From the Department of Orthopedic Surgery (Dr. Comadoll, Dr. Holton, Dr. Polly, Mr. Schmitz, Dr. Haselhuhn, Dr. Soriano, Dr. Martin, and Dr. Sembrano) and the Department of Neurosurgery (Dr. Polly and Dr. Jones), University of Minnesota, Minneapolis, MN.
J Am Acad Orthop Surg Glob Res Rev. 2023 Aug 4;7(8). doi: 10.5435/JAAOSGlobal-D-23-00039. eCollection 2023 Aug 1.
We present a case series of proximal junctional failure due to a Chance-type fracture.
This is a retrospective review of patients who developed proximal junctional kyphosis because of Chance-type proximal junctional failure after spinal fusion for adult spinal deformity.
Fifteen patients were identified (4M:11F). The average age was 61.4 years (range, 39 to 77). The mean time to fracture identification was 25.4 days (range, 3 to 65). The average number of levels instrumented was 6.7 (range, 2 to 17). No patients had antecedent trauma before fracture onset. In 67% of cases with a lumbar upper instrumented vertebra (UIV), there was overcorrection of lumbar lordosis (LL) and/or lower LL. The five cases with a lower thoracic UIV had undergone notable correction of preoperative thoracolumbar junction kyphosis. 14 of 15 patients were treated with extension of fusion. Pedicle screws at the fracture level were salvaged by changing to an anatomic trajectory.
Continued pain at 6 to 12 weeks with radiographs showing an increased proximal junctional angle and cephalocaudal pedicle widening at the UIV should raise suspicion for this unique fracture pattern. A CT scan is recommended. Low bone density, LL and/or lower LL overcorrection, and selection of lower thoracic UIV in the setting of notable thoracolumbar junction correction may contribute to fracture risk.
我们报告了一系列因 Chance 型骨折导致近端交界区失败的病例。
这是一项回顾性研究，纳入了因脊柱融合术后发生 Chance 型近端交界区失败而导致近端交界区后凸的成人脊柱畸形患者。
共确定了 15 例患者（4 例男性，11 例女性）。平均年龄为 61.4 岁（范围 39 岁至 77 岁）。骨折识别的平均时间为 25.4 天（范围 3 天至 65 天）。平均植入节段数为 6.7（范围 2 个至 17 个）。在骨折发生前，没有患者有明确的外伤史。在 67%的腰椎上位椎弓根螺钉（UIV）中，存在腰椎前凸（LL）和/或下 LL 的过度矫正。5 例下胸椎 UIV 患者术前胸腰椎交界处后凸有显著矫正。15 例患者中有 14 例接受了融合的延长治疗。通过改变解剖轨迹，保留骨折水平的椎弓根螺钉。
术后 6 至 12 周持续出现疼痛，X 线片显示 UIV 处近端交界角增加和头尾侧椎弓根增宽，应怀疑这种独特的骨折模式。建议进行 CT 扫描。骨密度低、LL 和/或下 LL 过度矫正，以及在明显胸腰椎交界处矫正的情况下选择下胸椎 UIV，可能会增加骨折风险。
