The Optimal Suture Site for the Repair of Posterior Horn Root Tears: Biomechanical Evaluation of Pullout Strength in Porcine Menisci

PURPOSE There are few studies on biomechanical evaluation of suture points in repair of root tears. The purpose of this study was to determine the point of greatest pullout strength for root tear repair. MATERIALS AND METHODS A total of 120 fresh porcine medial menisci were obtained. The red-red and red-white zones of the meniscus were divided by two lines designated as lines A and B (groups A and B). Groups A and B were further divided into three groups each by dividing lines A and B into three points: 3, 5, and 7 mm from the meniscal ligament root insertion. Vertical meniscal repair was performed on each point. The pullout failure strength was tested using a biaxial servohydraulic testing machine. RESULTS The average maximal load at failure was significantly greater in group A than group B (87.65 vs. 62.93; p<0.001) The average length at maximal load failure was greater in group A than group B (4.35 vs. 3.2; p<0.001). Among the subgroups of 3, 5, and 7 mm in both groups A and B, 7 mm showed the greatest maximal load (p<0.001). CONCLUSIONS The pullout strength was statistically significantly greater in group A than group B and in the 7 mm subgroup than the 3 and 5 mm subgroups. Thus, the 7 mm subgroup in group A showed the greatest pullout strength.