Abstract
Objectives:
Many hip fractures are considered rotationally unstable, especially during lag screw insertion. To counteract this instability, multiple provisional fixation constructs have been used to maintain the fracture reduction. This study aimed to compare the methods of provisional fixation biomechanically in ba sicervical femoral neck fractures.
Methods:
A web-based survey was sent by e-mail to members of three orthopedic assocations with questions concerning used techniques for provisional fixation of unstable basicervical femoral neck fractures and these results were used to guide our biomechanical assessment. Twenty, fourth-generation composite proximal femurs were osteotomized in the basicervical region to simulate a basicervical fracture. These fractures were anatomically reduced and one of the four provisional fixation constructs was applied. A sliding hip screw was then inserted with a torque limiter to the appropriate depth. The amount of fracture displacement during screw insertion was collected and analyzed.
Results:
Of the 142 respondents, 79.6% apply some form of provisional fixation. Derotational screw was the most commonly used provisional fixation (43.4%), followed by one superior Kirschner wire (K-wire) (39.8%). Biomechanically, the single derotation screw construct showed significantly less displacement (0.92 mm) than the one superior K-wire construct (3.09 mm). No other significant differences in fracture displacement were found between the groups.
Conclusion:
This study highlights that the majority of surgeons apply a form of provisional fixation during the surgical management of unstable basicervical femoral neck fractures. We have shown biomechanically that the single derotation screw had superior rotational stability when compared to the one superior K-wire.