The biomechanical changes of load distribution with longitudinal tears of meniscal horns on knee joint: a finite element analysis

Park

Orthopaedic Journal of Sports Medicine

et al. 2021

Background: The incidence of concomitant injuries, including meniscal and cartilage injuries, has not been adequately reported in previous studies on multiligament knee injury (MLKI) because their primary focal points have been the degree of ligament injury, treatment strategy, involvement of other soft tissues, and neurovascular injury. Purpose: To analyze the incidence of associated lesions in MLKIs, including medial and lateral meniscal injuries, cartilage lesions, and complications. Study Design: Systemic review; Level of evidence, 4. Methods: The PubMed, Embase, Cochrane Library, CINAHL, and Scopus databases were searched between inception and April 30, 2020. Studies were included if they reported the incidence rates of medial and/or lateral meniscal tears and cartilage injuries in cases of MLKIs. For the meta-analysis, data were extracted on clinical outcomes measured according to the number of medial and/or lateral meniscal tears, cartilage injuries, and complications. Results: A total of 45 studies were included in the MLKI analysis (3391 patients). The pooled rate of medial meniscal tears was 30.4% (95% CI, 24.1%-37.1%; P < .0001; I 2 = 85.8%). The pooled rate of lateral meniscal tears was 27.5% (95% CI, 20.3%-35.3%; P < .0001; I 2 = 89.6%). The pooled rate of cartilage injuries was 27.5% (95% CI, 22.1%-33.3%; P < .0001; I 2 = 86.8%). The pooled rates of peroneal nerve injuries, vascular injuries, and arthrofibrosis were 19.2% (95% CI, 14.2%-24.7%; P < .001; I 2 = 81.3%), 18.4% (95% CI, 13.2%-24.3%; P < .0001; I 2 = 81.0%), and 11.2% (95% CI, 8.1%-14.7%; P = .0018; I 2 = 54.0%), respectively. Conclusion: The pooled rates of meniscal tears and cartilage injuries concomitant with MLKIs were high, ranging from 27% to 30%, and the pooled rates of peroneal nerve injury, vascular injury, and arthrofibrosis were considerable, ranging from 11% to 19%. The influence of these associated lesions on clinical results should be evaluated in future clinical studies.

Section: Discussionmentioning

confidence: 99%

Incidence of Associated Lesions of Multiligament Knee Injuries: A Systematic Review and Meta-analysis

Park

Orthopaedic Journal of Sports Medicine

et al. 2021

Orthopaedic Journal of Sports Medicine

“…With a root tear, the medial meniscus is susceptible to extrusion. 34 The loss of hoop stress and increased meniscal extrusion after a root tear results in reduced contact area between the meniscus and tibia, and increased peak loads on the tibial plateau cartilage, 56 , 84 which then leads to rapid cartilage degeneration. 17 , 80 In small- and large-animal models, a surgical destabilization of the medial meniscus (DMM)—the equivalent of a root tear—has been effectively used to instigate joint degeneration by a number of research groups.…”

mentioning

confidence: 99%

Six-Month Outcomes of Clinically Relevant Meniscal Injury in a Large-Animal Model

Bansal

Meadows

Miller

et al. 2021

Background: The corrective procedures for meniscal injury are dependent on tear type, severity, and location. Vertical longitudinal tears are common in young and active individuals, but their natural progression and impact on osteoarthritis (OA) development are not known. Root tears are challenging and they often indicate poor outcomes, although the timing and mechanisms of initiation of joint dysfunction are poorly understood, particularly in large-animal and human models. Purpose/Hypothesis: In this study, vertical longitudinal and root tears were made in a large-animal model to determine the progression of joint-wide dysfunction. We hypothesized that OA onset and progression would depend on the extent of injury-based load disruption in the tissue, such that root tears would cause earlier and more severe changes to the joint. Study Design: Controlled laboratory study. Methods: Sham surgeries and procedures to create either vertical longitudinal or root tears were performed in juvenile Yucatan mini pigs through randomized and bilateral arthroscopic procedures. Animals were sacrificed at 1, 3, or 6 months after injury and assessed at the joint and tissue level for evidence of OA. Functional measures of joint load transfer, cartilage indentation mechanics, and meniscal tensile properties were performed, as well as histological evaluation of the cartilage, meniscus, and synovium. Results: Outcomes suggested a progressive and sustained degeneration of the knee joint and meniscus after root tear, as evidenced by histological analysis of the cartilage and meniscus. This occurred in spite of spontaneous reattachment of the root, suggesting that this reattachment did not fully restore the function of the native attachment. In contrast, the vertical longitudinal tear did not cause significant changes to the joint, with only mild differences compared with sham surgery at the 6-month time point. Conclusion: Given that the root tear, which severs circumferential connectivity and load transfer, caused more intense OA compared with the circumferentially stable vertical longitudinal tear, our findings suggest that without timely and mechanically competent fixation, root tears may cause irreversible joint damage. Clinical Relevance: More generally, this new model can serve as a test bed for experimental surgical, scaffold-based, and small molecule–driven interventions after injury to prevent OA progression.

“…Biomechanical studies investigating the effects on in vitro tibiofemoral joint mechanics in cadaveric knees, showed that longitudinal tears did not cause a significant change in contact pressure or area because this type of tear minimally disrupts the circumferential fiber arrangement and does not compromise the hoop stresses. 8,34 However, as those studies report cadaveric in vivo data, the results cannot be readily applied to the clinical setting. A recent finite-element analysis showed that in unstable longitudinal tears, the surfaces of the torn edges are pulled apart.…”

Section: Discussionmentioning

confidence: 99%

“…ACL injuries are accompanied by longitudinal LM tears in 5% to 20% of cases, 7,13,17,28 and biomechanical studies have revealed that longitudinal LM tears do not alter contact pressure significantly. 8,34 Thus, some surgeons favor leaving stable tears in situ. 20,33 However, finite-element analysis has revealed that in unstable longitudinal tears the surface of the tear site pulls apart and is less likely to heal.…”

mentioning

confidence: 99%

Outcomes More Than 2 Years After Meniscal Repair for Longitudinal Tears of the Lateral Meniscus Combined With Anterior Cruciate Ligament Reconstruction

et al. 2021

Background: Meniscal function after repair of longitudinal tears of the lateral meniscus (LM) with anterior cruciate ligament reconstruction (ACLR) has not been comprehensively investigated. Purpose: To evaluate not only the clinical outcomes and radiographic findings of patients who underwent repair of longitudinal tears of the LM combined with ACLR but also the healing status of the repaired meniscus and changes in chondral status with second-look arthroscopy. Study Design: Case series; Level of evidence, 4. Methods: Among 548 patients who underwent primary anatomic ACLR at our institution between 2010 and 2017, 39 who had concomitant longitudinal tears of the LM and underwent repair were studied. During follow-up for more than 2 years, all patients were evaluated clinically (pain, range of motion, swelling, and knee instability) and with imaging (plain radiograph and magnetic resonance imaging [MRI]), and compared with a matched control group (based on age, sex, body mass index, and follow-up period) without any concomitant injuries who underwent ACLR. Measurements on MRI were recorded preoperatively, immediately after surgery, and at final follow-up, and the change in the values over time was assessed. Of the 39 patients in each group, 24 were assessed by second-look arthroscopy with hardware removal 2 years postoperatively. Results: The mean follow-up times of the study and control group were at a mean of 42.4 and 45.4 months, respectively. There were no significant differences in clinical findings, lateral joint space narrowing on radiographs, and chondral status at the lateral compartment between groups, whereas lateral and posterior meniscal extrusion on MRI progressed significantly in the study group (0.43 ± 1.0 mm vs -0.29 ± 1.1 mm, P = .003; 1.9 ± 1.9 mm vs 0.14 ± 1.1 mm, P < .0001, respectively). Second-look arthroscopy revealed complete healing in 12 patients (50%), partial healing in 9 (37.5%), and failure in 3 (12.5%) in the study group, and no new tear in the control group. Conclusion: The clinical and imaging outcomes after repair of longitudinal tears of the LM combined with anatomic ACLR were successful and comparable with those after isolated ACLR without any other injuries at 42 months postoperatively, although meniscal extrusion showed progression on coronal/sagittal MRI. Based on the MRI findings and the result that only half of patients achieved complete healing, meniscal function could not be fully restored even after repair. Although degenerative changes were not apparent, longer-term follow-up is needed.