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

Abstract

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.

Radial Meniscal Tears Are Best Repaired by a Modified “Cross” Tie-Grip Suture Based on a Biomechanical Comparison of 4 Repair Techniques in a Porcine Model

“…The maximum loads for the tie-grip and cross tie-grip sutures in this study were congruent with the result for rebar repair recently published by Massey et al 17 in which the maximum load was 124.1 ± 27.1 N. In short, rebar repair is an inside-out technique with 2 horizontal sutures placed next to 2 vertical sutures that act as rip stops, which resemble the tie-grip suture. 17 Massey et al 17 also tested the double horizontal and cross sutures with maximum loads, resulting in 85.5 ± 22.0 N and 76.2 ± 28.8 N, respectively, which were also similar to findings in the current study. Buckley et al 8 performed biomechanical testing comparing the tie-grip suture to a 2-tunnel transtibial technique (horizontal mattress suture augmented with a 2-tunnel transtibial technique) and a combined hybrid tunnel technique (transtibial technique with vertical mattress sutures).…”

“…The strength of this study is that not only did it introduce a new cross tie-grip suture and compare it with the original method, but it also tested the commonly used cross and double horizontal sutures, making it possible for surgeons to make a direct comparison among the suture methods. Although there are previous studies 8 , 17 , 18 reporting biomechanical testing data for the tie-grip suture, cross suture, and double horizonal suture, direct comparisons could not be made because laboratory conditions differ depending on the report. Comparisons were made with the hope of being a source of evidence to provide biomechanical information for surgeons when repairing radial meniscal tears.…”

“… 14 Finally, load-to-failure testing was conducted at 5 mm/min, consistent with previous reports. 4 , 9 , 17 , 18 The failure mode (tissue failure, suture failure, or knot failure) was recorded. The gap distance was defined as the width of the gap at a given cycle, whereas displacement was the difference in the gap distance at a given cycle compared to the gap at cycle 0: gap distance at a given cycle (mm) – gap distance at cycle 0 (mm).…”

Rebar Repair of Radial Meniscus Tears: A Reinforced Suture Technique

“…Reproduced from Massey et al, Journal of Experimental Orthopaedics ( https://creativecommons.org/licenses/by/4.0/ ). 11

Fig 2 Right knee lateral meniscus mid-body radial meniscus tear. The arthroscope is viewing from the anterolateral portal with the knee in figure-4 supine position.

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“…Several techniques for meniscal repair have been used, including inside-out, all-inside, cross suture, hashtag, cross-tag, double-horizontal mattress suture, single-loop suture, and modified Mason–Allen stitch. 4 , 6 , 7 , 8 , 9 , 10 , 11 When comparing repairs of the meniscus, it is important to consider the factors of cost, minimizing damage to the meniscus, ease of use, healing capability, and restoration of normal biomechanics. The inside-out technique is considered the standard of care in meniscal repair because it allows for cheaper implant cost and the ability to use multiple sutures while maintaining the structural integrity of the meniscus.…”