Abstract: Objective To evaluate clinical effect of arthroscopic single thread double site ligation and suture technique in the treatment of medial meniscus posterior root tear (MMPRT). 
Methods In total, 17 knees from 17 patients with MMPRT were selected and treated with arthroscopic single thread double site ligation and suture in the Third Hospital of Hebei Medical University. The Kellgren-Larence grading of 17 knees on X-ray was grade 0 in 2 patients, grade 1 in 5 patients, and grade 2 in 10 patients. During preoperative and postoperative follow-up, patients were evaluated for relevant functional scores and knee joint degeneration, including visual analogue scale (VAS) pain score, international knee documentation committee (IKDC) score, Lysholm score, X-ray Kellgren-Larence grading, and medial meniscus extrusion (MME) value. 
Results Seventeen patients were followed up for 13 to 20 months, with an average of (16.28±3.54) months. At the last follow-up, the knee joint VAS score ［1.00 (1.00) points］ was lower than that ［5.00 (1.00) points］ before operation, while the IKDC score, Lysholm score, and MME value were［(60.29±3.98) points, (89.88±4.11) points, and (3.08±0.19) mm］ respectively, which were higher than those ［(38.82 ± 2.48) points, (51.65±4.27) points, and (2.98±0.11) mm］ before operation, with statistical significance (P＜0.001). At the last follow-up, there was no significant difference in the Kellgren-Lawrence grading of X-ray films compared with preoperative levels (P＞0.05). 
Conclusion Arthroscopic single thread double site ligation and suture for the treatment of MMPRT has good clinical efficacy, as well as good security and operability. 

Key words: meniscus, ligation and suture technique, arthroscopy