The anatomic relation among the nerve roots, intervertebral foramina, and intervertebral discs of the cervical spine

The Cervical Intervertebral Foramen: Microanatomy, Pathology, and Clinical Implications

STUDY DESIGN

This is an evidence-based narrative review article.

OBJECTIVE

We hope to provide a primer on cervical intervertebral foramen (cIVF) anatomy for spine surgeons, interventionalists, and physiatrists who regularly treat cervical spine pathology, and encourage further exploration of this topic.

BACKGROUND

This corridor for exiting cervical nerve roots is characterized by its intricate microanatomy involving ligamentous, nervous, and vascular structures. Degenerative changes such as facet hypertrophy and disc herniations alter these relationships, potentially leading to nerve root compression and cervical radiculopathy.

METHODS

This review synthesizes existing knowledge on the cIVF. Key imaging, cadaveric, and clinical studies serve as a foundation for this anatomic review.

RESULTS

We explore topics such as dynamic changes that affect foraminal size and their implications for nerve root compression, the relationship of the dorsal root ganglion to the cervical foramen, and the function and clinical significance of foraminal ligaments, arteries, and veins.

CONCLUSIONS

Changes in the cIVF are frequently the basis of cervical degenerative pathologies. A comprehensive understanding of its microanatomical structure will allow the practitioner to better treat the underlying disease process causing their symptoms and signs.

The Anatomical Relationship Between the Cervical Nerve Roots, Intervertebral Discs and Bony Cervical Landmark for Posterior Endoscopic Cervical Foraminotomy and Discectomy: A Cadaveric Study

STUDY DESIGN

Cadaveric anatomical studies.

OBJECTIVE

This study aims to investigate the anatomical relationship between bony landmark "V point", dural sac, nerve roots, and intervertebral disc for improving operative outcomes and decreasing post-operative complications in posterior endoscopic cervical foraminotomy or discectomy (PECF or PECD).

METHODS

10 soft adult cadavers were studied. We measured the distance of the V point to the lateral margin of dural sac, V point to the inferior border of intervertebral disc, and the inferior border of cervical nerve root to the inferior border of intervertebral disc. Then we calculated the mean of distance from V point to the inferior border of cervical nerve root.

RESULTS

The mean distance from the V point to the lateral margin of dural sac from C3/4 to C7/T1 ranged from 3.1 ± 1.38 mm to 3.37 ± 1.46 mm. The mean distances from V point to the inferior border of intervertebral disc from C3/4 to C7/T1 were .19 ± 1.16 mm at C3/4, .45 ± 1.23 mm at C4/5, .43 ± 1.01 at C5/6, -.43 ± 1.86 mm at C6/7 and -1.5 ± 1.2 mm at C7/T1. The mean distance between V point and the inferior border of cervical nerve root from C3/4 to C7/T1 showed all positive value, ranging from .06 ± 1.18 mm to 4.45 ± 2.57 mm, increasing caudally.

CONCLUSION

In performing PECF or PECD, a 3-4 mm radius of bone removal should be enough for exposure and neural decompression at C3/4 to C5/6. At C6/7 and C7/T1 a more extensive bone cut of more than 4 mm is recommended, especially in cranial direction.

Comparison of surgical outcomes for cervical radiculopathy by nerve root level

Cervical radiculopathy might affect finger movement and dexterity. Postoperative features and clinical outcomes comparing C8 radiculopathies with other radiculopathies are unknown. This prospective multicenter study analyzed 359 patients undergoing single-level surgery for pure cervical radiculopathy (C5, 48; C6, 132; C7, 149; C8, 30). Background data and pre- and 1-year postoperative neck disability index (NDI) and numerical rating scale (NRS) scores were collected. The C5-7 and C8 radiculopathy groups were compared after propensity score matching, with clinical significance determined by minimal clinically important differences (MCID). Postoperative arm numbness was significantly higher than upper back or neck numbness, and arm pain was reduced the most (3.4 points) after surgery among the C5-8 radiculopathy groups. The C8 radiculopathy group had worse postoperative NDI scores (p = 0.026), upper back pain (p = 0.042), change in arm pain NRS scores (p = 0.021), and upper back numbness (p = 0.028) than the C5-7 group. NDI achieved MCID in both groups, but neck and arm pain NRS did not achieve MCID in the C8 group. In conclusion, although arm numbness persisted, arm pain was relieved after surgery for cervical radiculopathy. Patients with C8 radiculopathy exhibited worse NDI and change in NRS arm pain score than those with C5-7 radiculopathy.

Effects of indirect foraminal decompression during anterior cervical disc fusion procedure: preliminary results of a prospective study with clinical and radiological outcomes

INTRODUCTION

The respective effects of direct and indirect decompression in the clinical outcome after anterior cervical disc fusion (ACDF) is still debated. The main purpose of this study was to analyze the effects of indirect decompression on foraminal volumes during ACDF performed in patients suffering from cervico-brachial neuralgias due to degenerative foraminal stenosis, i.e. to determine whether implant height was associated with increased postoperative foraminal height and volume.

METHODS

A prospective follow-up of patients who underwent ACDF for cervicobrachial neuralgias due to degenerative foraminal stenosis was conducted. Patient had performed a CT-scan pre and post-operatively. Disc height, foraminal heights and foraminal volumes were measured pre and post operatively.

RESULTS

37 cervical disc fusions were successfully performed in 20 patients, with a total of 148 foramina studied. Foraminal height and volume were measured bilaterally on the pre- and post-operative CT scans (148 foramina studied). After univariate analysis, it was found a significant improvement for every radiological parameter, with a significant increase in disc height, foraminal height and foraminal volume being respectively +3,22 mm (p < 0,001), +2,12 mm (p < 0,001) and +54 mm3 (p < 0,001). Increase in disc height was significantly associated with increase in foraminal height (p < 0,001) and foraminal volume (p < 0,001). At the same time, increase in foraminal height was significantly correlated with foraminal volume (p < 0,001), and seems to be the major component affecting increasing in foraminal volume.

CONCLUSION

Indirect decompression plays an important part in the postoperative foraminal volume increase after ACDF performed for cervicobrachial neuralgias.

Percutaneous full endoscopic foraminotomy for treatment of cervical spinal nerve compression in horses using a uniportal approach: Feasibility study

BACKGROUND

Cervical spinal nerve insult can be a sequel of osteoarthropathy in horses due to enlargement of the articular processes (AP).

OBJECTIVES

To describe the percutaneous endoscopic cervical foraminotomy procedure in horses.

STUDY DESIGN

Ex vivo experimental study and clinical case report.

METHODS

The technique was performed in three equine cadavers and in two clinical cases with history of forelimb lameness located in the caudal cervical region. Briefly, the horse was positioned in lateral recumbency, with the affected AP joint uppermost. Under fluoroscopic guidance, the endoscopic instruments (Ø 6.9 mm, length 207 mm, 25° angle of vision) were positioned at the dorsal bony margin of the intervertebral foramen (IVF). The bone was freed from soft tissues and removed using diamond various burrs, hence widening the IVF. The bone drilling was continued until the medial cortical surface of the caudal AP was removed. Thereafter, the endoscope was removed and the skin portal was closed.

RESULTS

The average of operation time in clinical cases was 98 ± 24 min. The horses recovered smoothly from the operation. At 12-month follow-up, the clinical signs had resolved completely without recurrence.

MAIN LIMITATION

Small number of clinical cases and absence of post-mortem examination or histopathology performed in the cadaver study to assess possible iatrogenic injuries.

CONCLUSION

Cervical spinal nerve decompression via minimal invasive foraminotomy is feasible in horses. More research is required before this procedure can be recommended in clinical cases.

Integrating jigsaw puzzle thinking into practice: the assessment of cervical spine radiculopathy

PURPOSE OF REVIEW

Cervical spine radiculopathy (CSR) presents a complex socioeconomic problem for patients, clinicians, families, employers and healthcare systems. Due to the heterogeneity of clinical presentation and underlying mechanisms, clinical assessment can be challenging. This review will examine the literature on the underlying pathophysiology and studies investigating the holistic assessment strategies for this disabling condition. The authors will focus particular attention on the psychological factors associated with CSR and the physical and imaging strategies to establish a diagnosis.

RECENT FINDINGS

Contemporary CSR assessment should identify the underlying pathomechanisms and how this may impact the somatosensory nervous system integrity and function. No physical assessment test in isolation will establish CSR diagnosis; therefore, clinicians should utilise a cluster of tests and recognise the potential limitations as part of a clinical reasoning framework. The assessment of the somatosensory nervous system can provide insights into particular subgroups of CSR presentation, which may provide interesting opportunities to continue to enhance individualised assessment and management strategies for CSR. The interplay between psychological factors can influence the diagnosis and recovery times for a person with CSR, and clinicians should continue to explore how these factors may influence a person's prognosis. The authors will discuss the opportunities for future research and limitations of contemporary approaches to assessment, underpinned by evidence, and how this supports a clinical assessment to establish CSR diagnosis.

SUMMARY

Research should continue to investigate how clinicians assess the interplay between physical and psychological factors to inform the establishment of CSR. Specifically, there is a need to investigate the validity and reliability of combining somatosensory, motor and imaging assessment findings to reach a diagnosis and inform onward management plans.

2. Cervical radicular pain

INTRODUCTION

Cervical radicular pain is pain perceived in the upper limb, caused by irritation or compression of a cervical spine nerve, the roots of the nerve, or both.

METHODS

The literature on the diagnosis and treatment of cervical radicular pain was retrieved and summarized.

RESULTS

The diagnosis is made by combining elements from the patient's history, physical examination, and supplementary tests. The Spurling and shoulder abduction tests are the two most common examinations used to identify cervical radicular pain. MRI without contrast, CT scanning, and in some cases plain radiography can all be appropriate imaging techniques for nontraumatic cervical radiculopathy. MRI is recommended prior to interventional treatments. Exercise with or without other treatments can be beneficial. There is scant evidence for the use of paracetamol, nonsteroidal anti-inflammatory drugs, and neuropathic pain medications such as gabapentin, pregabalin, tricyclic antidepressants, and anticonvulsants for the treatment of radicular pain. Acute and subacute cervical radicular pain may respond well to epidural corticosteroid administration, preferentially using an interlaminar approach. By contrast, for chronic cervical radicular pain, the efficacy of epidural corticosteroid administration is limited. In these patients, pulsed radiofrequency treatment adjacent to the dorsal root ganglion may be considered.

CONCLUSIONS

There is currently no gold standard for the diagnosis of cervical radicular pain. There is scant evidence for the use of medication. Epidural corticosteroid injection and pulsed radiofrequency adjacent to the dorsal root ganglion may be considered. [Correction added on 12 June 2023, after first online publication: The preceding sentence was corrected.].

Functional Anatomy and Biomechanics of the Craniovertebral Junction

The craniovertebral junction (CVJ) involves the atlas, axis, and occiput along with the atlanto-occipital and atlantoaxial joints. The anatomy and neural and vascular anatomy of the junction render the CVJ unique. Specialists treating disorders that affect the CVJ must appreciate its intricate anatomy and should be well versed in its biomechanics. This first article in a three-article series provides an overview of the functional anatomy and biomechanics of the CVJ.

Effect of preoperative contralateral foramen stenosis on contralateral root symptoms after unilateral transforaminal lumbar interbody fusion: a ambispective cohort study

PURPOSE

To evaluate the correlation between the degree of preoperative contralateral foraminal stenosis(CFS) and the incidence of contralateral root symptoms after unilateral transforaminal lumbar interbody fusion(TLIF) and to evaluate the appropriate candidate of preventive decompression according to the degree of preoperative contralateral foraminal stenosis.

METHODS

An ambispective cohort study was conducted to investigate the incidence of contralateral root symptoms after unilateral transforaminal lumbar interbody fusion (TLIF) and the effectiveness of preventive decompression. A total of 411 patients were included in the study, all of whom met the inclusion and exclusion criteria and underwent surgery at the Department of Spinal Surgery, Ningbo Sixth Hospital, between January 2017 and February 2021. The study was divided into two groups: retrospective cohort study A and prospective cohort study B. The 187 patients included in study A from January 2017 to January 2019 did not receive preventive decompression. They were divided into four groups based on the degree of preoperative contralateral intervertebral foramen stenosis: no stenosis group A1, mild stenosis group A2, moderate stenosis group A3, and severe stenosis group A4. A Spearman rank correlation analysis was used to evaluate the correlation between the preoperative contralateral foramen stenosis degree and the incidence of contralateral root symptoms after unilateral TLIF. From February 2019 to February 2021, 224 patients were included in the prospective cohort group B. The decision to perform preventive decompression during the operation was based on the degree of preoperative contralateral foramen stenosis. Severe intervertebral foramen stenosis was treated with preventive decompression as group B1, while the rest were not treated with preventive decompression as group B2. The baseline data, surgical-related indicators, the incidence of contralateral root symptoms, clinical efficacy, imaging results, and other complications were compared between group A4 and group B1.

RESULTS

All 411 patients completed the operation and were followed up for an average of 13.5 ± 2.8 months. In the retrospective study, there was no significant difference in baseline data among the four groups (P > 0.05). The incidence of postoperative contralateral root symptoms increased gradually, and a weak positive correlation was found between the degree of preoperative intervertebral foramen stenosis and the incidence of postoperative root symptoms (rs = 0.304, P < 0.001). In the prospective study, there was no significant difference in baseline data between the two groups. The operation time and blood loss in group A4 were less than those in group B1 (P < 0.05). The incidence of contralateral root symptoms in group A4 was higher than that in group B1 (P = 0.003). However, there was no significant difference in leg VAS score and ODI index between the two groups at 3 months after the operation (P > 0.05). There was no significant difference in cage position, intervertebral fusion rate, and lumbar stability between the two groups (P > 0.05). No incisional infection occurred after the operation. No pedicle screw loosening, displacement, fracture, or interbody fusion cage displacement occurred during follow-up.

CONCLUSION

This study found a weak positive correlation between the degree of preoperative contralateral foramen stenosis and the incidence of contralateral root symptoms after unilateral TLIF. Intraoperative preventive decompression of the contralateral side may prolong the operation time and increase intraoperative blood loss to some extent. However, when the contralateral intervertebral foramen stenosis reaches the severe level, it is recommended to perform preventive decompression during the operation. This approach can reduce the incidence of postoperative contralateral root symptoms while ensuring clinical efficacy.

Best Practices for Dorsal Root Ganglion Stimulation for Chronic Pain: Guidelines from the American Society of Pain and Neuroscience

With continued innovations in neuromodulation comes the need for evolving reviews of best practices. Dorsal root ganglion stimulation (DRG-S) has significantly improved the treatment of complex regional pain syndrome (CRPS), and it has broad applicability across a wide range of other conditions. Through funding and organizational leadership by the American Society for Pain and Neuroscience (ASPN), this best practices consensus document has been developed for the selection, implantation, and use of DRG stimulation for the treatment of chronic pain syndromes. This document is composed of a comprehensive narrative literature review that has been performed regarding the role of the DRG in chronic pain and the clinical evidence for DRG-S as a treatment for multiple pain etiologies. Best practice recommendations encompass safety management, implantation techniques, and mitigation of the potential complications reported in the literature. Looking to the future of neuromodulation, DRG-S holds promise as a robust intervention for otherwise intractable pain.

Effect of Anterior Cervical Decompression Fusion and Partial Resection of Uncinate Vertebra Joint on Cervical Sagittal Sequence in Patients with Non-Single-Segment Radiculopathy and its Correlation with Curative Effect: A Retrospective Analysis

OBJECTIVE

Analyze the effect of preservation or resection of the partial uncinate joint on the sagittal sequence of the cervical vertebrae in patients with non-single-segment radiculopathy and the correlation between the sagittal sequence of the cervical vertebrae and the long-term effect after surgery, we explored whether it is necessary to perform partial resection of the uncinate joint in patients with cervical spondylotic radiculopathy undergoing anterior cervical decompression and fusion (ACDF).

METHODS

The study retrospectively analyzed 96 patients with cervical spondylotic radiculopathy with more than two segments from August 2016 to January 2021, who underwent ACDF (ACDF group, 45 patients) or ACDF combined with partial uncinate joint resection (ACDF + UT group, 51 patients). Partial resection of the uncinate joint indicated removal of part of the uncinate joint and osteophyte based on the compression of the nerve root during surgery, whereas the uncinate joints in the ACDF group were retained completely. The imaging data and functional scores of the two groups were recorded before surgery, 1 month after surgery, and at the last follow-up. A paired t-test or rank sum test was applied to analyze the data. In addition, the correlation between the imaging parameters and functional scores was validated using the Pearson's test.

RESULTS

All 96 patients successfully completed the surgery and were followed up for at least 12 months, with an average follow-up time of 14 months. At the last follow-up, the pain visual analog scale (VAS), neck disability index (NDI), and neck pain and disability scale (NPAD) scores of the two groups were significantly lower than those before surgery, and the Japanese Orthopaedic Association (JOA) score was significantly higher than that before surgery. At the last follow-up, compared with the ACDF+UT group, the NDI and NPAD scores in the ACDF group decreased more significantly (p < 0.05), and C2-7SVA, △C2-7SVA (the difference between C2-7 SVA at last follow-up and before operation), and T1S values decreased significantly (p < 0.05). The C2-7 Cobb angle was positively correlated with the JOA score and T1S (p < 0.05) and negatively correlated with the VAS, NDI, and NPAD scores and CGH-C7SVA (p < 0.05). C2-7SVA was positively correlated with CGH-C7SVA and T1S (p < 0.05).

CONCLUSION

Patients with non-single-segmental cervical spondylotic radiculopathy and ACDF with or without uncinate joint resection can have effective improvement in the clinical effect and sagittal balance; however, partial uncinate joint resection has a certain negative impact on the long-term reconstruction of sagittal balance and long-term effects in patients after surgery.

Evaluation of enlarged laminectomy with lateral mass screw fixation in relieving nerve root symptoms and correcting kyphosis for cervical myelopathy and radiculopathy

Purpose

This study aimed to compare the surgical efficacy of enlarged laminectomy with lateral mass screw fixation (EL-LMSF) and anterior cervical decompression and fusion (ACDF) for multilevel cervical myelopathy and radiculopathy (CMR) related to kyphosis.

Methods

75 patients were retrospectively reviewed and divided into ACDF and EL-LMSF group. Clinical results including operative time, blood loss, and postoperative complications were compared. The JOA scoring system was used to evaluate spinal cord function and the VAS score evaluate nerve root pain severity. Cervical alignment a C2-C7 was measured with Cobb method and compared to confirm the reconstruction effect.

Results

Data on 75 patients (M/F: 41:34; EL-LMSF/ACDF:42/33) with the mean age of 57.5 years (range 43-72 year old) were reviewed retrospectively. Discectomy and/or sub-toal corpectomy in ACDF group was performed with a mean of 3.24 levels (range, 3-4). Enlarged laminectomy in EL-LMSF group was performed with a mean of 3.89 enlarged levels (range, 3-5). The procedure of ACDF group showed a shorter operation time (103 ± 22 min vs. 125 ± 37 min, P = 0.000) and less blood loss (78 ± 15 ml vs. 226 ± 31 ml, P = 0.000) compared than that of the EL-LMSF group. Patients treated with EL-LMSF indicated lower VAS for upper extremity (1.3 ± 1.7 vs. 3.3 ± 1.3, P = 0.003) and better curvature corrected (10.7 ± 4.2° vs. 8.5 ± 3.5°, P = 0.013). The difference were of statistical significance. No statistical difference was found after surgery in the JOA score (14.1 ± 1.7 vs. 13.5 ± 2.1, P = 0.222). During the follow-up period, 15.2% of patients in the ACDF group had complications including 2 cases with transient dysphagia, 1 case with C5 palsy, 1 case with axial pain, and 1 case with screw pullout 3 month after surgery. However, only 9.5% of cases in the EL-LMSF group experienced complications, including 3 cases of axial pain and 1 case of epidural hematoma.

Conclusion

The EL-LMSF procedure requires a longer operation time and more blood loss because of the incision of the stenosed foramen. However, the procedure has obvious advantages in relieving nerve root symptoms and correcting cervical curvature with fewer postoperative complications.

Variation in Cervical Pedicle Morphology: Important Considerations for Posterior Cervical Procedures

BACKGROUND

Safe posterior cervical spine surgery requires in-depth understanding of the surgical anatomy and common variations. The cervical pedicle attachment site to the vertebral body (VB) affects the location of exiting nerve roots and warrants preoperative evaluation. The relative site of attachment of the cervical pedicle has not been previously described.

OBJECTIVE

To describe the site of the pedicle attachment to the VB in the subaxial cervical spine.

METHODS

Cervical spine computed tomography scans without any structural, degenerative, or traumatic pathology as read by a board-certified neuroradiologist during 2021 were reviewed. Multiplanar reconstructions were created and cross-registered. The pedicle's attachment to the VB was measured relative to the VB height using a novel calculation system.

RESULTS

Fifty computed tomography scans met inclusion criteria yielding 600 total pedicles between C3-T1 (100 per level). The average patient age was 26 ± 5.3 years, and 21/50 (42%) were female. 468/600 (78%) pedicles attached in the cranial third of the VB, 132/600 (22%) attached in the middle third, and 0 attached to the caudal third. The highest prevalence of variant anatomy occurred at C3 (36/100 C3 pedicles; 36%).

CONCLUSION

In the subaxial cervical spine, pedicles frequently attach to the top third of the VB, but significant variation is observed. The rate of variation is highest at C3 and decreases linearly with caudal progression down the subaxial cervical spine to T1. This is the first report investigating this morphological phenomenon.

Cervical Radiculopathy: Focus on Factors for Better Surgical Outcomes and Operative Techniques

For patients with cervical radiculopathy, most studies have recommended conservative treatment as the first-line treatment; however, when conventional treatment fails, surgery is considered. A better understanding of the prognosis of cervical radiculopathy is essential to provide accurate information to the patients. If the patients complain of persistent and recurrent arm pain/numbness not respond to conservative treatment, or exhibit neurologic deficits, surgery is performed using anterior or posterior approaches. Anterior cervical discectomy and fusion (ACDF) has historically been widely used and has proven to be safe and effective. To improve surgical outcomes of ACDF surgery, many studies have been conducted on types of spacers, size/height/position of cages, anterior plating, patients' factors, surgical techniques, and so forth. Cervical disc replacement (CDR) is designed to reduce the incidence of adjacent segment disease during long-term follow-up by maintaining cervical spine motion postoperatively. Many studies on excellent indications for the CDR, proper type/size/shape/height of the implants, and surgical techniques were performed. Posterior cervical foraminotomy is a safe and effective surgical option to avoid complications associated with anterior approach and fusion surgery. Most recent literature demonstrated that all three surgical techniques for patients with cervical radiculopathy have clear advantages and disadvantages and reveal satisfactory surgical outcomes under a proper selection of patients and application of appropriate surgical methods. For this, it is important to fully understand the factors for better surgical outcomes and to adequately practice the operative techniques for patients with cervical radiculopathy.

Safety and Efficacy of Anterior Cervical Discectomy and Fusion with Uncinate Process Resection: A Systematic Review and Meta-Analysis

STUDY DESIGN

This is a meta-analysis and systematic review of the available literature.

OBJECTIVE

In the case of severe foraminal stenosis, conducting uncinate process resection (UPR) during ACDF could achieve complete nerve root decompression and significant relief of neurological symptoms for CR. However, there is some controversy regarding its necessity and safety. This study aims to compare the safety and efficacy of ACDF with UPR and ACDF.

METHODS

The following electronic databases were searched: Medline, PubMed, Embase, the Cochrane Central Register of Controlled Trials, Evidence Based Medicine Reviews, VIP, and CNKI. And the following data items were considered: baseline demographics, efficacy evaluation indicators, radiographic outcome, and surgical details.

RESULTS

10 studies were finally identified, including 746 patients who underwent ACDF with UPR compared to 729 patients who underwent ACDF. The group of ACDF with UPR had statistically longer intraoperative time (95% CI: 4.83, 19.77, P = .001) and more intraoperative blood loss (95% CI: 12.23, 17.76, P < .001). ACDF with UPR obtained a significantly better improvement of Arm VAS at postoperative first follow-up (95% CI: -1.85, -.14 P = .02). There was no significant difference found in improvement of Neck VAS at postoperative latest follow-up (95% CI: -.88, .27, P = .30), improvement of Arm VAS at postoperative latest follow-up (95% CI: -.59, -.01, P = .05), improvement of NDI (95% CI: -2.34, .33, P = .14), JOA (95% CI: -.24, .43, P = .56), change of C2-C7 lordosis (95% CI: -.87, 1.33, P = .68), C2-C7 SVA (95% CI: -.73, 5.08, P = .14), T1 slope (95% CI: -2.25, 1.51, P = .70), and fusion rate (95% CI: .83, 1.90 P = .29).

CONCLUSION

ACDF with UPR is an effective and necessary surgical method for CR patients with severe foraminal stenosis.

Biportal endoscopic spine surgery for cervical disk herniation: A technical notes and preliminary report

Biportal endoscopic spine surgery (BESS) for cervical disk herniation (CDH) has been rarely reported. The aim of the article is to describe a novel BESS as a posterior approach for CDH and report the preliminary outcomes and complications. This single-centered retrospective chart review included 109 consecutive patients who underwent BESS for symptomatic single-level CDH. Working and viewing portals were created in each unilateral paravertebral area at the target disk level. Endoscopic exploration allowed for effective and minimally invasive decompression via safe access to the medial foramen with minimal laminectomy and facetectomy. Clinical outcomes, including the visual analog scale, neck disability index, Macnab criteria, and the motor function of the involved arm, were evaluated at 4, 8, 12, and 24 postoperative weeks. Visual analog scale and neck disability index improved significantly at 24 weeks postoperatively (P < .01). According to the Macnab criteria, "excellent," "good," and "fair" results were obtained for 55.9%, 30.3%, and 13.8% of patients, respectively. The post 24-week distribution of the involved upper extremity strength grade was significantly improved compared to the initial value (P = .02). One patient had a motor weakness with a decreased grade over 4 weeks from excessive irrigation. The posterior approach of BESS was efficient and feasible for the treatment of CDH.

Tomodensitometric bone anatomy of the intervertebral foramen of the lower cervical spine: measurements and comparison of foraminal volume in healthy individuals and patients suffering from cervicobrachial neuralgia due to foraminal stenosis

PURPOSE

Degenerative foraminal stenosis of the cervical spine can lead to cervicobrachial neuralgias. Computed tomography (CT)-scan assists in the diagnosis and evaluation of foraminal stenosis. The main objective of this study is to determine the bony dimensions of the cervical intervertebral foramen and to identify which foraminal measurements are most affected by degenerative disorders of the cervical spine. These data could be applied to the surgical treatment of this pathology, helping surgeons to focus on specific areas during decompression procedures.

METHODS

A descriptive study was conducted between two groups: an asymptomatic one (young people with no evidence of degenerative cervical spine disorders) and a symptomatic one (experiencing cervicobrachial neuralgia due to degenerative foraminal stenosis). Using CT scans, we determined a method allowing measurements of the following foraminal dimensions: foraminal height (FH), foraminal length (FL), foraminal width in its lateral part ((UWPP, MWPP and IWPP (respectively Upper, Medial and Inferior Width of Pedicle Part)) and medial part (UWMP, MWMP and IWMP (respectively Upper, Medial and Inferior Width of Medial Part)), and disk height (DH). Foraminal volume (FV) was calculated considering the above data. Mean volumes were measured in the asymptomatic group and compared to the values obtained in the symptomatic group.

RESULTS

Both groups were made up of 10 patients, and a total of 50 intervertebral discs (100 intervertebral foramina) were analyzed in each group. Comparison of C4C5, C5C6 and C6C7 levels between both groups showed several significant decreases in foraminal dimensions (p < 0.05) as well as in foraminal volume (p < 0.001) in the symptomatic group. The most affected dimensions were UWPP, MWPP, UWMP, MWMP and FV. The most stenotic foraminal areas were the top of the uncus and the posterior edge of the lower plate of the overlying vertebra.

CONCLUSION

Using a new protocol for measuring foraminal volume, the present study refines the current knowledge of the normal and pathological anatomy of the lower cervical spine and allows us to understand the foraminal sites most affected by degenerative stenosis. Those findings can be applied to foraminal stenosis surgeries. According to our results, decompression of the foramen in regard of both uncus osteophytic spurs and inferior plate of the overlying vertebra might be an important step for spinal nerves release.

Anatomical Evaluation of Spinal Nerve and Cervical Intervertebral Foramina in Anterior Controllable Antedisplacement and Fusion Surgery: A Cadaveric and Radiologic Study

Objective

To achieve the anatomical evaluation of spinal nerve and cervical intervertebral foramina in anterior controllable antedisplacement and fusion (ACAF) surgery, a novel surgical technique with the wider decompression, through a cadaveric and radiologic study.

Methods

Radiographic data of consecutive 47 patients (21 by ACAF and 26 by anterior cervical corpectomy and fusion [ACCF]) who have accepted surgery for treatment of cervical ossification of the posterior longitudinal ligament(OPLL) and stenosis from March 2017 to March 2018 were retrospectively reviewed and compared between an ACAF group and ACCF group. Three postoperative radiographic parameters were evaluated: the decompression width and the satisfaction rate of decompression at the entrance zone of intervertebral foramina on computed tomography (CT), and the transverse diameter of spinal cord in the decompression levels on magnetic resonance imaging (MRI). In the anatomic study, three fresh cadaveric spines (death within 3 months) undergoing ACAF surgery were also studied. Four anatomic parameters were evaluated: the width of groove, the distance between the bilateral origins of ventral rootlets, the length of ventral rootlet from their origin to the intervertebral foramina, the descending angle of ventral rootlet.

Results

The groove created in ACAF surgery included the bilateral origins of ventral rootlets. The rootlets tended to be vertical from the rostral to the caudal direction as their takeoff points from the central thecal sac became higher and farther away from their corresponding intervertebral foramina gradually. No differences were identified between left and right in terms of the length of ventral rootlet from the origin to the intervertebral foramina and the descending angle of ventral rootlet. The decompression width was significantly greater in ACAF group (19.2 ± 1.2 vs 14.7 ± 1.2, 21.3 ± 2.2 vs 15.4 ± 0.9, 21.5 ± 2.1 vs 15.7 ± 1.0, 21.9 ± 1.6 vs 15.9 ± 0.8, from C₃ to C₆). The satisfactory rate of decompression at the entrance zone of intervertebral foramina tended to be better in the left side in ACAF group (significant differences were identified in the left side at C_3/4, C_4/5, C_6/7 level, and in the right side at C_4/5 level when compared with ACCF). And decompression width was significantly greater than the transverse diameter of spinal cord in ACAF group. Comparatively, there existed no significant difference in the ACCF group besides the C₅ level.

Conclusion

ACAF can decompress the entrance zone of intervertebral foramina effectively and its decompression width includes the origins and massive running part of bilateral ventral rootlets. Due to its wider decompression range, ACAF can be used as a revision strategy for the patients with failed ACCF.

Intervertebral Foramen Width Is an Important Factor in Deciding Additional Uncinate Process Resection in ACDF-a Retrospective Study

Background: Anterior cervical discectomy and fusion (ACDF) has been established as a classic procedure for the management of cervical radiculopathy. However, it is unclear whether combined uncinate process resection (UPR) is necessary for treating cervical radiculopathy. Here, we investigated the clinical outcome of ACDF combined with UPR compared to ACDF alone to determine the necessity of UPR in treating cervical radiculopathy. Hypothesis: Uncinate process resection may be necessary in certain patients along with ACDF to achieve better clinical outcomes of cervical radiculopathy. Patients and Methods: Fifty-five patients underwent ACDF with UPR, and 126 patients without UPR were reviewed. The width and height of the intervertebral foramen were measured by 45° oblique X-rays. We also measured the Japanese Orthopedic Association (JOA) score and visual analog scale (VAS) score. C2-C7 Cobb angles were obtained from all patients pre- and post-operatively. Meanwhile, linear regression analysis was used to evaluate the relationship between the clinical outcomes and the intervertebral foramen width before surgery. Results: Linear regression analysis indicated that the improvement in the JOA and VAS scores was irrelevant to both the pre-operative width of the intervertebral foramen (wIVF) and the height of the intervertebral foramen (hIVF) in the ACDF+UPR group. However, pre-operative wIVF was associated with post-operative JOA and VAS scores in the ACDF alone group. Those with pre-operative wIVF <3 mm in the ACDF group had the least improvement in post-operative clinical symptoms due to the change in wIVF (P > 0.05). The ACDF group whose wIVF was over 3 mm showed similar clinical outcomes to the ACDF + UPR group, and wIVF significantly increased post-operatively (P < 0.05). The fusion rate and C2-C7 Cobb angles did not show significant differences between the two groups (P > 0.05). Discussion: Our current findings suggest that UPR should be considered when wIVF is <3 mm pre-operatively. However, there is no need to sacrifice the uncovertebral joint in ACDF when the pre-operative wIVF is over 3 mm. Level of Evidence: Level III.

When Clinical Diagnosis Differs From Advanced Imaging: A Case Series of Disc Herniations Causing Radiculopathy and Review of Aberrant Nerve Root Innervation

ABSTRACT

Radiculopathy is diagnosed using a combination of history, physical examination, and imaging. Unfortunately, well-established dermatomal and myotomal maps are an oversimplification of the convoluted nature of spinal sensory and motor innervation. When clinical presentation and imaging seemingly contradict one another, it is important to consider variant innervation patterns. This article presents three patients with objective dermatomal and/or myotomal deficits due to disc herniations whose clinical presentations are "textbook" for nerve root pathology that is adjacent to the nerve root that is actually compromised. In addition, the literature is reviewed to discuss the history of dermatomal and myotomal maps, the effectiveness of a clinician's ability to determine the precise pathologic disc and nerve root level in patients presenting with radiculopathy, and anatomical explanations as to why inconsistencies such as those seen in the patients in these cases exist.

Effect of an intensive cervical traction protocol on mid-term disability and pain in patients with cervical radiculopathy: An exploratory, prospective, observational pilot study

BACKGROUND

Cervical radiculopathy is a relatively common and disabling condition involving local pain in the neck region and pain that radiates into the upper limb. Recent data suggest that cervical traction may effectively reduce disability and pain, with a dose-response relationship. The main aim of this study was therefore to evaluate the mid-term effect of an intensive cervical traction protocol for patients with cervical radiculopathy on disability, and to compare the effects with those reported by non-intensive protocols in the literature.

METHODS

We conducted a prospective open observational study of 36 patients referred by their general practitioner for symptoms suggestive of cervical radiculopathy. All patients underwent the same treatment: a 30-minute cervical traction protocol, twice a day, for five consecutive days. The main objective was the evaluation of disability at 3 months. We evaluated at baseline (D1), the end of the protocol (D5) and at mid-term (M3) disability, cervical pain, radiating pain, pain on motor imagery, presence of neuropathic pain and medication consumption. The primary outcome was the proportion of patients for whom the Neck Disability Index improved by more than the minimum clinically important difference of 7 points by M3.

RESULTS

Thirty-six patients were included in this study. The Neck Disability Index improved by more than the minimum clinically important difference in 48.3% at M3. Mean Neck Disability Index (p < .001), mean cervical VAS (p < .001), mean radiating VAS (p < .001), and mean VAS for imagined lateral flexion and rotation (p < .002) improved significantly from D1 to D5 and from D1 to M3. Consumption of medication reduced at each time point. The proportion of patients with neuropathic pain reduced from 61.1% at D1 to 33.3% at D5 and 48.3% at M3.

CONCLUSION

Disability reduced by more than the minimum clinically important difference in almost half of the participants following the intensive traction protocol. These results are encouraging and suggest that this complex condition can be treated with relatively simple methods.

Efficiency of minimal oblique resection of the uncinate process during an anterior cervical discectomy and fusion

ABSTRACT

Hypertrophy of the uncinate process (UP) can cause radiculopathy. Minimal UP resection is considered to remove the lesion while minimizing the risk of complications. This study aimed to elucidate the surgical results of minimal oblique resection of the UP. This study is a retrospective review of about sixty segments in 34 patients who underwent anterior cervical discectomy and fusion (ACDF) with minimal oblique uncinectomy between 2016 and 2018. The cross-sectional area of the UP was measured pre- and postoperatively. The interspinous distance, segmental Cobb angle, subsidence, fusion rate, surgical time, estimated blood loss, and postoperative complications were evaluated. The mean resected areas of the UP were 17.4 ± 8.7 mm2 (25.9%) on the right and 17.3 ± 11.2 mm2 (26.2%) on the left. The difference in interspinous distance in flexion-extension was 7.1 ± 3.2 and 1.6 ± 0.6 mm pre- and postoperatively, respectively (P = .000). The fusion rate after ACDF was 91.7% when measured according to segment (55/60) and 91.2% when measured according to patients (31/34). The difference in the segmental Cobb angle in flexion-extension was 8.3 ± 6.2° and 1.9 ± 0.3° pre and postoperatively, respectively (P = .000). Subsidence occurred in 4 (11.8%) patients and 5 (8.3%) segments. The average surgical time per segment was 68.8 ± 9.3 minute, and the estimated blood loss was 48.5 ± 25.0 mL. Postoperative complications comprised 1 case each of neck swelling, wound infection, pneumonia, and gastrointestinal bleeding. Our findings therefore revealed that minimal oblique uncinectomy during an ACDF can maintain the stability of the uncovertebral joint while sufficiently decompressing the neural foramen.

Intradural Neuroanatomy in the Cervical Spinal Canal: Importance of a New Anatomic Zone Division and Accurate Assessment of Neural Compression in Myeloradiculopathy Patients

This study defined different anatomic zones within the cervical spinal canal and provides detailed anatomical quantitative data for an accurate diagnosis of cervical spondylosis and a safe and effective anterior decompression surgery.

Segment-Specific Orientation of the Dorsal and Ventral Roots for Precise Therapeutic Targeting of Human Spinal Cord

OBJECTIVE

To provide precise description of the dorsal and ventral roots orientation along with the main spinal cord anatomical measurements and their segment-specific variations.

PATIENTS AND METHODS

We collected and analyzed the measurements of the spines, spinal cords, and dorsal and ventral roots (C2-L5) of nine adult cadavers (five males and four females).

RESULTS

This study for the first time provides analysis of the dorsal and ventral roots orientation along with spinal cord anatomical measurements and their segment-specific distribution. The results of this study showed less variability in rostral root angles compared with the caudal. Dorsal and ventral rootlets were oriented mostly perpendicular to the spinal cord at the cervical level and had more parallel orientation to the spinal cord at the thoracic and lumbar segments. The number of rootlets per root was greatest at dorsal cervical and lumbar segments. Spinal cord transverse diameter and width of the dorsal columns were largest at cervical segments. The strongest correlation between the spinal cord and vertebrae structures was found between the length of intervertebral foramen to rostral rootlet distance and vertebral bone length.

CONCLUSION

These results demonstrate consistent variation in spinal cord anatomical features across all tested subjects. The results of this study can be used to locate spinal roots and main spinal cord landmarks based on bone marks on computed tomography or X-rays. These results could improve stereotactic surgical procedures and electrode positioning for neuromodulation procedures.

One-stage posterior laminectomy with instrumented fusion and foraminotomy for cervical ossification of posterior longitudinal ligament with radiculopathy pain

OBJECTIVE

To explore the clinical efficacy of posterior LFF for cervical OPLL with radicular pain of upper limbs METHODS: Between January 2014 and January 2018, 48 OPLL patients with radicular pain symptoms of upper limbs who underwent a one-stage posterior laminectomy and instrumented fusion with/without foraminotomy were reviewed retrospectively and divided into two groups: LF group (laminectomy with instrumented fusion without foraminotomy) and LFF group (laminectomy with instrumented fusion and foraminotomy). Clinical data were assessed and compared between the two groups. The radicular pain of upper limbs and neck was measured using the visual analog scale (VAS). The neurological function was evaluated with the American Spinal Injury Association (ASIA) scale. Changes of sagittal alignment were investigated by postoperative plain x-ray or computed tomography (CT). Moreover, the decompression of the spinal cord was evaluated based on postoperative MRI.

RESULTS

All the 48 patients were followed up for 24-42 months with an average follow-up time of 31.1±5.3 months. A total of 56 cervical intervertebral foramens were enlarged in 48 patients, including 40 cases (83.3%) with 1 intervertebral foramen enlargement and 8 cases (16.7%) with 2 intervertebral foramen enlargements. There were no significant differences in intraoperative blood loss, postoperative drainage amount, Japanese Orthopaedic Association (JOA) scores, JOA recovery rates, VAS scores for neck pain, and ASIA grade between two groups. The mean operative time was shorter in the LF group compared with the LFF group. The VAS score for arm pain was significantly lower while the surgical duration was longer in group B. No statistical difference was observed between the two groups in terms of C2-C7 SVA, cervical lordosis, focal angulation at the foraminotomy segment, and local spinal cord angle. Compared with the LF group, there was no segmental kyphosis or instability where the additional posterior foraminotomy was performed in the LFF group.

CONCLUSIONS

One-stage posterior LFF can achieve satisfied clinical efficacy in improving neurological function and relieving the radicular pain of the upper limbs for OPLL patients with radiculopathy symptoms.

Diagnosis of Neurogenic Thoracic Outlet Syndrome Based on the Clinical Status

OBJECTIVES

At our institute, we devised a clinical algorithm for diagnosis of neurogenic thoracic outlet syndrome (TOS). Our approach assisted in the accurate diagnosis and in detection of patients likely to benefit from surgical treatment. The purposes of this study were to propose our diagnostic approach to neurogenic TOS, and to describe the outcomes of surgical and conservative treatment.

METHODS

Patients (n = 91) who were suspected to have neurogenic TOS, and therefore, underwent a routine clinical protocol from January 2012 to January 2018 were reviewed. Through the clinical protocol, diagnosis of "true neurologic TOS", "symptomatic TOS", and "not likely TOS" was made. The visual analog scale (VAS) pain score and Disabilities of the Arm, Shoulder and Hand (DASH) score were used to assess the treatment outcomes. Satisfaction with surgery was assessed according to the Derkash classification as excellent, good, fair, or poor.

RESULTS

Among 91 patients with presumed neurogenic TOS, 25 patients were "true neurologic TOS", 61 patients were "symptomatic TOS", and five patients were "not likely TOS". Nineteen patients underwent supraclavicular decompression of the brachial plexus whose mean age at the time of surgery was 36.4 years. The VAS average pain score improved from 3.6 to 0.8, and the DASH score improved from 38.4 to 17.1. According to the Derkash classification, ten patients (53%) rated their recovery as excellent, four (21%) as good, and five (26%) as fair. Sixty-seven patients underwent conservative treatment. At the last follow-up visit, their VAS and DASH score were 2.3 and 11.8, respectively.

CONCLUSIONS

By using an algorithm, we diagnosed the patients suspected to have neurogenic TOS into three groups based on clinical status. We surgically treated 19 patients using supraclavicular approach, and achieved favorable outcomes.

Systematic review of radiological cervical foraminal grading systems

The study design of this paper is systematic review. The purpose of this review is to evaluate the existing radiological grading systems that are used to assess cervical foraminal stenosis. The importance of imaging the cervical spine using CT or MRI in evaluating cervical foraminal stenosis is widely accepted; however, there is no consensus for standardized methodology to assess the compression of the cervical nerve roots. A systematic search of Ovid Medline databases, Embase 1947 to present, Cinahl, Web of Science, Cochrane Library, ISRCTN and WHO international clinical trials was performed for reports of cervical foraminal stenosis published before 01 February 2020. In collaboration with the University of Leeds, a search strategy was developed. A total of 6952 articles were identified with 59 included. Most of the reports involved multiple imaging modalities with standard axial and sagittal imaging used most. The grading themes that came from this systematic review show that the most mature for cervical foraminal stenosis is described by (Kim et al. Korean J Radiol 16:1294, 2015) and (Park et al. Br J Radiol 86:20120515, 2013). Imaging of the cervical nerve root canals is mostly performed using MRI and is reported using subjective terminology. The Park, Kim and Modified Kim systems for classifying the degree of stenosis of the nerve root canal have been described. Clinical application of these scoring systems is limited by their reliance on nonstandard imaging (Park), limited validation against clinical symptoms and surgical outcome data. Oblique fine cut images derived from three dimensional MRI datasets may yield more consistency, better clinical correlation, enhanced surgical decision-making and outcomes.

Anatomical study of cervical intervertebral foramen in patients with cervical spondylotic radiculopathy

PURPOSE

To determine the underlying anatomical characteristics in patients with cervical spondylotic radiculopathy (CSR) by comparing those of surgically treated CSR patients with those of healthy subjects.

METHODS

Computed tomography (CT) scans of the cervical spine in 42 patients who underwent decompression surgery for CSR were investigated. As a control group, 42 age- and sex-matched healthy subjects were randomly selected from the 1272 subjects who underwent CT examinations of the entire spine as their routine medical check-up. Image measurements included C2-7 sagittal Cobb angle, spinal canal diameters, and angles of the nerve root groove at each level from C3 to C7, and the size of the intervertebral foramen and the size of osteophytes at each level from C3/4 to C7/T1. As for the frequency of osteophytes at the surgical level, we compared the operated and nonoperated intervertebral foramina among the CSR patients, and all other parameters were compared with the corresponding segments in the control group.

RESULTS

Forty-eight intervertebral segments were surgically treated in the CSR group. There was a higher incidence of osteophytes in the operated foramen (70.8%) than in the nonoperated foramen (28.2%, p < 0.01) in the patients with CSR. The anteroposterior diameter (width) of the foramen was significantly smaller at all levels in the CSR patients, whereas the height of the foramen did not significantly differ between the two groups.

CONCLUSION

It can be speculated that the width of the intervertebral foramen (developmental factor) and the formation of osteophytes (spondylotic factor) were related to the onset of the CSR.

Neurological Disturbance of the Upper Extremities After Cervical Laminoplasty: A Morphological Assessment Focused on the Intervertebral Foramen

STUDY DESIGN

A retrospective study.

OBJECTIVE

The aim of this study was to explore the relationship between postoperative neurological disturbance of the upper extremities (NDUE) after cervical laminoplasty and intervertebral foraminal stenosis.

SUMMARY OF BACKGROUND DATA

The relationship between foraminal stenosis and neurological disturbance in the C5 segment (C5 palsy) has been reported, but the relationship at other levels has not been examined before. We evaluated foraminal stenosis morphologically using three-dimensional computed tomography (3D-CT), alongside other risk factors for NDUE.

METHODS

We retrospectively reviewed patients treated by open-door laminoplasty at the authors' institution between January and June 2016. NDUE was defined as postoperative motor deterioration and/or newly emerged sensory disturbance within 2 weeks of surgery. Radiological measurements were performed in bilateral intervertebral foramina from C5 to C8, using 3D-CT. Investigation using magnetic resonance imaging (MRI) was also performed.

RESULTS

Thirty-one patients were reviewed, and 10 (32.3%) developed NDUE. Nineteen NDUE were observed: seven were in the C5 segment, five in the C6 segment, three in the C7 segment, and four in the C8 segment. Four patients (40%) had NDUE from multiple segments. The mean width of the foramen was 2.60 ± 1.26 mm and 3.66 ± 1.66 mm (P = 0.007), and cross-sectional area was 32.8 ± 10.8 mm and 41.6 ± 12.4 mm (P = 0.003), in symptomatic (n = 19) and nonsymptomatic (n = 187) foramina, respectively. The mean transverse diameter of bony spurs and the maximum shift of the spinal cord on MRI was significantly larger in the NDUE group. The odds ratio of having a foraminal cross-sectional area under 28.0 mm in combination with a maximum spinal shift over 3.10 mm was 14.6 (P < 0.001).

CONCLUSION

Stenosis of the intervertebral foramen could be a risk factor for NDUE after cervical laminoplasty, and could be aggravated by excessive posterior spinal cord shift.

LEVEL OF EVIDENCE

3.

<p>Blood Flow Index and Skin Temperature Measured by Laser Speckle Contrast Imaging and Infrared Thermography After Specific Ultrasound-Guided Blocking of the C6, C7 Nerve Root: A Case Report</p>

Ultrasound-guided cervical nerve root block is the technique of injecting local anesthetic or steroid into the intertubercular groove outside of the cervical foramen under real-time ultrasound guidance. It has established diagnostic and therapeutic employment for patients suffering symptoms caused by cervical disc disorders and foraminal stenosis. Measures of selective nerve root blockade would have vital clinical utility, especially in multilevel disease or combined with atypical symptoms, where subjective assessment is difficult. This case reported a 47-year-old male patient who suffered from severe radicular pain confined to the index and middle fingers, with weakness of the right upper extremity. He was successfully treated with selective C6, C7 nerve root under ultrasound guidance. For confirmation of the proper analgesia range, laser speckle contrast imaging (LSCI) and infrared thermography (IT) were both constructed over the dorsum of the hands and forearms during the procedure. The results of the off-line analysis suggested LSCI and IT might be considered as alternative measurements for the selective cervical nerve root.

Three-dimensional morphological analysis of cervical foraminal stenosis using dynamic flexion-extension computed tomography images

BACKGROUND

Morphological features of foraminal stenosis in cervical spondylotic radiculopathy and the adequate extent of facet resection in posterior cervical foraminotomy remain uncertain. Herein, we evaluated quantitatively foraminal widths in cervical spondylotic radiculopathy on dynamic flexion-extension computed tomography using a novel three-dimensional analysis method and determined the extent of facet resection in posterior cervical foraminotomy.

METHODS

Seventeen patients undergoing posterior cervical foraminotomy for cervical spondylotic radiculopathy were evaluated. A neuroforamen three-dimensional model was built from preoperative images of flexion-extension computed tomography myelography, and an ordinary cervical spine coordinate system and an original neuroforaminal coordinate system, were established. In the neuroforaminal coordinate system, minimum areas perpendicular to the long axis by the slices from inlet to outlet of neuroforamen and narrowest foraminal width in a slice of minimum area were measured. The location of the narrowest region from inlet of the foramen was calculated. Ratios of minimum and sufficient facet resection were obtained from the location of the narrowest region in the neuroforaminal coordinate system.

RESULTS

The narrowest foraminal widths (flexion/extension) in the cervical spine coordinate system and the neuroforaminal coordinate system were 2.9/2.3 and 2.6/1.9 mm, respectively. The mean values of the location of the narrowest region (flexion/extension) were 0.27/0.22 and 0.50/0.45 mm, respectively, and the narrowest region in the neuroforaminal coordinate system was located on the outer side than in the cervical spine coordinate system (p < 0.001). The ratios of minimum and sufficient facet resection were 23 ± 8% and 32 ± 9%, respectively.

CONCLUSIONS

The narrowest regions both in flexion and extension are located at the middle of the foramen based on the neuroforaminal coordinate system. Ordinary evaluation of axial computed tomography images likely underestimates the extent of facet resection, whereas certain extent of facet resection does not exceed 50% in cases with single-level cervical spondylotic radiculopathy.

STUDY DESIGN

A retrospective case control study.

Sensory restoration by epidural stimulation of the lateral spinal cord in upper-limb amputees

Restoring somatosensory feedback to people with limb amputations is crucial to improve prosthetic control. Multiple studies have demonstrated that peripheral nerve stimulation and targeted reinnervation can provide somatotopically relevant sensory feedback. While effective, the surgical procedures required for these techniques remain a major barrier to translatability. Here, we demonstrate in four people with upper-limb amputation that epidural spinal cord stimulation (SCS), a common clinical technique to treat pain, evoked somatosensory percepts that were perceived as emanating from the missing arm and hand. Over up to 29 days, stimulation evoked sensory percepts in consistent locations in the missing hand regardless of time since amputation or level of amputation. Evoked sensations were occasionally described as naturalistic (e.g. touch or pressure), but were often paresthesias. Increasing stimulus amplitude increased the perceived intensity linearly, without increasing area of the sensations. These results demonstrate the potential of SCS as a tool to restore somatosensation after amputations.

Even some of the most advanced prosthetic arms lack an important feature: the ability to relay information about touch or pressure to the wearer. In fact, many people prefer to use simpler prostheses whose cables and harnesses pass on information about tension. However, recent studies suggest that electrical stimulation might give prosthesis users more sensation and better control.

After an amputation, the nerves that used to deliver sensory information from the hand still exist above the injury. Stimulating these nerves can help to recreate sensations in the missing limb and improve the control of the prosthesis. Still, this stimulation requires complicated surgical interventions to implant electrodes in or around the nerves. Spinal cord stimulation – a technique where a small electrical device is inserted near the spinal cord to stimulate nerves – may be an easier alternative. This approach only requires a simple outpatient procedure, and it is routinely used to treat chronic pain conditions.

Now, Chandrasekaran, Nanivadekar et al. show that spinal cord stimulation can produce the feeling of sensations in a person’s missing hand or arm. In the experiments, four people who had an arm amputation underwent spinal cord stimulation over 29 days. During the stimulation, the participants reported feeling electrical buzzing, vibration, or pressure in their missing limb. Changing the strength of the electric signals delivered to the spinal cord altered the intensity of these sensations.

The experiments are a step toward developing better prosthetics that restore some sensation. Further studies are now needed to determine whether spinal cord stimulation would allow people to perform sensory tasks with a prosthetic, for example handling an object that they cannot see.

Treatment of cervical spondylotic radiculopathy with posterior percutaneous endoscopic cervical discectomy: Short-term outcomes of 24 cases

To determine the short-term clinical outcomes of single-segment cervical spondylotic radiculopathy treated with posterior percutaneous endoscopic cervical discectomy (PPECD).Data of a total of 24 patients who underwent PPECD and local anesthesia for single-level segmental cervical spondylotic radiculopathy between March 2016 and December 2017 were reviewed. The Japanese Orthopaedic Association, visual analog scale (VAS), and neck disability index scores at preoperative 1 day, postoperative 1 day, 1 week, 1 month, 3 months, 6 months, and 1 year were recorded. The modified MacNab criteria at the last follow-up were re-recorded for the evaluation of clinical effectiveness.All operations were successfully completed under endoscopic guidance. No patient showed spinal cord, nerve root, vascular injuries, dural tears or other complications. The postoperative VAS scores of the arm and neck were significantly reduced compared with the preoperative VAS scores (P < .05), while postoperative the Japanese Orthopaedic Association scores were significantly increased (P < .05). The postoperative neck disability index scores were significantly reduced compared with preoperative scores (P < .05). The modified MacNab criteria at the last follow-up showed 16 excellent cases, 8 good cases, 0 fine cases, and 0 poor cases. Postoperative magnetic resonance imaging and cervical 3-dimensional computed tomography reconstruction showed that the intervertebral disc was adequately resected and the nerve root was not under compression.PPECD is safe and effective for the treatment of single-segment cervical spondylotic radiculopathy.

Endoscopic posterior cervical foraminotomy via a single stab incision for contiguous two-level cervical radiculopathy

BACKGROUND

Endoscopic posterior cervical foraminotomy (EPCF) is an effective surgical treatment method for single-level cervical radiculopathy. However, only few studies have used the technique for two-level EPCF via a single stab incision.

METHOD

In this study, the minimally invasive surgical method was used for two-level cervical radiculopathy, and useful information regarding perioperative care was presented.

CONCLUSION

EPCF is an alternative treatment for patients with symptoms of adjacent two-level lesions of the cervical spine, and such procedure is advantageous as it can be performed with a small access.

Use of an Internal Retractor for Percutaneous Full-Endoscopic Resection in Cervical Intervertebral Disc Herniation with a Posterior Approach

Study Design

A preliminary case series study.

Purpose

For the safety of performing a posterior percutaneous full-endoscopic cervical discectomy.

Overview of Literature

Because of the lack of space for inserting an outer sheath above the intervertebral disc in the spinal canal, grasping the herniated disc with forceps while retracting the nerves with the forceps itself was required. This procedure produces the risk of inadvertently injuring nerves because of inadequate visualization of the hernia and inadequate protection of the nerve.

Methods

Our new internal retractor can be inserted into the working channel of a percutaneous full-endoscope, enabling the insertion of a second tool. After partial foraminotomy, the internal retractor and forceps were manipulated to reliably retract the nerve root. Finally, the herniated disc was resected under an endoscopic view.

Results

All six cases had a good postoperative course, and postoperative neuropathy was not observed.

Conclusions

This internal retractor allows for the secure resection herniated cervical intervertebral discs.

Cervical Spondylotic Amyotrophy: Case Series and Review of the Literature

OBJECTIVE

Cervical spondylotic amyotrophy (CSA) is a relatively rare entity caused by cervical degenerative spinal diseases and characterized by motor weakness accompanied by remarkable muscle atrophy in the upper extremities without significant sensory deficits or spastic paraparesis in the lower extremities. Postoperative outcomes and predictive prognostic factors vary among previous reports. In the present report, we describe the surgical results in patients who were surgically treated for CSA and present a literature review.

METHODS

In total, 33 patients with CSA were retrospectively analyzed. Correlations between the surgical outcome and the following factors were statistically analyzed: age, sex, type of impaired muscle, preoperative severity of motor weakness, number of levels of cord or root compression, presence of a T2 high-intensity area in the spinal cord, cervical kyphosis, and methods of surgical procedure.

RESULTS

On postoperative neurological evaluation, 25 patients (75.8%) had favorable outcomes and 8 had unfavorable outcomes (proximal type, 72.2%; distal type, 78.6%). Patients with favorable outcomes were significantly younger than those with unfavorable outcomes (p=0.013). Patient's characteristics except for age and radiological factors were not correlated to surgical outcome.

CONCLUSION

The present study focused on the surgical results in patients who were surgically treated for CSA along with updated information from a literature review. Improvement of motor weakness is expected with acceptable prevalence although higher age can be a negative factor. Surgical outcomes and predictive factors related to a poor prognosis were determined and compared with those of previous articles.

Observed patterns of cervical radiculopathy: how often do they differ from a standard, "Netter diagram" distribution?

BACKGROUND CONTEXT

Traditionally, cervical radiculopathy is thought to present with symptoms and signs in a standard, textbook, reproducible pattern as seen in a "Netter diagram." To date, no study has directly examined cervical radicular patterns attributable to single level pathology in patients undergoing ACDF.

PURPOSE

The purpose of this study is to examine cervical radiculopathy patterns in a surgical population and determine how often patients present with the standard textbook (ie, Netter diagram) versus nonstandard patterns.

STUDY DESIGN/SETTING

A retrospective study.

PATIENT SAMPLE

Patients who had single-level radiculopathy with at least 75% improvement of preoperative symptoms following ACDF were included.

OUTCOME MEASURES

Epidemiologic variables were collected including age, sex, weight, body mass index, laterality of symptoms, duration of symptoms prior to operative intervention, and the presence of diabetes mellitus. The observed pattern of radiculopathy at presentation, including associated neck, shoulder, upper arm, forearm, and hand pain and/or numbness, was determined from chart review and patient-derived pain diagrams.

METHODS

We identified all patients with single level cervical radiculopathy operated on between March 2011 and March 2016 by six surgeons. The observed pattern of radiculopathy was compared to a standard textbook pattern of radiculopathy that strictly adheres to a dermatomal map Fisher exact test was used to analyze categorical data and Student t test was used for continuous variables. A one-way ANOVA was used to determine differences in the observed versus expected radicular pattern. A logistic regression model assessed the effect of demographic variables on presentation with a nonstandard radicular pattern.

RESULTS

Overall, 239 cervical levels were identified. The observed pattern of pain and numbness followed the standard pattern in only 54% (129 of 239; p=.35). When a nonstandard radicular pattern was present, it differed by 1.68 dermatomal levels from the standard (p<.0001). Neck pain on the radiculopathy side was the most prevalent symptom; it was found in 81% (193 of 239) of patients and did not differ by cervical level (p=.72). In a logistic regression model, none of the demographic variables of interest were found to significantly impact the likelihood of presenting with a nonstandard radicular pattern.

CONCLUSIONS

Observed patterns of cervical radiculopathy only followed the standard pattern in 54% of patients and did not differ by the cervical level involved. Cervical radiculopathy often presents with a nonstandard pattern. Surgeons should think broadly when identifying causative levels because they frequently may not adhere to textbook descriptions in actual clinical practice. We observed III level of evidence.

Virtual Reality-Based Evaluation of Surgical Planning and Outcome of Monosegmental, Unilateral Cervical Foraminal Stenosis

BACKGROUND

Foraminal cervical nerve root compression can be caused by lateral disk herniation or osteophyte formation of the vertebrae. Improved diagnosis and evaluation can be achieved using different imaging techniques: radiographs, computed tomography (CT), and magnetic resonance imaging. We retrospectively evaluated the potential influence of a virtual reality (VR) visualization technique on surgery planning and evaluation of postoperative results in patients with monosegmental, unilateral osseous cervical neuroforaminal stenosis.

METHODS

Seventy-three patients were included. Ventral decompression of the neuroforamen was performed in 41 patients, dorsal decompression in 32 patients. Patients' files were evaluated. CT scans were visualized via VR software to measure the smallest cross-sectional area of the intervertebral neuroforamen in the lateral resection region. A questionnaire evaluated the influence of VR technique on surgical planning and strategy.

RESULTS

The VR-technique had a moderate influence on the choice of the approach (ventral or dorsal), a significant influence on the ventral approach strategy, and no influence on the positioning of the patient or the dorsal approach strategy. A significant difference was found in the size of the smallest cross-sectional area of the intervertebral neuroforamen in the lateral resection region between ventral and dorsal approaches, with no correlation to the clinical outcome.

CONCLUSIONS

Reconstruction of pre- and postoperative 2D-CT images of the cervical spine into 3D images, and the spatial and anatomical reconstructions in VR models, can be helpful in planning surgical approaches and treatment strategies for patients with cervical foraminal stenoses, and for evaluation of their postoperative results.

The Prevalence of Cervical Foraminal Stenosis on Computed Tomography of a Selected Community-Based Korean Population

Background

Cervical foraminal stenosis (CFS) is one of the degenerative changes of the cervical spine; however, correlations between the severity of stenosis and that of symptoms are not consistent in the literature. Studies to date on the prevalence of stenosis are based on images obtained from the departments treating cervical lesions, and thus patient selection bias may have occurred. The purpose of this study was to investigate the prevalence of CFS according to the site, extent, and morphology of stenosis using cervical computed tomography (CT) images obtained from patients who were visiting not because of symptoms related to the cervical spine, cervical pain, or upper limb pain.

Methods

Among patients who underwent CT from January 2016 to March 2016 for reasons other than cervical spine symptoms, a total of 438 subjects were enrolled, and 2,628 cervical disc images (C4–5, C5–6, and C6–7; left and right sides) were examined. Three orthopedic surgeons performed two measurements each at 4-week intervals. Values were used for analysis if matched by more than two surgeons; if no match was found, the median values were used for analysis. The left and right sides on the same axial image were independently classified.

Results

Left C5–6 stenosis was most common (24.66%) among patients. At the left C6–7, there were 20 focal types and 33 diffuse types. At bilateral C4–5 and right C6–7, the focal type was more common, whereas at bilateral C5–6 and left C6–7, the diffuse type was more common. Age and the severity of stenosis showed statistically significant correlation at all cervical levels.

Conclusions

The prevalence of CFS was highest at the C5–6 level (19.06%). Compared to other levels, focal stenosis was more frequent at C4–5 and diffuse stenosis was more common at C5–6. At C6–7, the incidence of focal stenosis was higher on the right side and that of diffuse stenosis was higher on the left side.

Cervical Radiculopathy: Effectiveness of Adding Traction to Physical Therapy-A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Cervical radiculopathy (CR) is a common cervical spine disorder. Cervical traction (CT) is a frequently recommended treatment for patients with CR.

PURPOSE

The purpose of this study was to conduct a review and meta-analysis of randomized controlled trials (RCTs) on the effect of CT combined with other physical therapy procedures versus physical therapy procedures alone on pain and disability.

DATA SOURCES

Data were obtained from COCHRANE Controlled Trials Register, PubMed, CINAHL, Scopus, ISI Web of Science, and PEDro, from their inception to July 2016.

STUDY SELECTION

All RCTs on symptomatic adults with CR, without any restriction regarding publication time or language, were considered.

DATA EXTRACTION

Two reviewers selected the studies, conducted the quality assessment, and extracted the results. Meta-analysis employed a random-effects model. The evidence was assessed using GRADE criteria.

DATA SYNTHESIS

Five studies met the inclusion criteria. Mechanical traction had a significant effect on pain at short- and intermediate-terms (g = -0.85 [95% CI = -1.63 to -0.06] and g = -1.17 [95% CI = -2.25 to -0.10], respectively) and significant effects on disability at intermediate term (g = -1.05; 95% CI = -1.81 to -0.28). Manual traction had significant effects on pain at short- term (g = -0.85; 95% CI = -1.39 to -0.30).

LIMITATIONS

The most important limitation of the present work is the lack of homogeneity in CR diagnostic criteria among the included studies.

CONCLUSIONS

In light of these results, the current literature lends some support to the use of the mechanical and manual traction for CR in addition to other physical therapy procedures for pain reduction, but yielding lesser effects on function/disability.

Morphometric changes of the cervical intervertebral foramen: A comparative analysis of pre-manipulative positioning and physiological axial rotation

BACKGROUND

Cervical foraminal impingement has been described as a source of radicular pain. Clinical tests and head motions have been reported for affecting the intervertebral foramen (IVF) dimensions. Although manual approaches are proposed in the management of cervical radiculopathy, their influence on the foraminal dimensions remains unclear.

OBJECTIVES

To investigate the influence of pre-manipulative positioning versus cervical axial rotation on the foraminal dimensions of the lower cervical spine.

METHODS

Thirty asymptomatic volunteers underwent CT scan imaging in neutral position and axial rotation or pre-manipulative positioning. The manipulation task was performed at C4-C5 following a multiple components procedure. 3D kinematics and IVF (height, width and area) were computed for each cervical segment.

RESULTS

The results showed that foraminal changes are dependent on motion types and cervical levels. With reference to head rotation, IVF opening occurred on the ipsilateral side during pre-manipulative positioning while axial rotation involved the contralateral side. Regardless of the side considered, magnitudes of opening were similar between both attitudes while narrowing was lower at the target and adjacent levels during the pre-manipulative positioning. Some associations between segmental motion and IVF changes were observed for the target level and the overlying level.

CONCLUSIONS

The present study demonstrated that pre-manipulative positioning targeting C4-C5 modified IVF dimensions differently than the passive axial rotation. The findings suggest that techniques which incorporate combined movement positioning influence segmental motion and IVF dimensions differently at the target segment, compared to unconstrained rotation. Further investigations are needed to determine the clinical outcomes of such an approach.

Multilevel posterior foraminotomy with laminoplasty versus laminoplasty alone for cervical spondylotic myelopathy with radiculopathy: a comparative study

BACKGROUND CONTEXT

Conventional laminoplasty is useful for expanding a stenotic spinal canal. However, it has limited use for the decompression of accompanying neural foraminal stenosis. As such, an additional posterior foraminotomy could be simultaneously applied, although this procedure carries a risk of segmental kyphosis and instability.

PURPOSE

The aim of this study was to elucidate the long-term surgical outcomes of additional posterior foraminotomy with laminoplasty (LF) for cervical spondylotic myelopathy (CSM) with radiculopathy.

STUDY DESIGN/SETTING

A retrospective comparative study was carried out.

PATIENT SAMPLE

Ninety-eight consecutive patients who underwent laminoplasty for CSM with radiculopathy between January 2006 and December 2012 were screened for eligibility. This study included 66 patients, who were treated with a laminoplasty of two or more levels and followed up for more than 2 years after surgery.

OUTCOME MEASURES

The Neck Disability Index (NDI), Japanese Orthopedic Association (JOA) scores, JOA recovery rates, and visual analog scale (VAS) were used to evaluate clinical outcomes. The C2-C7 sagittal vertical axis distance, cervical lordosis, range of motion (ROM), and angulation and vertebral slippage at the foraminotomy level were used to measure radiological outcomes using the whole spine anterioposterior or lateral and dynamic lateral radiographs.

METHODS

Sixty-six patients with CSM with radiculopathy involving two or more levels were consecutively treated with laminoplasty and followed up for more than 2 years after surgery. The first 26 patients underwent laminoplasty alone (LA group), whereas the next 40 patients underwent an additional posterior foraminotomy at stenotic neural foramens with radiating symptoms in addition to laminoplasty (LF group). In the LF group, the foraminotomy with less resection than 50% of facet joint to avoid segmental kyphosis and instability was performed at 78 segments (unilateral-to-bilateral ratio=57:21) and 99 sites. Clinical and radiographic data were assessed preoperatively and at 2-year follow-up and compared between the groups.

RESULTS

The NDI, JOA scores, JOA recovery rates, and VAS for neck and arm pain were improved significantly in both groups after surgery. The improvement in the VAS for arm pain was significantly greater in the LF group (from 5.55±2.52 to 1.85±2.39) than the LA group (from 5.48±2.42 to 3.40±2.68) (p<.001). Although cervical lordosis and ROM decreased postoperatively in both groups, there were no significant differences in the degree of reduction between the LF and LA groups. Although the postoperative focal angulation and slippage were slightly increased in the LF group, this was not to a significant degree. Furthermore, segmental kyphosis and instability were not observed in the LF group, regardless of whether the patient underwent a unilateral or bilateral foraminotomy.

CONCLUSIONS

Additional posterior foraminotomy with laminoplasty is likely to improve arm pain more significantly than laminoplasty alone by decompressing nerve roots. Also, performing posterior foraminotomy via multiple levels or bilaterally did not significantly affect segmental malalignment and instability. Therefore, when a laminoplasty is performed for CSM with radiculopathy, an additional posterior foraminotomy could be an efficient and safe treatment that improves both myelopathy symptoms and radicular arm pain.

Area of Ostectomy in Posterior Percutaneous Endoscopic Cervical Foraminotomy: Images and Mid-term Outcomes

Study Design

Retrospective.

Purpose

To analyze whether the cross-sectional area of the intervertebral foramen at the outermost edge of the resection site is associated with postoperative outcomes and whether our fluoroscopic method for determining the resection area is appropriate.

Overview of Literature

There is no consensus on the criteria for determining an optimal resection area to obtain sufficient decompression while maintaining intervertebral stability in posterior percutaneous endoscopic cervical foraminotomy. Previous reports have recommended a facet resection rate (FRR) of ≤50%. Intervertebral foramen stenosis often extends to the exit zone. The cross-sectional area of the intervertebral foramen is occasionally small at the outermost edge of the resection site. No report has analyzed whether these aspects are associated with postoperative outcomes.

Methods

Lateral margins of the resection area were set at lateral borders of the vertebral body on frontal fluoroscopic view. Because the percutaneous endoscope has a small diameter, surrounding structures can easily be identified using frontal view fluoroscopy to determine the resection area. FRRs were calculated from postoperative computed tomography images. The smallest cross-sectional area of the intervertebral foramen around the lateral edge of the resection area (SALE) was measured and compared wit clinical outcomes.

Results

The mean FRR was 41.7% at C5–C6 and 48.9% at C6–C7. SALE was not correlated with clinical outcomes.

Conclusions

Residual stenosis in the lateral portion of the intervertebral foramen is weakly associated with postoperative outcomes. Our process achieved adequate FRRs and favorable postoperative outcomes, suggesting that our criteria for determining the resection area are appropriate.

Comparison of Surgical Results between Soft Ruptured Disc and Foraminal Stenosis Patients in Posterior Cervical Laminoforaminotomy

Objective

Posterior cervical laminoforaminotomy is used to relieve cervical nerve root compression caused by a laterally herniated soft cervical disc or spondylotic spur and its several advantages and disadvantages compared with anterior cervical discectomy were reported. We compared surgical results between soft ruptured disc and foraminal stenosis in posterior cervical laminoforaminotomy.

Methods

We performed a retrospective review of 47 patients performed single level posterior cervical laminoforaminotomy for cervical radiculopathy between 2004 and 2012. We divided these patients into two groups, Group A: 27 patients for ruptured disc and Group B: 20 patients for foraminal stenosis and analyzed the demographic factors, amount of medial facetectomy, postoperative instability with neck pain and clinical outcomes.

Results

According to the modified Odom's criteria, laminoforaminotomy for the ruptured disc showed 92.6% excellent results and 7.4% good results. For the foraminal stenosis, it was 55.0% excellent and 25.0% good results, which was statistically significant. However when both groups were included, overall success rate showed 91.5%. The extent of medial facetectomy for ruptured disc (31.2%) was smaller than for stenosis (48.8%) and it was statistically significant. Thirteen patients complained of postoperative neck pain for 2 months. There was no instability on dynamic X-ray until the last follow up period and we had two cases complications (4.3%).

Conclusion

Although the extent of facetectomy for ruptured disc was smaller than it for stenosis, posterior laminoforaminotomy for the ruptured disc showed the better outcomes than foraminal stenosis.

The Effect of Uncinate Process Resection on Subsidence Following Anterior Cervical Discectomy and Fusion

Objective

Subsidence is a frequent complication of anterior cervical discectomy and fusion. Postoperative segmental micro-motion, thought to be a causative factor of subsidence, has been speculated to increase with uncinate process resection area (UPR). To evaluate the effect of UPR on micro-motion, we designed a method to measure UPR area based on pre- and postoperative computed tomography images and analyzed the relationship between UPR and subsidence as a proxy of micro-motion.

Methods

We retrospectively collected clinical and radiological data from January 2011 to June 2016. A total of 38 patients (53 segments) were included. All procedures included bilateral UPR and anterior plate fixation. UPR area was evaluated with reformatted coronal computer tomography images. To reduce level-related bias, we converted UPR area to the proportion of UPR to the pre-operative UP area (pUPR).

Results

Subsidence occurred in 18 segments (34%) and positively correlated with right-side pUPR, left-side pUPR, and the sum of bilateral pUPR (sum pUPR) (R=0.310, 301, 364; p=0.024, 0.029, 0.007, respectively). Multiple linear regression analysis revealed that subsidence could be estimated with the following formula: subsidence=1.522+2.7×sum pUPR (R²=0.133, p=0.007). Receiver-operating characteristic analysis determined that sum pUPR≥0.38 could serve as a threshold for significantly increased risk of subsidence (p=0.005, area under curve=0.737, sensitivity=94%, specificity=51%). This threshold was confirmed by logistic regression analysis for subsidence (p=0.009, odds ratio=8.471).

Conclusion

The UPR measurement method confirmed that UPR was correlated with subsidence. Particularly when the sum of pUPR is ≥38%, the possibility of subsidence increased.

Feasibility of Posterior Cervical Foraminotomy in Cervical Foraminal Stenosis: Prediction of Surgical Outcomes by the Foraminal Shape on Preoperative Computed Tomography

STUDY DESIGN

A retrospective cohort study.

OBJECTIVE

The aim of this study was to compare the feasibility of posterior cervical laminoforaminotomy (PCF) for V- or parallel-shaped foraminal stenosis (FS).

SUMMARY OF BACKGROUND DATA

During PCF, the need for extensive facet resection would depend on the extent of any pathology. When resection is extensive, the possibilities of instability and incomplete decompression should be considered.

METHODS

From March 2004 to March 2015, we enrolled 36 patients following single-level PCF procedures for FS. We classified patients by foraminal shape on preoperative computed tomography (CT) scan into V-shaped and parallel-shaped groups. We then compared arm and neck pain using a numeric rating scale (NRS) and clinical outcomes using Odom criteria. Radiological evaluation included dynamic X-rays for instability and CT scans for facet resection.

RESULT

We enrolled 16 and 20 patients in the V-shape and parallel-shape groups, respectively. By Odom criteria, no patient was graded fair or poor in the V group, but five patients were graded as fair and one patient as poor in the parallel group. Continued postoperative arm pain at 1 year, which was related to incomplete decompression, was significantly higher in parallel group. Only one patient complained of postoperative neck pain with an NRS >5, and another five patients sustained radiculopathy with an NRS >5. Among five patients who complained sustained radiculopathy, one patient required revision surgery for incomplete decompression. The amount of facet removal was not different significantly between groups, and no patient had postoperative instability.

CONCLUSION

Although PCF seems to be a good surgical option for V-shaped FS, we experienced worse outcomes for patients with parallel-shaped FS. We recommend that ACDF or more aggressive posterior foraminotomy be performed with fusion when presented with parallel neuroforaminal compression.

LEVEL OF EVIDENCE

4.

Ultrasonography has a diagnostic value in the assessment of cervical radiculopathy: A prospective pilot study

OBJECTIVE

This study investigated the diagnostic accuracy of the difference in the cross-sectional areas (CSAs) of affected cervical nerve roots (NRs) for diagnosing cervical radiculopathy (CR).

METHODS

In total, 102 CR patients and 219 healthy volunteers were examined with ultrasound. The CSA of the cervical NR at each level was measured on the affected side and the contralateral side in CR patients by blinded ultrasonographic technicians. The difference between the CSAs of CR patients and normal volunteers and the difference in the laterality of CSA at the same affected level (ΔCSA) were calculated for each cervical level.

RESULTS

The CSAs of the affected NRs in CR patients were significantly larger than those of the unaffected NRs in CR patients and those of the control group at the C5, C6 and C7 levels (P<0.005). ΔCSA was also significantly larger in the CR group at all levels (P<0.001). A receiver operating characteristic analysis demonstrated that the threshold values were 9.6 mm² (CSA) for C5NR and 15 mm² for both C6NR and C7NR.

CONCLUSIONS

This study revealed that the CSAs of affected NRs were enlarged and that the laterality of the CSA (ΔCSA) was greater in CR patients than in control patients.

KEY POINTS

• Cervical radiculopathy is diagnosed through ultrasonographic measurement of the CSAs. • The CSAs of affected nerve roots were significantly enlarged. • The ΔCSA in the CR group was significantly higher than in the control group. • Diagnostic CSA and ΔCSA thresholds were identified.