Tibiofemoral Contact Mechanics After Horizontal or Ripstop Suture in Inside-Out and Transtibial Repair for Meniscus Radial Tears in a Porcine Model.

Purpose: To compare tibiofemoral contact mechanics after horizontal or ripstop (horizontal plus vertical) sutures in inside-out and transtibial repair for meniscal radial tears with 10 porcine knees in each group.

Methods: Ten matched pairs of porcine knees were tested under a 1500-N axial compressive load at 0°, 30°, 60°, and 90° of knee flexion. Each knee underwent 4 testing conditions consecutively: (1) intact, (2) medial meniscal radial tear, (3) horizontal suture repair configuration, and (4) ripstop suture repair configuration. Tekscan sensors measured tibiofemoral contact pressure and contact area in the medial and lateral compartments.

Results: All repair groups improved their contact mechanics when compared with the tear state among all flexion angles analyzed (all P < .05). Furthermore, ripstop sutures with both inside-out and transtibial repairs restored intact knee contact area and pressures (peak and mean) in the medial compartment at all flexion angles, whereas the horizontal sutures alone failed to do so for contact pressures at 60° and 90° and for contact surface areas at all flexion angles. However, the aforementioned parameters were not significantly different between inside-out sutures and transtibial sutures, regardless of horizontal or ripstop configuration (P > .05).

Conclusions: Radial tears of the meniscus in a porcine model significantly decreased medial contact area and increased mean and peak contact pressure. Both inside-out and transtibial ripstop repairs for radial tears aid in restoring intact tibiofemoral contact mechanics at all assessed knee flexion angles.

Clinical Relevance: Our results suggest that both inside-out and transtibial ripstop repairs for radial tears can restore tibiofemoral contact mechanics to the intact state. Since the study were performed in an open fashion porcine model, the results should be carefully used in clinical practices, and the efficacy of the techniques through arthroscopic method should be further explored.