ObjectiveTo investigate the methods and the effectiveness of arthroscopic treatment combined with repair of the cyst wall using the tendon flap of medial head of gastrocnemius muscle after resection of popliteal cyst. MethodsA retrospective analysis was made on the clinical data of 140 patients with popliteal cyst between August 2009 and June 2014, including 44 males and 96 females with a mean age of 54.68 years (range, 14-80 years). The median course of symptoms was 31 months (range, 20 days to 30 years). According to Rauschning and Lindgren criteria for popliteal cyst grade, 4 cases were rated as grade Ⅰ, 44 cases as grade Ⅱ, and 92 cases as grade Ⅲ. The preoperative Lysholm knee score was 68.99±8.23. Firstly, cyst was resected, then the hernia sac of joint capsule was repaired with the tendon flap of medial head of gastrocnemius muscle, and finally a knee arthroscopy was used for the diagnosis and treatment of intra-articular lesions. ResultsNo complication of nerve or blood vessel injury, infection, or necrosis occurred. The mean follow-up was 26 months (range, 6-64 months). During follow-up, 1 case (0.71%) had cyst recurrence. According to Rauschning and Lindgren criteria for popliteal cyst grade, 37 cases were rated as grade 0, 92 cases as grade Ⅰ, 10 cases as grade Ⅱ, and 1 case as grade Ⅲ at 6 months after operation, showing significant difference when compared with preoperative one (Z=-14.303, P=0.000); the Lysholm knee score (85.51±9.23) was significantly higher than preoperative score (t=-15.798, P=0.000). ConclusionArthroscopic treatment combined with repair of the cyst wall with the tendon flap of medial head of gastrocnemius muscle after resection of popliteal cyst is a better way to avoid recurrence.