Murphy Robert F, Mooney James F
From the Department of Orthopaedics, Medical University of South Carolina, Charleston, SC.
J Am Acad Orthop Surg. 2017 Sep;25(9):e185-e193. doi: 10.5435/JAAOS-D-16-00584.
The crankshaft phenomenon, a progressive rotational and angular spinal deformity that can occur after posterior spinal surgery, has been reported in pediatric patients with idiopathic, congenital, and neuromuscular scoliosis. In the skeletally immature patient, the crankshaft phenomenon is thought to occur secondary to continued growth of the anterior elements of the spine after solid posterior spinal fusion. The condition has also been reported in the setting of newer, so-called growth-friendly posterior distraction-based spinal instrumentation. The clinical evidence of crankshaft phenomenon is often subtle, whereas radiographic findings are usually more apparent. However, objective measurement of radiographic signs may be complicated by instrumentation and postoperative changes. Treatment options for patients with the crankshaft phenomenon are limited; in those with problematic deformity and/or risk of progression, additional surgery may be indicated.
曲轴现象是一种进行性脊柱旋转和角状畸形，可发生于后路脊柱手术后，在患有特发性、先天性和神经肌肉性脊柱侧弯的儿科患者中已有报道。在骨骼未成熟的患者中，曲轴现象被认为是在坚固的后路脊柱融合术后，继发于脊柱前部结构的持续生长。在更新的、所谓的基于后路撑开的生长友好型脊柱内固定情况下，也有该情况的报道。曲轴现象的临床证据往往很细微，而影像学表现通常更明显。然而，影像学征象的客观测量可能因内固定和术后改变而变得复杂。患有曲轴现象的患者的治疗选择有限；对于那些有严重畸形和/或进展风险的患者，可能需要额外的手术。
