The progress of research on crankshaft phenomenon

The Crankshaft Phenomenon (CSP) is a significant complication that can occur after posterior spinal fusion, particularly in growing patients with scoliosis. It results from continued anterior spinal growth while the posterior column remains fused, leading to progressive spinal deformities such as loss of correction, increased vertebral rotation, and rib prominence. This phenomenon has been predominantly observed in pediatric patients with idiopathic, congenital, and neuromuscular scoliosis. Although clinical symptoms may be subtle, radiographic signs are crucial for diagnosis but can be challenging to evaluate due to postoperative changes and instrumentation. Current treatment options are limited, often requiring revision surgeries in cases of progressive deformities. This review aims to provide a comprehensive overview of the current understanding of CSP, including its pathophysiology, diagnostic challenges, risk factors, prevention strategies, and potential treatments.