Removal technique for cold-welded titanium locking screws

Abstract

Titanium locking plates are commonly used for periarticular fracture fixation. Early clinical results have been encouraging in their use in treating distal femur and proximal tibia fractures, particularly with the advent of instrumentation for submuscular insertion and percutaneous fixation. 5 Kregor P.J. Stannard J.A. Zlowodzki M. Cole P.A. Treatment of distal femur fractures using the less invasive stabilization system: surgical experience and early clinical results in 103 fractures. J Orthop Trauma. 2004; 18: 509-520 Crossref PubMed Scopus (219) Google Scholar , 7 Stannard J.P. Wilson T.C. Volgas D.A. Alonso J.E. The less invasive stabilization system in the treatment of complex fractures of the tibial plateau: short-term results. J Orthop Trauma. 2004; 18: 552-558 Crossref PubMed Scopus (90) Google Scholar A unique feature of titanium locking plates is the phenomenon of cold-welded screws due to titanium being a softer metal. 1 Behring J.K. Gjerdet N.R. Molster A. Slippage between screwdriver and bone screw. Clin Orthop Relat Res. 2002; : 368-372 Crossref PubMed Scopus (21) Google Scholar , 3 Hak D.J. McElvany M. Removal of broken hardware. J Am Acad Orthop Surg. 2008; 16: 113-120 PubMed Google Scholar The removal of cold-welded screws in clinical practice can be frustrating. However, it is not commonly reported, as it is often viewed as an insignificant surgical event. Manufacturers promote a strict adherence to using a torque-limiting screwdriver to decrease the risk of cold-welding. Failure to be able to remove titanium screws can be attributed to fracturing or deforming the screw head recess, slippage of the screwdriver in the screw head, fracture of the screwdriver, or inadequate torque provided by the removal instrument. 1 Behring J.K. Gjerdet N.R. Molster A. Slippage between screwdriver and bone screw. Clin Orthop Relat Res. 2002; : 368-372 Crossref PubMed Scopus (21) Google Scholar , 3 Hak D.J. McElvany M. Removal of broken hardware. J Am Acad Orthop Surg. 2008; 16: 113-120 PubMed Google Scholar Biomechanical torque studies have shown failure of the screw head recess occurs as permanent deformation by reaming of the recess walls. 1 Behring J.K. Gjerdet N.R. Molster A. Slippage between screwdriver and bone screw. Clin Orthop Relat Res. 2002; : 368-372 Crossref PubMed Scopus (21) Google Scholar If the screwdriver has slipped once, additional attempts to drive the screw in or out will produce only one-half of the original maximum torque. Consequently, once slippage has occurred, removal of the screw becomes more difficult. As the screw deforms, changing the screwdriver is futile.