钛网容纳异体松质骨结合钛板内固定重建颈椎稳定性的影像学评估

Radiological assessment of cervical stability after anterior reconstruction by using titanium meshes containing allograft and titanium plate fixation

目的:以影像学评估钛网容纳异体松质骨的方式进行植骨结合钛板内固定重建颈椎稳定性的效果。方法:选取2001-04/2002-10解放军总医院骨科采用钛网容纳异体松质骨结合钛板固定治疗颈椎病的患者198例,排除存在系统性内分泌疾病可能影响骨质疏松的患者,共64例完成15个月随访。47例单纯椎间盘切除后节段间融合,行间隙减压;12例单椎体次全切除;5例为二椎体次全切除,患者均未发生钛网或钢板脱出。单节段切除病变部位间盘;两个节段以上进行多节段椎间盘切除或椎体次全切除,彻底刮除椎间盘组织、软骨终板及椎体后缘的骨赘。手术中将适量的冷冻干燥异体松质骨浸入庆大霉素生理盐水中浸润,切除椎间盘彻底减压后,测量椎间高度。将浸润后的松质骨剪成3～5mm碎块填入修剪成大小合适的钛网。将容纳异体松质骨的钛网植入椎间隙中,轻轻打入2mm左右,选择合适长度的钛板进行椎体间固定。所有病例伤口内均放置引流管,48h内拔除,术后两三天下地行走,佩带Philadelphia颈托固定两三个月。评估椎间融合的X线标准:在平片上钛网与上下椎板之间没有X线透光线或透光区,上下终板间有骨性连接,在伸屈位片上节段间没有活动。评估治疗前后单节段、双节段、三节段椎间高度:依据标准侧位X线片测量椎间隙前缘高度与后缘高度的平均值,并分析椎间融合情况。评估治疗后椎间的稳定性:依据伸屈侧位X线片。结果:按意向处理分析,纳入实验的64例患者全部完成15个月随访。①治疗前后单节段、双节段、三节段椎体间高度变化:与术前比较,术后5d、术后15个月均明显提高犤(4.5±0.6),(9.1±0.7),(9.2±0.5)mm,P均<0.05;(24.4±2.8),(36.8±2.4),(36.4±2.2)mm,P均<0.05;(43.9±3.0),(53.9±3.2),(53.5±2.7)mm,P均<0.05犦;术后5d和术后15个月基本一致(P>0.05)。②治疗后椎体间稳定性:X线片未见钛网脱出、移位或下沉进入上下椎体等情况,无钛板折断或螺丝钉脱出现象。术后5个月随访,X线片显示钛网后方椎间均有不同程度的新骨形成,少数病例MRI显示钛网中央存在长T2加权影像。③治疗后椎间融合情况:术后15个月随访,61例钛网后方均充满新骨,上下椎间骨性融合,3例钛网后方仍然存在透光区,融合率95%。结论:采用钛网容纳异体松质骨,同时结合前路钛板固定治疗颈椎病,术后椎间高度明显恢复并得到有效保持,且融合率高,融合节段稳定,未见钛网移位或下沉现象。由于术后随访时间较短,钛网内的异体骨能否被新骨替代还需要进一步观察远期疗效评定。

AIM：To assess the cervical stability after anterior reconstruction by using titanium meshes containing freeze-dried morselized cancellous allograft and titanium plate fixation by using radiological assessment. METHODS：198 patients who underwent decompression for cervical spondylotic myelopathy and reconstruction using titanium meshes containing freeze-dried morselized cancellous allograft combined with titanium plates in the Department of Orthopaedics, General Hospital of Chinese PLA from April 2001 to October 2002 were enrolled in the study. Patients with systemic endocrinopathy were excluded, and only 64 patients were followed for 15 months. Among the 64 patients, 47 had segmental fusion and decompression after intervertebral discectomy, 12 underwent subtotal resection of one vertebral body, 5 underwent subtotal resection of two vertebral bodies. No detachment of titanium mesh or plate occurred in all the 64 patients. Single segmental resection and multi-segmental resection or subtotal resection were performed, and surgical excision of osteophyte in intervertebral discs, cartilage end plate and vertebral posterior border was done. Freeze-dried morselized cancellous allograft was infiltrated in normal saline containing gentamicin, and intervertebral height was measured after complete decompression. Infiltrated cancellous sections at 3-5 mm were implanted into titanium meshes, and then the titanium meshes were implanted into intervertebral space at a deep of 2 mm and fixated with titanium plate. Drain tubes in all the patients were withdrawn within 48 hours, and the patients could recover to walk after 2-3 days. Philadelphia neck support was performed for 2-3 months. X-ray standard for assessment of intervertebral fusion： there were no X-ray or photic region in titanium meshes and between inferior and superior lamina of vertebrae, synostosis existed between end plates, no activities among segments were found. Intervertebral height： The average height of anterior border and posterior border was measured according to standard lateral X-ray picture to analyze the condition of intervertebral fusion. X-ray of lateral extension and flexion was used to assess intervertebral stability. RESULTS：According to the intention-to-treat analysis, 64 patients all completed 15-month follow-up. ①Intervertebral height of single segment, bisegment and trisegment： Compared with before operation, intervertebral height was heightened at 5 days and 15 months after operation [（4.5±0.6）, （9.1±0.7）, （9.2±0.5）mm,P 〈 0.05 ; （24.4±2.8）, （36.8±2.4）, （36.4±2.2）mm, P 〈 0.05 ; （43.9±3.0）, （53.9±3.2）, （53.5±2.7）mm, P 〈 0.05]. There was no difference between the intervertebral height at 5 days and 15 months after operation. ② Stability： There were no detachment, displacement and subsidence of titanium meshes, breakage of titanium plate or detachment of screw. New bone formation appeared at back of titanium meshes after 5 months of operation. MRI showed that there were T2 weighted image in a few cases. ③ Bony fusion between vertebral bodies was found in 61 patients and fusion rate was 95% at final follow-up. Only 3 cases had photic region in the rear of titanium meshes. CONCLUSION：Titanium meshes containing freeze-dried morselized cancellous allograft and titanium plate fixation can be used for treatment of cervical syndrome,and intervertebral height is recovered dramatically postoperatively. The fused segment is stable with a high fusion rate. There are no displacement or subsidence of titanium meshes.However, whether allograft in titanium meshes can be replaced by new bones needs further study.