The Association Between Cervical Foraminal Stenosis and Adhesive Capsulitis: An Imaging-based Case-Control Study.

STUDY DESIGN: Retrospective single-center imaging-based case-control study. OBJECTIVE: To determine the association between cervical foraminal stenosis and adhesive capsulitis. SUMMARY OF BACKGROUND DATA: Patients with cervical spondylosis often exhibit shoulder symptoms. Cervical radiculopathies, particularly C5, can cause severe shoulder pain and reduced shoulder mobility, mimicking glenohumeral adhesive capsulitis (frozen shoulder), a common shoulder condition. This is the first study investigating the connection between adhesive capsulitis and cervical radiculopathy. METHODS: 438 patients who underwent glenohumeral hydrodistension between 2012 and 2019 were reviewed. Included were individuals with unilateral frozen shoulder investigated using ultrasound and cervical spine MRI to investigate cervical spondylosis. Foraminal stenosis at C3/4, C4/5, C5/6 and C6/7 was graded in axial T2 MRI, ipsilateral and contralateral to the adhesive capsulitis. The presence of foraminal stenosis ipsilateral to the frozen shoulder (cases) was compared with the contralateral side (control). McNemar's exact test was used to assess the strength of a correlation. RESULTS: Among 438 patients, 107 reported frozen shoulder and neck pain (24.5%), with 48 matching the study criteria. A significant association between ipsilateral frozen shoulder and C4/5 foraminal stenosis was observed (P=0.00000008636). Ipsilateral foraminal stenosis was observed in 57.3% of these cases, with bilateral stenosis in 29.1%. Additionally, 78% had neck pain on the same side as their frozen shoulder, and 44% had pain radiating to the shoulder. 48% patients underwent nerve-targeted interventions, with 44% addressing the C5 nerve (25% C5 steroid injection and 19% C4/5 anterior cervical discectomy and fusion). CONCLUSION: A substantial association between C5 foraminal stenosis and ipsilateral frozen shoulder was found. C5 radiculopathy could be a risk factor for "neurogenic frozen shoulder". Those diagnosing frozen shoulder and cervicobrachialgia should recognize that frozen shoulder and C5 radiculopathy may coexist. A multidisciplinary approach involving both shoulder and spine specialists is recommended for a definitive diagnosis.

Postoperative C5 Palsy after Anterior or Posterior Decompression for Degenerative Cervical Myelopathy: A Subgroup Analysis of the Multicenter, Prospective, Randomized, Phase III, CSM-Protect Clinical Trial.

STUDY DESIGN: Retrospective cohort study of prospectively accrued data. OBJECTIVE: To evaluate a large, prospective, multicentre dataset of surgically-treated DCM cases on the contemporary risk of C5 palsy with surgical approach. SUMMARY OF BACKGROUND DATA: The influence of surgical technique on postoperative C5 palsy after decompression for degenerative cervical myelopathy (DCM) is intensely debated. Comprehensive analyses are needed using contemporary data and accounting for covariates. METHODS: Patients with moderate to severe DCM were prospectively enrolled in the multicenter, randomized CSM-Protect clinical trial and underwent either anterior or posterior decompression between Jan 31, 2012, to May 16, 2017. The primary outcome was the incidence of postoperative C5 palsy, defined as onset of muscle weakness by at least one grade in manual muscle test at the C5 myotome with slight or absent sensory disruption after cervical surgery. Two comparative cohorts were made based on anterior or posterior surgical approach. Multivariate hierarchical mixed-effects logistic regression was used to estimate odds ratios (OR) with 95% confidence intervals (CI) for C5 palsy. RESULTS: A total of 283 patients were included, and 53.4% underwent posterior decompression. The total incidence of postoperative C5 palsy was 7.4% and was significantly higher in patients that underwent posterior decompression compared to anterior decompression (11.26% vs. 3.03%, P=0.008). After multivariable regression, posterior approach was independently associated with greater than four times the likelihood of postoperative C5 palsy (P=0.017). Rates of C5 palsy recovery were comparable between the two surgical approaches. CONCLUSION: The odds of postoperative C5 palsy are significantly higher after posterior decompression compared to anterior decompression for DCM. This may influence surgical decision-making when there is equipoise in deciding between anterior and posterior treatment options for DCM. LEVEL OF EVIDENCE: Therapeutic Level II.

Prospective Randomized Comparison of Minimally Invasive Tlif versus Open Tlif: Clinical Effectiveness and Restoration of Working Capacity in Railway Workers.

STUDY DESIGN: Randomized Clinical Trial. OBJECTIVE: To compare the clinical efficacy and restoration of working capacity after MI (minimally invasive)-TLIF and O (open)-TLIF in railway workers with lumbar degenerative disease. METHODS: 83 patients, who were indicated for two-level lumbar decompression and fusion were randomly assigned to one of two groups: group 1 (n = 44) had MI-TLIF procedure and group 2 (n = 39) had O-TLIF procedure. The functional status was assessed using SF-36, ODI and VAS for back and leg pain, preoperatively, at discharge, and at 3, 6, and 12 months postoperatively. MRI and CT were obtained 1-year follow-up. The percentage of patients who returned to work at 1-year, work intensity and the time to return to work post-operatively were analyzed. RESULTS: At 1-year follow-up, the MI-TLIF group had significantly better ODI, VAS and SF-36 scores compared to the O-TLIF group. The postoperative MRIs revealed a statistically significantly less multifidus muscle atrophy in the MI group compared to the Open group. At 1-year follow-up, a comparable fusion ratio between MI group and Open group was recorded. After MI-TLIF procedure, depending on the workload, patients had a statistically significantly earlier return to work (P < .05) and statistically significantly higher return to work rate compared with the O-TLIF group (P < .05). CONCLUSIONS: The use of two-level MI-TLIF in railway workers has made it possible to significantly improve long-term clinical results, reduce the risk of surgical complications, muscle atrophy and time to return to work compared to O-TLIF.

AO Spine Guideline for the Use of Osteobiologics (AOGO) in Anterior Cervical Discectomy and Fusion for Spinal Degenerative Cases.

STUDY DESIGN: Guideline. OBJECTIVES: To develop an international guideline (AOGO) about the use of osteobiologics in anterior cervical discectomy and fusion (ACDF) for treating degenerative spine conditions. METHODS: The guideline development process was guided by AO Spine Knowledge Forum Degenerative (KF Degen) and followed the Guideline International Network McMaster Guideline Development Checklist. The process involved 73 participants with expertise in degenerative spine diseases and surgery from 22 countries. Fifteen systematic reviews were conducted addressing respective key topics and evidence was collected. The methodologist compiled the evidence into GRADE Evidence-to-Decision frameworks. Guideline panel members judged the outcomes and other criteria and made the final recommendations through consensus. RESULTS: Five conditional recommendations were created. A conditional recommendation is about the use of allograft, autograft or a cage with an osteobiologic in primary ACDF surgery. Other conditional recommendations are about the use of osteobiologic for single- or multi-level ACDF, and for hybrid construct surgery. It is suggested that surgeons use other osteobiologics rather than human bone morphogenetic protein-2 (BMP-2) in common clinical situations. Surgeons are recommended to choose 1 graft over another or 1 osteobiologic over another primarily based on clinical situation, and the costs and availability of the materials. CONCLUSION: This AOGO guideline is the first to provide recommendations for the use of osteobiologics in ACDF. Despite the comprehensive searches for evidence, there were few studies completed with small sample sizes and primarily as case series with inherent risks of bias. Therefore, high-quality clinical evidence is demanded to improve the guideline.

Simultaneous Versus Staged Surgery For Double Crush Syndrome Of Cervical Radiculopathy And Peripheral Nerve Compression At The Wrist: A Retrospective Single-Center Study.

STUDY DESIGN: Retrospective single-center study. OBJECTIVES: to evaluate the results of surgical treatment in patients with double crush syndrome associated with cervical radiculopathy and upper limb peripheral nerve compression after staged and simultaneous operations. SUMMARY OF BACKGROUND DATA: Currently, choosing the optimal diagnostic and therapeutic modalities in treating patients with double crush syndrome remains unresolved. METHODS: The study included 79 patients with double crush syndrome (cervical radiculopathy and syndrome of Guyon's canal or Carpal tunnel syndrome). Two independent groups were studied: In the Staged Group (n=35), we performed a cervical decompression with stabilization and peripheral nerve decompression at separate days due to ongoing clinical symptoms (average interval between interventions being 22 (18;26) days). In the Simultaneous Group (n=33), we performed both the cervical spine surgery, as well as the peripheral nerve procedures in one surgical session. Total operative time, estimate blood loss, length of hospitalization, complications and clinical data (NDI score, SF-36, VAS neck pain score, VAS arm pain score, Disabilities of Arm, Shoulder and Hand (DASH) score, Macnab scale) were compared. We used the Mann-Whitney (MW) test for intergroup comparisons, Wilcoxon criterion for dependent samples, and Fisher's exact test for binomial parameters. RESULTS: There was a significantly lower operative time, duration of inpatient treatment and temporary disability in the Simultaneous Group (P=0.01, P=0.04 and P=0.006 respectively). Comparative analysis did not reveal significant intergroup differences using NDI, VAS and DASH (P>0.05), whereas, at discharge, significantly better clinical parameters were appreciated for the Simultaneous Group using SF-36 and Macnab scores (P=0.04 and P=0.03, respectively). At Last Follow-up, an intra-group analysis revealed comparable clinical effectiveness between the two approaches (P>0.05). CONCLUSION: Comparison of the effectiveness of simultaneous and staged surgery revealed comparable long-term clinical outcomes. However, simultaneous surgery conveys clinically important advantages in terms of surgical time, anesthesia duration, length of hospitalization and patient disability. LEVEL OF EVIDENCE: 3.

Is neck pain treatable with surgery?

INTRODUCTION: Neck pain is one of the most common complaints in clinical practice and can be caused by a wide variety of conditions. While cervical spine surgery is a well-accepted option for radicular pain and myelopathy, surgery for isolated neck pain is controversial. The identification of the source of pain is challenging and subtle, and misdiagnosis can lead to inappropriate treatment. MATERIALS AND METHODS AND RESULTS: We conducted a thorough literature review to discuss and compare different causes of neck pain. We then supplemented the literature with our senior author's expert analysis of treating cervical spine pathology. CONCLUSIONS: This study provides an in-depth discussion of neck pain and its various presentations, as well as providing insight into treatment strategies and diagnostic pearls that may prevent mistreatment of cervical spine pathology.

The incidence of reoperation for pseudarthrosis after cervical spine surgery.

INTRODUCTION: Pseudarthrosis after cervical spine surgery represents an underreported and challenging complication. Using a large multi-center surgical database, we sought to: (1) report the incidence of cervical pseudarthrosis, (2) evaluate changes in rates of cervical pseudarthrosis, and (3) describe risk factors for suboptimal outcomes after cervical pseudarthrosis surgery. METHODS: The American College of Surgeons National Surgical Quality Improvement Program database from 2012 to 2019 was used. The primary outcome was occurrence of a cervical fusion procedure with a prior diagnosis of pseudarthrosis. Fusion for pseudarthrosis was divided into anterior and posterior approaches. Post-operative complications were classified as major or minor. Prolonged LOS was defined as exceeding the 75th percentile for total hospital stay. RESULTS: A total of 780 patients underwent cervical fusion for pseudarthrosis, and a significant increase in rates of surgery for pseudarthrosis was seen (0.25-1.2%, p < 0.001). The majority of cervical pseudarthrosis was treated with a posterior approach (66.5%). Postoperatively, 38 (4.9%) patients suffered a complication and 247 (31.7%) had a prolonged LOS. The three strongest risk factors for complications and extended LOS were > 10% weight loss preoperatively, congestive heart failure, and pre-operative bleeding disorder. CONCLUSION: Results from a large multi-center national database revealed that surgery to treat cervical pseudarthrosis has increased from 2012 to 2019. Most pseudarthrosis was treated with a posterior approach. Reoperation to treat cervical pseudarthrosis carried risk, with 5% having complications and 32% having an extended LOS. These results lay the groundwork for a future prospective study to discern the true incidence of cervical pseudarthrosis and how to best avoid its occurrence.

Do Grip Strength Dynamometer Readings Improve After Cervical Spine Surgery?

STUDY DESIGN: Retrospective, cohort study. OBJECTIVES: Hand function can be difficult to objectively assess perioperatively. In patients undergoing cervical spine surgery by a single-surgeon, we sought to: (1) use a hand dynamometer to report pre/postoperative grip strength, (2) distinguish grip strength changes in patients with radiculopathy-only vs myelopathy, and (3) assess predictors of grip strength improvement. METHODS: Demographic and operative data were collected for patients who underwent surgery 2015-2018. Hand dynamometer readings were pre/postoperatively at three follow-up time periods (0-3 m, 3-6 m, 6-12 m). RESULTS: 262 patients (mean age of 59 ± 14 years; 37% female) underwent the following operations: ACDF (80%), corpectomy (25%), laminoplasty (19%), and posterior cervical fusion (7%), with 81 (31%) patients undergoing multiple operations in a single anesthetic setting. Radiculopathy-only was seen in 128 (49%) patients, and myelopathy was seen 134 (51%) patients. 110 (42%) had improved grip strength by ≥10-lbs, including 69/128 (54%) in the radiculopathy-only group, and 41/134 (31%) in the myelopathy group. Those most likely to improve grip strength were patients undergoing ACDF (OR 2.53, P = .005). Patients less likely to improve grip strength were older (OR = .97, P = .003) and underwent laminoplasty (OR = .44, 95% CI .23, .85, P = .014). Patients undergoing surgery at the C2/3-C5/6 levels and C6/7-T1/2 levels both experienced improvement during the 0-3-month time range (C2-5: P = .035, C6-T2: P = .015), but only lower cervical patients experienced improvement in the 3-6-month interval (P = .030). CONCLUSIONS: Grip strength significantly improved in 42% of patients. Patients with radiculopathy were more likely to improve than those with myelopathy. Patients undergoing surgery from the C2/3-C5/6 levels and the C6/7-T1/2 levels both significantly improved grip strength at 3-month postoperatively.

Revision Strategies for Cervical Disc Arthroplasty.

STUDY DESIGN: Narrative review. OBJECTIVE: To review indications and strategies for revision of cervical disc arthroplasty (CDA). SUMMARY OF BACKGROUND DATA: No data were generated as part of this review. METHODS: A narrative review of the literature was performed. RESULTS: No results were generated as part of this review. CONCLUSIONS: CDA is a proven, motion-sparing surgical option for the treatment of myelopathy or radiculopathy secondary to cervical degenerative disc disease. As is the case with any operation, a small percentage of CDA will require revision, which can be a technically demanding endeavor. Here we review available revision strategies and associated indications, a thorough understanding of which will aid the surgeon in finely tailoring their approach to varying presentations.

Laminectomy with Laminar Reconstruction for Resection of Intradural Tumors at the Thoracolumbar Junction: A Technical Note.

OBJECTIVE: To introduce a new laminar reconstruction technique to treat primary spinal cord tumors. METHODS: Laminectomy and laminoplasty techniques have been used to treat intradural spinal tumors. The advantage of laminectomy is its superior exposure of the spinal cord, whereas the advantage of laminoplasty is the reconstruction of the dorsal roof of the spine. In this technical note, we present a technique that combines a full laminectomy to maximize exposure, with a reconstructive technique to repair the lamina. This technique restores the posterior ligamentous complex to preserve spinal biomechanics. RESULTS: In this illustrative case, a 55-year-old woman with severe back pain radiating to the right lower extremity was found to have an intradural tumor at the T12-L1 spinal level. Given the transitional level of the spine and potentially high biomechanical stresses on the posterior support structures, we used a T12 laminectomy to resect the tumor, followed by reconstruction using miniplates. The patient tolerated the surgery well, without any complications. She was discharged home and was doing well during the 3 months follow-up visit. Appropriate patient consent was obtained. CONCLUSIONS: Laminectomy and laminar reconstruction allow maximum visualization and manipulation of the tumor, followed by restoration of the dorsal roof of the spinal ring, and is an effective technique for treating spinal cord tumors.

Timing dependent synergies between motor cortex and posterior spinal stimulation in humans.

Volitional movement requires descending input from motor cortex and sensory feedback through the spinal cord. We previously developed a paired brain and spinal electrical stimulation approach in rats that relies on convergence of the descending motor and spinal sensory stimuli in the cervical cord. This approach strengthened sensorimotor circuits and improved volitional movement through associative plasticity. In humans it is not known whether dorsal epidural SCS targeted at the sensorimotor interface or anterior epidural SCS targeted within the motor system is effective at facilitating brain evoked responses. In 59 individuals undergoing elective cervical spine decompression surgery, the motor cortex was stimulated with scalp electrodes and the spinal cord with epidural electrodes while muscle responses were recorded in arm and leg muscles. Spinal electrodes were placed either posteriorly or anteriorly, and the interval between cortex and spinal cord stimulation was varied. Pairing stimulation between the motor cortex and spinal sensory (posterior) but not spinal motor (anterior) stimulation produced motor evoked potentials that were over five times larger than brain stimulation alone. This strong augmentation occurred only when descending motor and spinal afferent stimuli were timed to converge in the spinal cord. Paired stimulation also increased the selectivity of muscle responses relative to unpaired brain or spinal cord stimulation. Finally, paired stimulation effects were present regardless of the severity of myelopathy as measured by clinical signs or spinal cord imaging. The large effect size of this paired stimulation makes it a promising candidate for therapeutic neuromodulation.

The Feasibility of Multiple Fixation Points in C2.

STUDY DESIGN: Analysis using three-dimensional simulation software for spinal screw placement and computed tomographic scan images. PURPOSE: To assess the feasibility of achieving multiple (three or four) screw fixation points in C2 vertebra by using a combination of pedicle and laminar screws. OVERVIEW OF LITERATURE: Secure C2 fixation using multiple screws is required or beneficial in some unique cases. However, to the best of our knowledge, there have been no reports analyzing the feasibility of multiple screw fixation in C2. METHODS: We used 1.0-mm interval computed tomographic scan images of 100 patients (50 men and 50 women) and screw trajectory simulation software. The diameter of all screws was set at 3.5 mm, considering its common usage in real surgery. The anatomical feasibility of placing both pedicle and laminar screws on the same side was evaluated. For all feasible sides, the three-dimensional distance between the screw entry points was measured. RESULTS: In 85% of cases, both pedicle and laminar screws could be placed on both sides, allowing for the insertion of 4 screws. In 11% of cases, 2 screws could be placed on one side, while only 1 screw was feasible on the other side, resulting in the placement of 3 screws. In all 181 sides where both types of screws could be inserted, the distance between their entry points exceeded 16.1 mm, which was sufficient to prevent the collision between the screw heads. CONCLUSIONS: C2 vertebra can accommodate three (11%) or four (85%) screws in 96% of cases.

Prevalence of lumbosacral transitional vertebra among 4816 consecutive patients with low back pain: A computed tomography, magnetic resonance imaging, and plain radiographic study with novel classification schema.

Study Design: A retrospective single-center study. Background: The prevalence of the lumbosacral anomalies remains controversial. The existing classification to characterize these anomalies is more complex than necessary for clinical use. Purpose: To assessment of the prevalence of lumbosacral transitional vertebra (LSTV) in patients with low back pain and the development of clinically relevant classification to describe these anomalies. Materials and Methods: During the period from 2007 to 2017, all cases of LSTV were preoperatively verified, and classified according to Castellvi, as well as O'Driscoll. We then developed modifications of those classifications that are simpler, easier to remember, and clinically relevant. At the surgical level, this was assessed intervertebral disc and facet joint degeneration. Results: The prevalence of the LSTV was 8.1% (389/4816). The most common L5 transverse process anomaly type was fused, unilaterally or bilaterally (48%), to the sacrum and were O'Driscoll's III (40.1%) and IV (35.8%). The most common type of S1-2 disc was a lumbarized disc (75.9%), where the disc's anterior-posterior diameter was equal to the L5-S1 disc diameter. In most cases, neurological compression symptoms (85.5%) were verified to be due to spinal stenosis (41.5%) or herniated disc (39.5%). In the majority of patients without neural compression, the clinical symptoms were due to mechanical back pain (58.8%). Conclusions: LSTV is a fairly common pathology of the lumbosacral junction, occurring in 8.1% of the patients in our series (389 out of 4,816 cases). The most common types were Castellvi's type IIA (30.9%) and IIIA (34.9%) and were O'Driscoll's III (40.1%) and IV (35.8%).

A standardized anesthetic/analgetic regimen compared to standard anesthetic/analgetic regimen for patients with high-risk factors undergoing open lumbar spine surgery: a prospective comparative single-center study.

The objective of the study is to improve the results of patients undergoing lumbar spine surgery who are at high risk for anesthesia and/or surgical complications. Two independent groups were compared: the study group (SG, n = 40) (standardized neuroanesthetic protocol with multimodal analgesia) and the control group (CG, n = 40) (intravenous anesthesia based on propofol and fentanyl). The data were collected using prospective observation of early and long-term results of lumbar fusion. After 24 months, the level of functional state and quality of life were studied. Patients in the SG did not have statistically significant changes in intraoperative hemodynamics; the best indicators of cognitive functions were noted. The effectiveness of the SG compared with the CG was confirmed by a statistically significantly lower amount of perioperative opioid drugs required (p = 0.01) and a minimal level of incisional pain (p < 0.05). An intergroup comparison of the adverse effects of anesthesia revealed a significantly lower number in the SG (n = 4) compared to the CG (n = 16) (p = 0.004). The number of postoperative surgical complications was comparable (p = 0.72). Intergroup comparison showed improved ODI, SF-36, and the Macnab scale at 24 months after surgery in the SG compared to the CG (p < 0.05). Long-term clinical results correlated with the level of incisional pain in the first three postoperative days. Our standardized neuroanesthetic protocol ensured effective treatment of postoperative incisional pain, significantly decreased the perioperative use of opioids, reduced adverse anesthesia events, and improved long-term clinical results in patients with high risk factors for anesthetic complications who undergoing open lumbar spine surgery.

Clinical and radiological outcomes of one-level cervical corpectomy with an expandable cage for three-column uncomplicated subaxial type «B¼ injures: a multicenter retrospective study.

PURPOSE: To evaluate the clinical and radiological results of the operative management of three-column uncomplicated type «B¼ subaxial injures treated with a one-level cervical corpectomy with an expandable cage. METHODS: This study included 72 patients with a three-column uncomplicated type «B¼ subaxial injures who met the inclusion criteria, underwent a one-level cervical corpectomy with an expandable cage at one of three neurosurgical departments between 2005 and 2020, and were followed up for clinical and radiological outcomes at a minimum 3-yr follow-up. RESULTS: There was a decrease in the VAS pain score from an average of 80 mm to 7 mm (p = 0.03); a decrease in the average NDI score from 62 to 14% (p = 0.01); excellent and good outcomes according to Macnab's scale were 93% (n = 67/72). There was an average change in the cervical lordosis (Cobb method) from -9.10 to -15.40 (p = 0.007), without significant loss of lordosis (p = 0.27). There was no significant degeneration of the adjacent levels by 3 years post-op. The fusion rate, using the Cervical Spine Research Society criteria, was poor: it was 62.5% (n = 45/72), and using the CT criteria, it was 65.3% (n = 47/72). 15.4% patients (n = 11/72) suffered complications. Statistical difference between the fusion and pseudoarthrosis (according to X-ray criteria) subgroups showed that there were no statistically significant differences in the smoking status, diabetes, chronic steroid use, cervical injury level, subtypes of AO type B subaxial injuries and types of expandable cage systems. CONCLUSIONS: One-level cervical corpectomy with an expandable cage, despite a poor fusion rate, can be considered a feasible and relatively safe method for treating three-column uncomplicated subaxial type «B¼ injures, with the benefit of immediate stability, anatomical reduction, and direct decompression of the spinal cord. While no one in our series had any catastrophic complications, we did note a high complication rate.

Identification of Deep Cervical Fascial Layers During Anterior Cervical Spine Exposure.

BACKGROUND: Anterior approaches to the cervical spine are among the most common exposures by which neurosurgeons and orthopedic surgeons access the prevertebral space and ultimately the cervical disk and vertebral bodies. There is a paucity of literature describing the microanatomic fascial planes of the neck with respect to anterior cervical approaches. OBJECTIVE: To delineate the microanatomic connections of the cervical fascial planes pertinent to anterior cervical exposure. METHODS: Using a cadaveric model, original illustrations, the Visible Human Project, and an original surgical video, we demonstrate a stepwise method for identifying the correct planes for anterior cervical exposure. RESULTS: A step-by-step method for identifying the anterior cervical fascial planes intraoperatively is demonstrated. CONCLUSION: A comprehensive understanding of anterior cervical microsurgical anatomy is vital for performing a methodical yet efficient approach to the prevertebral space while minimizing retraction and iatrogenic injury to the surrounding neurovascular structures.

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.

Laminoplasty versus Laminectomy in the Treatment of Primary Spinal Cord Tumors in Adult Patients: A Systematic Review and Meta-analysis of Observational Studies.

The present systematic review and meta-analysis was conducted to compare the safety and efficacy of the two approaches for primary spinal cord tumors (PSCTs) in adult patients (laminoplasty [LP] vs. laminectomy [LE]). LE is one of the most common procedures for PSCTs. Despite advantages of LP, it is not yet widely used in the neurosurgical community worldwide. The efficacy of LP vs. LE remains controversial. Adult patients over 18 years of age with PSCT at the level of the cervical, thoracic, and lumbar spine were included in the study. A literature search was performed in MEDLINE via PubMed, EMBASE, The Cochrane Library, and Google Scholar up to December 2021. Operation time, hospital stay, complications, and incidence of postoperative spinal deformity (kyphosis or scoliosis were extracted. A total of seven retrospective observational studies with 540 patients were included. There were no significant differences between LP and LE group in operation time (p =0.25) and complications (p =0.48). The LE group showed larger postoperative spinal deformity rate than the LP group (odds ratio, 0.47; 95% confidence interval [CI], 0.27-0.84; p =0.01). The LP group had a shorter hospital stay (standardized mean differences, -0.68; 95% CI, -1.03 to -0.34; p =0.0001) than the LE group. Both LP and LE have comparable operative times and total complications in the treatment of PSCT. LP was superior to LE in hospital stay and postoperative spinal deformity rate. However, these findings are limited by the very low quality of the available evidence. Randomized controlled trials are needed for further comparison.

Intraoperative electrical stimulation of the human dorsal spinal cord reveals a map of arm and hand muscle responses.

Although epidural stimulation of the lumbar spinal cord has emerged as a powerful modality for recovery of movement, how it should be targeted to the cervical spinal cord to activate arm and hand muscles is not well understood, particularly in humans. We sought to map muscle responses to posterior epidural cervical spinal cord stimulation in humans. We hypothesized that lateral stimulation over the dorsal root entry zone would be most effective and responses would be strongest in the muscles innervated by the stimulated segment. Twenty-six people undergoing clinically indicated cervical spine surgery consented to mapping of motor responses. During surgery, stimulation was performed in midline and lateral positions at multiple exposed segments; six arm and three leg muscles were recorded on each side of the body. Across all segments and muscles tested, lateral stimulation produced stronger muscle responses than midline despite similar latency and shape of responses. Muscles innervated at a cervical segment had the largest responses from stimulation at that segment, but responses were also observed in muscles innervated at other cervical segments and in leg muscles. The cervical responses were clustered in rostral (C4-C6) and caudal (C7-T1) cervical segments. Strong responses to lateral stimulation are likely due to the proximity of stimulation to afferent axons. Small changes in response sizes to stimulation of adjacent cervical segments argue for local circuit integration, and distant muscle responses suggest activation of long propriospinal connections. This map can help guide cervical stimulation to improve arm and hand function.NEW & NOTEWORTHY A map of muscle responses to cervical epidural stimulation during clinically indicated surgery revealed strongest activation when stimulating laterally compared to midline and revealed differences to be weaker than expected across different segments. In contrast, waveform shapes and latencies were most similar when stimulating midline and laterally, indicating activation of overlapping circuitry. Thus, a map of the cervical spinal cord reveals organization and may help guide stimulation to activate arm and hand muscles strongly and selectively.