Biomechanical testing of a hybrid locking plate fixation of equine sesamoid osteotomies.
OBJECTIVE
To compare the biomechanical properties of a hybrid locking compression plate (LCP) construct with the compression screw technique as a treatment for transverse mid-body proximal sesamoid bone fractures.


METHODS
Ten paired forelimbs from abattoir horses were used. The medial proximal sesamoid bone of each limb was osteotomized transversely and randomly assigned, to either repair with a two-hole 3.5 mm LCP or a 4.5 mm cortical screw placed in lag fashion. Each limb was tested biomechanically by axial loading in single cycle until failure. The point of failure was evaluated from the load-displacement curves. Then a gross evaluation and radiographs were performed to identify the mode of failure.


RESULTS
The loads to failure of limbs repaired with the hybrid LCP construct (4968 N ± 2167) and the limbs repaired with the screw technique (3009 N ± 1091) were significantly different (p <0.01). The most common mode of failure was through a comminuted fracture of the apical fragment of the proximal sesamoid bone.


CONCLUSIONS
The LCP technique has potential to achieve a better fracture stability and healing when applied to mid-body fractures of the proximal sesamoid bone. Further testing, particularly fatigue resistance is required to corroborate its potential as a treatment option for mid-body fractures of the proximal sesamoid bone.
Eduardo Almeida da Silveira, DMV, M.Sc., 3200, Rue Sicotte, Saint-Hyacinthe, Québec J2S 2M2, Canada, Phone: +1 450 773 8521, ext. 8255, Fax: +1 450 773 8521, E-mail: edu_teatino@hotmail.com.
E
E
Almeida da Silveira
A
A
Levasseur
M
M
Lacourt
Y
Y
Elce
Y
Y
Petit
D000818:Animals; D001696:Biomechanical Phenomena; D001860:Bone Plates / Q000662:veterinary*; D005593:Fracture Fixation, Internal / Q000295:instrumentation / Q000379:methods / Q000662:veterinary*; D050723:Fractures, Bone / Q000601:surgery / Q000662:veterinary*; D006736:Horses / Q000293:injuries / Q000601:surgery*; D010027:Osteotomy / Q000295:instrumentation / Q000379:methods / Q000662:veterinary*; D011475:Prosthesis Failure; D012716:Sesamoid Bones / Q000293:injuries* / Q000601:surgery
Mid-body fracture; biomechanics; horses; locking compression plate; proximal sesamoid bone