Strain-guided revision of failed femoral shaft nonunion using a hybrid dual-plane construct around a retained dynamic hip lag screw

Abstract

Femoral shaft nonunion remains a challenging complication after high-energy trauma and internal fixation, and although exchange intramedullary nailing is widely accepted as the standard surgical strategy for aseptic femoral shaft nonunion, complex anatomical and mechanical situations may require alternative approaches. We report the case of a 45-year-old male who developed a painful aseptic femoral shaft nonunion with implant failure following fixation of an ipsilateral femoral shaft and femoral neck fracture. Revision surgery was performed using a strain-guided strategy. The dynamic hip screw (DHS) barrel plate was removed while the lag screw inserted for the femoral neck fracture was intentionally retained. Following meticulous debridement to bleeding bone, medullary canal recanalization and defect grafting, a hybrid dual-plane construct consisting of an anterior plate and a long barrel DHS plate was applied with controlled interfragmentary compression. Postoperatively, the patient progressed with protected weight bearing and subsequent gradual rehabilitation. Serial radiographs demonstrated maintained alignment, stable fixation and progressive bridging callus, and final follow-up confirmed solid fracture union with complete resolution of thigh pain and functional improvement. This case demonstrates that deliberate strain-guided construct redesign, selective implant retention and multiplanar stability can represent an effective and reproducible alternative strategy for femoral shaft nonunion in carefully selected patients, particularly when conventional exchange nailing is limited by associated proximal femoral fixation.