An ex vivo mechanical evaluation of single versus double semitubular plate fixation of a transverse distal-third scapular osteotomy in the dog.
OBJECTIVE
To compare single versus double semitubular plate fixation for scapular body fractures.


METHODS
Ex vivo mechanical study.


METHODS
Eighteen paired cadaveric canine scapulae.


METHODS
Transverse scapular body osteotomies were created in the distal third of 18 pairs of scapulae. One scapula of each pair was repaired with a single plate, whereas the contralateral scapula was repaired with 2 plates. Initial strength and stiffness of the constructs were measured in 10 pairs of scapulae. Eight pairs of scapulae underwent cyclic loading and then were subjected to failure testing.


RESULTS
Double-plate fixation was significantly stronger (3,899 +/- 632 N) but not stiffer (614 +/- 130 N/mm) than the single-plate fixation (3,238 +/- 935 N and 537 +/- 202 N/mm, respectively). Cyclic loading variables were not significantly different between the 2 methods of fixation. After cyclic loading, double-plate fixation was significantly stronger (2,916 +/- 618 N) than single-plate fixation (2,347 +/- 495 N). There was no significant difference (P =.11) in stiffness between double- versus single-plate fixations: 734 +/- 247 N/mm and 595 +/- 139 N/mm, respectively.


CONCLUSIONS
Double-plate fixation was generally stronger and stiffer than single-plate fixation. Because all constructs failed at loads that greatly exceeded those estimated to occur clinically, any difference between the 2 methods of fixation probably is not clinically relevant.


CONCLUSIONS
Single-plate fixation may be of sufficient strength for fixation of scapular body fractures.
Mair
Jacqueline J
JJ
Department of Clinical Sciences, Tufts University School of Veterinary Medicine, North Grafton, MA 01536, USA.
Belkoff
Stephen M
SM
Boudrieau
Randy J
RJ
D000818:Animals; D001860:Bone Plates / Q000662:veterinary*; D002102:Cadaver; D004285:Dogs / Q000293:injuries* / Q000601:surgery; D019544:Equipment Failure Analysis; D005260:Female; D005593:Fracture Fixation, Internal / Q000379:methods / Q000662:veterinary*; D050723:Fractures, Bone / Q000601:surgery / Q000662:veterinary*; D008297:Male; D010027:Osteotomy / Q000379:methods / Q000662:veterinary; D012540:Scapula / Q000293:injuries* / Q000601:surgery; D013314:Stress, Mechanical