A repair technique using two simple stitches reduces the short-term postoperative medial meniscus extrusion after pullout repair for medial meniscus posterior root tear

Background: Two types of repair techniques, FasT-Fix modified Mason–Allen (F-MMA) and two simple stitches (TSS), for the treatment of a medial meniscus posterior root tear (MMPRT) were previously reported. However, whether these techniques could prevent postoperative medial meniscus extrusion (MME) progression is unknown. This study investigated and compared postoperative MME of the two repair techniques. Methods: Forty-seven knees that had undergone pullout repair for MMPRT were retrospectively reviewed. These knees were divided into two groups as follows: In 26 knees, MMPRT was treated using the F-MMA technique and fixed with the knee flexed at 45° and 20 N of tension [F-MMA (45°–20 N) group], and in 21 knees, MMPRT was treated using the TSS technique and fixed with the knee flexed at 20° and 30 N of tension [TSS (20°–30 N) group]. The medial meniscus body width (MMBW), absolute MME (aMME), and relative MME (rMME = absolute MME/MMBW) were measured and compared using magnetic resonance imaging 3 months postoperatively. The Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales for clinical outcomes were compared between the two groups at 6 months postoperatively. Results: At 3 months postoperatively, the aMME and rMME significantly decreased in the TSS (20°–30 N) compared to the F-MMA (45°–20 N) group. The TSS (20°–30 N) group had better KOOS subscale scores than the F-MMA (45°–20 N) group at 6 months postoperatively. Conclusions: The TSS technique with appropriate tibial fixation can decrease MME soon after surgery. This may prevent osteoarthritis progression and improve clinical outcomes.