Current diagnostic methods for detecting avascular necrosis and irreversible bone death of the proximal pole of the scaphoid: a systematic review

INTRODUCTION: Owing to the scaphoid's retrograde blood supply, fractures can compromise perfusion to the proximal pole, making it vulnerable to avascular necrosis (AVN) or irreversible bone death. Despite their differing prognoses, both conditions are evaluated using the same diagnostic methods. This review aims to determine the most reliable method of distinguishing between AVN and irreversible bone death, considering factors such as magnetic resonance imaging (MRI), computed tomography (CT), intraoperative findings, and histology. METHODS: A comprehensive literature search was conducted until November 2024. The diagnostic methods and criteria for AVN were collected, and the outcome was measured dichotomously as either resolution of AVN or irreversible bone death. Each AVN diagnostic method was categorized and the healing outcomes of all patients diagnosed with AVN in the study were compared. RESULTS: This systematic review included 27 studies and 423 patients. With regard to AVN healing, 195 out of 223 patients diagnosed with AVN via MRI eventually healed. Of those diagnosed with AVN via CT, nine out of 21 went on to heal, as did 308 out of 356 patients with no intraoperative punctate bleeding. Histologic evaluation had the lowest incidence of AVN resolution, with only six out of 19 patients healing. CONCLUSION: All diagnostic methods identified AVN resolution and irreversible bone death. However, all patients were solely diagnosed with AVN. There is no standardized method for diagnosing irreversible bone death because the existing literature conflates irreversible bone death with AVN, despite their distinct pathologies and prognoses. Consequently, our understanding of AVN and the point at which irreversible bone death occurs in the scaphoid is limited.