Root tear of the meniscus: biomechanical evaluation of an arthroscopic refixation technique.

Background: Aim of the current study was to evaluate the structural properties of an arthroscopic refixation technique for meniscal root tears.

Hypothesis: Arthroscopic two suture root tear refixation technique using a transtibial approach restores the structural properties of the intact meniscus attachment more closely than a one suture technique.

Methods: Lateral root tear refixation was performed in a porcine knee model. Using a material testing machine, structural properties were determined after a cyclic loading protocol comparing transtibial tunnel reconstruction using one or a double suture technique. Intact posterior horn served as control group.

Results: Elongation after cyclic testing was significantly lower for intact and two suture technique when compared to single suture technique. Stiffness was significantly higher for intact constructs with a mean of 53.7 (±6.5) N/m and two suture technique with 44.8 (±9.9) N/m when compared to one suture technique with a mean of 37.1 (±5.4) N/m. In elongation and stiffness, no differences were found between intact and two suture technique. Ultimate failure loads were 325.6 (±77) N for the intact, 273.6 (±45.6) N for two suture technique and 149.8 (±24.3) N for the one suture technique. Both reconstruction techniques showed significantly lower ultimate failure load when compared to the intact control.

Conclusion: Structural properties of root tear fixation using a transtibial single suture technique showed significantly higher elongation and lower stiffness and failure load after cyclic loading compared to the intact, whereas a two suture technique showed no difference in elongation and stiffness; however, lower failure load.