Windshield Wiper Effect in Human Bone-Peri-Implant Benign Diaphyseal Expansile Lesion with Humerus Shaft Fracture Non-Union with Implant in situ - Case Report.

Introduction: Humerus shaft fractures account for 3% of all adult fractures. Union rate after surgical management is around 84-97% with no difference between compression plating and intramedullary (IM) nailing. Non-union of humeral shaft fracture is not unusual complication of both conservative and operative treatment. IM nailing has been known to have several benefits from its relative stability with minimal soft-tissue dissection but with drawbacks such as less perfect reduction with higher risk of distraction, inability to take down interpositional tissue, risk of radial nerve injury and technical difficulty to pass guide wire and locking of nail. Many methods have been described for nonunion of humeral fracture with good results. However, treatment of a long-standing nonunion of the humerus with bone defect is challenging, as it may be complicated by broken implants. Very less research documented for long standing nonunion of humeral bone with diaphyseal bone defect.

Case Report: We report a case report of middle-aged female who suffered a closed traumatic humeral shaft fracture which was managed with open reduction and fixation with IM nailing with some distraction and distal locking screw missing the nail making it an unstable construct traditionally called Wind shield, wiper effect was noticed in this patient and was the cause of nonunion in this case at some other institute 5 years back lending up in to nonunion with diaphyseal bone defect showing peri-implant expansile benign lesion treated at our institute with implant removal, excision of lytic lesion, and stabilized with extra articular distal humerus locking plate after strut fibular auto bone grafting .

Conclusion: Humerus shaft non-union in a middle-aged patient is heterogeneous entity and has to be managed after ruling out neoplastic (metastasis) as well as infective etiology, and locking plate is the gold standard for its management along with strut grafting being osteoporotic bone with some bony defect.