A Study in Vivo of the Effects of a Static Compressive Load on the Proximal Tibial Physis in Rabbits

• DOI: 10.2106/jbjs.k.00340
• Publication Date: 2012-11-15T20:56:49Z
• Authors: Andrew D. Bries; Dennis S. Weiner; Robin Jacquet; Mark J. Adamczyk; Melanie A. Morscher; Elizabeth Lowder; Michael J. Askew; Richard P. Steiner; Walter I. Horne; William J. Landis
• Keywords: Aggrecan; Physis; Type II collagen; SOX9; Hindlimb; Type I collagen

Background: The effect of compression on the physis is generally defined by Hueter-Volkmann principle, in which decreased linear growth results from increased compression. This investigation examined whether mechanically induced rabbit physes causes changes gene expression, cells, and extracellular components that promote physeal resilience strength (type-II collagen aggrecan) cartilage hypertrophy (type-X matrix metalloprotease-13). Methods: Static compressive loads (10 N or 30 N) were applied for two six weeks across one hind limb proximal tibial thirteen-week-old female New Zealand White rabbits (n = 18). contralateral all underwent sham surgery with no load to serve as an internal control. Harvested divided into portions histological, immunohistochemical, quantitative reverse transcription-polymerase chain reaction analysis. Gene expression was statistically analyzed means comparisons between loaded samples unloaded shams use analysis variance a Tukey post hoc test. Results: Compared shams, at 10 showed histological cells matrices. Physes thickness had structurally disorganized chondrocyte columns, matrix, less intense type-II X immunohistochemical staining. Quantitative compared yielded significantly (p ≤ 0.05) aggrecan significant > metalloprotease-13 increasing load. Conclusions: Compressed generate biochemical collagens, proteoglycan, cellular tissue architecture. Changes potentially weaken overall strength, consistent lend understanding pathological conditions physis. Clinical Relevance: Compressive forces cause molecular biology, biochemistry, structure, may provide insight disorders open humans.