Neurosurgery Service, Alicante University General Hospital, Alicante, Spain.
The assessment, diagnosis, operative and nonoperative management of degenerative cervical myelopathy (DCM) have evolved rapidly over the last 20 years. A clearer understanding of the pathobiology of DCM has led to attempts to develop objective measurements of the severity of myelopathy, including technology such as multiparametric magnetic resonance imaging, biomarkers, and ancillary clinical testing. New pharmacological treatments have the potential to alter the course of surgical outcomes, and greater innovation in surgical techniques have made surgery safer, more effective and less invasive. Future developments for the treatment of DCM will seek to improve the diagnostic accuracy of imaging, improve the objectivity of clinical assessment, and increase the use of surgical techniques to ensure the best outcome is achieved for each individual patient 1).
Goel was troubled by the fact that his several PubMed and MEDLINE indexed articles on the subject published in leading journals dedicated to the study of the spine have not found any place in the huge reference list of 137 articles 2)
A review of Tetreault et al. summarizes current knowledge of the pathophysiology of DCM and describes the cascade of events that occur after compression of the spinal cord, including ischemia, destruction of the blood-spinal cord barrier, demyelination, and neuronal apoptosis. Important features of the diagnosis of DCM are discussed in detail, and relevant clinical and imaging findings are highlighted. Furthermore, this review outlines valuable assessment tools for evaluating functional status and quality of life in these patients and summarizes the advantages and disadvantages of each. Other topics of this review include epidemiology, the prevalence of degenerative changes in the asymptomatic population, the natural history and rates of progression, risk factors of diagnosis (clinical, imaging and genetic), and management strategies 3).
Histological findings
MEDLINE and Embase were systematically searched (CRD42021281462) for primary research reporting on histological findings of DCM in the human cadaveric spinal cordtissue. Data were extracted using a piloted proforma. The risk of bias was assessed using Joanna Briggs Institute critical appraisal tools. Findings were compared to a systematic review of animal models (Ahkter et al. 2020 Front Neurosci 14).
The search yielded 4127 unique records. After the abstract and full-text screening, 19 were included in the final analysis, reporting on 150 autopsies (71% male) with an average age at death of 67.3 years. All findings were based on hematoxylin and eosin (H&E) staining. The most commonly reported grey matter findings included neuronal loss and cavity formation. The most commonly reported white matter finding was demyelination. Axon loss, gliosis, necrosis, and Schwann cell proliferation were also reported. Findings were consistent amongst cervical spondylotic myelopathy and ossification of the posterior longitudinal ligament. Cavitation was notably more prevalent in human autopsies compared to animal models.
Few human spinal cord tissue studies have been performed. Neuronal loss, demyelination and cavitation were common findings. Investigating the biological basis of DCM is a critical research priority. Human spinal cord specimen may be an underutilized but complementary approach 4).
A National Institutes of Health-funded (1R13AR065834-01) investigator meeting was held before the initiation of the trial to bring multiple stakeholders together to finalize the study protocol. Study investigators, coordinators, and major stakeholders were able to attend and discuss strengths of, limitations of, and concerns about the study. The final protocol was approved for funding by the Patient-Centered Outcomes Research Institute (CE-1304-6173). The trial began enrollment on April 1, 2014 6).
Wilson JRF, Badhiwala JH, Moghaddamjou A, Martin AR, Fehlings MG. Degenerative Cervical Myelopathy; A Review of the Latest Advances and Future Directions in Management. Neurospine. 2019 Sep;16(3):494-505. doi: 10.14245/ns.1938314.157. Epub 2019 Aug 26. PubMed PMID: 31476852; PubMed Central PMCID: PMC6790745.
Dohle E, Beardall S, Chang A, Mena KPC, Jovanović L, Nath U, Lee KS, Smith AH, Thirunavukarasu AJ, Touzet AY, Norton EJ, Mowforth OD, Kotter MRN, Davies BM. Human spinal cord tissue is an underutilised resource in degenerative cervical myelopathy: findings from a systematic review of human autopsies. Acta Neurochir (Wien). 2023 Feb 23. doi: 10.1007/s00701-023-05526-5. Epub ahead of print. PMID: 36820887.
Augusto MT, Diniz JM, Rolemberg Dantas FL, Fernandes de Oliveira M, Rotta JM, Botelho RV. Development of the Portuguese version of the modified Japanese Orthopaedic Association Score: cross-cultural adaptation, reliability, validity and responsiveness. World Neurosurg. 2018 Jun 1. pii: S1878-8750(18)31127-6. doi: 10.1016/j.wneu.2018.05.173. [Epub ahead of print] PubMed PMID: 29864576.
A simple treatment such as a cervical sympathetic nerve block may be an effective therapy but is not routinely performed as cerebral vasospasm treatment/DCI. cervical sympathetic nerve block consists of injecting local anesthetic at the level of the cervical sympathetic trunk, which temporarily blocks the innervation of the cerebral arteries to cause arterial vasodilatation. cervical sympathetic nerve block is a local, minimally invasive, low cost and safe technique that can be performed at the bedside and may offer significant advantages as a complementary treatment in combination with more conventional neurointerventional surgery interventions. Bombardieri et al. reviewed the literature that describes cervical sympathetic nerve block for vasospasm/DCI prevention or treatment in humans after aSAH. The studies outlined in this review show promising results for a cervical sympathetic nerve block as a treatment for vasospasm/DCI. Further research is required to standardize the technique, explore how to integrate a cervical sympathetic nerve block with conventional neurointerventional surgery treatments of vasospasm and DCI, and study its long-term effect on neurological outcomes 2).
SCG was surgically identified in 15 swine and were electrically stimulated to achieve sympathetic activation. CT perfusion scans were performed to assess for changes in cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), and time-to-maximum (TMax). Syngo. via software was used to determine regions of interest and quantify perfusion measures.
Results: SCG stimulation resulted in 20-30% reduction in mean ipsilateral CBF compared to its contralateral unaffected side (p < 0.001). Similar results of hypoperfusion were seen with CBV, MTT and TMax with SCG stimulation. Prior injection of lidocaine to SCG inhibited the effects of SCG stimulation and restored perfusion comparable to baseline (p > 0.05).
Conclusion: In swine, SCG stimulation resulted in significant cerebral perfusion deficit, and this was inhibited by prior local anesthetic injection into the SCG. Inhibiting sympathetic activation by targeting the SCG may be an effective treatment for sympathetic-mediated cerebral hypoperfusion 3).
Hu et al. investigated the therapeutic effects of SGB in a rat model of subarachnoid hemorrhage (SAH) complicated by delayed CVS and explore the underlying mechanisms. The SAH model was established by the double injection of autologous arterial blood into the cisterna magna. They simulated SGB by transection of the cervical sympathetic trunk (TCST), and measured changes in the diameter, perimeter, and cross-sectional area of the basilar artery (BA) and middle cerebral artery (MCA) to evaluate its vasodilatory effect. To investigate the underlying mechanisms, we determined the expression level of vasoactive molecules endothelin-1 (ET-1) and calcitonin gene-related peptide (CGRP) in the plasma, and apoptotic modulators Bcl-2 and Bax in the hippocampus. We found a significant increase in the diameter, perimeter, and cross-sectional area of the BA and right MCA in SAH rats subjected to TCST. Application of SGB significantly reduced the expression of ET-1 while increasing that of CGRP in SAH rats. We also found a significant increase in the expression of Bcl-2 and a decrease in the expression of Bax in the hippocampus of SAH rats subjected to TCST, when compared to untreated SAH rats. The mechanism of action of SGB is likely mediated through alterations in the ratio of ET-1 and CGRP, and Bax and Bcl-2. These results suggest that SGB can alleviate the severity of delayed CVS by inducing dilation of intracerebral blood vessels, and promoting anti-apoptotic signaling. Our findings provide evidence supporting the use of SGB as an effective and well-tolerated approach to the treatment of CVS in various clinical settings 4)
After successful modeling of cervical sympathetic block, 18 healthy male white rabbits were randomly divided into three groups (n=6), ie, sham operation group (Group A), SAH group (Group B) and SAH with cervical sympathetic block group (Group C). Models of delayed CVS were established by puncturing cisterna magna twice with an injection of autologous arterial blood in Groups B and C. A sham injection of blood through cisterna magna was made in Group A. 0.5 ml saline was injected each time through a catheter for cervical sympathetic block after the first injection of blood three times a day for 3 d in Group B (bilateral alternating). 0.5 ml of 0.25% bupivacaine was injected each time through a catheter for cervical sympathetic block after the first injection of blood three times a day for 7 d in Group B. 2 ml venous blood and cerebrospinal fluid were obtained before (T1), 30 min (T2) and 7 d (T3) after the first injection of blood, respectively, and conserved in a low temperature refrigerator. Basilar artery value at T1, T2 and T3 was measured via cerebral angiography. The degree of damage to nervous system at T1 and T3 was recorded.
Results: There was no significant difference in diameter of basilar artery at T1 among three groups. The diameters of basilar artery at T2 and T3 of Groups B and C were all smaller than that in Group A, which was smaller than Group C, with a significant difference. There was no significant difference in NO and NOS in plasma and cerebrospinal fluid among three groups. The NO and NOS contents at T2 and T3 of Groups B and C were all lower than Group A; Group C was higher than Group B, with a significant difference. The nerve function at T3 of Groups B and C were all lower than Group A and that of Group C higher than Group B, with a significant difference.
Cervical sympathetic block can relieve cerebral vasospasm after subarachnoid hemorrhage and increase NO content and NOS activity in plasma and cerebrospinal fluid to promote neural functional recovery 5)
Hu N, Wu Y, Chen BZ, Han JF, Zhou MT. Protective effect of stellate ganglion block on delayed cerebral vasospasm in an experimental rat model of subarachnoid hemorrhage. Brain Res. 2014 Oct 17;1585:63-71. doi: 10.1016/j.brainres.2014.08.012. Epub 2014 Aug 13. PMID: 25128600.
Chun-jing H, Shan O, Guo-dong L, Hao-xiong N, Yi-ran L, Ya-ping F. Effect of cervical sympathetic block on cerebral vasospasm after subarachnoid hemorrhage in rabbits. Acta Cir Bras. 2013 Feb;28(2):89-93. doi: 10.1590/s0102-86502013000200001. PMID: 23370920.
Juxtafacet cysts (JFCs) seem to be a degenerative change of the cervical spine rather than a traumatic event. Similar to their counterparts in the lumbar spine, they tend to arise in segments with increased mobility.
Sivakumar et al. have reported on the development of JFCs adjacent to anterior cervical fusion constructs, and consideration of JFCs as a form of adjacent level disease (ALD) has been hypothesized 5).
Moon et al. reported one patient that developed a C5/6 JFC 20 months after C4/5 anterior fusion and C5/6 anterior foraminotomy. In this case, despite progressive subluxation at C5/6 and solid C4/5 fusion demonstrated on flexion films 20 months after the original surgery, the patient underwent partial hemilaminectomy alone for cyst decompression. Outcome was favorable at 4 months follow-up 6)
Trauma
After a cervical spine fracture and, hence, was probably related to trauma. Surgical therapy resulted in a satisfactory recovery 7).
Clinical Features
Chronic expansion of the extradural mass may lead to compression of the nerve root, thecal sac, or both, and may follow long periods of axial back pain without neurological deficit 8).
They are rare causes of neurological deficits. Their imaging characteristics, relationship to segmental instability, and potential for inducing acute symptomatic deterioration have only been described in a few case reports and small case series 9).
Less commonly, neurological deterioration has been attributed to rapid cystic growth with hemorrhage 10)11)
Attwell et al., reported acute symptomatology secondary to spontaneous haemorrhage into a cervical facet joint cyst 12).
Combination with discal herniation and spina bifida occulta was diagnosed with computed tomography (CT) and magnetic resonance imaging (MRI) in one case 13).
Myelopathy
In the series of Christophis all cervico-thoracic or thoracic cysts presented myelopathy 14).
Till 1999 there have been only two previously reported cases of subaxial degenerative synovial cysts of the cervical spine in patients who presented with a clinical picture of spinal cord compression. Cudlip et al. report three additional patients treated for degenerative cervical synovial cysts who presented with myelopathy. In all three patients the cyst was successfully excised and a good clinical outcome achieved 15).
Cho el al. describe a case of an 80-year-old man with a gradual weakness of the lower extremities not linked to any known traumatic episode over the 2 weeks before admission. CT scan and MRI of the spine revealed a cystic formation, measuring about 1 cm in diameter, at C7-T1 at the left posterolateral site at the level of the articular facet. During surgery, the mass appeared to be in the ligamentum flavum at the level of the articular facet and was in contact with the dura mater. After the removal of the mass, there was an immediate and significant improvement of the patient’s symptoms. Histopathologic examination showed the cyst to be composed of nonspecific degenerative fibrous tissue with mild inflammatory change and confirmed the cyst as a synovial cyst. Synovial cyst in the cervical region is a very rare lesion causing myelopathy. Surgical removal of the cyst and decompression of the spinal cord results in good neurological recovery 16).
Brown-Sequard syndrome
Cheng et al. published a rare case of a patient with a ganglion cyst of the lower cervical spine presenting with acute Brown-Sequard syndrome. The patient had no history of trauma. Magnetic resonance imaging of the cervical spine showed a cystic lesion connecting to the synovial joint C6-7 and compressing the posterior aspect of the spinal cord. The patient underwent emergent C6-7 laminectomy with total removal of the cyst. Neurological function recovered completely 4 months after operation 17).
Diagnosis
Magnetic resonance imaging reveal an intraspinal extradural cystic lesion in contact with the facet joint. The spinal cord can severely compressed by this lesion which is hypointense on T1-weighted imaging and hyperintense on T2-weighted imaging and short T1 inversion recovery. The cyst wall can strongly enhance after contrast injection 18).
Sasamori et al. report a case of cervical juxtafacet cyst with extensive rim enhancement on gadolinium-diethylenetriamine pentaacid magnetic resonance imaging.
Operative finding revealed the epidural space around the mass filled with abundant venous plexus. Histological examination demonstrated that cyst wall was composed of the well-vascularized fibrous connective tissue with some inflammatory changes. They speculate that extensive rim enhancement of juxtafacet cyst may be attributed not only to the chronic inflammatory changes of cyst wall, but to engorged venous plexus within the widened epidural space 19)
Colen and Rengachary report a spontaneous resolution of a cervical synovial cyst 21)
Technique
The head is positioned in Mayfield pins under gentle capital flexion, and the patient was positioned prone on gel rolls. Dissection proceeded in the subperiosteal plane, either unilaterally (e.g., hemilaminectomy) or bilaterally, depending on the goals of the decompression and the extent of spinal canal compromise. During resection of the lesion, the lateral facet and capsule were preserved as much as possible. When deemed necessary for complete decompression or visualization of the lesion, the laminectomy was extended to include a conservative medial facetectomy on the affected side.
The putative medial facet joint is carefully cauterized to minimize risk of cyst regrowth.
Instrumentation and fusion can be performed at the discretion of the operating surgeon. Loss of cervical lordosis, spondylolisthesis, hypermobility, index level neck pain, and iatrogenic instability following decompression are each relative indications for fusion.
Fixation can be accomplished using bilateral lateral mass/pedicle screw and rod constructs. Fusion can be augmented with morselized local autograft, with or without bone allograft.
Case series
2013
12 consecutive patients (mean age 63.4 years, range 52-83 years) harboring 14 JFCs treated across 9 years was retrospectively reviewed. Clinical history, neurological status, preoperative imaging, operative findings, pathology, and postoperative outcomes were obtained from medical records. The mean follow up was 9.2 ± 7.8 months.
Most JFCs in this series involved the C7/T1 level. Nine patients reported axial neck pain, 12 patients had radicular symptoms, four patients had myelopathy, and one patient experienced rapid neurological decline attributable to cystic hemorrhage. Cyst expansion without hemorrhage caused subacute deterioration in one patient. All patients experienced sensory and/or motor improvement following surgical decompression. Preoperative axial neck pain improved in eight of nine patients (89 %). Seven out of 12 patients (58 %) underwent fusion either at the time of decompression (six patients) or at a delayed timepoint within the follow-up period (one patient). Prior history of cervical instrumentation, hypermobility on dynamic imaging, and other risk factors for segmental instability were more common in this series than in previous reports 22).
1988
13 patients with synovial or ganglion cysts of the spinal facet joints causing nerve root compression. These cysts were found in both the cervical and the lumbar spine, and the anatomical location of each cyst corresponded to the patient’s signs and symptoms. In no case was there evidence of intervertebral disc abnormality found at operation. The patients ranged from 49 to 77 years of age and included 4 men and 9 women. Radiographic evidence of facet degenerative change and degenerative spondylolisthesis was frequently but not invariably noted. The extradural defects defined with positive contrast myelography or postmyelography computed tomographic scanning were usually posterior or posterolateral to the common dural sac and were misinterpreted as extruded discs in the majority of cases. Treatment consisted of laminectomy and surgical excision of cysts. All patients reported improvement or resolution of their presenting symptoms 23).
Case reports
Chun et al. described an interesting case of cervical juxtafacet that developed outside the intervertebral foramen, compressing the cervical medial branch and causing neuropathic pain in the posterior inferior neck pain. A 61-year-old woman visited a local pain clinic due to neuropathic pain with a tingling and burning nature (numeric rating scale [NRS]: 5 out of 10) on the left posterior inferior neck area for 4 months. Paresthesia was observed in the left posterior inferior neck area. On cervical radiography, segmental instability was observed at the C3-4 and C4-5 levels. Moreover, on the magnetic resonance imaging (MRI) of the cervical spine, a cyst (size: 1.3 cm × 0.7 cm × 1 cm) was outside the intervertebral foramen, contacting the left C4-5 facet joint and left C5 articular pillar. We thought that compression of the left C5 medial branch by the cyst could cause the patient’s pain. We conducted computed tomography (CT)-guided percutaneous needle aspiration of a cervical juxtafacet cyst. An 18-gauge needle was advanced under the guidance of CT into the largest portion of the cyst through a posterolateral oblique approach. Gelatinous mucoid fluid (approximately 0.5 cc) was aspirated. Immediately after the aspiration, 80% of the patient’s pain was disappeared, and dysesthesia was completely disappeared. At the 1-, 3-, and 6-month follow-ups, the patient reported slight pain (NRS: 1) on the left posterior inferior neck. Cervical juxtafacet cysts can develop outside of the intervertebral foramen and spinal canal. Percutaneous needle aspiration can be a useful therapeutic tool for the treatment of such cysts 24)
Third reported case of a degenerative articular cyst of the upper cervical spine, involving the quadrate ligament of the odontoid process. Magnetic resonance examination reveals typical images. A new, more general terminology is proposed 25).
Costa F, Menghetti C, Cardia A, Fornari M, Ortolina A. Cervical synovial cyst: case report and review of literature. Eur Spine J. 2010 Jul;19 Suppl 2:S100-2. doi: 10.1007/s00586-009-1094-6. Epub 2009 Jul 15. Review. PubMed PMID: 19603197; PubMed Central PMCID: PMC2899642.
Sasamori T, Hida K, Anzai K, Yano S, Kato Y, Tanaka S, Saito H, Houkin K. A case of cervical juxtafacet cyst with extensive rim enhancement on Gd-DTPA MRI. Clin Imaging. 2014 Mar-Apr;38(2):199-201. doi: 0.1016/j.clinimag.2013.10.002. Epub 2013 Nov 7. PubMed PMID: 24332973.
Moon HJ, Kim JH, Kim JH, Kwon TH, Chung HS, Park YK. Cervical juxtafacet cyst with myelopathy due to postoperative instability. Case report. Neurol Med Chir (Tokyo). 2010;50(12):1129-31. PubMed PMID: 21206195.
Boviatsis EJ, Stavrinou LC, Kouyialis AT, Gavra MM, Stavrinou PC, Themistokleous M, Selviaridis P, Sakas DE (2008) Spinal synovial cysts: pathogenesis, diagnosis and surgical treatment in a series of seven cases and literature review. Eur Spine J 17:831– 837
Akhaddar A, Qamouss O, Belhachmi A, Elasri A, Okacha N, Elmostarchid B, Boucetta M (2008) Cervico-thoracic juxtafacet cyst causing spinal foraminal widening. Joint Bone Spine 75:747–749
Christophis P, Asamoto S, Kuchelmeister K, Schachenmayr W. “Juxtafacet cysts”, a misleading name for cystic formations of mobile spine (CYFMOS). Eur Spine J. 2007 Sep;16(9):1499-505. Epub 2007 Jan 4. PubMed PMID: 17203271; PubMed Central
Cho BY, Zhang HY, Kim HS. Synovial cyst in the cervical region causing severe myelopathy. Yonsei Med J. 2004 Jun 30;45(3):539-42. PubMed PMID: 15227744.
Cheng YY, Chen CC, Yang MS, Hung HC, Lee SK. Intraspinal extradural ganglion cyst of the cervical spine. J Formos Med Assoc. 2004 Mar;103(3):230-3. PubMed PMID: 15124052.
Chun YM, Boudier-Revéret M, Lee SH, Chang MC. Neuropathic Pain due to Compression of Cervical Medial Branch by Cervical Juxtafacet Cyst: A Case Report. Pain Pract. 2022 May 24. doi: 10.1111/papr.13129. Epub ahead of print. PMID: 35607892.
where the anterior pathology is superimposed on cervical stenosis, and the latter is more diffuse and/or more significant
in professional speakers or singers where the 4% risk of permanent voice change due to recurrent laryngeal nerve injury with ACD may be unacceptable.
Laminectomy and facetectomy are commonly used surgical procedures for decompressing cervical spinal stenosis. Resection of the posterior structures causes instability and affects the internal stresses of the cervical spinal components. However, the influence of these surgical procedures on the biomechanical responses of the cervical spine has not been studied.
A nonlinear finite element model of the intact C2-C7 was constructed and validated. Ten surgically altered models were created from the intact model and were tested under physiologic loading. Because of the inclusion of five motion segments, it was possible to determine the intersegmental responses and internal cortical shell and disc stresses in the adjacent altered and unaltered spinal components.
Under combined flexion and extension, intersegmental motions at C4-C5 and C5-C6 increased significantly after C5 laminectomy. Subsequent facetectomy performed at C5 and C6 on the laminectomized model only affected the responses at the C5-C6 segment. Overall, slight intersegmental responses of up to 5% were observed at the adjacent levels of C3-C4 and C6-C7. Laminectomy did not cause any significant increase in the intersegmental motions under lateral bending and axial rotation. Extending the surgical procedures to unilateral and bilateral facetectomy only increased the intersegmental motions slightly. Similar increases in the intervertebral disc and the cortical shell stresses were observed. These findings may partially explain the clinical observations of enhanced osteophytes formation.
This study provides a better understanding of the surgically altered cervical spinal biomechanics and may help formulate treatment strategies such as spinal implants 1).
Its a posterior cervical spine surgery, for cervical spinal stenosis. The spine surgeon removes a small section of the lamina to relieve compression on the nerve. The remaining spinal bones are connected back together with titanium metal rods and screws.
The skin incision is in the midline of the back of the neck and is about 3 to 4 inches long. The paraspinal muscles are then elevated from multiple levels. Removal of the lamina. A high-speed burr can be used to make a trough in the lamina on both sides right before it joins the facet joint. The lamina with the spinous process can then be removed as one piece (like a lobster tail). Removal of the lamina and spinous process allows the spinal cord to float backwards and gives it more room.
Cervical laminectomy resulted in the greatest increase in global cervical ROM. Resection of the intraspinous and supraspinous ligaments [ISLs).ISLs at C2-3 and C7-T1 increased segmental ROM at these specific levels to a similar extent that laminectomy increased ROM at each cervical level. This segmental ROM may contribute to pain or postprocedural deformity and highlights the importance of the ISLs at the terminal ends of the cervical open door laminoplasty (ODL) 2).
4. neuromonitoring: some surgeons used SSEP/MEP: Use of intra-op EP monitoring during a routine surgery for CSM or cervical radiculopathy is not recommended as an indication to alter the surgical plan or administer steroids since this paradigm has not been observed to reduce the incidence of neurologic injury (Level D Class III).
5. consent (in lay terms for the patient—not all-inclusive):
a) procedure: surgery through the back of the neck to remove the bone over the compressed spinal cord and nerves and possibly to place screws and rods to fuse the boned together
b) alternatives: nonsurgical management, surgery from the front of the neck, posterior surgery without fusion, laminoplasty
c) complications: nerve root weakness (C5 nerve root is the most common), may not relieve symptoms, further surgery may be needed, possible seizures with MEPs. If fusion is not done, there is a risk of progressive bone slippage, which would require further surgery.
Hong-Wan N, Ee-Chon T, Qing-Hang Z. Biomechanical effects of C2-C7 intersegmental stability due to laminectomy with unilateral and bilateral facetectomy. Spine (Phila Pa 1976). 2004 Aug 15;29(16):1737-45; discussion 1746. PubMed PMID: 15303016.
The most common surgical techniques are cervical discectomy with or without fusing the two adjacent intervertebral bodies. Robinson and Smith 1)2)3)4). introduced the anterior cervical decompression technique without microscope, but with fusion by inserting a bone graft harvested from the iliac crest of the patient.
Hankinson and Wilson 5) improved the procedure with the use of an operating microscope; however, they performed the surgery without leaving a graft behind; the results of both types of surgery were entirely comparable 6)7)8).
In time several modifications of these surgical techniques have been made 9)10)11).
Robinson RA, Smith GW. Anterolateral cervical disc removal and interbody fusion for cervical disc syndrome. Bull John Hopkins Hosp. 1955;96(Suppl):223–224.
SMITH GW, ROBINSON RA. The treatment of certain cervical-spine disorders by anterior removal of the intervertebral disc and interbody fusion. J Bone Joint Surg Am. 1958 Jun;40-A(3):607-24. PubMed PMID: 13539086.
Hankinson HL, Wilson CB. Use of the operating microscope in anterior cervical discectomy without fusion. J Neurosurg. 1975 Oct;43(4):452-6. PubMed PMID: 1159482.
Baskin DS, Ryan P, Sonntag V, Westmark R, Widmayer MA. A prospective, randomized, controlled cervical fusion study using recombinant human bone morphogenetic protein-2 with the CORNERSTONE-SR allograft ring and the ATLANTIS anterior cervical plate. Spine (Phila Pa 1976). 2003 Jun 15;28(12):1219-24; discussion 1225. PubMed PMID: 12811263.
Madawi AA, Powell M, Crockard HA. Biocompatible osteoconductive polymer versus iliac graft. A prospective comparative study for the evaluation of fusion pattern after anterior cervical discectomy. Spine (Phila Pa 1976). 1996 Sep 15;21(18):2123-9; discussion 2129-30. PubMed PMID: 8893437.
Cage subsidence was defined as the sum subsidence of the superior and inferior part of the cage into the vertebral body. Mild and major cage subsidence was defined as ≤2 mm and >2 mm, respectively. The extent of cage subsidence was greater after ACDF with cage alone. Cage subsidence occurred more often when the end plate was removed. Additional anterior plate fixation is recommended when the end plate is removed 1).
Subsidence in ACDF with cages occurs in 21% of patients. The risk for subsidence seems lower using PEEK or titanium cages or adding screws 2).
Zero profile anchored spacer (ROI-C) use resulted in a higher subsidence rate than conventional cage and plate construct (CPC) use in multi-segment ACDF procedures. The male sex, the use of ROI-C, operation in multiple segments, and over-distraction were the most significant factors associated with an increase in the risk of cage subsidence 3).
The greater the cage height, the greater the risk of cage subsidence in ACDF. Polyetheretherketone cages are superior to titanium cages for the maintenance of intervertebral height in cases where cage height is >5.5 mm 4)
Subsidence irrespective of the measurement technique or definition does not appear to have an impact on successful fusion and/or clinical outcomes. A validated definition and standard measurement technique for subsidence is needed to determine the actual incidence of subsidence and its impact on radiographic and clinical outcomes 5).
PEEK cages showed a high rate of secondary subsidence (32%) 6).
Titanium Wing cage-augmented ACDF was associated with comparatively good long-term results. Subsidence was present but did not cause clinical complications. Furthermore, radiological studies demonstrated that the physiological alignment of the cervical spine was preserved and a solid bone arthrodesis was present at 2 years after surgery 7).
There is evidence documenting relatively frequent complications in stand-alone cage assisted ACDF, such as cage subsidence and cervical kyphosis8).
Subsidence irrespective of the measurement technique or definition does not appear to have an impact on successful fusion and/or clinical outcomes. A validated definition and standard measurement technique for subsidence is needed to determine the actual incidence of subsidence and its impact on radiographic and clinical outcomes 9).
Findings suggest that the value of ratio of anterior endplate more than 1.18, alignment of titanium mesh cage (TMC) and poor bone mineral density are the risk factors for subsidence. TMC subsidence does not negatively affect the clinical outcomes after operation. Avoiding over expansion of intervertebral height, optimizing placing of TMC and initiation of anti-osteoporosis treatments 6 months prior to surgery might help surgeons to reduce subsidence after ACCF 10).
Case series
2021
Lee et al. from Yangsanretrospectively reviewed the medical records of 40 patients who underwent stand-alone single-level ACDF using a polyetheretherketone (PEEK) cage between January 2012 and December 2018. The study population comprised 19 male and 21 female patients aged 24-70 years. The minimum follow-up period was 1 year. Twenty-seven patients had preoperative bone mineral density (BMD) data on dual-energy X-ray absorptiometry. Clinical parameters included sex, age, body mass index, smoking history, and prior medical history. Radiologic parameters included the C2-7 cobb angle, segmental angle, sagittal vertical axis, disc height, and total intervertebral height (TIH) at the preoperative and postoperative periods. Cage decrement was defined as the reduction in TIH at the 6-month follow-up compared to preoperative TIH. To evaluate the bone quality, Hounsfield unit (HU) value was calculated in the axial and sagittal images of conventional computed tomography.
Lumbar BMD values and cervical HU values were significantly correlated (r=0.733, p<0.001). They divided the patients into two groups based on cage decrement, and 47.5% of the total patients were regarded as cage decrement. There were statistically significant differences in the parameters of measuring the HU value of the vertebra and intraoperative distraction between the two groups. Using these identified factors, we performed a receiver operating characteristic (ROC) curve analysis. Based on the ROC curve, the cut-off point was 530 at the HU value of the upper cortical and cancellous vertebrae (p=0.014; area under the curve [AUC], 0.727; sensitivity, 94.7%; specificity, 42.9%) and 22.41 at intraoperative distraction (p=0.017; AUC, 0.722; sensitivity, 85.7%; specificity, 57.9%). Using this value, they converted these parameters into a bifurcated variable and assessed the multinomial regression analysis to evaluate the risk factors for cage decrement in ACDF. Intraoperative distraction and HU value of the upper vertebral body were independent factors of postoperative subsidence.
Insufficient intraoperative distraction and low Hounsfield unit (HU) value showed a strong relationship with postoperative intervertebral height reduction following single stand-alone PEEK cage ACDF 11).
2017
Mende et al. performed a retrospective analysis of ACDF patients from 2004 to 2010. Numeric analog scale (NAS) score pre-op and post-op, Oswestry Disability Index (ODI) on x-rays, endplate (EP) and cage dimensions, implant position, lordotic/kyphotic subsidence patterns (>5°), and cervical alignment were recorded. Subsidence was defined as height loss >40%. Patients were grouped into single segment (SS), double segment (DS), and plated procedures. We included 214 patients. Prevalence of subsidence was 44.9% overall, 40.9% for SS, and 54.8% for DS. Subsidence presented mostly for dorsal (40.7%) and mid-endplate position (46.3%, p < 0.01); dorsal placement resulted in kyphotic (73.7%) and central placement in balanced implant migration (53.3%, p < 0.01). Larger cages (>65% EP) showed less subsidence (64.6 vs. 35.4%, p < 0.01). There was no impact of subsidence on ODI or alignment. NAS was better for subsided implants in SS (p = 0.06). Cages should be placed at the anterior endplate rim in order to reduce the risk of subsidence. Spacers should be adequately sized for the respective segment measuring at least 65% of the segment dimensions. The cage frame should not rest on the vulnerable central endplate. For multilevel surgery, ventral plating may be beneficial regarding construct stability. The reduction of micro-instability or over-distraction may explain lower NAS for subsided implants 12).
2014
a retrospective observational cohort study to test the hypothesis that radiographic subsidence of cervical cages is not associated with adverse clinical outcomes. 33 cervical segments were treated surgically by ACDF with stand-alone cage in 17 patients (11 female, 6 male), mean age 56 years (33-82 years), and re-examined after eight and twenty-six months (mean) by means of radiology and score assessment (Medical Outcomes Study Short Form (MOS-SF 36), Oswestry Neck Disability Index (ONDI), painDETECT questionnaire and the visual analogue scale (VAS)).
Results: Subsidence was observed in 50.5% of segments (18/33) and 70.6% of patients (12/17). 36.3% of cases of subsidence (12/33) were observed after eight months during mean time of follow-up 1. After 26 months during mean time of follow-up 2, full radiographic fusion was seen in 100%. MOS-SF 36, ONDI and VAS did not show any significant difference between cases with and without subsidence in the two-sample t-test. Only in one type of scoring (painDETECT questionnaire) did a statistically significant difference in t-Test emerge between the two groups (p = 0.03; α = 0.05). However, preoperative painDETECT score differ significantly between patients with subsidence (13.3 falling to 12.6) and patients without subsidence (7.8 dropped to 6.3).
Conclusions: The radiological findings indicated 100% healing after stand-alone treatment with ACDF. Subsidence occurred in 50% of the segments treated. No impact on the clinical results was detected in the medium-term study period 13).
Noordhoek I, Koning MT, Jacobs WCH, Vleggeert-Lankamp CLA. Incidence and clinical relevance of cage subsidence in anterior cervical discectomy and fusion: a systematic review. Acta Neurochir (Wien). 2018 Apr;160(4):873-880. doi: 10.1007/s00701-018-3490-3. Epub 2018 Feb 21. PMID: 29468440; PMCID: PMC5859059.
Jin ZY, Teng Y, Wang HZ, Yang HL, Lu YJ, Gan MF. Comparative Analysis of Cage Subsidence in Anterior Cervical Decompression and Fusion: Zero Profile Anchored Spacer (ROI-C) vs. Conventional Cage and Plate Construct. Front Surg. 2021 Oct 27;8:736680. doi: 10.3389/fsurg.2021.736680. PMID: 34778358; PMCID: PMC8579909.
Karikari IO, Jain D, Owens TR, Gottfried O, Hodges TR, Nimjee SM, Bagley CA. Impact of Subsidence on Clinical Outcomes and Radiographic Fusion Rates in Anterior Cervical Discectomy and Fusion: A Systematic Review. J Spinal Disord Tech. 2014 Feb;27(1):1-10. PubMed PMID: 24441059.
König SA, Spetzger U. Distractable titanium cages versus PEEK cages versus iliac crest bone grafts for the replacement of cervical vertebrae. Minim Invasive Ther Allied Technol. 2013 Nov 29. [Epub ahead of print] PubMed PMID: 24289173.
Schmieder K, Wolzik-Grossmann M, Pechlivanis I, Engelhardt M, Scholz M, Harders A. Subsidence of the wing titanium cage after anterior cervical interbody fusion: 2-year follow-up study. J Neurosurg Spine. 2006 Jun;4(6):447-53. PubMed PMID: 16776355.
Ji C, Yu S, Yan N, Wang J, Hou F, Hou T, Cai W. Risk factors for subsidence of titanium mesh cage following single-level anterior cervical corpectomy and fusion. BMC Musculoskelet Disord. 2020 Jan 14;21(1):32. doi: 10.1186/s12891-019-3036-8. PMID: 31937288; PMCID: PMC6961320.
Lee JS, Son DW, Lee SH, Ki SS, Lee SW, Song GS, Woo JB, Kim YH. The Effect of Hounsfield Unit Value with Conventional Computed Tomography and Intraoperative Distraction on Postoperative Intervertebral Height Reduction in Patients Following Stand-Alone Anterior Cervical Discectomy and Fusion. J Korean Neurosurg Soc. 2021 Dec 29. doi: 10.3340/jkns.2021.0131. Epub ahead of print. PMID: 34963207.
Mende KC, Eicker SO, Weber F. Cage deviation in the subaxial cervical spine in relation to implant position in the sagittal plane. Neurosurg Rev. 2017 Apr 4. doi: 10.1007/s10143-017-0850-z. [Epub ahead of print] PubMed PMID: 28374128.
Zajonz D, Franke AC, von der Höh N, Voelker A, Moche M, Gulow J, Heyde CE. Is the radiographic subsidence of stand-alone cages associated with adverse clinical outcomes after cervical spine fusion? An observational cohort study with 2-year follow-up outcome scoring. Patient Saf Surg. 2014 Nov 7;8(1):43. doi: 10.1186/s13037-014-0043-4. PMID: 25408710; PMCID: PMC4234826.
These conditions appear as a curvature of the neck and are neck deformities that cause neck pain and instability.
The stability of the cervical spine, and its ability to resist kyphosis, depends on several different parts of the spine. First, the vertebral bodies need to be strong enough to support the head and keep a normal shape. Second, the facet joints, ligaments, and soft tissues in the back of the spine must be strong enough to keep the neck from curving forward due to the pull of the weight of the head. Finally, the muscles in the back must be strong enough to resist the forward pull of the weight of the head. If there is damage to any of these three areas, a kyphotic deformity can develop. After the kyphosis begins, the weight of the head can cause a progression of the curvature.
Patients with cervical kyphotic deformity exhibit different patterns of reciprocal changes depending on whether they have head-balanced or trunk-balanced kyphosis. These reciprocal changes should be considered to in order to prevent secondary spine disorders. It is important to evaluate the global spinal alignment to assess postoperative changes 1)
Classification
Cervical kyphosis can be classified into two different groups:
The treatment option for correcting a cervical kyphotic deformity is currently controversial. Lots of studies examined the one/stage combined anterior-posterior treatment, although the rate of fusion and the long term follow up controls are rarely mentioned in the literature 2)3)4)5)6)7)8).
Fusion of cervical spine in kyphosis alignment has been proven to produce an acceleration of cervical adjacent segment disease. Stand-alone cervical cages are reported to have a relatively high incidence of implant subsidence with secondary kyphotic deformity. This malalignment may theoretically lead to adjacent segment disease in the long term.
A prospective study analysed possible risk factors leading to cage subsidence with resulting sagittal malalignment of cervical spine. Radiographic data of 100 consecutive patients with compressive radiculo-/myelopathy due to degenerative disc prolapse or osteophyte formation were prospectively collected in those who were treated by anterior cervical discectomy and implantation of single type interbody fusion cage. One hundred and forty four implants were inserted altogether at one or two levels as stand-alone cervical spacers without any bone graft or graft substitute. All patients underwent standard anterior cervical discectomy and the interbody implants were placed under fluoroscopy guidance. Plain radiographs were obtained on postoperative days one and three to verify position of the implant. Clinical and radiographic follow-up data were obtained at 6 weeks, 3 and 6 months and than annually in outpatient clinic. Radiographs were evaluated with respect to existing subsidence of implants. Subsidence was defined as more than 2 mm reduction in segmental height due to implant migration into the adjacent end-plates. Groups of subsided and non-subsided implants were statistically compared with respect to spacer distance to the anterior rim of vertebral body, spacer versus end-plate surface ratio, amount of bone removed from adjacent vertebral bodies during decompression and pre- versus immediate postoperative intervertebral space height ratio. There were 18 (18%) patients with 19 (13.2%) subsided cages in total. No patients experienced any symptoms. At 2 years, there was no radiographic evidence of accelerated adjacent segment degeneration. All cases of subsidence occurred at the anterior portion of the implant: 17 cases into the inferior vertebra, 1 into the superior and 1 into both vertebral bodies. In most cases, the process of implant settling started during the perioperative period and its progression did not exceed three postoperative months. There was an 8.7 degrees average loss of segmental lordosis (measured by Cobb angle). Average distance of subsided intervertebral implants from anterior vertebral rim was found to be 2.59 mm, while that of non-subsided was only 0.82 mm (P < 0.001). Spacer versus end-plate surface ratio was significantly smaller in subsided implants (P < 0.001). Ratio of pre- and immediate postoperative height of the intervertebral space did not show significant difference between the two groups (i.e. subsided cages were not in overdistracted segments). Similarly, comparison of pre- and postoperative amount of bone mass in both adjacent vertebral bodies did not show a significant difference. Appropriate implant selection and placement appear to be the key factors influencing cage subsidence and secondary kyphotisation of box-shaped, stand-alone cages in anterior cervical discectomy and fusion. Mechanical support of the implant by cortical bone of the anterior osteophyte and maximal cage to end-plate surface ratio seem to be crucial in the prevention of postoperative loss of lordosis.
The results were not able to reflect the importance of end-plate integrity maintenance; the authors would, however, caution against mechanical end-plate damage. Intraoperative overdistraction was not shown to be a significant risk factor in this study. The significance of implant subsidence in acceleration of degenerative changes in adjacent segments remains to be evaluated during a longer follow-up 9).
Etiology
There are several causes of cervical kyphosis. This condition can develop in children and adults.
The first cause is degenerative disc disease. The process of degeneration of the intervertebral discs causes many spine problems. In older adults, the wear and tear of aging on the discs between each vertebra can cause the disc to collapse. As the discs collapse and grow thinner, the head tilts forward and the neck begins to curve forward. This begins a process that may continue to progress for years. The weight of the head causes an imbalance of forces pushing the neck increasingly forward. This slowly leads to an increasing curve and may end with a kyphosis.
The second cause of cervical kyphosis is congenital, meaning it is a birth defect affecting the development of the spine. A person is born with some sort of defect, such as incomplete formation of the spine, which leads to an increasing kyphosis type curve in the neck. Congenital kyphosis usually leads to a growth disturbance of the vertebrae themselves. Instead of growing normally, the vertebrae grow into a triangular-shape with the small end pointing forward. Because the vertebrae are stacked one atop the other, the triangle shape causes the spine to have a forward curvature.
When a child has congenital kyphosis, there are generally additional birth defects in other areas of the body. Most commonly, there are defects of the kidneys and urinary system.
Treatment for congenital kyphosis is typically surgery. Early surgical intervention usually produces the best results and can prevent progression of the curve. The type of surgical procedure will depend on the nature of the abnormality. Conservative (non-surgical) treatment plans do not have much success at correcting this type of kyphosis. Without surgery, there is a critical need for observation and close medical follow-up to prevent serious problems.
The third cause of cervical kyphosis is traumatic, meaning it is the result of an injury to the cervical spine. This may be from a compression fracture of the vertebrae or from an injury to the ligaments in the back of the cervical spine. When a compression fracture of the vertebra occurs, the vertebral body may heal in a wedge shape. This causes a similar situation discussed above for the triangle-shaped vertebrae of a congenital kyphosis. The resulting imbalance can lead to increasing forward curvature of the neck. If the kyphosis becomes bad enough, it can narrow the spinal canal causing a condition known as spinal stenosis. Pressure on the spinal cord due to the narrowing can lead to neurological problems, such as pain, numbness, and a loss in muscle strength.
The fourth, and the most common cause of cervical kyphosis, is iatrogenic. Iatrogenic means the problem results from the effects of a medical treatment, such as surgery. Kyphosis following laminectomy surgery is quite common. It happens much more frequently with children than with adults.
Problems can also arise if the fusion fails to heal properly. Failure of a fusion site to heal is called a pseudoarthrosis. If the fusion fails to heal, the spine may begin to curve forward leading to a kyphosis. Even in a healed fusion, improper alignment of the fused vertebrae can result in an imbalance that leads to a kyphosis.
Other less common causes of cervical kyphosis include infection in the spine, tumors of the spine, and systemic diseases that affect the spine (such as ankylosing spondylitis). A cervical kyphosis may also occur years after radiation therapy for cancer involving the neck. The radiation therapy may affect the growth of the cervical vertebrae in children who received radiation therapy in childhood.
The symptoms of cervical kyphosis can range from a simple nuisance to a severe deformity, which can lead to paralysis if untreated. Symptoms can include mechanical neck pain if the kyphosis is due to degenerative changes in the cervical spine. You may have a reduced range of motion in the neck. This means you may not be able to rotate your neck fully and you may have difficulty looking up for any length of time.
If the kyphosis is severe, you may begin to have problems with the nerve roots or the spinal cord, due to pressure on the nerves in the cervical spine. This may cause: weakness in the arms or legs, loss of grip strength, or difficulty walking due to spasticity in the legs. You may have problems controlling your bladder or bowels. In extremely severe cases that are left untreated, paralysis from the neck down may even result.
Diagnosis
Regular X-rays, are usually a first step in looking into any neck problem and will help determine if more tests will be needed.
Magnetic Resonance Imaging (MRI)
The MRI is the most commonly used test to evaluate the spine because it can show abnormal areas of the soft tissues around the spine. The MRI is better than X-ray because in addition to the bones, it can also show pictures of the nerves and discs. The MRI is done to find tumors, herniated discs, or other soft-tissue disorders.
Treatment
Excessive kyphosis can be treated, and the methods of treatment have evolved over time. Today, surgery to treat cervical kyphosis is usually a spinal fusion combined with “segmental instrumentation”. This means that some type of metal plate or rod is used to hold the spine in the proper alignment in order to straighten it.
If the deformity is fixed (meaning that it is not getting worse), and there are no neurological problems due to pressure on the spinal cord, surgery is usually not recommended because the problem is not going to get worse. Spinal surgery is serious, and unless necessary, it is rarely recommended. However, if the fixed deformity is accompanied by neurological problems from pressure on the spinal cord, surgery becomes more likely. Surgical correction is the most difficult type of treatment for cervical kyphosis. Surgery may require an operation from the front of the spine to relieve the pressure on the spinal cord, and an operation from the back to fuse the spine and prevent the kyphosis from returning.
If the kyphosis is flexible, the decision to go ahead with surgery should be based upon: the progression of the deformity, the severity of the deformity, and the amount of pain it causes. If the curve and pain are minor, surgery will not be recommended simply because the deformity looks bad. However, if the deformity is severe and the pain is chronic, surgery may be a good option.
If the kyphosis is due to ankylosing spondylitis, the problem area of the spine usually extends over the area where the cervical and thoracic spines join each other. This type of cervical kyphosis is usually a fixed deformity. Ankylosing spondylitis (AS) causes the discs between each vertebra of the entire spine to calcify and actually creates a fusion of the entire spine. If there is a cervical kyphosis after the spine fuses due to AS, the surgery may have to include performing an “osteotomy” of the fused spine. The term osteotomy means “bone (osteo) cut (otomy)”. During an osteotomy, the front of the spine column may need to be cut to allow the surgeon to straighten the spine. The spinal cord is not cut, only the bone of the vertebrae in the front of the spinal column.
Kim CW, Hyun SJ, Kim KJ. Systematic Review of EOS Evaluations of Global Spinal Alignment : Do Not Miss the Forest for the Trees. J Korean Neurosurg Soc. 2021 Oct 8. doi: 10.3340/jkns.2020.0234. Epub ahead of print. PMID: 34619822.
Abumi K, Shono Y, Taneichi H, Ito M, Kaneda K. Correction of cervical kyphosis using pedicle screw fixation systems. Spine (Phila Pa 1976) 1999;24:2389–2396.
Kanter AS, Wang MY, Mummaneni PV. A treatment algorithm for the management of cervical spine fractures and deformity in patients with ankylosing spondylitis. Neurosurg Focus. 2008;24:E11.
Ferch RD, Shad A, Cadoux-Hudson TA, Teddy PJ. Anterior correction of cervical kyphotic deformity: effects on myelopathy, neck pain, and sagittal alignment. J Neurosurg. 2004;100:13–19.
Lin D, Zhai W, Lian K, Kang L, Ding Z. Anterior versus posterior approach for four-level cervical spondylotic myelopathy. Orthopedics. 2013;36:e1431–e1436.
Barsa P, Suchomel P. Factors affecting sagittal malalignment due to cage subsidence in standalone cage assisted anterior cervical fusion. Eur Spine J. 2007 Sep;16(9):1395-400. Epub 2007 Jan 13. PubMed PMID: 17221174; PubMed Central PMCID: PMC2200763.
Lin JH, Chien LN, Tsai WL, Chen LY, Hsieh YC, Chiang YH. Reoperation rates of anterior cervical discectomy and fusion versus posterior laminoplasty for multilevel cervical degenerative diseases: a population-based cohort study in Taiwan. Spine J. 2016 Dec;16(12):1428-1436. doi: 10.1016/j.spinee.2016.08.017. PubMed PMID: 2752008
Indications and optimal timing for surgical treatment of degenerative cervical myelopathy (DCM) remain unclear, and data from daily clinical practice are warranted.
Gulati et al. investigated clinical outcomes following decompressive surgery for DCM.
They included 905 patients operated between January 2012 and June 2018. There were significant improvements in all Patient-reported outcome measures (PROMs) including NDI (mean -10.0, 95% CI -11.5 to -8.4, P < .001), EMS (mean 1.0, 95% CI 0.8-1.1, P < .001), EQ-5D index score (mean 0.16, 95% CI 0.13-0.19, P < .001), EQ-5D visual analogue scale (mean 13.8, 95% CI 11.7-15.9, P < .001), headache NRS (mean -1.1, 95% CI -1.4 to -0.8, P < .001), neck pain NRS (mean -1.8, 95% CI -2.0 to -1.5, P < .001), and arm pain NRS (mean -1.7, 95% CI -1.9 to -1.4, P < .001). According to GPE scale assessments, 229/513 patients (44.6%) experienced “complete recovery” or felt “much better” at 1 yr. There were significant improvements in all PROMs for both mild and moderate-to-severe DCM. A total of 251 patients (27.7%) experienced adverse effects within 3 mo.
Surgery for DCM is associated with significant and clinically meaningful improvement across a wide range of PROMs 1).
Objective scoring of the post-operative neurological function did not correlate with patient-perceived outcomes in Degenerative cervical myelopathy outcome (DCM). Traditional testing of motor and sensory function as part of the neurological assessment may not be sensitive enough to assess the scope of neurological changes experienced by Degenerative cervical myelopathy patients 2).
This retrospective observational study was conducted on twenty-five patients with degenerative cervical disc prolapse associated with MRI T2WI hyperintense cord signal, at the Department of Neurosurgery, Qena University Hospital, South Valley University from August 2014 to December 2016. A complete clinical and radiological evaluation of the patients was done. Anterior cervical discectomy and fusion was done for all patients. Patients were clinically assessed preoperatively and postoperatively at 3, 6, and 12 months using Modified Japanese Orthopaedic Association scale (MJOA). Radiographic assessment was done by preoperative and postoperative T2WI MRI. The statistical analysis was done using Statistical Package for the Social Sciences (SPSS) software (version 22.0).
There were 25 patients included in the study; 16 (64%) females and 9 (36%) males. The mean age was 46.89 ± 7.52 standard deviation (SD) years with range from 26 to 64 years, 3 (12%) patients had worsened in the form of postoperative motor power deterioration, and 14 (56%) patients has no improvement and remain as preoperative condition. The remaining 8 (32%) patients had a reported postoperative improvement of symptoms and signs according to MJOA score. The mean follow-up period (in months) was 11 ± 2.34 (SD). Conclusion:
The presence of T2W hyperintense signal on preoperative MRI predicts a poor surgical outcome in patients with cervical disc prolapse. The regression of T2W ISI postoperatively correlates with better functional outcomes 3).
Whilst decompressive surgery can halt disease progression, existing spinal cord damage is often permanent, leaving patients with lifelong disability.
Early surgery improves the likelihood of recovery, yet the average time from onset of symptoms to correct diagnosis is over 2 years. The majority of delays occur initially, before and within primary care, mainly due to a lack of recognition. Symptom checkers are widely used by patients before medical consultation and can be useful for preliminary triage and diagnosis. Lack of recognition of Degenerative Cervical Myelopathy (DCM) by symptom checkers may contribute to the delay in diagnosis.
The impact of the changes in myelopathic signs following cervical decompression surgery and their relationship to functional outcome measures remains unclear.
Surgery is associated with a significant quality of life improvement. The intervention is cost effective and, from the perspective of the hospital payer, should be supported 4).
Surgical decompression for CSM is safe and results in improved functional status and quality of life in patients around the world, irrespective of differences in medical systems and socio-cultural determinants of health 5).
The successful management of CSM depends upon an early and accurate diagnosis, an objective assessment of impairment and disability, and an ability to predict outcome. In this field, quantitative measures are increasingly used by clinicians to grade functional and neurological status and to provide decision-making support 6).
In addition, objective assessment tools allow clinicians to quantify myelopathy severity, predict outcome, and evaluate surgical benefits by tracking improvements throughout follow-up 7)8)9).
Several outcome measures assess functional impairment and quality of life in patients with cervical myelopathy 10)11)12)13)14).
A validated “gold standard,” however, has not been established, preventing the development of quantitative guidelines for CSM management 15).
Some studies have found that resolution of T2 hyperintensity in subjects with CSM who undergo ventral decompressive surgery correlates with improved functional outcomes. Other studies have found little correlation with postoperative outcome 16)17).
Machine learning for degenerative cervical myelopathy
1) Gulati S, Vangen-Lønne V, Nygaard ØP, Gulati AM, Hammer TA, Johansen TO, Peul WC, Salvesen ØO, Solberg TK. Surgery for Degenerative Cervical Myelopathy: A Nationwide Registry-Based Observational Study With Patient-Reported Outcomes. Neurosurgery. 2021 Jul 29:nyab259. doi: 10.1093/neuros/nyab259. Epub ahead of print. PMID: 34325471.2) McGregor SM, Detombe S, Goncalves S, Doyle-Pettypiece P, Bartha R, Duggal N. Does the Neurological Exam Correlate with Patient Perceived Outcomes in Degenerative Cervical Myelopathy? World Neurosurg. 2019 Aug 2. pii: S1878-8750(19)32111-4. doi: 10.1016/j.wneu.2019.07.195. [Epub ahead of print] PubMed PMID: 31382071.3) Hamdan ARK. The Relation between Cord Signal and Clinical Outcome after Anterior Cervical Discectomy in Patients with Degenerative Cervical Disc Herniation. Asian J Neurosurg. 2019 Jan-Mar;14(1):106-110. doi: 10.4103/ajns.AJNS_262_17. PubMed PMID: 30937019; PubMed Central PMCID: PMC6417293.4) Witiw CD, Tetreault LA, Smieliauskas F, Kopjar B, Massicotte EM, Fehlings MG. Surgery for degenerative cervical myelopathy: a patient centered quality of life and health economic evaluation. Spine J. 2016 Oct 25. pii: S1529-9430(16)31022-1. doi: 10.1016/j.spinee.2016.10.015. [Epub ahead of print] PubMed PMID: 27793760.5) Fehlings MG, Ibrahim A, Tetreault L, Albanese V, Alvarado M, Arnold P, Barbagallo G, Bartels R, Bolger C, Defino H, Kale S, Massicotte E, Moraes O, Scerrati M, Tan G, Tanaka M, Toyone T, Yukawa Y, Zhou Q, Zileli M, Kopjar B. A Global Perspective on the Outcomes of Surgical Decompression in Patients with Cervical Spondylotic Myelopathy: Results from the Prospective Multicenter AOSpine International Study on 479 patients. Spine (Phila Pa 1976). 2015 May 27. [Epub ahead of print] PubMed PMID: 26020847.6) , 15) Singh A, Tetreault L, Casey A, et al. A summary of assessment tools for patients suffering from cervical spondylotic myelopathy: a systematic review on validity, reliability, and responsiveness [published online ahead of print September 5, 2013]. Eur Spine J. doi:10.1007/s00586-013-2935-x.7) Laing RJ. Measuring outcome in neurosurgery. Br J Neurosurg 2000;14:181–4.8) Holly LT, Matz PG, Anderson PA, et al. Clinical prognostic indicators of surgical outcome in cervical spondylotic myelopathy. J Neurosurg Spine 2009;11:112–8.9) Kalsi-Ryan S, Singh A, Massicotte EM, et al. Ancillary outcome measures for assessment of individuals with cervical spondylotic myelopathy. Spine (Phila Pa 1976) 2013;38:S111–22.10) Singh A, Crockard HA. Quantitative assessment of cervical spondylotic myelopathy by a simple walking test. Lancet 1999;354:370–3.11) Nurick S. The natural history and the results of surgical treatment of the spinal cord disorder associated with cervical spondylosis. Brain 1972;95:101–8.12) Olindo S, Signate A, Richech A, et al. Quantitative assessment of hand disability by the nine-hole-peg test (9-HPT) in cervical spondylotic myelopathy. J Neurol Neurosurg Psychiatry 2008;79:965–7.13) Hosono N, Sakaura H, Mukai Y, et al. A simple performance test for quantifying the severity of cervical myelopathy [erratum in: J Bone Joint Surg Br 2008;90:1534]. J Bone Joint Surg Br 2008;90:1210–3.14) Casey AT, Bland JM, Crockard HA. Development of a functional scoring system for rheumatoid arthritis patients with cervical myelopathy. Ann Rheum Dis 1996;55:901–6.16) Sarkar S, Turel MK, Jacob KS, Chacko AG. The evolution of T2-weighted intramedullary signal changes following ventral decompressive surgery for cervical spondylotic myelopathy. J Neurosurg Spine. 2014;21(4):538-546.17) Vedantam A, Rajshekhar V. Change in morphology of intramedullary T2- weighted increased signal intensity after anterior decompressive surgery for cervical spondylotic myelopathy. Spine (Phila Pa 1976). 2014;39(18):1458-1462.
Currently, the incidence of SSEH is expected to increase. Pain physicians must include SSEH in their differential diagnosis for patients with axial pain or radicular symptoms alone, particularly when risk factors are present 1).
Etiology
The cause of bleeding in the current literature is both venous and arterial in origin. Venous bleeding owing is the commonly accepted hypothesis for the source of the hematoma because spinal epidural venous plexus have no sphincters, and thus have no protection against pressure changing 2). This theory seems to be invalid in the cervical region because the venous pressure is low. It is said that the cervical epidural hematoma has an arterial source from free anastomotic arteries in connection with radicular arteries that exist in the epidural space3).
Diagnosis
Acute cervical epidural hematoma is definitely a condition of neurologic emergency. Although it is a rare condition, it must be considered in nontraumatic patients with sudden onset of neurologic deficits. Patients with spontaneous spinal epidural hematoma typically present with acute onset of severe back pain, and they rapidly develop signs of compression of the spinal cord or cauda equina 4)
High index of suspicion followed by T2-weighted gradient echo sequences are particularly useful in early diagnosis. 5)
Prompt surgical evacuation of the hematoma leads to a favorable neurological outcome, whereas delay in treatment can be disastrous. The role of conservative management needs to be proven and should be tailored on an individual basis 6)
Outcome
This is a rare idiopathic condition that leads to acute onset of neurologic deficits, which if not recognized early can have catastrophic consequences.
A 65 year old male presented with six months of worsening signs and symptoms of cervical myelopathy. He had progressive deterioration over the course of two weeks leading to ambulatory dysfunction requiring a cane for assistance. While undergoing his medical workup in the emergency department, the patient became acutely plegic in the right lower extremity prompting emergent surgical decompression and stabilization.
Based on imaging, pathology, and intraoperative findings, it was concluded that the patient had an extruded disc segment that may have precipitated venous bleeding in the epidural space and findings of acute cervical spinal cord compression. Cervical disc extrusion may lead to venous damage, epidural hematoma, and spinal cord compression. If this unique presentation is recognized and addressed in a timely manner, patient outcomes may still be largely positive as this case demonstrates 7).
2019
A 41-year-old male, diagnosed with SCEH, with a presenting chief complaint of cervical pain followed by progressive quadriparesis and urgency of micturition who was managed surgically.
SCEH is a rare pathologic entity. Due to the high risk of poor neurological outcome without treatment, SCEH should be a diagnostic possibility when the presentation is even slightly suggestive. Prompt surgical evacuation of the hematoma and hemostasis leads to a favorable neurological outcome, whereas delay in treatment can be disastrous 8).
A 31-year-old man who presented with acute onset of neck pain with radicular component with progressive neurologic deficit. Emergent magnetic resonance imaging revealed cervical extradural hematoma with cord compression that was promptly evacuated. Functional recovery was achieved within 48 hours. The level of preoperative neurologic deficit and its severity, as well as operative interval, are important factors significantly affecting the postoperative outcome 9)
A 28-year-old healthy man developed a sudden onset of severe neck and right shoulder pain with mild arm weakness. The MRI revealed an SSEH that was compressing his spinal cord in the right posterolateral epidural space from C2-C6. On the second hospital day, his symptoms suddenly improved, and most of the hematoma had spontaneously resolved Currently, the incidence of SSEH is expected to increase. Pain physicians must include SSEH in their differential diagnosis for patients with axial pain or radicular symptoms alone, particularly when risk factors are present 10).
A 70-year-old man presented with acute onset neck pain with a radicular component and rapidly progressive quadriparesis. Magnetic resonance imaging revealed a posteriorly located cervical extradural hematoma with cord compression that was promptly evacuated. Functional recovery to near normal function occurred within 24 hours of surgery.
SSEH in its true idiopathic form is a rare pathologic entity. Because of the high risk of poor outcome without treatment, SSEH should be a diagnostic possibility when presentation is even slightly suggestive. Prompt surgical evacuation of the hematoma leads to a favorable neurological outcome, whereas delay in treatment can be disastrous. The role of conservative management needs to be proven and should be tailored on an individual basis 11)
A 25-year-old male presented with a history of sudden onset of complete quadriplegia with sensory loss below the neck along with loss of bowel and bladder control. He had no history of any constitutional symptoms. He reported 10 days later. He was managed conservatively and after two weeks of intensive rehabilitation he had complete neural recovery. The spontaneous recovery of neurological impairment is attributed to the spreading of the hematoma throughout the epidural space, thus decreasing the pressure with partial neural recovery. Conservative treatment is a fair option in young patients who present late and show neurological improvement. The neurological status on presentation will guide the further approach to management 12).
Gopalkrishnan CV, Dhakoji A, Nair S. Spontaneous cervical epidural hematoma of idiopathic etiology: case report and review of literature. J Spinal Cord Med. 2012 Mar;35(2):113-7. doi: 10.1179/2045772312Y.0000000001. Epub 2012 Feb 4. PMID: 22333537; PMCID: PMC3304555.
Taha MM, Elsharkawy AM, Al Menshawy HA, AlBakry A. Spontaneous cervical epidural hematoma: A case report and review of literature. Surg Neurol Int. 2019 Dec 13;10:247. doi: 10.25259/SNI_543_2019. PMID: 31893148; PMCID: PMC6935966.
Axial neck pain remains the most important problem of cervical laminoplasty. Hosono et al. 1)), reviewed a series of 72 laminoplasties conducted to treat cervical spondylotic myelopathy, and found a 60% incidence of axial pain. Kawaguchi et al. 2)), reported significant axial neck pain in 44% of their patiensts. Other authors have reported incidence of axial neck pain after laminoplasty of about 30% 3), 4)5). The possible causes of axial neck pain after cervical laminoplasty are ischemia of the shoulder muscles, atrophy of nuchal muscles, and delayed union in the facet joints 6)).
Axial pain after cervical laminoplasty has been reported to be due to neck muscle disruption, especially because of detachments of muscle insertions to the C2 or C7 spinous processes, or deep extensor muscles 7)8)9)
A study demonstrated that C7 spinous process preserving laminoplasty decreases the incidence of aggravated axial neck pain after cervical laminoplasty 10).
The presence of anterolisthesis was associated not only with the highest odds ratio of persistent neck pain but also with significantly poorer functional outcomes. Indications for cervical laminoplasty should be carefully determined in patients with cervical anterolisthesis 11).
The use of a rigid collar after laminoplasty leads to less axial neck pain in the first 2 wk after surgery. However, there is no additional benefit with regards to range of motion, quality of life, and complication risk 12).
Seventy-six patients with a mean age of 64 years were included. The average follow-up was 22.53 months. The overall average CSA of the DEM was 2274.55 mm2 and that of the SC was 275.64 mm2. Means of both CSAs were higher in men (P<0.001). Linear regression showed no correlation between LL with CSA of the DEM or the SC (r=0.005, P=0.119; r=0.001, P=0.095). Univariate and multivariate regression showed no differences in the CSA of the DEM and SC between groups with and without LL (P=0.092, 0.117 and 0.163, 0.292). There was no correlation in LL with sex or body mass index (P>0.05).
Axial neck pain after C3-6 laminoplasty has been reported to be significantly lesser than that after C3-7 laminoplasty because of the preservation of the C-7 spinous process and the attachment of nuchal muscles such as the trapezius and rhomboideus minor, which are connected to the scapula. The C-6 spinous process is the second longest spinous process after that of C-7, and it serves as an attachment point for these muscles. The effect of preserving the C-6 spinous process and its muscular attachment, in addition to preservation of the C-7 spinous process, on the prevention of axial neck pain is not well understood. The purpose of the current study was to clarify whether preservation of the paraspinal muscles of the C-6 spinous process reduces postoperative axial neck pain compared to that after using nonpreservation techniques.
Montano et al. studied 60 patients who underwent C3-6 double-door laminoplasty for the treatment of cervical spondylotic myelopathy or cervical ossification of the posterior longitudinal ligament; the minimum follow-up period was 1 year. Twenty-five patients underwent a C-6 paraspinal muscle preservation technique, and 35 underwent a C-6 nonpreservation technique. A visual analog scale (VAS) and VAS grading (Grades I-IV) were used to assess axial neck pain 1-3 months after surgery and at the final follow-up examination. Axial neck pain was classified as being 1 of 5 types, and its location was divided into 5 areas. The potential correlation between the C-6/C-7 spinous process length ratio and axial neck pain was examined.
The mean VAS scores (± SD) for axial neck pain were comparable between the C6-preservation group and the C6-nonpreservation group in both the early and late postoperative stages (4.1 ± 3.1 vs 4.0 ± 3.2 and 3.8 ± 2.9 vs 3.6 ± 3.0, respectively). The distribution of VAS grades was comparable in the 2 groups in both postoperative stages. Stiffness was the most prevalent complaint in both groups (64.0% and 54.5%, respectively), and the suprascapular region was the most common site in both groups (60.0% and 57.1%, respectively). The types and locations of axial neck pain were also similar between the groups. The C-6/C-7 spinous process length ratios were similar in the groups, and they did not correlate with axial neck pain. The reductions of range of motion and changes in sagittal alignment after surgery were also similar.
The C-6 paraspinal muscle preservation technique was not superior to the C6-nonpreservation technique for preventing postoperative axial neck pain 14).
Hosono N, Yonenobu K, Ono K. Neck and shoulder pain after laminoplasty. A noticeable complication. Spine (Phila Pa 1976). 1996 Sep 1;21(17):1969-73. doi: 10.1097/00007632-199609010-00005. PMID: 8883196.
Kawaguchi Y, Kanamori M, Ishiara H, Nobukiyo M, Seki S, Kimura T. Preventive measures for axial symptoms following cervical laminoplasty. J Spinal Disord Tech. 2003 Dec;16(6):497-501. doi: 10.1097/00024720-200312000-00002. PMID: 14657744.
Hidai Y, Ebara S, Kamimura M, Tateiwa Y, Itoh H, Kinoshita T, Takaoka K, Ohtsuka K. Treatment of cervical compressive myelopathy with a new dorsolateral decompressive procedure. J Neurosurg. 1999 Apr;90(2 Suppl):178-85. doi: 10.3171/spi.1999.90.2.0178. PMID: 10199246.
Satomi K, Nishu Y, Kohno T, Hirabayashi K. Long-term follow-up studies of open-door expansive laminoplasty for cervical stenotic myelopathy. Spine (Phila Pa 1976). 1994 Mar 1;19(5):507-10. doi: 10.1097/00007632-199403000-00003. PMID: 8184342.
Wada E, Suzuki S, Kanazawa A, Matsuoka T, Miyamoto S, Yonenobu K. Subtotal corpectomy versus laminoplasty for multilevel cervical spondylotic myelopathy: a long-term follow-up study over 10 years. Spine (Phila Pa 1976). 2001 Jul 1;26(13):1443-7; discussion 1448. doi: 10.1097/00007632-200107010-00011. PMID: 11458148.
Iizuka H, Shimizu T, Tateno K, Toda N, Edakuni H, Shimada H, Takagishi K. Extensor musculature of the cervical spine after laminoplasty: morphologic evaluation by coronal view of the magnetic resonance image. Spine (Phila Pa 1976). 2001 Oct 15;26(20):2220-6. doi: 10.1097/00007632-200110150-00013. PMID: 11598512.
Shiraishi T, Fukuda K, Yato Y, Nakamura M, Ikegami T. Results of skip laminectomy-minimum 2-year follow-up study compared with open-door laminoplasty. Spine (Phila Pa 1976). 2003 Dec 15;28(24):2667-72. doi: 10.1097/01.BRS.0000103340.78418.B2. PMID: 14673367.
Takeshita K, Seichi A, Akune T, Kawamura N, Kawaguchi H, Nakamura K. Can laminoplasty maintain the cervical alignment even when the C2 lamina is contained? Spine (Phila Pa 1976). 2005 Jun 1;30(11):1294-8. doi: 10.1097/01.brs.0000163881.32008.13. PMID: 15928555.
Cho CB, Chough CK, Oh JY, Park HK, Lee KJ, Rha HK. Axial neck pain after cervical laminoplasty. J Korean Neurosurg Soc. 2010 Feb;47(2):107-11. doi: 10.3340/jkns.2010.47.2.107. Epub 2010 Feb 28. PMID: 20224708; PMCID: PMC2836444.
Kimura A, Shiraishi Y, Inoue H, Endo T, Takeshita K. Predictors of Persistent Axial Neck Pain After Cervical Laminoplasty. Spine (Phila Pa 1976). 2018 Jan 1;43(1):10-15. doi: 10.1097/BRS.0000000000002267. PMID: 28591073.
Liu J, Xie R, Ruan H, Rivera J, Li B, Mahmood B, Lee J, Guizar R 3rd, Mahmoudieh Y, Mummaneni PV, Chou D. The PreoperativeCross-sectional Area of the Deep Cervical Extensor Muscles Does Not Predict Loss of Lordosis After Cervical Laminoplasty. Clin Spine Surg. 2021 May 24. doi: 10.1097/BSD.0000000000001199. Epub ahead of print. PMID: 34029263.
Mori E, Ueta T, Maeda T, Yugué I, Kawano O, Shiba K. Effect of preservation of the C-6 spinous process and its paraspinal muscular attachment on the prevention of postoperative axial neck pain in C3-6 laminoplasty. J Neurosurg Spine. 2015 Mar;22(3):221-9. doi: 10.3171/2014.11.SPINE131153. Epub 2014 Dec 19. PubMed PMID: 25525962.
