Biomechanical Stability of a Volar Locking-Screw Plate Versus Fragment-Specific Fixation in a Distal Radius Fracture Model
Ellis O. Cooper, MD, Keith A. Segalman, MD, Brent G. Parks, MSc, Krishn M. Sharma, MD, and Augustine Nguyen, BSc
Dr. Cooper is Hand Fellow; Dr. Segalman is Attending; Mr. Parks is Director, Biomechanics Lab; Dr. Sharma is Orthopaedics Resident; and Mr. Nguyen is Research Assistant, Curtis National Hand Center, Union Memorial Hospital, Baltimore, Maryland.
Eight matched pairs of cadaveric radii were osteotomized by removing a 4-mm dorsal wedge of bone at the level of the sigmoid notch designed to simulate dorsal comminution. They were then fixed with either a volar locking-screw plate or fragment-specific fixation. All constructs underwent biomechanical testing in a custom-designed, custom-fabricated 4-point bending device. No statistically significant difference in stiffness was noted between the groups. Linear displacement and angulation at the osteotomy site were significantly less in the group with fragment-specific fixation at loads expected to be encountered during postoperative rehabilitation. Angulation at the osteotomy site was significantly less in the locking-screw plate group at higher loads.