Current concepts on meniscal repairs

Suture Tying Force for Cut-Out during Radial Meniscus Tear Repair: A Biomechanical Evaluation of Failure Loads during the Knot-Tying Process

OBJECTIVE

The purpose of the study was to determine average tensile forces resulting in suture failure while tying a knot during repair of complete radial meniscus tears and to compare the failure tensile force based on meniscus tissue location: the peripheral (red-red) versus inner (white-white).

DESIGN

This study was designed as a cadaveric biomechanical study using 24 menisci harvested from fresh frozen cadaveric knees with midbody radial tears. Tears were repaired using 2-0 nonabsorbable suture in both the inner meniscus and the peripheral meniscus. A force gauge was used to measure the tension of a surgeon's knot until failure of either the suture or the meniscus tissue. Statistical analysis was performed comparing suture failure tensile forces between inner and peripheral sutures using 2-sample t test.

RESULTS

Suture repairs primarily failed due to meniscal tissue cut-out after suture tensioning (96%). There was no statistical difference in failure mode between medial and lateral meniscus for both the inner (100% cut-out) and the peripheral (92% cut-out; P = 0.703) sutures. The peripheral sutures failed as significantly higher loads (54 ± 26 N) than the inner sutures (36 ± 11 N, P = 0.006). The peripheral meniscus tissue tolerated significantly higher tension at failure (36 ± 7 N) than the inner meniscus (26 ± 7 N, P < 0.001).

CONCLUSION

When tying parallel sutures to repair a radial meniscus tear, suture tensile forces above 30 N may tear through meniscus tissue. Surgeons should not use suture tying forces above 30 N when repairing radial meniscus tears with parallel sutures. The peripheral meniscus can withstand higher knot-tying forces than the inner meniscus, so surgeons should consider tying the peripheral suture before the inner suture.

Surgical Management of Traumatic Meniscus Injuries

The menisci increase the contact area of load bearing in the knee and thus disperse the mechanical stress via their circumferential tensile fibers. Traumatic meniscus injuries cause mechanical symptoms in the knee, and are more prevalent amongst younger, more active patients, compared to degenerative tears amongst the elderly population. Traumatic meniscus tears typically result from the load-and-shear mechanism in the knee joint. The treatment depends on the size, location, and pattern of the tear. For non-repairable tears, partial or total meniscal resection decreases its tensile stress and increases joint contact stress, thus potentiating the risk of arthritis. A longitudinal vertical tear pattern at the peripheral third red-red zone leads to higher healing potential after repair. The postoperative rehabilitation protocols after repair range from immediate weight-bearing with no range of motion restrictions to non-weight bearing and delayed mobilization for weeks. Pediatric and adolescent patients may require special considerations due to their activity levels, or distinct pathologies such as a discoid meniscus. Further biomechanical and biologic evidence is needed to guide surgical management, postoperative rehabilitation protocols, and future technology applications for traumatic meniscus injuries.

The meniscotibial ligament role in meniscal extrusion: a systematic review and meta-analysis

INTRODUCTION

The meniscotibial ligament (MTL) limits extrusion of the medial meniscus (MM). While meniscal extrusion may be detrimental to knee joint biomechanics, the role of the MTL in meniscal extrusion is debatable. We sought to perform a systematic review and meta-analysis to evaluate the role of the MTL and surgical techniques for MTL repair.

MATERIALS AND METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines we searched PubMed, Cochrane Library, and Embase for: (("Meniscotibial") OR ("Coronary") OR ("Ramp")) AND ("Extrusion"). After screening and applying eligibility criteria, data were extracted for MTL pathology types ("traumatic" ruptures or "induced" injuries) and meniscal extrusion. A meta-analysis evaluated the mean difference of extrusion between "intact" MTLs (native or repaired) and "injured" MTLs (induced or traumatic). We further performed a subgroup analysis between traumatic and induced MTL lesions.

RESULTS

This systematic review included six studies, which all evaluated MM extrusion. There were 74 knees with induced MTL injuries and 19 knees with traumatic MTL ruptures. Study designs were heterogenic and utilized three types of MTL repair procedures. The meta-analysis included 18 human knees and revealed that sectioning the MTL created a 2.92 mm [- 0.18 to 6.03] MM extrusion, while MTL repair decreased MM extrusion by - 2.11 mm [- 3.03 to - 1.21].

CONCLUSIONS

MTL injury may result in approximately 3 mm of MM extrusion, while repair of the MTL can decrease extrusion by 2 mm. Several novel surgical techniques exist to repair the MTL. However, studies reporting clinical outcomes of these various procedures are scarce.

A Comparative Study on Outcomes of Partial Meniscectomy for Horizontal Cleavage Tear of Medial Meniscus: Complete versus Partial Resection of Inferior Leaf

The extent to which resection of unstable leaf should be performed in horizontal cleavage meniscus tear has not yet been elucidated. The purpose of this study was to compare the clinical outcomes of partial meniscectomy for horizontal cleavage tear of medial meniscus between complete resection of inferior leaf including the periphery up to the joint capsule and partial resection leaving stable peripheral torn meniscal tissue. A total of 126 patients who underwent partial meniscectomy for horizontal cleavage tear of medial meniscus were divided into two groups: group C (n = 34), treated with the complete resection of the inferior leaf; and group P (n = 92), treated with partial resection of the inferior leaf. The minimum follow-up duration was 3 years. Functional outcomes were evaluated using the Lysholm knee scoring scale, International Knee Documentation Committee (IKDC) subjective knee evaluation form, and knee injury and osteoarthritis outcome score (KOOS). Radiologic assessments were performed using the IKDC radiographic assessment scale and measurement of the height of the joint space in the medial compartment of the tibiofemoral joint. The functional outcomes including the Lysholm knee, IKDC subjective score, activities of daily living and sport and recreation subscale of KOOS were worse in group C than in group P (p < 0.001). The radiologic outcomes including postoperative IKDC radiographic scale (p = 0.003) and the postoperative joint space on the affected side (p < 0.001) were also worse in group C than in group P. In the horizontal cleavage tear of medial meniscus, complete resection of the inferior leaf including the periphery up to the joint capsule showed inferior clinical outcomes compared with partial resection leaving stable peripheral rim of torn meniscus at minimum 3-year follow-up. If the peripheral part of the inferior leaf is stable in horizontal cleavage tear of medial meniscus, partial resection of the inferior leaf preserving peripheral rim can be recommended.