A tapered-sleeve transcortical pin external skeletal fixation device for use in horses: development, application, and experience.
OBJECTIVE
To report development, configuration, application, and results of a tapered-sleeve transcortical pin external skeletal fixation device (TSP ESFD) for use on fractures of the distal aspect of the equine limb.


METHODS
Optimization analysis of a TSP ESFD was carried out with mechanical testing and review of clinical case outcomes.


METHODS
Cadaveric adult third metacarpal bones (MC3) for mechanical testing; horses (n=7) with severely comminuted proximal (6; P1) or second (1) phalanx fractures.


METHODS
Mechanical testing of methods for attachment of TSP to the sidebars were tested as well as optimization of pin diameters. Outcome of clinical cases managed with the TSP ESFD were compared with outcomes of horses treated with previous ESFD.


RESULTS
A TSP ESFD using 7.94 mm diameter pins was used. Survival rate was 71%. One horse with an infected P1 fracture and contralateral laminitis subsequently fractured MC3 through the distal pin hole while wearing the TSP ESFD. One mare with contralateral laminitis was euthanatized. Three horses had open fractures.


CONCLUSIONS
Design improvements incorporated into the TSP ESFD should increase treatment success.


CONCLUSIONS
External skeletal fixation continues to be a viable treatment alternative for severe injuries of the distal aspect of the equine limb. TSP ESFD should improve on the success of treatment by decreasing complications of bone fracture at the pin interface.
Nunamaker
David M
DM
Richard S. Reynolds, Jr. Comparative Orthopedic Research Laboratory, Department of Clinical Studies, New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19348, USA. dmn@vet.upenn.edu
Nash
Ronald A
RA
D000818:Animals; D001696:Biomechanical Phenomena; D001858:Bone Nails / Q000662:veterinary*; D005121:Extremities / Q000601:surgery; D005260:Female; D005592:Fracture Fixation / Q000295:instrumentation / Q000379:methods / Q000662:veterinary*; D017102:Fracture Healing; D050723:Fractures, Bone / Q000601:surgery / Q000662:veterinary*; D005597:Fractures, Open / Q000601:surgery / Q000662:veterinary; D006736:Horses / Q000293:injuries* / Q000601:surgery*; D008297:Male; D008422:Materials Testing / Q000662:veterinary; D050279:Metacarpal Bones / Q000293:injuries / Q000601:surgery; D016019:Survival Analysis; D050277:Toe Phalanges / Q000293:injuries / Q000601:surgery; D016896:Treatment Outcome