A biomechanical comparison of a dorsal 3.5-mm T-plate and a volar fixed-angle plate in a model of dorsally unstable distal radius fractures.
OBJECTIVE
To compare the biomechanical stability of internal fixation of extra-articular, dorsally unstable distal radius fractures fixed by 1 of 2 methods, either a standard dorsal nonlocked T-plate or a volar locked fixed-angle plate.


METHODS
Biomechanical cadaveric study.


METHODS
Biomechanical testing laboratory.


METHODS
In 6 matched pairs of fresh-frozen cadaveric specimens, a simulated unstable extra-articular distal radius fracture was created. The fractures were stabilized with either a dorsal 3.5-mm stainless steel T-plate or a titanium locked volar fixed-angle plate. Specimens were axially loaded at 5 points (centrally, volarly, dorsally, radially, and ulnarly) and then cyclically loaded for 5000 cycles with an 80 N central load. Postcyclical loading, specimens were once again axially loaded at the 5 points.


METHODS
Initial fixation stiffness and stiffness after midaxial cyclical loading was compared at the 5 points.


RESULTS
With the volar locked fixed-angle plate, fixation was significantly stiffer than with the dorsal nonlocked T-plate for ulnar and volar loading in single-cycle testing. After cyclic loading, the locked volar fixed-angle plate maintained more of its initial stiffness than the dorsal nonlocked T-plate. The dorsal 3.5-mm stainless steel T-plate's stiffness when dorsally loaded significantly decreased after cyclical loading.


CONCLUSIONS
The volar locked fixed-angle plate maintained a greater percentage of its initial stiffness after cyclic loading compared to the dorsal nonlocked plate. Also, the volar locked plate was stiffer than the dorsal nonlocked plate for all loading configurations tested except when subjected to a dorsally applied eccentric load.
Liporace
Frank A
FA
NYU-Hospital for Joint Diseases, New York, NY, USA.
Gupta
Salil
S
Jeong
Gerard K
GK
Stracher
Michael
M
Kummer
Fredrick
F
Egol
Kenneth A
KA
Koval
Kenneth J
KJ
D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena; D001860:Bone Plates; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011885:Radius Fractures / Q000601:surgery*