Innovative use of the hollow mill for broken pedicle screw extraction

Removal of fractured pedicle screws is technically demanding. Despite significant advances in transpedicular screw instrumentation and surgical techniques, screw breakage continues to account for 25% of complications and affecting 0.8-24.6% of patients. Here, we developed an innovative technique that employs the hollow mill set for broken pedicle screw retrieval.

We describe our innovative technique for broken pedicle screw retrieval utilizing a hollow mill set. We also provide a comparison of its safety/efficacy with established extraction methodologies.

Our technique begins with tulip head removal followed by careful curettage of newly formed bone; this exposes the fracture surface without compromising pedicle structural integrity. Next, the hollow mill sleeve is advanced clockwise until achieving >50% engagement with the retained screw fragment. Subsequently, with counterclockwise rotation of the handle-mechanism, the broken screw fragment can be extracted within a protective sleeve. This approach requires minimal bone exposure and avoids aggressive pedicle bone removal, thereby preserving anatomical integrity essential for larger-diameter screw placement (i.e., without extending to additional fusion levels). Further, the hollow mill is part of standard orthopedic instrumentation readily available in most surgical suites.

The hollow mill set for retrieving broken pedicle screw is readily available, cost-effective, technically simple, and effective for addressing fractured screws of varying diameters.