Cervical Conjoined Nerve Root During Posterior Percutaneous Endoscopic Cervical Diskectomy

Cervical conjoined nerve root is rare, and medical imaging, such as magnetic resonance imaging and computed tomography, cannot give an accurate preoperative diagnosis.¹ Treatment of cervical radiculopathy with root anomaly can be challenging. We report here a case of cervical conjoined nerve root with a 2-dimensional video. A 41-year-old woman without systemic disease presented with a 2-month history of neck and bilateral shoulder pain, upper back tightness, and left upper limb painful numbness, especially of the first to third fingers. The visual analog scale scores of the neck and left upper limb were 4 and 8, respectively. The Neck Disability Index was 26. The diagnosis of retrolisthesis at C5-C6 and cervical disk herniation with severe neuroforaminal narrowing at the left C5-C6 and C6-C7 levels were made with radiographs and magnetic resonance imaging. Posterior percutaneous endoscopic cervical diskectomy at the left C5-C6 and C6-C7 levels via an interlaminar shoulder approach was performed. During operation, a left-sided conjoined nerve root at the C6-C7 level was found (Video 1). Upon removal of a calcified disk and osteophytes at the C6-C7 level, the dura was torn slightly with traction without nerve root exposure or cerebrospinal fluid leakage. The 3-month postoperative follow-up visual analog scale scores of the neck and left upper limb were 0 and 0, respectively. The 3-month postoperative follow-up Neck Disability Index was 1. Posterior percutaneous endoscopic cervical diskectomy has become a favored treatment for cervical disk herniation because it offers sufficient decompression, smaller incisions, minimal blood loss, shorter hospital stay, and less postoperative pain.^2,3 Nonetheless, if unexpected variation of the nerve root is noted during decompressive procedures, iatrogenic nerve root injury is a risk. Seven cases of cervical nerve root anomalies have been reported; all were found during posterior cervical surgery, which may indicate that the posterior approach provides better visualization of nerve root variants, especially in endoscopic surgery.⁴.