TY - JOUR
T1 - Comparison of macrostructural and microstructural bone features in Thoroughbred racehorses with and without midbody fracture of the proximal sesamoid bone
AU - Anthenill, Lucy A.
AU - Gardner, Ian
AU - Pool, Roy R.
AU - Garcia, Tanya C.
AU - Stover, Susan M
PY - 2010/7
Y1 - 2010/7
N2 - Objective - To compare macrostructural and microstructural features of proximal sesamoid bones (PSBs) from horses with and without PSB midbody fracture to gain insight into the pathogenesis of PSB fracture. Sample Population - PSBs from 16 Thoroughbred racehorses (8 with and 8 without a PSB midbody fracture). Procedures - Parasagittal sections of fractured and contralateral intact PSBs from horses with a PSB fracture and an intact PSB from age- and sex-matched control horses without a PSB fracture were evaluated for visual, radiographic, microradiographic, histologic, and histomorphometric differences in bone porosity, vascular channels, heme pigment, trabecular anisotropy, and pathological findings. Results - Fractured PSBs and their contralateral intact PSBs had more compacted trabecular bone than did control PSBs. Focal repair or remodeling was evident in the palmar aspect of many fractured and contralateral intact PSBs. Fracture coincided with microstructural features and propagated from the flexor to the articular surface. Conclusions and Clinical Relevance - Fractured PSBs had adapted to high loading but had focal evidence of excessive remodeling and porosity that likely predisposed the horses to complete fracture and catastrophic injury. Detection of focal injury before complete fracture provides an opportunity for prevention of catastrophic injury. Development of diagnostic imaging methods to assess porosity of PSBs may help to identify at-risk horses and allow for modifications of training and racing schedules to reduce the incidence of PSB fracture in Thoroughbred racehorses.
AB - Objective - To compare macrostructural and microstructural features of proximal sesamoid bones (PSBs) from horses with and without PSB midbody fracture to gain insight into the pathogenesis of PSB fracture. Sample Population - PSBs from 16 Thoroughbred racehorses (8 with and 8 without a PSB midbody fracture). Procedures - Parasagittal sections of fractured and contralateral intact PSBs from horses with a PSB fracture and an intact PSB from age- and sex-matched control horses without a PSB fracture were evaluated for visual, radiographic, microradiographic, histologic, and histomorphometric differences in bone porosity, vascular channels, heme pigment, trabecular anisotropy, and pathological findings. Results - Fractured PSBs and their contralateral intact PSBs had more compacted trabecular bone than did control PSBs. Focal repair or remodeling was evident in the palmar aspect of many fractured and contralateral intact PSBs. Fracture coincided with microstructural features and propagated from the flexor to the articular surface. Conclusions and Clinical Relevance - Fractured PSBs had adapted to high loading but had focal evidence of excessive remodeling and porosity that likely predisposed the horses to complete fracture and catastrophic injury. Detection of focal injury before complete fracture provides an opportunity for prevention of catastrophic injury. Development of diagnostic imaging methods to assess porosity of PSBs may help to identify at-risk horses and allow for modifications of training and racing schedules to reduce the incidence of PSB fracture in Thoroughbred racehorses.
UR - http://www.scopus.com/inward/record.url?scp=77956624045&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=77956624045&partnerID=8YFLogxK
U2 - 10.2460/ajvr.71.7.755
DO - 10.2460/ajvr.71.7.755
M3 - Article
C2 - 20594077
AN - SCOPUS:77956624045
VL - 71
SP - 755
EP - 765
JO - American Journal of Veterinary Research
JF - American Journal of Veterinary Research
SN - 0002-9645
IS - 7
ER -