Wang Lijun, Yang Huilin, Shi Yuanxin, Luo Zongping, Jiang Weimin, Bao Zhaohua, Chen Kangwu, Wang Genlin
Department of Orthopaedic Surgery, The No. 2 People’s Hospital of Changshu, Changshu, China.
Orthopedics. 2012 Aug 1;35(8):e1225-30. doi: 10.3928/01477447-20120725-24.
The literature is inconclusive on the development of adjacent-level vertebral fracture after initial cement augmentation. A preliminary hypotheses is that cement injection exaggerates force transmission to the adjacent vertebral bodies, thereby predisposing those levels to future fractures. A sandwich vertebra is an intact vertebral body located between 2 previously cemented vertebrae. The purpose of this study was to determine whether the risk of adjacent-level fracture increased due to load shift after a cement injection procedure. The authors retrospectively investigated the rate of adjacent-level fracture after sandwiching compared with conservative treatment and determined the potential causative factors of sandwich vertebral fracture. Age, sex, weight, height, body mass index, follow-up period, and location of sandwich level (T10-L2 or nonT10-L2 junction) were assessed. Surgical variables, including surgical procedure (vertebroplasty or balloon kyphoplasty), surgical approach (through uni- or bilateral pedicle), volume of cement injected into the painful vertebrae, cement leakage into the intervertebral disk, cumulative number of treated levels, and pre- and postoperative kyphotic angulation of the sandwich region, were also analyzed. Nine of 42 sandwiched levels developed fatigue fractures, whereas 11 of 71 patients treated with conservative therapy sustained new vertebral fractures adjacent to the treated levels. Only preoperative kyphotic angulation was the variable positively associated with sandwich vertebral fracture at follow-up (P=.021). Although subjected to double load shifts, the sandwich vertebra was not prone to structural failure. Thus, cement augmentation protocol does not increase the incidence of adjacent vertebral fracture.
关于初次骨水泥强化后相邻节段椎体骨折的发生，文献尚无定论。一个初步假说是，骨水泥注射会加剧向相邻椎体的力传递，从而使这些节段更容易发生未来骨折。夹心椎体是位于两个先前已进行骨水泥强化的椎体之间的完整椎体。本研究的目的是确定骨水泥注射术后负荷转移是否会增加相邻节段骨折的风险。作者回顾性研究了夹心椎体与保守治疗相比相邻节段骨折的发生率，并确定了夹心椎体骨折的潜在致病因素。评估了年龄、性别、体重、身高、体重指数、随访时间以及夹心节段的位置（T10-L2或非T10-L2节段交界处）。还分析了手术变量，包括手术方式（椎体成形术或球囊后凸成形术）、手术入路（单侧或双侧椎弓根）、注入疼痛椎体的骨水泥量、骨水泥渗漏至椎间盘、治疗节段的累计数量以及夹心区域术前和术后的后凸角度。42个夹心节段中有9个发生了疲劳骨折，而71例接受保守治疗的患者中有11例在治疗节段附近出现了新的椎体骨折。随访时，仅术前后凸角度是与夹心椎体骨折呈正相关的变量（P = 0.021）。尽管承受了双重负荷转移，但夹心椎体并不容易发生结构破坏。因此，骨水泥强化方案不会增加相邻椎体骨折的发生率。
