Paper 08: In Vitro Effects of Triamcinolone and Methylprednisolone on the Viability and Mechanics of Native Articular Cartilage

Objectives: The chondrotoxic effects of methylprednisolone acetate (MP) and triamcinolone acetonide (TA) have been well described. Prior studies demonstrated a dose-dependent effect intra articular (IA) steroids starting at 7 mg for MP 18 TA. However, the these on mechanical properties cartilage are largely unknown. purpose this study was to investigate in vitro single one-hour or TA exposure viability, mechanics, biochemical content native explants. Methods: Articular explants (n=6 per group) were harvested from femoral condyle bovine stifle. Explants exposed chondrogenic medium containing clinical dose one hour, followed by fresh wash exchange. negative control group underwent same treatment with alone. At t=24 hours post-treatment, samples assessed viability (live/dead), (creep indentation Instron tensile testing), (collagen glycosaminoglycan) content, pyridinoline cross linking via mass spectrometry. Results: Mean cell significantly decreased (35.5%) compared (49.8%, p < 0.001) (45.7%, = 0.003) (Figure 1). There significant weakening steroid-treated when 2), decreases aggregate modulus (646.3 kPa vs 312.8 [MP] 257.0 [TA), 0.001), shear (370.1 191.2 157.4 [TA], ultimate strength (UTS) (9.650 MPa 5.648 [MP], 0.021 6.065 0.040). Young’s TA-exposed (7.924 MPa) lower than (12.35 MPa, 0.026) but not different (11.97 =0.072). No differences collagen glycosaminoglycan found groups 3). Pyridinoline (p 0.027). Conclusions: results suggest that is can lead substantial early both compressive cartilage. steroid-exposed dropped 48-57% healthy control. In human knee cartilage, drops magnitude correlated progression ICRS grade 1-2 osteoarthritis. Furthermore, 25-50% degree osteoarthritis, steroid an average 34% study. Although there no detectable changes extracellular matrix composition structure, enough cause chondrotoxicity altered mechanics 24 after exposure, which raises concern risk failure tissue. Clinicians should be judicious regarding use intra-articular steroids, particularly patients intact