Mapping Articular Cartilage Biomechanical Properties of Normal and Osteoarthritic Mice Using Indentation

J.-F. Lavoie; S. Sim; E. Quenneville; M. Garon; A. Moreau; M.D. Bushmann; C.-É. Aubin
Osteoarthritis and Cartilage 23 Suppl. 2, p. A254 (2015)

https://doi.org/10.1016/j.joca.2015.02.463

8 citations · 3 en 2025–2026

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Purpose: Due to their size (~1mm), mouse models pose significant challenges to map biomechanical properties over their articular surfaces. The purpose of this study was to determine if an automated indentation technique could be used to map the biomechanical properties of the articular surfaces in murine knees and to identify early alterations of the articular cartilage of a mouse strain (STR/ort) that spontaneously develops osteoarthritis (OA) on the medial side of their knees.

Methods: The biomechanical measurements were performed ex vivo, on the left femoral condyles and tibial plateaus of five healthy Balb/c males (age of 12-15 weeks) and five age- and sex-matched STR/ort mice, using a 3-axis mechanical tester (Mach-1 v500css, Biomomentum, Laval) equipped with a multiple-axis load cell. Indentation measurements (30-42/surfaces) were performed using a 0.35 mm diameter spherical indenter (30 mm indentation in 1 second with 20 seconds relaxation). Following biomechanical testing, the articular surfaces were fixed in 4% paraformaldehyde for histological assessment. Data reported is the structural stiffness at an indentation depth of 10mm. To compare the structural stiffness between healthy and OA-developing animals each articular surface were divided into 4 regions, exterior medial (I), inner medial (II), inner lateral (III) and exterior lateral (IV). Data is reported as the mean ± SE (n¼ 5) for each of these regions. Statistical analysis was performed by ANOVA.

Results: In healthy animals, mapping of the structural stiffness at an indentation depth of 10 um showed a spatial distribution similar to that of larger animals (Figure 1A,B, inserts). The structural stiffness of the lateral and inner half of the medial condyles (Figure 1A) was similar in OA and healthy mice. The stiffness of the exterior lateral plateau was also not significantly different OA and healthy mice. In contrast, the stiffness of the exterior half of the medial condyle in OA mice (5.9±0.7 N/mm) was significantly lower than that of the healthy mice (10.2±1.1 N/mm, ANOVA, p<0.05). The structural stiffness of the exterior medial condyle and the inner half of the lateral plateaus in OA mice was inferior to that of healthy mice (ANOVA, p<0.05).

Conclusions: This study shows that this automated indentation technique can map the biomechanical properties of murine knee joints. The mapping of mechanical properties shows similar distribution patterns to those previously observed for larger species (human, sheep and rat). The identification of cartilage regions with lower structural stiffness, at sites known to develop OA in the STR/ort strain, suggests this method can be used to identify and characterize OA affected articular surfaces. Studies are ongoing to validate, by histology, the cartilage quality of the affected areas. These results show that indentation mapping could be used in mouse models to test the efficacy of drugs aiming to inhibit cartilage degradation or improving its healing in OA or following a joint injury.