Comparison of computer assisted surgery with conventional technique for treatment of abaxial distal phalanx fractures in horses: an in vitro study.
OBJECTIVE
To (1) evaluate and compare computer-assisted surgery (CAS) with conventional screw insertion (conventional osteosynthesis [COS]) for treatment of equine abaxial distal phalanx fractures; (2) compare planned screw position with actual postoperative position; and (3) determine preferred screw insertion direction.


METHODS
Experimental study.


METHODS
Cadaveric equine limbs (n=32).


METHODS
In 8 specimens each, a 4.5 mm cortex bone screw was inserted in lag fashion in dorsopalmar (plantar) direction using CAS or COS. In 2 other groups of 8, the screws were inserted in opposite direction. Precision of CAS was determined by comparison of planned and actual screw position. Preferred screw direction was also assessed for CAS and COS.


RESULTS
In 4 of 6 direct comparisons, screw positioning was significantly better with CAS. Results of precision analysis for screw position were similar to studies published in human medicine. None of evaluated criteria identified a preferred direction for screw insertion.


CONCLUSIONS
For abaxial fractures of the distal phalanx, superior precision in screw position is achieved with CAS technique compared with COS technique.


CONCLUSIONS
Abaxial fractures of the distal phalanx lend themselves to computer-assisted implantation of 1 screw in a dorsopalmar (plantar) direction. Because of the complex anatomic relationships, and our results, we discourage use of COS technique for repair of this fracture type.
Rossol
Melanie
M
Equine Department, University of Zurich, Zurich, Switzerland.
Gygax
Diego
D
Andritzky-Waas
Juliane
J
Zheng
Guoyan
G
Lischer
Christoph J
CJ
Zhang
Xuan
X
Auer
Joerg A
JA
D000818:Animals; D001863:Bone Screws / Q000662:veterinary*; D002102:Cadaver; D005552:Forelimb / Q000601:surgery; D005592:Fracture Fixation / Q000379:methods / Q000662:veterinary*; D050723:Fractures, Bone / Q000601:surgery / Q000662:veterinary*; D006614:Hindlimb / Q000601:surgery; D006736:Horses; D025321:Surgery, Computer-Assisted; D016896:Treatment Outcome