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Increased Distraction Rates Influence Precursor Tissue Composition Without Affecting Bone Regeneration
Author(s) -
Richards Mark,
Kozloff Kenneth M.,
Goulet James A.,
Goldstein Steven A.
Publication year - 2000
Publication title -
journal of bone and mineral research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.882
H-Index - 241
eISSN - 1523-4681
pISSN - 0884-0431
DOI - 10.1359/jbmr.2000.15.5.982
Subject(s) - distraction osteogenesis , femur , medicine , x ray microtomography , cartilage , bone tissue , chondrogenesis , anatomy , chemistry , surgery , distraction , biology , radiology , neuroscience
Abstract The effect of increased distraction rate on bony tissue differentiation was studied using a paired bilateral model of rat femur lengthening. After a 6‐day latency period, one randomly selected femur for each rat was distracted at 0.5 mm/day (normal rate) for 12 days, and the contralateral femur was distracted at 1.5 mm/day (increased rate) for 4 days. Femoral lengthening for each side was 6.0 mm, leaving the increased rate leg with an extra 8 days of consolidation compared with the normal rate limb. Group I rats ( n = 9) were killed at day 18 postsurgery and analyzed for cartilage tissue composition and distribution. Group II rats ( n = 7) were killed on day 36 postsurgery and analyzed by three‐dimensional microcomputed tomography (MCT) for changes in new bone volume. Digital color analysis of slides stained with type II collagen antibody showed increases in cartilaginous tissue formation on the increased rate side (1.51 mm 2 vs. 0.83 mm 2 ; p = 0.10). No differences in new bone volume were detected between increased rate limbs and their contralateral controls (46.13 mm 3 vs. 42.69 mm 3 ; p = 0.63). These findings suggest that intermediate distraction rates may influence precursor tissue composition without affecting the final amount of new bone formed. Because damage to the tissue was not detected at either time point, these changes in chondrogenesis may reflect sensitivity of the pluripotential gap tissue to tension accumulation during lengthening. Future work with this in vivo model is focused on improving our understanding of the mechanisms behind this strain sensitivity. (J Bone Miner Res 2000;15:982–989)