Related Experiment Video
Updated: Jun 25, 2026

An Intramedullary Locking Nail for Standardized Fixation of Femur Osteotomies to Analyze Normal and Defective Bone Healing in Mice
Published on: November 13, 2016
Delayed union, non-union and mal-union in 442 dogs
William George Marshall1, Barbro Filliquist2, Emmanouil Tzimtzimis1
1Small Animal Hospital, School of Veterinary Medicine, University of Glasgow, Glasgow, UK.
Objectives:
(1) To estimate the prevalence of delayed union, non-union and mal-union in canine fractures; (2) to describe fracture, demographic, and treatment characteristics for these outcomes; (3) to identify risk factors for delayed or non-union.
Study Design:
Retrospective study.
Sample Population:
Four hundred and forty two dogs (461 fractures).
Methods:
A review was conducted of clinical records and radiographs from 2 teaching hospitals. "Union," "delayed union," "non-union" and "mal-union" were defined, and fracture, demographic, treatment, and outcome variables described. Differences in proportions or medians between "union," "delayed union" and "non-union" were tested using χ2 and Mann-Whitney U-tests for categorical and continuous variables respectively. Potential explanatory variables for "delayed or non-union" were tested using logistic regression to identify risk factors.
Results:
Median radiographic follow up was 53 days (14-282). Delayed union occurred in 13.9% of fractures (64/461), non-union in 4.6% (21/461), and mal-union in 0.7% (3/461). Risk factors for delayed or non-union were age (OR 1.21, 95% CI 1.12-1.31); comminuted fracture (OR 4.24, 95% CI 2.4-7.5); treatment with bone graft (all types) (OR 3.32, 95% CI 1.3-8.5); surgical site infection (OR 3.24, 95% CI 1.17-8.97), and major implant failure (OR 12.94, 95% CI 5.06-33.1).
Conclusion:
Older dogs, dogs with comminuted fractures, surgical site infection, or major implant failure were at increased odds of delayed or non-union. Radius and ulna fractures in toy breed dogs were not at increased odds of delayed or non-union.
Clinical Significance:
The identified risk factors should inform fracture planning and prognosticating. The prognosis for radial fractures in toy breeds appears better than historically believed.
Related Concept Videos
Incomplete Dominance
Structure of Conjugated Dienes
Conjugated dienes are compounds characterized by the presence of alternating double and single bonds. In a conjugated system like 1,3-butadiene, the unhybridized 2p orbital on each carbon overlaps continuously, allowing the π electrons to be delocalized across the entire molecule. In contrast, this type of overlap does not occur in cumulated and isolated dienes, such as 2,3-pentadiene and 1,4-pentadiene, respectively. Instead, the π electrons remain localized between the double...
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
Sign Test for Nominal Data
For example, consider a...
Classical Conditioning
Ivan Pavlov observed that dogs salivated...

