Unexpected viability in avascular necrosis of proximal pole of scaphoid with nonunion: a case of spontaneous revascularization.

INTRODUCTION

Avascular necrosis (AVN) of the proximal pole of the scaphoid is a well-recognized complication of scaphoid fractures, particularly when diagnosis or treatment is delayed. Due to the scaphoid's retrograde blood supply, the proximal pole is highly susceptible to ischemia, often necessitating surgical intervention to prevent long-term complications such as scaphoid nonunion advanced collapse and wrist osteoarthritis.

CASE PRESENTATION: We report a rare case of a 23-year-old male who sustained a scaphoid fracture that was initially misdiagnosed as a wrist sprain. The patient presented 8 months later with persistent wrist pain. Imaging revealed a nonunion fracture of the proximal scaphoid, with magnetic resonance imaging (MRI) findings suggestive of AVN. He was advised to undergo surgery but was lost to follow-up for 2 months. During this 2-month period, he received conservative management and, surprisingly, intraoperatively, the proximal fragment appeared viable with callus formation, contradicting the radiological diagnosis of AVN with nonunion. He underwent a decompression procedure instead of definitive AVN surgery and recovered uneventfully.

DISCUSSION: This case challenges the traditional belief that AVN of the proximal scaphoid is irreversible. Possible mechanisms for spontaneous revascularization include partial preservation of microvascular supply, angiogenesis mediated by hypoxia-induced factors, and collateral circulation from the surrounding soft tissues.

CONCLUSION

This case highlights that MRI findings alone may overestimate AVN in proximal pole scaphoid fractures, and that intraoperative assessment remains essential for determining true bone viability. Spontaneous revascularization, though rare, is possible and should inform individualized management decisions.