ObjectiveTo evaluate the effectiveness of proximal fibular osteotomy combined with arthroscopic debridement in the treatment of medial knee osteoarthritis with varus. MethodsBetween December 2013 and June 2015, 61 patients with medial knee osteoarthritis with varus were treated by arthroscopic debridment in 32 cases (group A) and by proximal fibular osteotomy combined with arthroscopic debridement in 29 cases (group B). No significant difference was found in gender, age, side, disease duration, OA stage, visual analogue scale (VAS) score, and knee society score (KSS) between 2 groups (P > 0.05). The clinical outcome was evaluated by VAS score and KSS score at 1 week, 3 months, and 12 months after operation. ResultsThe patients in 2 groups were followed up 12 months. All incisions healed by first intention. There was no significant difference in complication incidence between groups A and B (0 vs. 3.4%; χ2=0.723, P=0.432). The VAS scores were significantly decreased at 1 week, 3 months, and 12 months after operation when compared with preoperative score in 2 groups (P < 0.05). The VAS score of group A was significantly lower than that of group B at 1 week after operation (P < 0.05), but the VAS score of group A was significantly higher than that of group B at 3 months, and 12 months after operation (P < 0.05). The knee function was obviously improved in 2 groups, and the KSS scores at 1 week, 3 months and 12 months after operation were significantly better than preoperative score (P < 0.05). The KSS score of group A was significantly lower than that of group B at 3 months, and 12 months after operation (P < 0.05). ConclusionProximal fibular osteotomy combined with arthroscopic debridement can treat knee malalignment and disease in knee, it is an effective and safe method to treat the medial knee osteoarthritis with varus.