Use of the Schanz screw as a joystick and the Poller screw in intramedullary nailing for subtrochanteric or proximal femoral fracture

Abstract

We read with great interest the article titled ‘‘Use of blocking screws in intramedullary fixation of subtrochanteric fractures’’ by Amin et al. [1]. We congratulate the authors on their success in using intramedullary nailing in conjunction with the placement of blocking screws to treat six patients with subtrochanteric fractures. All their patients demonstrated satisfactory results, with alignment and bony union maintained at the final radiographic followup. These types of fractures present with characteristic musculature-induced difficulties to control reduction. The abductors and short external rotators insert over the greater trochanter, and the lesser trochanter is the insertion site for the iliacus and psoas hip flexors. These muscles cause the proximal fragment to develop a flexed, abducted and externally rotated position after a fracture [2]. This deformity cannot be resolved with traction on the fracture table with traction, and it is difficult to find a precise point of entry and achieve excellent reduction. Sadighi et al. [3] reported that percutaneously placed Schanz screws used as joysticks could facilitate closed reduction. Kim et al. [4] described a procedure in which they reamed the proximal fragment progressively up to 13 mm, selected a nail that was 2–3 mm smaller than the estimated diameter of the isthmic portion, and inserted the nail into the proximal fragment and manipulated it in an extended, adducted, and internally rotated direction to achieve good reduction and cross the fracture site. Otherwise, the proximal fragment would have a larger canal diameter compared with the distal fragment, and inadequate alignment with translation would be noted if the proximal reamed canal deviated toward the medial or lateral cortex. Krettek et al. [5] described the clinical application of Poller screws to prevent axial deformities during intramedullary nailing for proximal and distal tibial fractures during intramedullary nailing. Amin et al. [1] termed these screws ‘‘blocking screws’’ and applied them to the proximal femoral fragment, separately targeting the medial one-third and posterior one-third. We developed a simple synthesized technique using the Schanz screw as a joystick and the Poller screw for treatment of subtrochanteric or proximal femoral fractures. With the injured limb under traction on the fracture table, one Schanz screw is inserted over the proximal fragment under fluoroscopic guidance and pushed to cause proximal fragment adduction. It is convenient to find a precise entry point for the nail. A ball-tip guide wire is inserted into the proximal canal after using an awl to create the entry point. The Shanz screw is unscrewed until the lateral third of the canal is occupied as Poller screw. The Schanz screw is maintained in position to keep the make medial cortex contact (extended, adducted, and internally rotated), and the guide wire is progressed across the fracture site. This is C.-Y. Chen K.-C. Lin (&) S.-W. Yang Y.-W. Tarng C.-J. Hsu J.-H. Renn Department of Orthopaedics, Kaohsiung Veterans General Hospital, 386 Ta-Chung 1st Road, Kaohsiung, Taiwan e-mail: orthokcl@gmail.com