothesis is that bilateral simultaneous applications are safe in comparison to the staged ones in terms of complications.

Knee osteoarthritis is the most common orthopedic chronic disease, and varus knee abnormalities can often be related. The load from the medial tibiofemoral joint increases significantly in varus alignment disorder and it plays an important role in the structural progression of knee osteoarthritis. Varus malalignment and patients with medial tibiofemoral disease comprise a common patient subset. The probability of progressing to severe disease is 3 to 4 times higher in these patients compared to those with a neutral knee alignment. Although the long-term results of high tibial osteotomy are well documented, but data on bilateral simultaneous HTO are insufficient. In general, staged surgery is preferred in bilateral cases due to the difficult rehabilitation, healing of the osteotomy line, and complications related to surgery. Advances in post-surgical rehabilitation have been made due to increased confidence in stability due to improvements in the technology of plates.The advantages of an bilateral simulatneous HTO is single administration of anesthesia, total shortening of the hospitalization periof and reduced costs.

Inclusion Criteria:

• Bilateral primary genu varus gonarthrosis

Exclusion Criteria:

• Secondary gonarthrosis

Patients with bilateral genu varus gonarthrosis operated by the tertiary step hospital high-volume knee surgeons