1. 2022;25;E1289-E1296Postoperative Upper-limb Palsy After Posterior Percutaneous Endoscopic Cervical Foraminotomy and Discectomy
   Observational Study
   Xin Gu, MD, Yanhai Xi, MD, Bing Xiao, MD, Liang Tang, MD, Gonghao Zhang, MD, Weiheng Wang, MD, and Xiaojian Ye, MD.

BACKGROUND: Postoperative upper-limb palsy (ULP) is a serious complication after cervical spine surgery. ULP after posterior percutaneous endoscopic cervical foraminotomy and discectomy (PPCED) has not yet been reported.

OBJECTIVE: To introduce cases of postoperative ULP after PPCED and associated risk factors.

STUDY DESIGN: A single-center, retrospective, observational study.

SETTING: Shanghai Changzheng Hospital, Naval Medical University, Shanghai, China.

METHODS: From January 2016 through January 2022, PPCED involving a total of 663 segments was performed in 610 patients with radiculopathy who were diagnosed with cervical radiculopathy or mixed cervical spondylosis caused by foraminal stenosis or posterolateral disc herniation.

RESULTS: PPCED was successfully completed in 610 patients, 6 of whom (0.98%) developed ULP. Two patients were diagnosed with double-segment cervical nerve root canal stenosis (C4/5/6, C5/6/7) and 2 with migrated cervical disc soft herniation (a magnetic resonance image of one showed a migrated disc herniation downward from C4/5 in the sagittal plane; another showed this upward from C5/6); one patient was diagnosed with C5/6 intervertebral foraminal stenosis, and one had simple C4/5 lateral disc herniation. Postoperative ULP rates for C4/5 (2/30, 6.67%) and C5/6 (2/177, 1.13%) were much higher than those for the other levels. Anatomically, the width of the intervertebral foramen on computed tomography was 2.3 ± 1.12 mm in ULP cases, which was significantly lower than that in non-ULP cases (3.4 ± 1.83, P < 0.05). This suggests that preoperative foramen width correlates highly negatively with postoperative ULP incidence.

LIMITATIONS: This was a single-center, retrospective, nonrandomized study with a low level of evidence.

CONCLUSIONS: PPCED is a good treatment for cervical radiculopathy. The rate of postoperative ULP after PPCED is much lower than that after posterior cervical foraminotomy. Perturbation to the C5 (or C6) nerve root, thermal injury due to burr use or the radiofrequency applied, and marked foraminal stenosis are possible relevant factors associated with postoperative ULP.

KEY WORDS: Postoperative upper limb palsy, complications, posterior percutaneous endoscopic cervical foraminotomy and discectomy, preoperative foramen width