The relationship between lateral meniscus shape and joint contact parameters in the knee: a study using data from the Osteoarthritis Initiative

Introduction

The meniscus has an important role in force transmission across the knee, but adetailed three-dimensional (3D) morphometric shape analysis of the lateralmeniscus to elucidate subject-specific function has not been conducted. The aim ofthis study was to perform 3D morphometric analyses of the lateral meniscus inorder to correlate shape variables with anthropometric parameters, thereby gaininga better understanding of the relationship between lateral meniscus shape and itsload-bearing function.

Methods

The lateral meniscus (LM) was manually segmented from magnetic resonance imagesrandomly selected from the Osteoarthritis Initiative (OAI) non-exposed controlsubcohort. A 3D statistical shape model (SSM) was constructed to extract theprincipal morphological variations (PMV) of the lateral meniscus for 50 subjects(25 male and 25 female). Correlations between the principal morphologicalvariations and anthropometric parameters were tested. Anthropometric parametersthat were selected included height, weight, body mass index (BMI), femoral condylewidth and axial rotation.

Results

The first principal morphological variation (PMV) was found to correlate withheight (r = 0.569), weight (r = 0.647), BMI(r = 0.376), and femoral condyle width (r = 0.622). Thethird PMV was found to correlate with height (r = 0.406), weight(r = 0.312), and femoral condyle width (r = 0.331). Thepercentage of the tibial plateau covered by the lateral meniscus decreases asanthropometric parameters relating to size of the subject increase. Furthermore,when the size of the subject increases, the posterior and anterior horns becomeproportionally longer and wider.

Conclusion

The correlations discovered suggest that variations in meniscal shape can be atleast partially explained by the levels of loads transmitted across the knee on aregular basis. Additionally, as the size of the subject increases and body weightrises, the coverage percentage of the meniscus is reduced, suggesting that therewould be an increase in the load-bearing by the cartilage. However, this reducedcoverage percentage is compensated by the proportionally wider and longer meniscalhorn.