Repair of Longitudinal Meniscal Tears by Single or Double Vertical Loop Sutures: In vitro Biomechanical Study under Cyclic Loading

One of the factors affecting the healing of a meniscus repair is the primary stability of the tear. The purpose of this study is to compare single and double vertical loop (SVL vs. DVL) meniscal suture configurations by measuring elongation under cyclic loading and failure properties under ultimate load. We hypothesized that DVL configuration would have superior biomechanical properties than SVL. Twenty-two intact lateral menisci were harvested from patients who required total knee arthroplasty. A 20-mm longitudinal full-thickness cut was made 3 mm from the peripheral rim to simulate a longitudinal tear. Two groups were formed and group randomization was done according to patient age and gender (SVL group: mean age 68.3 years [range, 58–78 years], five males, six females; DVL group: mean age 67.4 years [range, 59–77 years], six males, five females). Cyclic loading was performed between 5 and 30 N at a frequency of 1 Hz for 500 cycles. Then, the meniscus repair construct was loaded until failure. Statistical analysis was performed using the t-test and the Mann–Whitney's U-test. During the early phases of cyclic loading, three specimens from each group failed because of suture pull out and are excluded from the study. At the end of 500 cycles, there was significantly less displacement in the DVL group than the SVL group (6.13 ± 1.04 vs. 9.3 ± 2.59 mm) (p   0.05). All specimens in SVL and five specimens in DVL groups failed in the form of suture pull out from the meniscus tissue. Longitudinal meniscal tears repaired with DVL configuration had less elongation value under cyclic loading compared with SVL configuration. Because of its superior biomechanical properties, it would be more secure to repair large and instable longitudinal meniscal tears by the DVL technique. This is a level II study.