Background: Cannulated screws (4.0 mm) provide inter-fragmentary compression and stability to fractures. A guide wire is used to define the screw trajectory and hold the fracture fragment while the screw is being inserted. The cannulated shaft typically accommodates a 1.25 mm guide pin. Since the guide pin is very slender and undergoes elastic deformation during insertion, there is a high probability of pin breakage.
Methods: The authors have devised a new way to place the 4.0 mm cannulated screws in a manner that prevents the intraoperative complication of guide wire breakage. For this technique, predrilling was achieved using a 2.0 mm K-wire which was subsequently replaced with a 1.25 mm guide pin under the protection of sleeve. 4.0 mm cannulated screws were then inserted into a defined trajectory over the guide pin.
Results: Using the technique, over 20 patients were managed in our department over a period of two years without any complications.
Conclusion: We have observed that patients treated with this method experience short operation time, combined with good clinical outcome and we recommend its use in cases where cannulated screw use is warranted.
Keywords: Cannulated screws; defined trajectory; elastic deformation; fracture fragment; pin breakage; screw trajectory.