title: Experimental study on internal fixation of femoral neck fractures.
abstract: The relative strength and the failure mode of internal fixation by multiple pinning and nailing was investigated on 35 specimens. Internal fixation consisted of 3, 5 and 7 Knowles pins, a Smith-Petersen nail or a sliding nail plate. The strength of a specimen with a triflanged nail is only half of that with multiple Knowles pins. There is no significant difference in strength of 3, 5, or 7 pin specimens. The strength of an internal fixation with a sliding nail plate is not superior to the strength of multiple pinning. The mode of failure for the different types of internal fixation is primarily a crush fracture of the supporting trabecular bone at the femoral neck with downward and outward migration of the pins or nail. Except with the fixation with 3 pins where an initial bending could be observed, failure is not a plastic deformation of the internal fixation device.
mesh_terms: D001858:Bone Nails / Q000009:adverse effects; D002102:Cadaver; D005265:Femoral Neck Fractures / Q000601:surgery*; D005593:Fracture Fixation, Internal / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D008875:Middle Aged; D009984:Orthopedic Fixation Devices; D013314:Stress, Mechanical