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The following is a summary of “Anterior cruciate ligament tissue stiffness and anterior tibial translation are increased in patients with medial meniscus posterior root tear,” published in the March 2025 issue of the Journal of Orthopaedic Surgery and Research by Karatekin et al.

Medial meniscus posterior root tears (MMPRT) are known to disrupt knee biomechanics, yet their impact on anterior cruciate ligament (ACL) structure and function remains incompletely understood. This study aims to evaluate the relationship between MMPRT and ACL integrity by assessing ACL stiffness, structural characteristics, and tibial anterior translation in affected patients. A total of 56 patients with unilateral MMPRT, confirmed via magnetic resonance imaging (MRI), and 31 healthy controls were enrolled between January and June 2024. The tibial anterior translation was quantified using the KT-1000 arthrometer, while ACL stiffness and elasticity were measured through shear wave elastography (SWE) ultrasound imaging. The tibial slope was determined at 30 degrees of knee flexion using lateral radiographs with overlapping femoral condyles. 

Among the 87 participants, the study group (48 females, 8 males) exhibited significantly higher ACL SWE values (26.6 ± 8.9 kPa) compared to controls (21.2 ± 5.7 kPa, p = 0.004), indicating increased ligament stiffness in patients with MMPRT. The tibial anterior translation was also significantly greater in MMPRT-affected knees (6.19 ± 1.4 mm) compared to the contralateral, unaffected knees (4.9 ± 0.78 mm, p < 0.05). Furthermore, multivariable regression analysis identified a positive association between ACL SWE values and tibial slope (β = 1.11; CI, 0.24–1.99; p = 0.01), suggesting that alterations in tibial slope may contribute to increased ACL stiffness. 

These findings highlight a structural and functional interplay between MMPRT and ACL properties, with implications for knee joint stability. The observed increase in ACL stiffness and anterior tibial translation in patients with MMPRT suggests that MMPRT may predispose individuals to further biomechanical alterations, potentially influencing long-term joint function. Understanding these relationships could aid in refining treatment strategies for MMPRT and mitigating its effects on ACL integrity.

Source: josr-online.biomedcentral.com/articles/10.1186/s13018-025-05601-w