单开门椎管扩大成形术后颈椎曲度与C_5神经根麻痹的关系

目的探讨单开门椎管扩大成形术后颈椎曲度与C5神经根麻痹发生率的关系。方法对254例颈椎病患者采取3种不同术式治疗:A组(126例)行颈椎单开门椎管成形术;B组(70例)行颈椎单开门椎管成形+未明显改变颈椎曲度的后路内固定术;C组(58例)行颈椎单开门椎管成形+明显改变颈椎曲度的后路内固定术。结果患者均获得随访,时间12~18个月。X线、MRI和CT检查显示:3组患者脊髓均有不同程度的向后漂移,侧块螺钉均没有进入椎间孔和椎管内,椎板没有再关门,椎板合页处没有向内陷入椎管,亦没有明显压迫硬膜脊髓的硬膜外血肿。A组颈椎曲度无改变;B组颈椎曲度无显著性改变;C组颈椎曲度改善明显,曲度增加值为5.3 mm±2.7 mm。18例术后发生C_5神经根麻痹,其中A组2例(1.59%)、B组4例(5.71%)、C组12例(20.69%);A、B两组比较差异无统计学意义(P0.05),A、B组与C组比较差异均有统计学意义(P0.017);脊髓型组5例(3.09%),混合型组13例(14.13%),两组比较差异有统计学意义(P0.05)。18例C_5神经根麻痹患者于术后2~4 d出现颈肩痛或原有颈肩痛加重,其中12例随后迅速出现肌力下降,而感觉减退不明显。18例均给予保守治疗,术后2~3周患者颈肩部麻痛消失;术后4~24周12例肌力下降中11例完全康复,1年后另1例C_5神经支配区肌力恢复至4+级。结论颈椎单开门椎管扩大成形术后可发生C_5神经根麻痹,无内固定时发生率最低,在颈椎生理曲度明显改变时发生率最高;术后混合型较脊髓型更易出现C_5神经根麻痹,其损伤机制可能与脊髓漂移有关。

Comparison the probability of appearing C5 nerve injury after three kinds of surgical treat-ment of cervical spondylosis

Objective To explore the relationship between the cervical curvature with the incidence of C5 nerve root palsy after single open-door posterior decompression. Methods A total of 254 cases of cervical spondylosis were treated with three different operations. Group A (126 cases) was operated by expansion of single open-door cervical laminoplasty;group B (70 cases) was operated by expansion of single open-door cervical laminoplasty and cervical lateral mass fixation with no significantly changed cervical curvature;group C (58 cases) was operated by expansion of single open-door cervical laminoplasty and cervical lateral mass fixation and rebuild physiological curvature of cervi-cal spine. Results All patients were followed up for 12~18 months. X-ray, MRI and CT showed that the spinal cords had drift back in varying degrees and all lateral mass screws were not into the intervertebral foramen and spinal canal and vertebral plate didn′t close the door again and vertebral plate hinges didn′t enter into the vertebral canals and no spinal epidural hematoma compressed the spinal cord obviously in all patients. The cervical curvatures had no change in group A. The cervical curvatures had slight change in group B. The cervical curvatures had obvious change in group C,and curvature change value was 5. 3 mm ± 2. 7 mm. Eighteen cases of patients appeard C5 nerve root palsy postoperatively. There were 2 cases of C5 nerve injury in group A and 4 cases of C5 nerve injury in group B and 12 ca-ses of C5 nerve injury in group C. The probability of appearing C5 nerve injury after three kinds of surgical treatment of cervical spondylosis were respectively 1. 59% ( group A ) , 5. 71% ( group B ) , 20. 69%( group C ) , 3. 09%(group myelopathic type) and 14. 13% (group mixed type). There was no significant difference between group A and B(P>0. 05). The difference between group C with group A and B were significant statistically (P<0. 017). Five cases of C5 nerve injury appeared in myelopathic type cervical vertebra disease, and 13 cases of C5 nerve injury appeared in the mixed type cervical spondylosis. The difference between group myelopathic type and group mixed type were significant statistically (P<0. 05). Eighteen cases of patients who had C5 nerve root palsy characterized for pain and hemp in neck and shoulder or aggravating of neck and shoulder pain and hemp, muscle strength of C5 innervation decline quickly, but hypesthsia decline were not obvious. All patients were given conservative treatment. Neck and shoulder pains of all patients disappeared after 2~3 weeks in postoperation. After 4~24 weeks, 11 cases of C5 nerve injury recovered fully. After 1 year, the another case of C5 nerve injury recovered to 4 + grade level of muscle strength of C5 innervation. Conclusions C5 nerve root injury can be appeared in all kinds of cervical spondylosis posterior expansion of open-door cervical laminoplasty. The lowest incidence rate is appeared in operation of single open-door posterior decompression. The incidence rate is lowest when cervical curvature changes significantly. The mechanism of C5 nerve root damage may have a connection with the large drift of spinal cord.