Original Research
Two-Screw Femoral Neck Fracture Fixation: A Biomechanical Analysis of 2 Different Configurations
Am J Orthop. 2007 September;36(9):481-485
Author and Disclosure Information
Virak Tan, MD, Kirk L. Wong, MD, Christopher T. Born, MD, Robert Harten, PhD, and William G. DeLong, Jr., MD
Dr. Tan is Associate Professor, Department of Orthopaedics, New Jersey Medical School, University of Medicine and Dentistry of New Jersey, Newark, New Jersey.
Dr. Wong is Orthopaedic Surgeon, Rebound Orthopaedics, Vancouver, Washington.
Dr. Born is Professor, Department of Orthopaedics, Brown Medical School, Providence, Rhode Island.
Dr. Harten is Engineer, Synthes Corp., West Chester, Pennsylvania.
Dr. DeLong is Professor, Department of Orthopaedic Surgery, Temple University School of Medicine, Philadelphia, Pennsylvania.
In the study reported here, we evaluated 2-screw femoral neck fixation. Femoral necks from 5 paired fresh-frozen cadavers were fractured and then fixed with two 7.3-mm cannulated cancellous screws. Vertical (parallel screws in sagittal plane of femoral neck) and horizontal (parallel screws in superior aspect of femoral neck) configurations were used for each matched pair. Mechanical testing was performed. Load, displacement, and stiffness at the yield point were significantly higher in the horizontal group, which also had a higher mean maximal failure load (P = .019). Preliminary data suggest that 2 horizontal screws in the superior aspect of the femoral neck provide more secure fixation than 2 vertical screws.