Posterior Percutaneous Transpedicular Endoscopic Approach for Treating Single-Segment Cervical Myelopathy

Abstract

Background. Standard posterior percutaneous endoscopic cervical discectomy (PECD) is considered an effective minimally invasive surgery. Although standard PECD can be used to treat radiculopathy with relatively minimal trauma, it is still a challenge to use this approach for treating myelopathy. Objective. This report is aimed at first describing a posterior transpedicular approach under endoscopy for myelopathy and evaluating the feasibility and short-term clinical effects of this approach. Methods. In our retrospective analysis between Feb. 2016 to Mar. 2017, 16 patients managed with PECD using the posterior transpedicular approach for symptomatic single-segment myelopathy. Surgery involved drilling 1/2 to 2/3 of the medial portion of the pedicle under endoscopy to provide sufficient space and an appropriate angle for inserting the endoscope into the spinal canal, followed by ventral decompression of the spinal cord. Computed tomography and magnetic resonance imaging were used to evaluate pedicle healing and spinal cord decompression. The primary outcomes included a visual analog scale (VAS) scores of axial neck pain and Japanese Orthopaedic Association (JOA) scores of neurological conditions. Results. All patients completed a 1-year follow-up examination. The mean duration of surgery was $95.44\pm 19.44\min$ (52–130 min). The fluoroscopy duration was $5.88\pm 1.05$ (4–7). The VAS scores of axial pain significantly improved from $6.94\pm 0.75$ preoperatively to $2.88\pm 1.22$ postoperatively ( $P<0.05$ ). The mean JOA scores improved from $8.50\pm 1.12$ preoperatively to $14.50\pm 1.46$ at the final follow-up ( $P<0.05$ ). The effects were excellent in 8 cases, good in 6 cases, and fair in 2 cases. After partial pedicle excision, the width of the remaining pedicle was $1.70\pm 0.22\text{mm}$ postoperatively and significantly recovered to $3.38\pm 0.49\text{mm}$ at the 1-year follow-up. There were no surgery-related complications, such as dural tearing, spinal cord injury, nerve root injury, pedicle fracture, and cervical hematocele or infection. Conclusions. The posterior transpedicular approach is an effective method for the treatment of myelopathy in select patients and is a supplement to the described surgical approach for PECD.