An in vitro biomechanical comparison of equine proximal interphalangeal joint arthrodesis techniques: an axial positioned dynamic compression plate and two abaxial transarticular cortical screws inserted in lag fashion versus three parallel transarticular cortical screws inserted in lag fashion.
OBJECTIVE
To compare in vitro monotonic biomechanical properties of an axial 3-hole, 4.5 mm narrow dynamic compression plate (DCP) using 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws inserted in lag fashion (DCP-TLS) with 3 parallel transarticular 5.5 mm cortical screws inserted in lag fashion (3-TLS) for the equine proximal interphalangeal (PIP) joint arthrodesis.


METHODS
Paired in vitro biomechanical testing of 2 methods of stabilizing cadaveric adult equine forelimb PIP joints.


METHODS
Cadaveric adult equine forelimbs (n=15 pairs).


METHODS
For each forelimb pair, 1 PIP joint was stabilized with an axial 3-hole narrow DCP (4.5 mm) using 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws inserted in lag fashion and 1 with 3 parallel transarticular 5.5 mm cortical screws inserted in lag fashion. Five matching pairs of constructs were tested in single cycle to failure under axial compression, 5 construct pairs were tested for cyclic fatigue under axial compression, and 5 construct pairs were tested in single cycle to failure under torsional loading. Mean values for each fixation method were compared using a paired t-test within each group with statistical significance set at P<.05.


RESULTS
Mean yield load, yield stiffness, and failure load under axial compression and torsion, single cycle to failure, of the DCP-TLS fixation were significantly greater than those of the 3-TLS fixation. Mean cycles to failure in axial compression of the DCP-TLS fixation was significantly greater than that of the 3-TLS fixation.


CONCLUSIONS
The DCP-TLS was superior to the 3-TLS in resisting the static overload forces and in resisting cyclic fatigue.


CONCLUSIONS
The results of this in vitro study may provide information to aid in the selection of a treatment modality for arthrodesis of the equine PIP joint.
Sod
Gary A
GA
Equine Health Studies Program, Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA. gsod@vetmed.lsu.edu
Riggs
Laura M
LM
Mitchell
Colin F
CF
Hubert
Jeremy D
JD
Martin
George S
GS
D000818:Animals; D001174:Arthrodesis / Q000295:instrumentation / Q000379:methods / Q000662:veterinary*; D001696:Biomechanical Phenomena / Q000502:physiology; D001860:Bone Plates / Q000662:veterinary*; D001863:Bone Screws / Q000662:veterinary*; D019245:Compressive Strength / Q000502:physiology; D004868:Equipment Failure / Q000662:veterinary; D005552:Forelimb; D006734:Horse Diseases / Q000503:physiopathology / Q000601:surgery; D006736:Horses / Q000502:physiology / Q000601:surgery*; D066298:In Vitro Techniques; D014033:Toe Joint / Q000502:physiology / Q000601:surgery*; D054159:Torsion, Mechanical