Novel Cervical Endoscopic Unilateral Laminoforaminotomy for Bilateral Decompression in Cervical Spondylosis Myeloradiculopathy: A Technical Note and Clinical Results

Background: This study investigates the efficacy of the Cervical Endoscopic Unilateral Laminoforaminotomy for Bilateral Decompression (CE-ULFBD) technique in treating cervical myeloradiculopathy, primarily caused by degenerative spondylosis. Traditionally managed through multisegmental anterior cervical discectomy and fusion (ACDF) or laminoplasty combined with foraminotomy, this condition has recently experienced a promising shift towards minimally invasive approaches, particularly endoscopic spinal decompression. While empirical evidence is still emerging, these techniques show potential for effective treatment. Method: The objective was to evaluate the outcomes of CE-ULFBD in achieving single or multilevel bilateral foraminal and central decompression, emphasizing the reduction of injury to posterior cervical muscles and the associated postoperative neck soreness common in conventional procedures. This paper delineates the surgical procedures involved in CE-ULFBD and presents the clinical outcomes of nine patients diagnosed with myeloradiculopathy due to severe cervical stenosis. Result: Assessments were conducted using the Visual Analogue Scale (VAS) for neck and arm pain and the Modified Japanese Orthopaedic Association scale (mJOA) for the activity measurement of daily living. Results indicated a considerable decrease in pain levels according to the VAS, coupled with significant improvements in functional capacities as measured by the mJOA scale. Additionally, no major postoperative complications were noted during the follow-up period. Conclusion: The study concludes that CE-ULFBD is a safe and effective approach for the treatment of cervical myeloradiculopathy resulting from severe cervical stenosis, offering a viable and less invasive alternative to traditional decompressive surgeries.

Posterior Cervical Keyhole Laminoforaminotomy: A Cadaveric Comparative Study to Evaluate Limits of Bony Resection

BACKGROUND

The posterior cervical keyhole (KH) laminoforaminotomy has been described to involve the lateral portion of cervical laminae of the upper vertebra alone (small KH) or of both upper and lower vertebrae (large KH).

OBJECTIVE

To microscopically compare the two keyhole techniques in terms of their ability to expose the corresponding cervical roots.

METHODS

Ten cadaveric specimens were operated bilaterally from C3-4 to C6-7 level to expose a total of 80 nerve roots. The large KH was applied to the left side, the small KH to the right side. The maximal length of exposed nerve roots was measured under microscope. The virtual optimal KH surface area was determined using digital software. Each root was inspected for exposure of its root and axilla.

RESULTS

The maximal exposed nerve root length on the large KH side was significantly larger than on the small KH side at C3-4, C5-6, and C6-7 levels (P = .031, P = .002, P = .003). No significance was reported for C4-5 (P = .06). We could expose right axillae in (3/40) and left axillae in (33/40; P < .001). Optimal keyhole surface areas were 37.9, 38.2, 38.7, and 46.2 mm2 in craniocaudal order.

CONCLUSION

Large KH defects involving both upper and lower laminae and facets can expose the roots to greater extent than small KH defects at C3-4, C5-6, and C6-7 levels. Large KH defects may allow better exposure of nerve roots axillae than small KH defects.

Morphometric Analysis for Surgical Treatment of Cervical Discopathy by Posterior Laminoforaminotomy: Radiologic Study and Technical Note

BACKGROUND

The main concern with the posterior approach is the risk of postoperative segmental instability. The most commonly cited rule is that removal of the medial half of the articular facet provides adequate surgical exposure and has no effect on stability. The aim of this study was to define the areas of the articular processes in the cervical spine that can be safely removed.

METHODS

Computed tomography scans of 50 cervical spines were analyzed. Measurements were analyzed for bone removal assuming the standard technique of posterior laminoforaminotomy. The width of the facet was measured at the level of the widest dimension. The height of the articular process was taken from the bottom (in the case of inferior process) or top (in the case of superior process) of the process.

RESULTS

The mean width of the articular process ranged from 11.8 ± 1.5 mm (range, 8.3-15.7 mm) at the C2-C3 level to 14.6 ± 1.7 mm at the C6-C7 level. At the cervicothoracic junction (C7-T1 level), the mean width decreased to 14.0 ± 1.7 mm. The mean value for both sides when the inferior articular process was measured at all levels was 5.0 ± 1.4 mm (range, 4.5-5.8 mm). The mean height of the superior articular process was 7.7 ± 1.5 mm (range, 6.8-8.3 mm).

CONCLUSIONS

Based on our findings, our "5-5-7 mm rule" corresponds to the amount of bone removal for each step of the laminoforaminotomy.

Development of postoperative C5 palsy is associated with wider posterior decompressions: an analysis of 41 patients

BACKGROUND CONTEXT

C5 palsy is a postoperative complication, characterized by deltoid weakness. The pathogenesis of C5 palsy after laminoforaminotomies in patients with degenerative spinal disease is poorly understood. We hypothesize that the spinal cord fallback is associated with postoperative C5 palsy.

PURPOSE

We investigate radiographic parameters associated with the development of postoperative C5 palsy.

STUDY DESIGN/SETTING

This is a retrospective single-institutional clinical study.

PATIENT SAMPLE

The source population was all patients undergoing a C4-C5 posterior laminoforaminotomy plus instrumented fusion for the management of degenerative spinal disease at a single institution over a 7-year period. The study population was 41 patients who had both preoperative and postoperative imaging.

OUTCOME MEASURE

The outcome measure was postoperative C5 palsy, defined as transient motor decline of the deltoid function.

METHODS

Of those patients with both preoperative and postoperative radiographic studies, we measured cord position, Cobb angle, width of the C5 foramen, and width of the dura.

RESULTS

Nine patients with C5 palsy and 32 patients without C5 palsy fit the inclusion criteria for this study. In comparison with the non-C5 palsy group, the C5 palsy group had a statistically greater widening of the C5 foramen (p<.001), dural expansion (p<.001), and posterior cord shift (p<.001). Change in lordosis did not differ (p=.985). Lordotic correction was not correlated with the posterior cord shift in linear regression analysis (p=.67) or C5 palsy in univariate analysis (p=.627). Conversely, widening of the C5 foramen was correlated with greater cord displacement (p=.002), and both of these factors statistically predicted C5 palsy after the multivariate regression analysis.

CONCLUSION

Our findings suggest that wider decompressions at C4-C5 are correlated with greater fallback of the spinal cord, which statistically increases the risk of C5 palsy.

Cervical pedicle screw insertion using the technique with direct exposure of the pedicle by laminoforaminotomy

Objective

To present the accuracy and safety of cervical pedicle screw insertion using the technique with direct exposure of the pedicle by laminoforaminotomy.

Methods

We retrospectively reviewed 12 consecutive patients. A total of 104 subaxial cervical pedicle screws in 12 patients had been inserted. We also assessed the clinical and radiological outcomes and analyzed the direction and grade of pedicle perforation (grade 0: no perforation, 1: <25%, 2: 20% to 50%, 3: >50% of screw diameter) on the postoperative vascular-enhanced computed tomography scans. Grade 2 and 3 were considered as incorrect position.

Results

The correct position was found in 95 screws (91.3%); grade 0-75 screws, grade 1-20 screws and the incorrect position in 9 screws (8.7%); grade 2-6 screws, grade 3-3 screws. There was no neurovascular complication related with cervical pedicle screw insertion.

Conclusion

This technique (technique with direct exposure of the pedicle by laminoforaminotomy) could be considered relatively safe and easy method to insert cervical pedicle screw.