Summary

All-suture anchor was another technique for posterior medial meniscal root repair that could be restored contact area, contact pressure and peak pressure comparable with intact condition better than transtibial pullout suture and reduced gap distance in all knee flexion angle.

Abstract

Background

The posterior medial meniscal root tear (PMMRT) has a serious consequence on tibiofemoral joint biomechanics. Two available techniques for PMMRT repair include transtibial pull-out (TP) repair and all-suture anchor (ASA) repair technique. These techniques have not been compared biomechanically. The purpose of this study was to compare the tibiofemoral contact mechanics between TP technique and ASA techniques for PMMRT repair in an in vitro porcine model.

Methods

A total of twenty fresh porcine cadaveric knee specimens were used. All twenty knees were randomly and evenly distributed to one of four groups: (1) intact posterior meniscal root, (2) PMMRT, (3) TP repair technique of PMMRT, and (4) ASA repair techniques for PMMRT, (five specimens per group). The tibiofemoral contact mechanics were investigated in each knee specimen utilizing a pressure sensor. All knee specimens were tested by being loaded with 600 N axial compressive force at three different flexion angles (0o,45o, and 90o). The contact surface area, contact pressure, peak pressure, and time-zero displacement were recorded.

Results

The PMMRT caused a significant decrease in contact surface area, an increase in contact pressure and peak pressure from the reference values observed in the intact meniscus group (P = 0.003, 0.002, <0.001 respectively). After fixation, there was no significant difference observed between the ASA and intact group. Meanwhile, significant differences were found between the TP and intact group in terms of contact surface area, contact pressure, and peak pressure. In the comparison between the two techniques, the ASA group demonstrated higher contact surface area than the TP group at averaged knee flexion angle (p = 0.007).

Conclusion

For most testing conditions, the ASA technique demonstrated superior biomechanical property in terms of contact surface area compared with the TP technique under compressive loading conditions. ASA technique could also restore the tibiofemoral contact mechanics compared with the native intact knee. Meanwhile, the significant difference in tibiofemoral mechanics compared with the intact knee could be observed in the TP technique.
LEVEL OF EVIDENCE:
Level III, Controlled laboratory Study
KEYWORDS:
meniscus root; root tear; meniscus tear; meniscus root repair; transtibial pull-out repair, all-suture anchor repair