Biomechanical Comparison of Fixed- versus Variable-Angle Locking Screws for Distal Humerus Comminuted Fractures
Clinics in Orthopedic Surgery
;
: 302-308, 2019.
Article
in English
| WPRIM
| ID: wpr-763585
ABSTRACT
BACKGROUND:
To compare the stability of fixed- versus variable-angle locking constructs for the comminuted distal humerus fracture (AO/OTA 13-A3).METHODS:
Eight pairs of complete humeri harvested from eight fresh frozen cadavers were used for the study. We fixed the intact humeri using 2.7-mm/3.5-mm locking VA-LCP stainless steel distal humerus posterolateral (nine-hole) and medial (seven-hole) plates. An oscillating saw was used to cut a 1-cm gap above the olecranon fossa. The specimens were loaded in axial mode with the rate of 1 mm per 10 seconds to failure, and stress-strain curves were compared in each pair. The mode of failure was recorded as well as the load needed for 2- and 4-mm displacement at the lateral end of the gap.RESULTS:
The stiffness of the constructs, based on the slope of the stress-strain curve, did not show any difference between the fixed- versus variable-angle constructs. Likewise, there was no difference between the force needed for 2- or 4-mm displacement at the lateral gap between the fixed- and variable-angle constructs. The mode of failure was bending of both plates in all specimens and screw pull-out in four specimen pairs in addition to the plate bending.CONCLUSIONS:
Our results did not show any difference in the biomechanical stability of the fixed- versus variable-angle constructs. There was not any screw breakage or failure of the plate-screw interface.
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Stainless Steel
/
Bone Screws
/
Cadaver
/
Fractures, Comminuted
/
Olecranon Process
/
Fracture Fixation
/
Humerus
Language:
English
Journal:
Clinics in Orthopedic Surgery
Year:
2019
Type:
Article
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