Biomechanical comparison of humeral condyles with experimental intracondylar fissures immobilized with a transcondylar positional or a lag screw: An ex-vivo study in dogs.
Vet Surg
; 50(7): 1443-1448, 2021 Oct.
Article
em En
| MEDLINE
| ID: mdl-34382699
ABSTRACT
OBJECTIVE:
To compare the axial biomechanical properties of intracondylar humeral osteotomies fixed with 4.5 mm transcondylar positional or cortical lag screws. STUDYDESIGN:
Ex vivo study. SAMPLE POPULATION Paired humeri from 21 canine cadavers. MATERIALS ANDMETHODS:
An intracondylar osteotomy was created on each humerus to mimic an intracondylar fissure. Paired humeri were randomly assigned to fixation with a positional or a lag screw. All specimens were radiographed postinstrumentation to document proper screw placement. Axial load was applied to the distal articular surface of the trochlea at a rate of 1 mm/s until a 40% decrease in load was measured. Specimens were assessed for mode of failure with visual inspection and radiographs.RESULTS:
Stiffness (1236.7 ± 181 N/mm vs. 1050.8 ± 265 N/mm), yield load (3284.3 ± 1703 N vs. 2071.1 ± 740 N), and maximum load (7378.0 ± 1288 vs. 5793.7 ± 2373 N) were greater in constructs fixed with a positional rather than a lag screw (p = .0008, .044, and .040, respectively).CONCLUSION:
In our model, mechanical properties were improved when the transcondylar osteotomy was stabilized with a 4.5 mm positional screw rather than a lag screw. CLINICALSIGNIFICANCE:
This ex vivo study suggests that a transcondylar lag screw and positional screw are not biomechanically equal. Additional in vivo studies are need to help with clinical decision making when prophylactically treating HIF.
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Base de dados:
MEDLINE
Assunto principal:
Doenças do Cão
/
Fraturas do Úmero
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Ano de publicação:
2021
Tipo de documento:
Article