AJSM - 2026-03-08 - Journal Article
Biomechanical Roles of the Popliteomeniscal Fascicles and Meniscofibular and Meniscotibial Ligaments in Stabilizing the Lateral Meniscus Posterior Horn: A Cadaveric Study.
Horita K, Kamiya T, Hamaoka K, Shiwaku K, Mori Y, Ikeda Y, Okada Y, Suzuki D, Emori M, Fujie H, Teramoto A
Topics
Key Takeaway
Sequential transection of popliteomeniscal fascicles, meniscofibular ligament, and posterior meniscotibial ligament progressively increased lateral meniscus posterior horn anterior displacement from 6.3 mm (intact) to 11.4 mm, with internal rotation laxity rising from 32.6° to 40.2°.
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Summary
This cadaveric robotic testing study quantified the individual and cumulative biomechanical contributions of the anterior and posterior popliteomeniscal fascicles (aPMF, pPMF), meniscofibular ligament (MFibL), lateral meniscotibial ligament (LMTL), and posterior meniscotibial ligament (PMTL) to lateral meniscus posterior horn (LMPH) stability using a 6-DOF robotic system with sequential transection under two cutting-order protocols. Either PMF alone increased LMPH anterior displacement from 6.3 mm to 8.1–8.4 mm and shifted tibial rotation toward external rotation during passive flexion; additional MFibL and PMTL transection further increased displacement to 10.2 mm and 11.4 mm, respectively, with internal rotation laxity reaching 40.2° versus 32.6° intact. Cutting order of aPMF versus pPMF did not affect the magnitude of instability, and external rotation laxity was not significantly altered at any transection state.
Key Limitation
The small cadaveric sample (n=10) with no age or sex stratification limits generalizability and statistical power, and the model cannot replicate in vivo dynamic loading or the effect of concomitant ACL/PCL deficiency on LMPH kinematics.
Original Abstract
BACKGROUND
The posterolateral corner (PLC) structures restraining the mobility of the lateral meniscus posterior horn (LMPH) have been described in greater anatomic detail in recent years. However, biomechanical evidence regarding their functional role remains limited.
HYPOTHESIS/PURPOSE
The purpose was to investigate the biomechanical roles of the popliteomeniscal fascicles (PMFs), meniscofibular ligament (MFibL), lateral meniscotibial ligament (LMTL), and posterior meniscotibial ligament (PMTL) in stabilizing the LMPH. It was hypothesized that transecting the PMFs would increase mobility regardless of cutting order, that additional PLC transection would further increase instability, and that these injuries would alter knee kinematics.
STUDY DESIGN
Controlled laboratory study.
METHODS
Ten fresh-frozen cadaveric knees were mounted on a 6 degrees of freedom robotic testing system. Sequential transections of the anterior PMF (aPMF), posterior PMF (pPMF), MFibL, LMTL, and PMTL were performed under 2 dissection protocols to compare the effect of cutting order between the aPMF and pPMF. LMPH anterior displacement under 10-N traction, tibial rotation during passive flexion-extension, and rotational laxity under ±5 N·m torque were measured. Differences among transection states were analyzed using linear mixed models with Bonferroni correction, with significance set at P < .05.
RESULTS
LMPH anterior displacement significantly increased from 6.3 mm in the intact state to 8.1 to 8.4 mm after transection of either the aPMF or pPMF ( P = .007) and further increased to 10.2 mm after MFibL ( P < .001) and 11.4 mm after PMTL ( P < .001) transection. Passive flexion significantly shifted tibial rotation toward external rotation after aPMF or pPMF transections ( P = .043). Internal rotation laxity increased from 32.6° in the intact state to 36.4° after combined PMF cuts ( P = .001), 37.3° after MFibL transection ( P < .001), and 40.2° after PMTL transection ( P < .001), whereas the external rotation laxity did not significantly change.
CONCLUSION
Anterior movement of the LMPH occurred after transection of either the aPMF or pPMF, regardless of cutting order in the cadaveric model. Concomitant injury to other posterolateral structures, particularly the MFibL and PMTL, further increased this instability.
CLINICAL RELEVANCE
PLC structures restraining the LMPH may be important for detecting abnormal meniscal motion. Assessing not only the PMFs but also the MFibL and PMTL may improve diagnostic accuracy and treatment planning.