1型神经纤维瘤病合并萎缩性腰椎侧凸术后 冠状面失代偿的发生率及转归

Postoperative Coronal Imbalance in Dystrophic Lumbar Scoliosis Secondary to Neurofibromatosis Type 1: Incidence and Outcomes

摘要: 目的：通过1型神经纤维瘤病合并萎缩性腰椎侧凸(Dystrophic lumbar scoliosis secondary to type 1 neurofibromatosis, DLS-NF1)患者的影像学数据，评估并分析术后冠状面失代偿的发生率及转归。方法：回顾性分析2007年1月至2018年3月于南京市鼓楼医院接受手术的DLS-NF1患者的病历及影像学资料。根据术前冠状面平衡的鼓楼分型分为3型：A型——术前冠状面平衡距离(Coronal balance distance, CBD) ≤ 30 mm，B型——术前CBD > 30 mm且C7铅垂线向凹侧偏移，C型——术前CBD > 30 mm且C7铅垂线向凸侧偏移，根据术后即刻影像学参数分为冠状面失平衡(coronal imbalanced)组(CIB组)和冠状面平衡(coronal balanced)组(CB组)。记录患者的术前、术后即刻及末次随访时的影像学参数：包括脊柱Cobb角(主弯、代偿弯)，CBD，远端固定椎(Lowest Instrumented Vertebra, LIV)，远端代偿椎间盘数目，并记录其冠状面形态的变化情况。结果：本研究共纳入39例DLS-NF1患者，其中26例(66.7%)男性，13例(33.3%)女性。平均随访时间为34.1 ± 26.2个月。术前冠状面平衡(鼓楼A型)患者22例(56.4%)，术前冠状面失衡(鼓楼C型)患者17例(43.6%)。术后即刻CIB组23例(59.0%)，CB组16例(41.0%)，两组术前主弯角度分别为CIB组57.3˚ ± 19.7˚和CB组62.3˚ ± 16.9˚，术后分别矫正至20.5˚ ± 12.1˚和26.0˚ ± 19.5˚，末次随访时分别为22.2˚ ± 12.5˚和29.4˚ ± 20.3˚。术后矫正率分别为65.1% ± 13.8%和61.6% ± 22.9%。13.04% (3例)的CIB组患者远端代偿椎间盘数目 ≥ 2个，CB组中则为68.75% (11例)，两组间差异有统计学意义(P < 0.001)；在远端椎间盘代偿数量 < 2的组别中，CIB组共有20例，CB组则为5例，两组间差异有统计学意义(P < 0.001)。两组术前CBD分别为(24.7 ± 19.5) mm和(21.3 ± 16.8) mm，术后为(41.6 ± 10.8) mm和(13.3 ± 11.1) mm，差异有统计学意义(P < 0.001)。术前分型为冠状面平衡组的患者中有9例术后早期出现冠状面失平衡，而术前鼓楼C型患者中有14例术后早期仍保持冠状面失平衡，差异有统计学意义(P = 0.020)。在末次随访时，共有37例(94.8%)鼓楼A型患者，1例(2.5%)鼓楼B型患者及1例(2.5%)鼓楼C型患者。结论：DLS-NF1患者术后早期冠状面失代偿发生率较高(59.0%)，主要受术前鼓楼C型冠状面失衡、主弯矫正率偏高及远端代偿椎间盘不足(LIV延伸至L3以下)驱动，但绝大多数患者在远期随访中最终能通过自发重塑获得满意的冠状面平衡与临床结局。

Abstract: Objective: Through the imaging data of patients with dystrophic lumbar scoliosis secondary to type 1 neurofibromatosis (DLS-NF1), the incidence and outcome of postoperative coronal decompensation were evaluated and analyzed. Methods: The medical records and imaging data of patients with DLS-NF1 who underwent surgery in Nanjing Drum Tower Hospital from January 2007 to March 2018 were retrospectively analyzed. According to the drum tower classification of preoperative coronal balance, it was divided into three types: type A—preoperative coronal balance distance (CBD) ≤ 30 mm, type B—preoperative CBD > 30 mm and C7 plumb line shifted to the concave side, type C—preoperative CBD > 30 mm and C7 plumb line shifted to the convex side. According to the immediate postoperative imaging parameters, it was divided into coronal imbalance group (CIB group) and coronal balance group (CB group). The preoperative, immediate postoperative and final follow-up imaging parameters of the patients were recorded, including the Cobb angle of the spine (main curve, compensatory curve), CBD, Lowest Instrumented Vertebra (LIV), the number of distal compensatory intervertebral discs, and the changes of coronal morphology. Results: A total of 39 patients with DLS-NF1 were included in this study, including 26 males (66.7%) and 13 females (33.3%). The mean follow-up time was 34.1 ± 26.2 months. There were 22 patients (56.4%) with preoperative coronal balance (type A) and 17 patients (43.6%) with preoperative coronal imbalance (type C). Immediately after operation, there were 23 cases (59.0%) in CIB group and 16 cases (41.0%) in CB group. The preoperative main curve angles of the two groups were 57.3˚ ± 19.7˚ in CIB group and 62.3˚ ± 16.9˚ in CB group, which were corrected to 20.5˚ ± 12.1˚ and 26.0˚ ± 19.5˚ after operation, and 22.2˚ ± 12.5˚ and 29.4˚ ± 20.3˚ at the last follow-up. The postoperative correction rates were 65.1% ± 13.8% and 61.6% ± 22.9% respectively. 13.04% (3 cases) of the CIB group had more than 2 distal compensatory intervertebral discs, and 68.75% (11 cases) of the CB group, the difference between the two groups was statistically significant (P < 0.001); in the group with distal disc compensation < 2, there were 20 cases in CIB group and 5 cases in CB group, the difference between the two groups was statistically significant (P < 0.001). The preoperative CBD of the two groups was (24.7 ± 19.5) mm and (21.3 ± 16.8) mm, respectively, and the postoperative CBD was (41.6 ± 10.8) mm and (13.3 ± 11.1) mm, respectively, the difference was statistically significant (P < 0.001). There were 9 patients with coronal imbalance in the preoperative classification of coronal balance group, while 14 patients with preoperative tympanic floor type C still maintained coronal imbalance in the early postoperative period, and the difference was statistically significant (P = 0.020). At the last follow-up, there were 37 patients (94.8%) with type A, 1 patient (2.5%) with type B and 1 patient (2.5%) with type C of the Drum Tower. Conclusion: The incidence of early postoperative coronal decompensation in patients with DLS-NF1 was high (59.0%), which was mainly driven by preoperative tympanic type C coronal imbalance, the correction rate of the main bend is high and insufficient distal compensatory disc (LIV extended below L3), but most patients could finally obtain satisfactory coronal balance and clinical outcome through spontaneous remodeling during long-term follow-up.