Combined monolateral external fixation and intramedullary nailing for oligotrophic femoral nonunion with limb length discrepancy: a case series of technical strategy and surgical outcomes.

Bone lengthening using a monolateral external fixator is an effective technique for treating femoral nonunion associated with limb length discrepancy (LLD). This method involves gradual femoral lengthening to correct shortening and rotational deformities, while promoting bone healing through compression at the nonunion site. We present a case series of three patients demonstrating the successful integration of monolateral external fixation with intramedullary nailing for oligotrophic nonunions (4-8 cm LLD). Preoperative planning includes assessment of limb length discrepancy, evaluation the cause of nonunion, and selection of appropriate implant and surgical strategies. During surgery, a controlled corticotomy and correction of rotational deformity were performed, followed by application of a monolateral external fixator. Gradual distraction was initiated after a latency period, allowing for simultaneous correction of the limb length and compression at the nonunion site. All patients achieved radiographic union and LLD correction within 6-8 months, returning to pain-free ambulation. This combined approach offers biological and mechanical advantages in the management of complex femoral nonunions, while preserving patient mobility during treatment.