The meniscus distributes the axial loads across the knee joint by hoop stresses, which are devastated by complete radial tears. Repair of complete radial meniscus tears is the key to restore the biomechanical stability necessary to maintain the hoop stresses. However, the biomechanical properties of different repair techniques remain unknown. This study aimed to compare the biomechanical properties of three novel repair techniques employing two stitches with the conventional double horizontal suture technique.
In this controlled laboratory study, 36 fresh-frozen porcine menisci were repaired using four different repair techniques. The repaired menisci were then subjected to total 900 cycles of cyclic loading followed by load to failure. Gap formation and strength were measured, and mode of failure was recorded.
Group differences in gap formation did not reach statistical significance at 100 cycles (p=.42), 300 cycles (p=.679), and 500 cycles (p=.703). A trend was found toward higher ultimate load to failure in Double Vertical Cross (276.826 ± 39.494N, p<.001), Double Vertical (241 ± 30.278N, p<.001), and Hybrid (237.565 ± 25.156N, p<.001) compared with the Double Horizontal (148.531 ± 22.295N). Double Vertical Cross had significantly higher failure load than Hybrid (p=.004). Stiffness was also higher in Double Vertical Cross (60.683 ± 13.578N/mm, p<.001), Double Vertical (55.330 ± 17.025N/mm, p=.001), and Hybrid (52.063 ± 8.553N/mm, p=.005), than Double horizontal (30.455 ± 7.213N/mm). Tissue failure was observed uniformly across all tested specimens.
All three novel meniscus repair techniques have superior biomechanical properties than the conventional Double Horizontal technique as demonstrated by higher stiffness and higher strength.