Biomechanics in uniaxial compression of three distal radius volar plates.
OBJECTIVE
A new fixed-angle volar plate for a dorsally displaced distal radius fracture was designed with the aim of avoiding soft tissue problems due to dorsal plating. The purpose of this study was to compare the biomechanical properties of this new plate with 2 existing volar plates in a cadaver model.


METHODS
Three different plates were applied on surgically simulated unstable extra-articular distal radius fractures in formalin-fixed cadaver radiuses. Group 1 (volarly placed AO titanium Distal Radius plates [Synthes Ltd, Paoli, PA]; n = 6), group 2 (volarly placed titanium Symmetry plates [DePuy ACE Co, El Segundo, CA]; n = 6), and group 3 (volarly placed newly designed titanium plates; n = 6) were tested to failure under axial compression with a materials testing machine. Specimens of all 3 groups had similar bone mineral density.


RESULTS
Group 3 specimens had significantly greater elastic limit and ultimate strength than the other 2 groups. Specimens of group 3 had the greatest rigidity, although this was statistically insignificant compared with the other 2 groups. All plates (groups 1, 2, 3) failed in apex volar angulation.


CONCLUSIONS
The newly designed plate fixation system is the strongest of the systems tested and may offer adequate stability for the treatment of a distal radius fracture in which the dorsal and/or volar metaphyseal cortex is comminuted severely.
Osada
Denju
D
Department of Orthopedics, Dokkyo University School of Medicine, Tochigi, Japan.
Fujita
Satoshi
S
Tamai
Kazuya
K
Iwamoto
Akira
A
Tomizawa
Kazuo
K
Saotome
Koichi
K
D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D001860:Bone Plates; D002102:Cadaver; D019544:Equipment Failure Analysis; D006801:Humans; D007593:Joint Instability / Q000601:surgery; D008297:Male; D008422:Materials Testing; D008875:Middle Aged; D011474:Prosthesis Design; D011885:Radius Fractures / Q000601:surgery*; D013314:Stress, Mechanical; D014025:Titanium; D016474:Weight-Bearing / Q000502:physiology
D014025:Titanium