Comparison between muscle-preserving selective laminectomy and laminoplasty for multilevel cervical spondylotic myelopathy

Shoulder Traction as a Possible Risk Factor for C5 Palsy in Anterior Cervical Surgery: A Cadaveric Study

Background and Objectives: Many risk factors for postoperative C5 palsy (PC5P) have been reported regarding a "cord shift" after a posterior approach. However, there are few reports about shoulder traction as a possible risk factor of anterior cervical surgery. Therefore, we assessed the stretched nerve roots when shoulder traction was applied on cadavers. Materials and Methods: Eight cadavers were employed in this study, available based on age and the presence of foramen stenosis. After dissecting the sternocleidomastoid muscle of the cadaver, the shoulder joint was pulled with a force of 2, 5, 8, 10, 15, and 20 kg. Then, the stretched length of the fifth nerve root was measured in the extra-foraminal zone. In addition, the same measurement was performed after cutting the carotid artery to accurately identify the nerve root's origin. After an additional dissection was performed so that the superior trunk of the brachial plexus could be seen, the stretched length of the fifth and sixth nerve roots was measured again. Results: Throughout the entire experiment, the fifth nerve root stretched out for an average of 1.94 mm at 8 kg and an average of 5.03 mm at a maximum force of 20 kg. In three experiments, the elongated lengths of the C5 nerve root at 8 kg and 20 kg were 1.69/4.38 mm, 2.13/5.00 mm, and 0.75/5.31 mm, respectively, and in the third experiment, the elongated length of the C6 nerve root was 1.88/5.44 mm. Conclusions: Although this was a cadaveric experiment, it suggests that shoulder traction could be the risk factors for PC5P after anterior cervical surgery. In addition, for patients with foraminal stenosis and central stenosis, the risk would be higher. Therefore, the surgeon should be aware of this, and the patient would need sufficient explanation.

Uniportal full endoscopic spinous process-preserving laminectomy for bilateral decompression in cervical stenotic myelopathy: patient series

BACKGROUND

Endoscopic decompression for cervical stenotic myelopathy has several advantages over conventional open surgery. However, sometimes performing bilateral decompression, especially contralateral decompression, can be dangerous. The cervical spine has specific characteristics, including a shallower lamina angle and thinner lamina than the lumbar or thoracic lamina. These characteristics may cause cord compression when instruments approach the contralateral side of the lamina. This article introduces a novel surgical technique that can overcome the specificities of the cervical spine and discusses the efficacy and safety of uniportal full endoscopy for cervical decompression.

OBSERVATIONS

Fourteen patients underwent uniportal full endoscopic spinous process-preserving laminectomy (ESP-L) for bilateral decompression of multilevel cervical stenotic myelopathy. The mean follow-up period was 13.44 months (range: 4-17 months). The preoperative and postoperative cervical spine angle and cervical range of motion did not differ significantly. The Japanese Orthopaedic Association score significantly improved postoperatively. The numeric rating scale scores significantly improved postoperatively. The mean duration of postoperative hospitalization was 2.3 days.

LESSONS

ESP-L is a new, safe, effective, and noninvasive technique that can achieve complete decompression of multilevel cervical stenotic myelopathy.

Clinical Efficacy and Safety of Anterior Cervical Decompression versus Segmental Fusion and Posterior Expansive Canal Plasty in the Treatment of Multilevel Cervical Spondylotic Myelopathy

Objective

To compare the clinical efficacy and safety of anterior cervical decompression and segmental fusion and posterior expansive canal plasty in the treatment of multisegment cervical myelopathy.

Methods

Retrospective analysis was performed of 56 cases of multisegment cervical myelopathy patients admitted from July 2018 to June 2021, 32 male patients and 24 females, aged 56.9 ± 12.8 years with an average duration of 10.6 ± 3.2 years. All patients' preoperative imaging examination revealed multiple-segmented cervical disc herniation and had clinical manifestations of cervical myelopathy.

Results

No neurovascular complications occurred in both groups, and 24 to 36 months of follow-up (mean 28.6 months) were obtained. The height of the cervical spondylosis segment was higher than that 2 weeks after surgery (p < 0.05), and the curvature of the cervical spine was significantly lower than that before surgery. There was no statistical significance in the height of the anterior column and curvature of the cervical vertebra at 2 weeks after surgery and at the last follow-up (p > 0.05). There were statistically significant differences in anterior curvature of the cervical spine between the two groups at 2 weeks after surgery and the last follow-up (p < 0.05). Japanese Orthopaedic Association (JOA) scores in both groups recovered significantly after surgery. At 3 months and the last follow-up, the improvement rate of JOA score in the anterior approach group was significantly higher than that in the posterior approach group (p < 0.05), and the improvement rate of JOA score in the anterior approach group was also better than that in the posterior approach group (p < 0.05).

Conclusion

This segmented anterior fusion procedure can effectively restore the anterior cervical column height and can significantly improve spinal cord function compared with posterior spinal canal enlargement plasty, thus could be considered an effective option for the treatment of multisegment cervical myelopathy.