Increased Intra-Articular Internal Tibial Rotation Is Associated With Unstable Medial Meniscus Ramp Lesions in ACL-Injured Athletes: An MRI Matched-Pair Comparative Study

Failure rate of isolated medial meniscus repair in the stable knee: Systematic review and meta-analysis

PURPOSE

The present meta-analysis aims to determine the outcomes and failure rates for medial meniscus repairs in patients with stable knees.

METHODS

A literature search was conducted using PubMed and Scopus with the terms '(medial meniscus OR medial meniscal) AND (repair)'. The search strategy was based on the PRISMA (Preferred Reporting Items for Systematic Meta-Analyses) protocol and included 93 articles assessed for eligibility. The search criteria were limited to studies reporting outcomes and failure rates. The exclusion criteria included languages other than English, biomechanical studies, letters to editors, non-full text, review articles, meta-analyses and case reports.

RESULTS

In total, 10 studies with 595 patients were included. Degenerative tears or studies reporting meniscus repair outcomes on root repairs, revision or primary anterior cruciate ligament reconstruction, discoid menisci or ramp lesions were excluded. All studies included revision surgery and/or clinical symptoms as failure definitions. The overall medial meniscal repair failure rate was 26% with a 95% confidence interval (CI) [15%-37%]. The mean time to failure from isolated medial meniscus repair surgery was 27.7 months with 95% CI [18.5-36.9 months]. The postoperative Lysholm and IKDC scores were reported in three articles. At the final follow-up, the mean postoperative Lysholm and IKDC scores were 92.3 with 95% CI [84.5-100] and 88.6 with 95% CI [83.5-93.8], respectively.

CONCLUSION

The current meta-analysis revealed an overall failure rate of 26% in the case of medial meniscus repair in a stable knee. For these reasons, the patient should be aware of the substantial risk of revision surgery (one out of four cases). Medial meniscus repair in a stable knee yielded good clinical results.

LEVEL OF EVIDENCE

Level II.

Editorial Commentary: Medial Meniscal Ramp Lesions in the Setting of Anterior Cruciate Ligament Tears Contribute to High-Grade Anterior and Rotatory Laxity That Are Normalized by Repair

Meniscal ramp lesions are reported to occur in 9% to 42% of anterior cruciate ligament tears. Biomechanical research shows that the presence of a meniscal ramp lesion, in the setting of an anterior cruciate ligament tear, leads to increased knee anteroposterior and rotatory laxity when compared with an uninjured medial meniscus. This finding also has been verified clinically. Repair of ramp lesions has been shown to improve biomechanics. Accordingly, the influence of meniscal ramp lesions on knee laxity necessitates a comprehensive physical examination, imaging review, and diagnostic arthroscopy to support identification and treatment of these injuries. Arthroscopic probing is required to assess ramp lesion stability. It is generally accepted that up to 30% of ramp lesions are unstable and warrant repair, as determined by tear ≤1 cm, displacement into the medial compartment with probing, and extension beyond the lower pole of the femoral condyle.

Anterior Cruciate Ligament-Injured Knees With Meniscal Ramp Lesions Manifest Greater Anteroposterior and Rotatory Instability Compared With Isolated Anterior Cruciate Ligament-Injured Knees

PURPOSE

To investigate the effects of ramp lesion (RL) and its repair on knee instability in patients with anterior cruciate ligament (ACL) injury by quantitatively assessing anteroposterior and rotational knee instability before and after ACL reconstruction.

METHODS

All primary double-bundle ACL reconstructions using hamstring autografts between 2016 and 2021 were evaluated retrospectively. Patients with RLs without other meniscal injuries were included in group R, whereas those with isolated ACL injuries constituted group C. RL was repaired using all-inside devices in all patients in group R. Knee instability, including the amount of anterior tibial translation (ATT), and the acceleration and external rotational angular velocity of the knee joint (ERAV) during the pivot-shift test were assessed at the time of surgery. The pivot-shift test grade was recorded.

RESULTS

A total of 73 patients were included in this study. Preoperatively, group R (n = 23) had significantly greater pivot-shift grades (P = .039), ATT (6.0 mm, group R; 4.5 mm, group C, P < .001), acceleration (6.8, 2.8; P = .037), and ERAV (3.9, 2.8; P = .001) than group C (n = 50). Intraoperatively, ATT (-1.0 mm, -1.0 mm; P < .001), acceleration (1.2, 1.1; P < .001), and ERAV (1.4, 1.2; P < .001) were significantly decreased compared with the preoperative values in both groups. No significant differences in these values were observed between groups R and C.

CONCLUSIONS

ACL-injured knees accompanied by RLs exhibited significantly greater anteroposterior and rotatory instability than knees with isolated ACL injuries; increased knee instability can be effectively addressed by performing RL repair in conjunction with ACL reconstruction. The quantitative assessments employed-specifically measuring ATT, acceleration, and ERAV during the pivot-shift test-have allowed us to delineate these aspects of knee instability with greater precision.

LEVEL OF EVIDENCE

Level Ⅲ, retrospective comparative study.

Anterolateral corner of knee: Current concepts

The anatomy of the antero-lateral corner (ALC) has been the topic of recent interest, as evidenced by the increasing number of publications. Knowledge needs to be improved amongst clinicians regarding the anatomy and biomechanical function of this vital structure and its implications on the rotational stability of the knee. There has yet to be a consensus on the role of surgical procedures and their indications for addressing the instability associated with the injury to these structures. Through this article, the authors have tried to outline the existing literature regarding Anterolateral knee instability, the associated structures, and the management of its injuries, emphasising the role of the anterolateral capsule and reconstructive procedures in combined ligamentous knee injuries.

Meniscotibial Ligament Repair of a Ramp Lesion of the Posterior Horn of the Medial Meniscus

The ramp area, which is the junction between the posterior horn of the medial meniscus and the synovium, prevents anterior knee translation, transmits and distributes load, and assumes some rotational stability. Ramp lesions occur in approximately 9% to 15% of patients with anterior cruciate ligament tears. We describe an all-inside repair technique with suture for a meniscotibial ligament tear-type ramp lesion of the posterior horn of the medial meniscus.

Biomechanical impact of meniscal ramp lesions on knee joint contact characteristics in ACL deficient knees: a cadaveric analysis

PURPOSE

To evaluate the changes in contact characteristics of the tibiofemoral joint resulting from a meniscal ramp lesion in the medial meniscus.

METHODS

Twelve cadaveric knees (six matched pairs) were subjected to a 600 N axial load using a custom testing jig, which allowed for knee positioning at 0°, 45°, and 90° of flexion without other constraints. The knees were randomly assigned to either a ramp lesion group (n = 6) or a posterior root lesion group (n = 6). Four testing conditions were examined: (1) intact, (2) isolated ramp lesion, (3) isolated posterior root tear of the medial meniscus, and (4) combined ramp lesion and posterior root tear of the medial meniscus. Contact characteristics were evaluated using a flexible pressure sensor, the I-Scan System.

RESULTS

Peak contact pressure in isolated ramp lesions (4.15 ± 0.98 MPa, P = 0.206) showed non-significant increases compared to the intact condition (3.86 ± 1.32 MPa). Peak contact pressure in isolated posterior root tears (4.58 ± 1.70 MPa, P = 0.040) and, combined ramp and posterior root lesions (4.67 ± 1.47 MPa, P = 0.003) were significantly higher than that in the intact condition. The knee flexion position significantly affected the medial tibiofemoral joint's contact area, contact pressure, and peak contact pressure (P < 0.001 for all).

CONCLUSION

Isolated ramp lesions did not significantly impact force transmission, contact area, or contact pressure. In contrast, isolated root lesions and combined ramp and posterior root tears of the medial meniscus significantly intensified the changes in contact characteristics in the medial tibiofemoral joint compared to the intact condition.

LEVEL OF EVIDENCE

Level III.