Biomechanical Comparison of 4 Radial Meniscal Repair Techniques Including a Novel Dual Tie-Grip Configuration.

BACKGROUND

Complex repairs of radial meniscal tears have shown increased fixation strength compared to conventional sutures. A simplified 2-suture hybrid and a novel dual tie-grip repair with interconnected vertical mattress sutures spanning the tear were tested and compared to all-inside double-horizontal and tie-grip repairs.

HYPOTHESIS: The dual tie-grip repair would increase the initial compression load across the tear and show the least cyclic displacement and highest failure strength.

STUDY

DESIGN

Controlled laboratory study.

METHODS

A total of 40 porcine medial menisci were assigned to 4 repair groups: double-horizontal, hybrid, tie-grip, and dual tie-grip (10 per group). Results from tie-grip repairs were used to assess the effect of vertical mattress suture interconnection. After suture placement according to the described technique and fixation, the initial compressive load, stiffness, and relief displacement were measured. The repaired specimens underwent cyclic loading between 5 and 30 N over 1000 cycles (0.75 Hz), while cyclic stiffness and displacement were measured. Ultimate stiffness and load-to-failure were analyzed at 3.15 mm/s.

RESULTS

Analysis of variance revealed that dual tie-grip and hybrid repairs showed higher initial compressive load and relief displacement than the other techniques, with dual tie-grip repair reaching the highest values for both metrics (load: 19.3 ± 2.3 N [P < .001]; displacement: 0.75 ± 0.19 mm [P < .001]). The double-horizontal repair had the lowest initial stiffness (P < .001). Cyclic displacement was lowest for the dual tie-grip repair and highest for the double-horizontal repair (both P < .001). All repaired specimens stiffened during cycling without intergroup differences. Analysis of covariance for stiffness over displacement revealed higher stabilization (P < .040) with dual tie-grip repair and reduced stabilization (P < .001) with double-horizontal repair. Despite comparable ultimate stiffness across groups, the dual tie-grip repair failed predominantly by suture rupture at the highest ultimate load (275.5 ± 26.2 N; P < .001), whereas the double-horizontal repair failed by tissue rupture the earliest (127.2 ± 15.9 N; P < .001).

CONCLUSION

The dual tie-grip repair provided the highest initial compression across the radial meniscal tear, the lowest cyclic displacement, and the greatest load-to-failure among all techniques in a porcine cadaveric model. The simplified 2-suture hybrid repair showed higher initial compression than other repairs and comparable cyclic stability to the tie-grip repair.

CLINICAL RELEVANCE: The dual tie-grip repair provided high compression across the radial tear and strong resistance to cyclic displacement. Future clinical series assessing differences in healing rates among different repair groups are warranted.