Q. Fu, Changhai Hospital,Shanghai, Shanghai, China; S. Xu, C. Zhang, Changhai Hospital, The Second Military Medical University, Shanghai, China; X. W. Liu, Second Military Medical University,, China, Shanghai, China
Objective: To study the effect of internal fixation with nitinol swan-like memory compressive connector (SMC) on temporal expression patterns of TGF-β at fracture site. Methods: Double sided humeral fracture in 35 New Zealand rabbits were internally fixed by SMC or dynamic compression plate (DCP) severally. Animals were killed in group of 5 at different time points (1, 3, 7, 14, 21, 28, 56 d postoperat ively) , and immunohistochemistry combined with computer image analysis system was used to examine distribution and density of TGF-βat fracture sites. Results: The TGF-βstaining was localized to the mesenchymal cells, osteoblasts, chondrocytes and extracellular matrix during fracture healing. At the early and late stage after operation, no significant differences of local TGF-β content were found between the two groups. From day 7 to day 28, the expression of local TGF-β in SMC group was significantly stronger than that in DCP group. Conclusion: The sustained dynamic memory compressive stress produced by SMC may enhance the biosynthesis and excretion of TGF-β at fracture sites, thus promote bone healing.
[KEY WORDS]swan-like memory compressive connector; dynamic compression plate; fracture fixation, internal; transforming growth factor-β
Summary: To study the effect of internal fixation with nitinol swan-like memory compressive connector (SMC) on temporal expression patterns of TGF-â at fracture site.
