Unexpected Spontaneous Consolidation of a Chronic Scaphoid Nonunion: A Report of a Rare Case and Review of Previously Published Cases

Scaphoid nonunion is a common complication of missed or inadequately treated scaphoid fractures and is generally considered an indication for surgical treatment because of the risk of progressive carpal collapse and degenerative arthritis. Spontaneous union of an established scaphoid nonunion is exceptionally rare, particularly in the presence of radiological findings suggestive of proximal pole vascular compromise. We report the case of a 23-year-old right-handed manual worker with a chronic scaphoid nonunion. The patient sustained an initial wrist injury in 2017 that was treated conservatively after normal radiographs and was subsequently lost to follow-up. Following a new wrist trauma in 2023, imaging revealed a stage IIA scaphoid nonunion according to the Alnot classification. Computed tomography demonstrated a persistent fracture line with sclerotic margins and increased density of the proximal fragment, suggestive of avascular compromise. Surgical reconstruction using a vascularized bone graft according to the Zaidemberg technique was planned. However, radiographs obtained 13 months after the diagnosis and immediately before surgery unexpectedly demonstrated complete union of the scaphoid. Computed tomography confirmed trabecular bridging and complete consolidation, leading to cancellation of the planned procedure. Spontaneous healing of an established scaphoid nonunion has been reported only rarely in the literature. Although the mechanisms remain poorly understood, progressive revascularization, favorable biological healing potential, and intrinsic mechanical stability have been proposed as possible explanations. This case highlights the exceptional possibility of spontaneous union in chronic scaphoid nonunion, even in the presence of adverse radiological features, and emphasizes the importance of repeat imaging before undertaking surgical treatment.