The indication selection of posterior percutaneous endoscopic cervical discectomy for cervical intervertebral disc herniation / 中华骨科杂志

ABSTRACT

Objective To reduce the risk of cervical spinal cord injury,the most medial point of the cervical intervertebral disc that the posterior percutaneous endoscopic sheath could reach was evaluated.And that could help to determine the indication of posterior percutaneous endoscopic cervical discectomy for cervical intervertebral disc herniation.Methods Cervical MRI images for 50 randomly selected patients,21 males and 29 females with ages from 20 to 60(average 33.5± 10.03 years),were analysed.All 50 patients underwent MRI examination at our institution between January 2014 and December 2017.As 50％ of the zygapophyseal joint was preserved,on the cross-section T2-weighted MRI images,when the sheath just touched the spinal cord,the intersection point of the medial wall of sheath and cervical spinal cord (Point L) was the most medial point of the posterior percutaneous endoscopy could get.The distance between Point L and the line through and tangent to the most lateral point of cervical disc border was the length of the line section DL.The distance between the middle sagittal line of the cervical disc and the line through and tangent to the most lateral point of cervical disc border was the length of the line section D.D1/D was the most medial distance ratio of the posterior percutaneous endoscopic cervical discectomy when 50％ of the lateral zygapophyseal joint was preserved.In the same way,D'1/D was the most medial distance ratio of the posterior percutaneous endoscopic cervical discectomy when 75％ of the lateral zygapophyseal joint was preserved.Results When 50％ of the lateral zygapophyseal joint was preserved,the upper limit of 95％ confidence intervals of the most medial distance ratio that the posterior percutaneous endoscopy could get were 78％,76％,81％,93％ in C3,4,C4,5,C5,6,C6,7 respectively.This meant that the most medial distance the posterior percutaneous endoscopy could get were the 78％,76％,81％,0.93％ of the length of the line section D in C3,4,C4,5,C5,6,C6,7 respectively.The most medial distance the posterior percutaneous endoscopy could get in C5,6 or C6,7 was longer than that in C3,4,C4,5.Conclusion When 50％ of the lateral zygapophyseal joint was preserved,the upper limit of the most medial distance ratio that the posterior percutaneous endoscopy should get were 78％,76％,81％,93％ in C3,4,C4,5,C5,6,C6,7 respectively.This meant that the most medial distance the posterior percutaneous endoscopy could get were the 78％,76％,81％,93％ of the length of line section D in C3,4,C4,5,C5,6,C6,7 respectively.If the resected disc was beyond this range,the cervical spinal cord should be in the risk of being injured.