Poller (blocking) screw with intramedullary femoral nailing for subtrochanteric femoral non-unions: clinical outcome and review of concepts.

Abstract

Surgery to treat nonunion resulted from malalignment is challenging since correction and bone union should be achieved simultaneously. To report the clinical outcomes achieved through reconstruction of sub-trochanteric femoral fractures by femoral nailing using a poller screw and to review the current concepts. Fourteen patients (11 men and 3 women; mean age 56.4years) who were diagnosed with non-union of subtrochanteric femoral fractures and who underwent intramedullary nailing with blocking screws between August 2013 and March 2019, with at least 1year follow-up, were analyzed retrospectively. The preoperative and postoperative Centrum-Collum-Diaphyseal angle and anterior angulation angle were measured. Bone union time, position and number of poller screws used, and complications were analyzed. Functional assessment was performed by evaluating the Harris hip score. The related literature was searched, and 14 clinical studies on the treatment of sub-trochanteric non-union were analyzed. Bone union was achieved in 12/14 cases (85.7%) at the final follow-up within a mean of 6.52 (3-12)months. Bone union was also achieved in two patients lacking bone union at the final follow-up through bone grafting and augmented plating. No cases developed complications, including infection and bone necrosis, and the varus deformity and anterior angulation significantly improved from a preoperative mean of 12.4° and 9.4° to postoperative mean 3.8° and 2.4°, respectively. The mean Harris hip score at the final follow-up was 87.07 (73-98) points. Analysis of published literature revealed high rates of bone union (78-100%) through various fixation methods. Correction with blocking screws and rigid fixation with intramedullary nailing to treat sub-trochanteric-non-union-caused malalignment can yield good clinical and radiological outcomes.