Pediatric Meniscotibial Ligament Complex Anatomy and Biomechanics.

BACKGROUND

Meniscal repair is increasingly performed in pediatric patients, with capsular-based techniques remaining the gold standard despite limitations such as high failure rates and risk of meniscal extrusion. Recent studies highlight the potential role of accessory knee ligaments in improving meniscal stability and repair outcomes. The meniscotibial ligament complex (MTLC) has emerged as a potential area of interest to produce more normal anatomic and biomechanical meniscal function in meniscal repair.

PURPOSE: To evaluate the native anatomy and biomechanical strength of the MTLC of the medial and lateral meniscus of pediatric knees.

STUDY

DESIGN

Descriptive laboratory study.

METHODS

Fourteen fresh-frozen pediatric human knees (mean age, 7.5 years; range, 5-10 years; 6 male, 8 female) were used in this study. The depth of the recess between the MTLC and the meniscocapsular complex was measured. Subsequently, the medial and lateral menisci were divided into approximate thirds, creating anterior, central, and posterior testing zones for each meniscus. Each meniscus/MTLC complex underwent monotonic load-to-failure testing on an Instron 5944 test frame with a 2-kN load cell with load applied superiorly. Biomechanical properties were analyzed using linear mixed models with donor as a random factor and aspect (medial/lateral) and position (anterior/central/posterior) as fixed factors.

RESULTS

The posterior recess depth was significantly larger (mean, 5.4 mm; 95% CI, 4.6-6.3 mm) than anterior (mean, 3.4 mm; 95% CI, 2.6-4.2 mm) (P = .049). Maximal load to failure in the posterior MTLC (mean, 93.5 N; 95% CI, 80.0-107.0 N) was significantly higher than anterior (mean, 69.2 N; 95% CI, 56.7-81.7 N) (P = .01).

CONCLUSION

This study defines a clear space in which the MTLC is distinct from the joint capsule, which is deepest in the posterior third of the medial and lateral meniscus. Our results demonstrate that the posterior region of the MTLC can withstand higher loads than the anterior region in pediatric knees.

CLINICAL RELEVANCE: These findings offer foundational insights into the native anatomy and biomechanics of the MTLC, guiding future studies involving the MTLC in meniscal repair. This knowledge may be particularly relevant to ramp lesions, other posterior meniscal tear patterns, and meniscal transplants.