颈椎后纵韧带骨化合并硬脊膜骨化的影像学表现及颈椎前入路显微手术治疗

Cervical ossified posterior longitudinal ligament with dural ossification: imaging features and microsurgery through trans-anterior cervical approach

目的探讨颈椎后纵韧带骨化(OPLL)合并硬脊膜骨化(DO)的影像学表现及颈椎前入路显微手术疗效。方法2015年1月至2020年1月浙江省人民医院神经外科采用经颈椎前入路显微外科手术治疗颈椎OPLL合并DO患者12例,回顾性分析影像学特征、显微外科手术疗效及并发症情况。结果12例患者骨化的后纵韧带和硬脊膜累及范围涉及1~4个颈椎节段,所致的椎管狭窄率为32%~70%;根据颈椎节段形态分为局限型4例、节段型3例、连续型4例和混合型1例;骨化物呈单层征5例,双层征7例,其中有4例合并钩状结构。12例患者均顺利完成手术,其中3例行颈前路椎间盘切除植骨融合内固定术,9例行颈前路椎体次全切除植骨融合内固定术;术中采用浅层硬脊膜切开+半层硬脊膜保留技术切除骨化物7例,漂浮技术减压2例,骨化物切除+硬脊膜修补技术3例。术后3个月X线片检查示颈椎椎间融合器和钛网位置良好,内固定钛板位置准确,椎体间固定融合效果良好;CT和MRI检查示骨化的后纵韧带及硬脊膜全切除10例,“蛋壳化”薄层骨化物残留2例,脊髓及神经根减压效果均满意。3例因手术致硬脊膜破裂而发生脑脊液漏,经硬脊膜缝合或修补、术后引流及颈部加压包扎后消失。术后1年日本骨科协会评分较术前明显提高(P<0.05)。结论双层征、钩状结构是OPLL合并DO的特征性影像学表现;颈椎前入路显微手术可安全有效地切除短节段颈椎骨化的后纵韧带和硬脊膜,达到直接减压的目的,但应注意预防和处理硬脊膜破裂伴脑脊液漏等并发症。

Objective To investigate the image features of cervical ossified posterior longitudinal ligament with dural ossification(OPLL/DO)and the efficacy of microsurgical treatment by trans-anterior cervical approach.Methods The clinical data of 12 patients with OPLL/DO treated by microsurgery through trans-anterior cervical approach in Zhejiang Provincial People's Hospital during January 2015 to January 2020 were analyzed retrospectively.The image features and therapeutic efficacy were observed.Results The OPLL/DO lesions involved 1 to 4 segment of cervical vertebra and the incidence of cervical stenosis was 32%-70%in all of 12 cases.Based on the classification of OPLL,there were 4 cases of circumscribed type,3 cases of segmental type,4 cases of continuous type and 1 case of mixed type.A single-layer sign of cervical OPLL was observed in 5 cases and a double-layer sign was in 7 cases.Among them,a hook-like structure merged together in 4 cases.The operations were performed successfully in all of 12 cases.The operation of anterior cervical discectomy and fusion was performed in 3 patients,anterior cervical corpectomy and fusion was in 9 cases.During the operation,the procedure of superficial dural incision and half-layer dural preservation technique for removing ossified objects was administrated in 7 cases,floating technique was used in 2 patients for decompression and 3 cases was by ossified objects resection spinal dural repair technique.Three months after surgery,the X-ray examination showed the good location of both cervical intervertebral fusion cage and titanium mesh.The accurate location of internal fixated titanium plate was also revealed with good effect of intervertebral fixation and fusion.DO was totally removed in 10 patients and eggshell-like calcified lamella was reserved in 2 cases as demonstrated in CT and MR images.Full decompression was achieved in all patients.In 3 cases,the surgery-caused cerebrospinal fluid leakage was managed and cured by spinal dural repairing,drainage and local pressing.The postoperative JOA score assessed after 1-year followed-up was significantly higher than that of preoperatively(P<0.05).Conclusion The double-layer sign and a hook-like structure may be characteristic for the diagnosis of OPLL with DO.The microsurgery through trans-anterior cervical approach can effectively and safely resect the short-segment ossified cervical posterior longitudinal ligament for cervical spinal decompression,but attention should be paid to prevent and manage dural rupture with cerebrospinal fluid leakage and other complications.