Multifactorial Non-union After First Metatarsophalangeal Arthrodesis Revised With Structural Iliac Crest Autograft: A...

First metatarsophalangeal (MTP-I) arthrodesis is a reliable procedure for end-stage hallux rigidus and selected complex first-ray deformities. Non-union is uncommon but clinically important, particularly when associated with pain, osteolysis, implant fatigue, and loss of correction. Revision is challenging because failure is usually multifactorial rather than the consequence of an isolated implant problem.

A 62-year-old woman with a 45 pack-year smoking history underwent MTP-I arthrodesis for advanced hallux rigidus with hallux varus and associated lesser-toe deformity. The index procedure used cup-and-cone joint preparation and dorsal plate fixation. Radiographs at 3 months showed maintained alignment but incomplete consolidation. Progressive pain and swelling developed during weight-bearing, and at 6 months radiographs demonstrated dorsal plate breakage. Computed tomography (CT) confirmed established pseudarthrosis with osteolysis involving the base of the proximal phalanx. Before revision, white blood cell count, erythrocyte sedimentation rate, and C-reactive protein were normal; intraoperative cultures obtained during revision were negative. Revision included removal of failed hardware, complete debridement of fibrous pseudarthrosis and sclerotic bone, insertion of a tricortical iliac crest autograft to restore length and bone stock, interfragmentary compression screw fixation, stronger revision dorsal plating, correction of the second-ray deformity, and prolonged post-operative protection. Smoking cessation was achieved after revision.

The post-operative course was uncomplicated. At 3 months, the patient walked in regular footwear without pain or swelling. CT at 6 months demonstrated graft incorporation, bridging trabecular bone and stable fixation. The American Orthopaedic Foot and Ankle Society hallux metatarsophalangeal-interphalangeal score improved from 29/100 before revision (pain 0, function 29, and alignment 0) to 85/100 after revision (pain 30, function 40, and alignment 15).

Failed MTP-I arthrodesis should be analyzed systematically through biological, mechanical, and whole-forefoot factors. Structural autografting, compression-based revision fixation, correction of associated deformity, and individualized protection can achieve union even after plate breakage and established pseudarthrosis.