The Different Influence Of Suture Methods On In Situ Force After Repairing Of Lateral Meniscus Longitudinal Tears: An In Vitro Study

Objective: It has been long accepted as common sense that the contact force between rims of meniscal longitudinal tear decrease with the lapse of time.However,the postoperative decreasing pattern of contact force among different repair techniques remains ambiguous.Current study aimed to investigate the postoperative foece variation in the repaired meniscal lesion via a quantitative protocol.Methods: 90 porcine lateral menisci were enrolled in current study.A 20 mm longitudinal vertical tear was created at the midbody,which was 3 mm from the lateral synovial membrane of meniscus;thereafter,the meniscus was sutured with non-absorbable suture with 3 different repair methods(vertical,horizontal,and modified vertical loop suture).Before suture tensioning,an electrical pressure sensor was inserted into the lesion.The value of contact force in the sutured lesion could been certified by a sensor-connected digital pressure system.The menisci were grouped into 9 based on the method and the initial tension applied(10,15 and 20 N),and the position of the meniscus-suture structure was kept static for 10 minutes.All continuous measurement data of contact force were inputted to a computer.Results: A significant lower remaining contact force in sutured lesion was observed in all groups after 10 minutes(10 N group: mean,4.3 ± 0.2 N;range,3.7-4.6 N;15 N group:mean,6.6 ± 1.1 N;range,5.2-8.2 N;20 N group: mean,8.7 ± 1.0 N;range,7.1-9.8 N).An average tension reduction of 56%,compared to the initial value,was detected in all groups.And for any certain magnitude of initial pressure,the remaining force between 3methods always demonstrated a relationship of: modified vertical> vertical > horizontal.Though the modified vertical loop suture demonstrated the best ability to maintain contact force in lesions,the significant differences between methods were only noticed in the 20 N specimens.Conclusion: The preloaded repairing structure presented a tendency to loss the better portion of pressure after the simulated meniscal repair,regardless to the magnitude of initial tension applied.In addition,the residual contact force among all groups presented a multiplicative incremental tendency with the increase of initial pressure,rather thanreduce randomly or down to any approximation.During multiple methods that applied in clinical work,the residual force also different from one to another.Thus,thorough consideration must be taken before surgery applied.