INTRODUCTION
Cervical myelopathy is a debilitating condition characterized by progressive spinal cord dysfunction, commonly caused by degenerative changes in the cervical spine resulting in spasticity, hyperreflexia, pathologic reflexes, digit/hand clumsiness and/or gait disturbance. Classically it has an insidious onset progressing in a stepwise manner with functional decline [1]. A poor prognosis is associated with more than 18 months of symptomatic duration. Without treatment, patients may progress toward significant paralysis and loss of function [2]. Age is one of the important predictors of perioperative morbidity and unfavourable neurologic recovery [3].
Traditional surgical interventions for this condition, such as anterior cervical discectomy and fusion or cervical disc arthroplasty, have shown good outcomes. However, these approaches can be associated with complications, including adjacent segment degeneration and the need for further operations [4]. Unilateral biportal endoscopic (UBE) decompression is a minimally invasive surgical technique that has emerged as a potential alternative to address cervical myelopathy [1]. This approach aims to provide adequate decompression of the spinal cord and nerve roots while minimizing tissue disruption and promoting a faster recovery [1,5].
Management of myelopathy often involves surgery involving either anterior or posterior decompression of the stenotic area and likely fusion. The above management does not address the foraminal stenosis if it exists concomitantly to myelopathy in one surgical approach. This is because treatment of myelopathy posteriorly will require laminoplasty which will not allow bilateral access to foraminal stenosis. To overcome this limitation and carry out laminoplasty which allows both foraminal decompression at affected levels in single stage surgery to relieve the patient of radicular symptoms we implemented this technique as described in this case report and technical note.
CASE REPORT
Our patient was a 67-year-old male from presented with progressive neck pain, bilateral upper extremity radiculopathy, and gait imbalance with a power of 2/5 as per Medical Research Council grading in both deltoids causing the patient unable to lift his arms. Preoperative patient was unable to hold a spoon due to weakness in grip. Patient had episodes of neck pain and radiculopathy in the past which were managed conservatively. Symptoms of severe both upper limb weakness and radiculopathy has started since 4 weeks. Patient had sleep disturbances since 5 consecutive nights due to severe radiculopathy related symptoms. The patient had no history of any recent traumatic or infective condition and distal vascular deficit. He was admitted and conservative trial with intravenous analgesics and steroids were given but there was no improvement in symptoms (Tables 1, 2).
Patient’s x-ray cervical spine anterior-posterior and lateral views showed complete loss of cervical lordosis along with osteophytic growth at anterior vertebral bodies implying auto fusion and stabilisation. Clawing of osteophytes was most predominant at C4–5 followed by C5–6 and less at C3–4 levels. These findings were suggestive of multisegmental spondylosis. Foraminal stenosis at the same level was also suspected (Figure 1).
Magnetic resonance imaging (MRI) revealed cord signal changes on T2 weighted images involving the C5, C6, and C7 nerve roots bilaterally at C4–5, C5–6, and C6–7 levels. It showed bilateral foraminal narrowing at C4–5, C5–6, and C6–7 levels along with ossification of the posterior longitudinal ligament with anterior osteophytes on the cervical spine [3].
There was no developmental canal stenosis as assessed by the Torg-Pavlov ratio [6]. (Figures 2-7). Patient has central cervical myelopathy with bilateral foraminal stenosis. To address this condition patient had to undergone surgical procedure as to carry out the laminoplasty that would allow both foramina also to be explored at affected levels to relive radicular symptoms.
Therefore, we tried out a novel approach of UBE decompression with bilateral foraminotomy at C4–5, C5–6, and C6–7 levels and laminoplasty by the floating tip technique.
This study was an observational study. Informed consent was obtained from the patient. The authors have confirmed that no ethical approval is required.
SURGICAL PROCEDURE
1. Positioning
The procedure was performed under general anesthesia, with the patient positioned prone on a radiolucent table using bolsters to reduce abdominal pressure. The neck was supported on a firm sponge/gel headrest. The eyelids were padded and lubricated.
When the table was kept in a cranial high position, 2 advantages were observed. First, the neck was made horizontal to the ground, allowing a surgeon to perform UBE with better ergonomics. Second, the pressure on the ocular system was reduced. For this, the patient was secured obliquely to the table, and the knees were bent and supported by a foot plate to ensure that the patient did not slide downwards.
2. Surface Markings and Portals Entry Zone
1) Foraminotomy
The midline was marked as line 1.
A line was marked 1 cm lateral to the lateral facet line, designated as line 2.
The scopic portal was positioned above the cranial lateral mass in line with line 2.
The instrument portal was positioned below the lower lateral mass in line with line 2.
The above portals were suitable for foraminotomy.
2) Foraminotomy with laminectomy portals
If 2 levels of foraminotomy and hemilaminectomy were performed, the instrument portal was shifted to the lateral mass of the lower vertebrae (e.g., for C4–5 and C5–6 with a C5 laminectomy, the scopic portal was placed at the C4 cranial mass midpoint and the C6 midpoint became the instrument portal). This was done to reduce the gap and allow for one fewer portal.
The scope sheath was anchored on the C5 lamina and stripped down to the V junctions of both C4–5 and C5–6. Both V junctions were identified, and all 4 laminas were stripped to the flavum on both sides of the C5 lamina. The muscle was lifted up from the C5 lamina.
The surgical zone was identified. The lateral-most extent of the facet joint was burred as identified on the C-arm and measured using a 2.5-mm ball tip hook to twice its length, which was determined to be 5 mm of the facet. That point was marked and burred first to prevent the surgeon from transgressing more laterally and accidentally overdrilling the facet.
Both foraminotomies were performed first. The bridge between the 2 laminae was cut; in this example, the C5 lamina. Then the rest of the lamina, which had been cut through, was cut. The remnant lamina was cut towards the foraminotomies first, then towards the midline, and finally, the flavectomy was completed.
An additional portal was needed for a C6–7 foraminotomy, which was completed on the left side. The result was foraminotomies at C4–5, C5–6, and C6–7, with a hemilaminectomy at the C5 level.
3) Contralateral side
A similar procedure was performed on the opposite side, with the C6 lamina removed, foraminotomies at C5–6 and C6–7 completed, and an additional foraminotomy performed at C4–5. Bilateral foraminotomies from C4–5 to C6–7 and bilateral hemilaminectomies decompressing the spinal cord from the lower border of C4 to the upper border of C7 were carried out. A long-segment decompression with bilateral foraminal decompression was performed for relief from myelopathy and radiculopathy symptoms.
5) Blood Loss
Visual and hidden both approximately 400 mL. individual meticulousness can decrease it significantly.
Postoperative computed tomography (CT) findings showed an intact complete muscular mass with an intact central spinous process. Therefore, this was labelled as a floating tip technique.
The importance of this was that the nuchal membrane and insertion of all muscular mass were kept intact and dynamically active. Postoperative MRI and CT scan show no loss of muscle mass and minimal fibrosis. (Figures 8 and 9).
The patient tolerated the procedure well, with no intraoperative complications. Postoperatively, the patient reported significant improvement in his neck pain, upper extremity radiculopathy, and gait instability [1,7]. At 18-month follow-up his recovery shows no spasticity, no need of support for walking, reflexes return to normal with good grip strength in both hands and shoulder deltoid power improved (Figure 10).
Radiographic evaluation done at follow-up demonstrated adequate decompression of the spinal cord and neural foramina [8]. The minimally invasive nature of this approach may also contribute to a faster recovery and reduced postoperative morbidity compared to traditional open surgical techniques.
DISCUSSION
The study of literature was carried out. All various types of myelopathic decompression techniques were considered. Spinal cord injury during and immediately after surgery, inadequate decompression caused by limited laminectomy, and malalignment of the cervical spine are the complications with conventional surgical techniques [9].
However, the common factor that came out was that in conventional myelopathic decompressive surgery release of the central spinal stenosis and 1-sided lamino foraminotomies can be done but our patient requirement was bilateral foraminoplasty and laminoplasty.
Several surgical approaches have been described for the management of cervical myelopathy, each with its own advantages and limitations [10-13].
Conventional surgical interventions are associated with some complications and limitations when long segments are involved. Long-segment anterior approaches with fixation tend to fail, especially when involving upper cervical segments, and have high associated morbidity and mortality with the procedure and associated foraminal stenosis, which is difficult to resolve [12,13].
Posterior approaches, which involve laminoplasty or laminectomy with bilateral facetal screw rod fixation over long segments, are a more preferred approach but are not without their limitations and complications [12-14]. Posterior laminoplasty surgical techniques would have required cutting the midline structure and paraspinal muscular mass spreading and detachment of the nuchal ligament and severe fibrosis in paraspinal muscles. All cervical muscles involved in movements get affected which can result in swan neck deformity in the presence of the anteriorly shifted K-line [9].
In our technique with limited laminectomy and flavectomy, preservation of nuchal and interspinous ligaments, intact muscle mass with minimal fibrosis ensures sufficient functional capacity of all dynamic structures of spine and no further progression of K-line.
Especially when faced with the situation as seen in this patient with bilateral involvement of the C5, C6, and C7 nerve roots, laminoplasty would not have relieved the nerve root compression on the hinge side. And laminectomy over 3 segments with bilateral fixation after bilateral foraminotomy is impossible to do since 3 consecutive segments are involved, and there is risk of failure with inadequate mechanical stability of fixation. This adoption of UBE for central with bilateral foraminal decompression in the treatment of cervical myelopathy has several advantages over conventional open surgical approaches. The minimally invasive nature of this technique results in less tissue disruption, reduced blood loss, and shorter hospital stays, potentially leading to faster recovery and improved patient satisfaction.
The case reported here demonstrates the feasibility and potential benefits of UBE central with bilateral foraminal decompression for the management of cervical myelopathy [5,15]. This minimally invasive technique offers a viable alternative to traditional open surgical approaches, with the potential to provide effective decompression of the spinal cord and nerve roots while minimizing procedural trauma and promoting a faster recovery [1].
This technique allows for targeted removal of the compressive pathology, including osteophytes, hypertrophied ligamentum flavum, and herniated disc material, without the need for extensive muscle dissection or bone removal. The use of biportal endoscopic access facilitated a comprehensive decompression, addressing both the central and lateral recess stenosis, which is a key consideration in the management of cervical myelopathy.
Additionally, the targeted decompression of the central and lateral spinal elements, facilitated by the biportal endoscopic access, allows for a comprehensive treatment of the underlying pathology while minimizing the need for extensive bone removal or fusion [7,16]. This precision-based approach aims to preserve the normal spinal biomechanics and potentially reduce the risk of adjacent segment degeneration, a common complication associated with cervical fusion procedures.
CONCLUSION
This technique offers a promising option as a surgical technique for patients with bilateral foraminal stenosis and associated cervical myelopathy. By providing a viable alternative, it enhances future perspectives for these patients and has the potential to become the suitable standard surgical technique for managing this type of conditions.
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