Fatigue microdamage in the radial predilection site for osteosarcoma in dogs.
OBJECTIVE
To evaluate whether body size and anatomic site influence the quantity of bone microdamage in dogs without osteosarcoma (OS).


METHODS
Pairs of radii were collected from 10 small dogs (< 15 kg) and 10 large dogs (> 25 kg).


METHODS
Specimens were stained in basic fuchsin for bone microdamage. Transverse sections were cut from each proximal and distal radial metaphysis at 15 and 85% of bone length. The following variables were determined for each region: mean microcrack length (CrLe, microM), microcrack density (CrDn, microcracks/mm2), microcrack surface density (CrSDn, microm/mm2), and estimated activation frequency (Acf, microcracks/mm2/y).


RESULTS
Metaphyseal region did not significantly influence CrDn, CrLe, and CrSDn. The CrDn and CrSDn were influenced by body size, with microdamage being increased in large dogs, compared with small dogs. However, mean CrLe was not significantly influenced by body size. Acf significantly decreased with age and was significantly decreased in large dogs and in the distal radial metaphysis, compared with small dogs and the proximal radial metaphysis, respectively.


CONCLUSIONS
Our data did not reveal an increase in microdamage or remodeling at the OS predilection site (ie, the distal metaphysis of the radius), suggesting that induction of microdamage and an associated increase in bone remodeling are unlikely to be an important risk factor for induction of OS.
Gellasch
Kelly L
KL
Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison 53706, USA.
Kalscheur
Vicki L
VL
Clayton
Murray K
MK
Muir
Peter
P
D000818:Animals; D001859:Bone Neoplasms / Q000209:etiology / Q000662:veterinary*; D016723:Bone Remodeling / Q000502:physiology*; D004283:Dog Diseases / Q000209:etiology* / Q000473:pathology; D004285:Dogs / Q000502:physiology*; D005221:Fatigue / Q000150:complications / Q000662:veterinary*; D005260:Female; D008297:Male; D012516:Osteosarcoma / Q000209:etiology / Q000662:veterinary*; D011884:Radius / Q000473:pathology*; D012394:Rosaniline Dyes / Q000737:chemistry
D012394:Rosaniline Dyes; C025485:basic fuchsin