[Percutaneous endoscopic Key-Hole technology for treatment of paracentral cervical disc herniation]

To investigate the effectiveness of percutaneous endoscopic posterior cervical Key-Hole fenestration decompression and nucleus pulposus extirpation in the treatment of paracentral cervical disc herniation.

Between December 2015 and October 2018, 29 cases of paracentral cervical disc herniation were treated with percutaneous endoscopic posterior cervical Key-Hole fenestration decompression and nucleus pulposus extirpation. There were 16 males and 13 females, with an average age of 49.7 years (range, 39-78 years). The disease duration was 3.5-15.0 months (mean, 6.2 months). The herniated disc located at C _{3, 4} in 2 cases, C _{4, 5} in 5 cases, C _{5, 6} in 9 cases, C _{6, 7} in 12 cases, and C ₇, T ₁ in 1 case. The main symptoms were radiculopathy symptom. The operation time, intraoperative blood loss, hospital stay, and complications were observed and recorded. Visual analogue scale (VAS) score, Japanese Orthopaedic Association (JOA) score, cervical range of motion (ROM), Macnab standard, and cervical segment stability were used to evaluate the efficacy and safety of the operation.

All patients were followed up 11-43 months, with an average of 19.4 months. The operation time was 67-89 minutes (mean, 73.3 minutes); the intraoperative blood loss was 18-30 mL (mean, 22.9 mL); the hospital stay was 5-10 days (mean, 7.3 days). All the incisions healed by first intention. There was 1 case of hypodynia and hyperalgesia in the affected limb after operation,1 case of decreased limb muscle strength. The VAS scores and JOA scores at each time point after operation were superior to those before operation ( P<0.05). There was no significant difference between the time points after operation ( P>0.05). At last follow-up, the effectiveness was rated according to the Macnab standard as excellent in 11 cases, good in 15 cases, fair in 2 cases, and bad in 1 case, with an excellent and good rate of 89.7%. The CT and MRI showed the decompression of spinal canal and nerve canal. There was no significant difference in cervical ROM between pre- and post-operation ( t=1.427, P=0.165), and no surgical segment instability occurred by X-ray films of flexion and extension of cervical vertebrae.

For the paracentral cervical disc herniation with simultaneous compression of nerve roots and spinal cord, percutaneous endoscopic posterior cervical Key-Hole fenestration decompression and nucleus pulposus extirpation has the advantages of small trauma, quick recovery, and satisfactory effectiveness, and can be used as a safe and effective minimally invasive procedure.