FiberWire as a Non-Metallic Binding Material for Dorsal K-Wire Spinal Stapling: An Ex Vivo Rabbit Thoracolumbar Biomechanical Study

Dorsal spinal stapling secures a Kirschner wire (K-wire) staple to adjacent spinous processes, but whether flexible non-metallic suture can replace stainless steel wire remains unclear. This study compared FiberWire and stainless steel wire in an ex vivo thoracolumbar model from 20 male New Zealand White rabbit cadavers. An isolated bone-hole tensile test was performed at L5 and L6. For constructs, a U-shaped 1.0 mm K-wire staple was passed through the L3 spinous process, positioned along both sides of T13–L2, and secured with either No. 2 FiberWire or 0.76 mm stainless steel wire. Gross flexion–extension and lateral range of motion (ROM) were measured, followed by destructive three-point bending under ventral and lateral loading. Isolated bone-hole maximum load did not differ significantly between FiberWire and stainless steel wire (89.0 vs. 118.2 N; p = 0.20). Both constructs reduced ROM vs. intact controls (p < 0.01), without differences between binding materials. Under ventral bending, FiberWire had a higher median maximum load than stainless steel wire (77.4 vs. 50.0 N; p < 0.05), whereas lateral bending loads did not differ. FiberWire therefore provided gross motion restriction comparable to stainless steel wire and greater resistance to ventral destructive bending, while isolated bone-hole strength did not differ significantly between materials.