Biomechanical comparison of arthroscopic repair constructs for meniscal root tears

Abstract

Background: Complete meniscal root tears render the meniscus nonfunctional. Repair constructs have been presented and tested; however, prior studies have evaluated suture patterns placed ex vivo without simulating an in vivo surgical setting. This study introduces a new double-locking loop suture pattern and compares its biomechanical properties and execution time with commonly used suture patterns. All constructs were performed using an all-inside arthroscopic technique.

Hypothesis: Complex suture repair constructs have higher failure loads, stiffness, and execution times compared with simple constructs.

Study design: Controlled laboratory study.

Methods: Sutures were placed arthroscopically into the posterior horn root region of the medial and lateral menisci in 21 cadaveric knees. Four repair constructs were evaluated: 2 simple sutures (2SS), 1 inverted mattress suture (1MS), 1 double-locking loop suture (1DLS), and 2 double-locking loop sutures (2DLS). In total, 40 posterior meniscal roots were tested, with 10 trials for each construct. After arthroscopic placement of the root repair constructs, each meniscus was explanted and tested to failure on a uniaxial materials testing machine. The Kruskal-Wallis test was used to evaluate for the significance of maximum failure loads and stiffness between groups.

Results: The mean maximum failure loads were 137 ± 49 N (2SS), 126 ± 44 N (1MS), 186 ± 43 N (1DLS), and 368 ± 76 N (2DLS). Interconstruct comparison revealed a statistical difference between 2DLS and all 3 remaining constructs (P < .01) and 1DLS when compared with 2SS and 1MS (P < .01 for both). Statistical significance was not found between 2SS and 1MS (P = .8). The mean times for repair of the 4 fixation techniques were 1.8 ± 0.9 minutes (2SS), 2.4 ± 1.9 minutes (1MS), 4.7 ± 2.0 minutes (1DLS), and 5.4 ± 0.6 minutes (2DLS).

Conclusion: The double-locking loop suture repair technique had significantly higher failure loads compared with the 3 other methods tested. As the complexity of repair constructs increases, failure loads and surgical times increase.

Clinical relevance: Complex suture patterns can be placed via an all-inside arthroscopic technique delivering higher failure loads for meniscal root repair with little increase in surgical time.

Keywords: failure load; meniscus; repair; root tear.