Vet Comp Orthop Traumatol 2005; 18(04): 199-207
DOI: 10.1055/s-0038-1632964
Original Research
Schattauer GmbH

In vivo axial dynamization of canine tibial fractures using the Securos external skeletal fixation system

S. C. Gorman
1   Departments of Clinical Sciences
,
K. H. Kraus
1   Departments of Clinical Sciences
,
J. H. Keating
2   Departments of Biomedical Sciences, Cummings School of Veterinary Medicine at Tufts University, North Grafton, Massachusetts, USA
,
A. S. Tidwell
1   Departments of Clinical Sciences
,
W. M. Rand
3   Department of Family Medicine and Community Health, Tufts University School of Medicine, Boston, Massachusetts, USA
,
J. D. Parkington
4   Wyeth Pharmaceuticals, Cambridge, Massachusetts, USA
,
R. J. Boudrieau
1   Departments of Clinical Sciences
› Author Affiliations
Further Information

Publication History

Received 20 May 2005

Accepted 04 July 2005

Publication Date:
22 February 2018 (online)

Summary

Bilateral transverse mid-shaft tibial osteotomies, with a 4-mm gap, were performed in purpose-bred research dogs and stabilized using a Securos™ Type 2 external skeletal fixator (ESF). Full (100%) axial dynamization of one randomly selected ESF in each dog was performed at 31 days postoperatively. Caudo-cranial radiographs were obtained at weekly intervals, which were qualitatively and quantitatively evaluated (densitometry and ImageJ analysis). The dogs were euthanatized 13 weeks postoperatively, at which time dual energy x-ray absorptiometry (DEXA), peripheral quantitative computed tomography (pQCT), mechanical testing in torsion, and qualitative histological analysis were performed. A two-tailed paired Student's t-test was performed for statistical analysis of all parameters of interest, with significance set at p<0.05. Three of five dynamized bones bridged quicker, and four of five dynamized bones appeared to have greater callus formation, however, statistically significant differences could not be definitively determined. Statistically significant differences were not found with densitometry (any time frame), DEXA, pQCT, torsional stiffness or maximum torque. Despite the lack of statistically relevant data, trends were observed with larger callus size and density in the dynamized tibiae. The dynamized tibiae appeared to fracture more consistently outside of the area of the healing callus as compared to the control tibiae. Histological evaluation showed greater remodelling in four of five control limbs when compared to the dynamized limb. Dynamization at 31 days postoperatively may delay bone remodelling, despite a trend towards a larger callus size. The results of this study failed to show a definitive role for early full axial dynamization.

 
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