Salvaging Pull-Out Strength in a Previously Stripped Screw Site: A Comparison of Three Rescue Techniques

Abstract

Screw stripping during bone fixation is a common occurrence during operations that results in decreased holding capacity and bone healing. We aimed to evaluate the rescue of the stripped screw site using screws of different dimensions. Five screw configurations were tested on cadaveric specimens for pull-out strength (POS). The configurations included a control screw tightened without stripping, a configuration voluntarily stripped and left in place, and three more configurations in which the stripped screws were replaced by a different screw with either increased overall length, diameter, or thread length. Each configuration was tested five times, with each screw tested once. The POS of the control screw, measured to be 153.6 ± 27 N, was higher than the POS measured after stripping and leaving the screw in place (57.1 ± 18 N, p = 0.001). The replacement of the stripped screw resulted in a POS of 158.4 ± 64 N for the screw of larger diameter, while the screws of the same diameter but increased length or those with extended thread length yielded POS values of 138.4 ± 42 and 185.7 ± 48 N, respectively. Screw stripping is a frequent intraoperative complication that, according to our findings, cannot be addressed by leaving the screw in place. The holding capacity of a stripped screw implanted in cancellous bone can successfully be restored with a different screw of either larger diameter, longer length, or extended thread length.

Biomechanics of PHILOS plates in Vancouver B1 periprosthetic femoral fracture

“…Unfortunately, we have not studied the relationship between fracture healing and the different number of screws on the plate and the position of the screws. Simultaneous simplified methods of screw placement and threading were used for plate fixation, without the consideration of torque and extrusion forces that increase fracture fixation strength (Bronsnick et al, 2015;Mejia et al, 2018;Addevico et al, 2020;Addevico et al, 2021). In recent years, with the development of mechanical and biomechanical techniques (Travascio et al, 2021), the use of coated screws has increased the osteogenic effect, particularly in patients with osteoporosis (Patel et al, 2015), while increasing the screw-to-bone friction, which is critical for implant fixation and implant stability (Bronsnick et al, 2015).…”

Biomechanics and finite element analysis comparing posterior T-plates with LCP for fixation of posterolateral tibial plate fractures

“…Additionally, the study did not explore the relationship between screw characteristics, insertion torque, and stability (Addevico et al, 2020). Other factors impacting stability such as intrannular materials (Bronsnick et al, 2015), insertion torque (Addevico et al, 2021), porous media for bone (Travascio et al, 2015), bone mechanobiology (Volz et al, 2021) were not conferred in our study.…”

Fixation stability comparison of bone screws based on thread design: buttress thread, triangle thread, and square thread

“…Improving the fixation strength of bone screws is a feasible way to reduce the failure rate [8]. Screw thread is the determinant component that governs the initial screw stability of fixation, therefore, it is extremely important to choose the right thread profile for the bone screw [9][10][11]. Bone screws are derived from industrial screws with various thread designs for different purposes [12].…”