Inadequate Surgical Decompression in Patients with Cervical Myelopathy: A Retrospective Review

Anterior Cervical Discectomy and Fusion Combined with Foraminotomy Assisted by High-Definition 3-Dimensional Exoscope in the Treatment of Cervical Spondylotic Radiculopathy Secondary to Bony Foraminal Stenosis

Objective

To evaluate the outcomes of cervical spondylotic radiculopathy secondary to bony foraminal stenosis treated with anterior cervical discectomy and fusion (ACDF) combined with anterior cervical foraminotomy (ACF) assisted by High‐Definition 3‐Dimensional Exoscope.

Methods

In this retrospective study, a total of 19 consecutive patients (12 males and seven females, with an average of 49.2 years, range from 40 to 59 years) with spondylotic radiculopathy caused by bony foraminal stenosis underwent ACDF combined with ACF assisted by High‐Definition 3‐Dimensional Exoscope in our hospital between January 2019 and December 2019 were included in this study. All patients signed the consent form before the surgery. The patient baseline information such as gender, age, body mass index (BMI), surgery time, blood loss, hospital stay, lesion segment, side, follow‐up time and postoperative complications were recorded. The Japanese Orthopedic Association (JOA), Neck Disability Index (NDI), and Visual Analogue Scale (VAS) were measured and compared before surgery, 1 months and final follow‐up after surgery. The radiographic outcomes were evaluated using the C₂‐C₇ angel, disc height, foraminal height, superior diagonal distance, inferior diagonal distance, and foraminal area.

Results

The involved levels included C₄‐C₅ (six cases), C₅‐C₆ (10 cases), C₆‐C₇ (three cases). The mean duration of the surgery, mean blood loss, mean hospital stay, and mean follow‐up were 100 ± 11.10 min, 19.4 ± 7.05 mL, 7.1 ± 0.99 days, and 12.1 ± 2.25 months, respectively. The average preoperative JOA score was 11.9 ± 1.31, then improved to 15.7 ± 0.73 (t = −13.45, P < 0.001) and 16.2 ± 0.74 (t = −14.39, P < 0.001) at 1 month after operation and at last follow‐up, respectively. The average preoperative NDI score was 27.3 ± 3.36, then decreased to 5.1 ± 1.79 (t = 20.63, P < 0.001) and 4.5 ± 1.21 (t = 25.53, P < 0.001) 1 month after operation and at last follow‐up, respectively. The average preoperative VAS score was 6.7 ± 0.93, then decreased to 2.4 ± 0.69 (t = 15.05, P < 0.001) and 1.9 ± 0.78 (t = 16.40, P < 0.001) 1 month after operation and at last follow‐up, respectively. As compared with the condition before surgery, there was a significant improvement in the C₂‐C₇ angel, disc height, foraminal height, and foraminal area (P < 0.05). None of the patients developed postoperative vascular injury, nerve injury, loosening and rupture of the internal fixation, displacement of interbody fusion cage, and pseudarthrosis.

Conclusion

ACDF combined with ACF assisted by High‐Definition 3‐Dimensional Exoscope is effective and safe for the treatment of CSR caused by secondary to bony foraminal stenosis.

Perioperative major neurologic deficits as a complication of spine surgery

STUDY DESIGN

Retrospective review of spine surgery patients with new major neurologic complication.

OBJECTIVE

To define the causes and severity of new neurologic damage to the spinal cord or cauda equina caused by spinal surgery.

MATERIALS AND METHODS

Consult records were reviewed for all postoperative spine surgery patients referred to a tertiary spinal cord injury rehabilitation center over a 12-year period. Any patients with a new perioperative surgery-related decrement in American Spinal Injury Association (ASIA) Impairment Scale (AIS), loss of bowel or bladder function, or loss of ability to ambulate were examined and final 1-year gaps for neurologic loss reported.

RESULTS

64 patients had a new perioperative major neurologic event with: 41% thoracic, 39% cervical, and 20% lumbar; 61% intraoperative, 31% in the immediate 2-week postoperative period, 8% unknown. Chronic myelopathy (44%) was the most common indication. The causes of neurologic injury were postoperative fluid collection (25%), malposition of instrumentation (14%), traumatic decompression (14%), cord infarct (11%), deformity correction (2%), and unknown (34%). Overall, 87% lost the ability to ambulate and 66% lost volitional bowel-bladder control. AIS decrement and loss of ambulation and bowel-bladder function did not differ statistically significantly by surgical indication. However, among the main root causes, traumatic decompressions and cord infarcts had significantly worse neurologic deterioration than fluid collections or malposition of instrumentation.

CONCLUSION

The relative rate of major neurologic injury in spine surgery is higher in thoracic and cervical cases at spinal cord levels, especially when done for myelopathy, even though lumbar surgeries are most common. The most common causes of neurologic injury were potentially avoidable postoperative fluid collections, malposition of instrumentation, and traumatic decompression.

Development and Achievement of Cervical Laminoplasty and Related Studies on Cervical Myelopathy

Cervical laminoplasty (CL) is one of the surgical methods via the posterior approach for treating patients with multilevel affected cervical myelopathy (CM). The main purpose of CL is to decompress the cervical spinal cord by widening the narrowed spinal canal, combined with preserving the posterior anatomical structures to the degree possible and preserving the widened space stably. During the development and improvement of spine surgeries including CL, various studies on CM have progressed and useful achievements have been obtained: (1) posterior cervical spine fixation systems that can be used in combination with CL simultaneously have been developed; (2) various materials to stably maintain the enlarged spinal canal have been developed; (3) the main influential factors on the surgical results are the inner factors of the patients, such as the patient's age and the disease duration; (4) various surgical methods to preserve the function of the posterior cervical muscles have been tried to avoid postoperative kyphotic changes of the cervical spine; (5) postoperative complications, such as C5 palsy and axial pain, have been examined, and the countermeasures have been tried; (6) K-line on lateral X-ray films has been applied to evaluate the indication of CL in patients with CM due to ossification of the posterior longitudinal ligament (OPLL) preoperatively; and (7) the method and idea of CL have been adapted to surgeries at the thoracic and lumbar spine. However, some issues remain to be resolved, such as the deterioration of neurological findings, especially in patients with continuous or mixed-type OPLL, the postoperative kyphotic-directional alignment change of the cervical spine, C5 palsy, and axial pain.

Minimally Invasive Cervical Laminectomy for Cervical Spondylotic Myelopathy

OBJECTIVE

Cervical spondylotic myelopathy is a common cause of neurological disability, especially in aging populations. There are several approaches to decompress the cervical spinal cord, including anterior cervical discectomy and fusion, corpectomy and fusion, arthroplasty, posterior cervical laminectomy with or without fusion, and laminoplasty. Less well described is minimally invasive cervical laminectomy. The authors report their technique and results for minimally invasive cervical laminectomy.

MATERIALS AND METHODS

The authors describe in detail their surgical technique and results of 30 consecutive cases. Preoperative and postoperative modified Japanese Orthopaedic Association (mJOA) myelopathy scores were recorded.

RESULTS

In total, 30 cases were included. Mean age was 69 years (range, 57-89 y). Twelve procedures were at C3-4, 4 at C4-5, 5 at C5-6, 4 at C7-T1, 3 at C3-4 and C4-5, 1 at C4-5 and C5-6, and 1 at C5-6 and C6-7. Mean preoperative mJOA score was 12.1 (range, 4-15). Average length of surgery was 142 minutes. Mean follow-up was 27 months (range, 3-64 mo). At 3 months, mean postoperative mJOA score was 14.0 (range, 5-17). Mean mJOA improvement of 1.9 was statistically significant (P<0.001). Seventeen patients had magnetic resonance imaging (MRI) available at 3 months postoperatively (5 patients had no MRI, 3 patients had MRI contraindications, and 5 are pending). No MRI findings led to further surgery. There were no durotomies and no wound infections. A single patient had an unexplained new neurological deficit that resolved over 6 months.

CONCLUSIONS

Minimally invasive laminectomy for cervical myelopathy is safe and effective and may be an underutilized procedure.