The rebar repair for radial meniscus tears: a biomechanical comparison of a reinforced suture repair versus parallel and cross-stitch techniques

BACKGROUND: Radial meniscus tears can cause the meniscus to be completely incompetent. This serious type of meniscus tear can be difficult to repair. Techniques have been developed that juxtapose the meniscus tear edges and are able to withstand high loads. The purpose of this study was to determine the load to failure of a reinforced suture bar repair (Rebar Repair) for radial meniscus tear and compare it to the parallel suture technique and cross-stitch technique and to compare mode of failure among all three groups. The hypothesis was that the Rebar Repair will have a higher load to failure than both the parallel technique and the cross-stitch technique and that the Rebar Repair would have a lower rate of suture cutting through the meniscus. METHODS: Forty-eight menisci were tested from 24 human knee specimens, with 16 menisci in each group evenly distributed between medial and lateral menisci. Radial mid body meniscal tears were recreated and repaired with one of three inside-out techniques: the 2-parallel suture technique, 2 cross-stitch sutures, and the Rebar Repair. The specimens were cycled between 5 N to 30 N and axially loaded to failure perpendicularly across the repair site. RESULTS: The average load to failure of the parallel group, cross-stitch group and Rebar Repair was 85.5 N ± 22.0, 76.2 N ± 28.8 and 124.1 N ± 27.1 respectively. The Rebar Repair had a higher load to failure than the parallel group (p < 0.01) and cross-stitch group (p < 0.01). There was no difference in the load to failure between the cross-stitch and parallel group (p = 0.49). The failure mechanism was different when comparing the 3 groups (p < 0.01). The predominant mode of failure for both the parallel and cross-stitch group was suture cutout through the meniscus (88% and 94% respectively). The Rebar Repair failed due to suture rupture in 50% and suture cutout through the meniscus in 50%. CONCLUSION: The Rebar Repair for radial meniscus tear has a higher load to failure and a lower rate of suture cutout through the meniscus than the parallel technique and cross-stitch technique. CLINICAL RELEVANCE: Radial meniscus tears lead to decreased hoop stresses of the meniscus and effectively a non-functional meniscus. Newer techniques may have a higher load to failure leading to more successful repairs.