Ma Litai, Liu Hao, Gong Quan, Li Tao, Song Yueming, Zeng Jiancheng, Liu Limin
Department of Orthopedics, West China Hospital, Sichuan University, Chengdu Sichuan 600041, PR China.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2009 Nov;23(11):1329-33.
To explore the correlation between the inserting angle of vertebral screws and the extent of post-operative lateral angulation instantly in surgery via anterior approach for thoracolumbar fractures.
The clinical data were from 172 patients consecutively treated with surgery via anterior approach in thoracic and lumbar fractures between May 2004 and January 2008. These cases included 124 males and 48 females at the age of 15-70 years old (mean 39 years old). One fracture were located at T11, 37 at T12, 88 at L1, 30 at L2, 15 at L3, 3 at L4. One segment was involved in 170 cases and two segments in 2 cases. According to Frankel assessment for neurological status, there were 19 cases of grade A, 24 cases of grade B, 45 cases of grade C, 53 cases of grade D, and 31 cases of grade E. The time from injury to operation was 2-30 days (median 8 days). According to the coronal Cobb angle instantly after surgery, the patients were divided into three groups: 0-5 degrees group, 5-10 degrees group and over 10 degrees group. Every group was further divided into four subgroups according to the type of the internal fixation instruments: Z-plate subgroup, Antares subgroup, Profile subgroup and single screw rod (SSR) subgroup. Radiograph images were used to evaluate the coronal Cobb angle and inserting angle between the screws and end-plates. The screws were named as A, B, C and D in vertebral bodies from the cephalic to the caudal portion. The angles between the superior endplate and the screws A, B were named as angles A, B, and the angles between the inferior endplate and the screws C, D were named as angles C, D. The differences were compared between the screw's inserting angle A+D (or/and B+C) and the post-operative coronal Cobb angle instantly, and linear regression analysis was done. The satisfaction survey was accomplished.
Surficial infection occurred in 1 patient at 7 days and incision healed well after debridement; other incisions healed by first intention. A total of 172 cases were followed up for 6-49 months (mean 39 months). The degree of satisfaction was 3-10 points, median 8.5 points. Various degrees of neurological function recovered in final follow-up except patients for Frankel A grade. The mean coronal Cobb angles were (0.75 +/- 3.91) degrees for pre-operatively, (3.17 +/- 4.07) degrees for instantly post-operatively and (3.46 +/- 4.21) degrees at last follow-up; showing statistically differences between pre-operatively and instantly post-operatively, between pre-operatively and at last follow-up (P < 0.05). Comparing the screw's inserting angle A+D (or/and B+C) and the coronal Cobb angle, there was statistically significant difference between Z-Plate subgroup and other subgroups in 0-5 degrees group (P < 0.05), and there were no statistically significant differences between other subgroups in each group (P > 0.05). Except the screw's inserting angle A+D (Z-Plate and SSR subgroups) and angle B+C (Antares subgroup) in 0-5 degrees group, the post-operative coronal Cobb angle correlated closely with the screw's inserting angle A+D (or/and B+C) in other subgroups of 3 groups.
Nonparallelism between the vertebral screws and the correlative end plate is one of the main causes of post-operative spinal lateral angulation.
探讨胸腰椎骨折前路手术中椎弓根螺钉置入角度与术后即刻侧方成角程度的相关性。
临床资料来自2004年5月至2008年1月连续行胸腰椎骨折前路手术治疗的172例患者。其中男性124例，女性48例，年龄15 - 70岁（平均39岁）。骨折部位：T11 1例，T12 37例，L1 88例，L2 30例，L3 15例，L4 3例。单节段损伤170例，双节段损伤2例。根据Frankel神经功能分级，A级19例，B级24例，C级45例，D级53例，E级31例。受伤至手术时间为2 - 30天（中位数8天）。根据术后即刻冠状面Cobb角将患者分为三组：0 - 5度组、5 - 10度组和大于10度组。每组再根据内固定器械类型分为四个亚组：Z-plate亚组、Antares亚组、Profile亚组和单螺杆（SSR）亚组。采用X线片评估冠状面Cobb角及螺钉与终板的置入角度。椎体从上至下的螺钉分别命名为A、B、C、D。上端板与螺钉A、B的夹角分别命名为A角、B角，下端板与螺钉C、D的夹角分别命名为C角、D角。比较螺钉置入角度A + D（或/和B + C）与术后即刻冠状面Cobb角的差异，并进行线性回归分析。进行满意度调查。
1例患者术后7天发生浅表感染，清创后切口愈合良好；其他切口一期愈合。172例患者均获随访，随访时间6 - 49个月（平均39个月）。满意度评分3 - 10分，中位数8.5分。末次随访时，除Frankel A级患者外，其余患者神经功能均有不同程度恢复。术前冠状面Cobb角平均为（0.75 ± 3.91）度，术后即刻为（3.17 ± 4.07）度，末次随访时为（3.46 ± 4.21）度；术前与术后即刻、术前与末次随访比较，差异均有统计学意义（P < 0.05）。在0 - 5度组中，Z-Plate亚组与其他亚组比较，螺钉置入角度A + D（或/和B + C）与冠状面Cobb角差异有统计学意义（P < 0.05），各组内其他亚组间差异无统计学意义（P > 0.05）。在三组的其他亚组中，除0 - 5度组的螺钉置入角度A + D（Z-Plate和SSR亚组）和角度B + C（Antares亚组）外，术后冠状面Cobb角与螺钉置入角度A + D（或/和B + C）密切相关。
椎弓根螺钉与相关终板不平行是术后脊柱侧方成角的主要原因之一。
