Relationship Between Foraminal Area and Degenerative Changes in the Lower Cervical Spine With Implications for C5 Nerve Root Palsy.

Preoperative foraminal stenosis at C4/5 is a predisposing risk factor for C5 nerve root palsy in elderly patients. However, the area of the C4/5 intervertebral foramen and its relationship to the extent of arthrosis and lower foraminal areas (C5/6 and C6/7) are unknown. The authors sought to compare the areas of the cervical intervertebral foramen at the C4/5, C5/6, and C6/7 levels, noting any differences across race or sex and the relationship between foraminal area and arthrosis grade. A total of 600 cervical foramina from an osseous collection were examined. One hundred specimens between the ages of 60 and 80 years were selected, 50 from each sex and race (white and African American). Foramina were photographed bilaterally at C4/5, C5/6, and C6/7. Vertical height and mid-sagittal width were digitally measured. The degree of arthrosis within each intervertebral foramen was graded by 2 of the authors independently using the Kellgren-Lawrence grading system. Average age of death for specimens was 69.3±5.9 years. The mean foraminal areas at C4/5 (P=.001) and C5/6 (P<.001) were significantly smaller than at C6/7. Whites had larger foraminal areas than African Americans at C4/5 (P=.05) and C6/7 (P=.01). Arthrosis grade was found to make a significant contribution to foraminal area at C4/5 (standardized beta=-0.267; P<.001), but not at C5/6 or C6/7. A higher grade of arthrosis was associated with a narrower intervertebral foramen at the C4/5 level in osseous specimens from elderly individuals. [Orthopedics. 2018; 41(4):e506-e510.].

Defining hyoplasia of the atlas: a cadaveric study.

STUDY DESIGN: Cadaveric study. OBJECTIVE: To define congenital hypoplasia of the atlas. SUMMARY OF BACKGROUND DATA: Little has been written about hypoplasia of the atlas and it is usually described in the setting of other skeletal dysplasias or syndromes. METHODS: A total of 543 cervical spine specimens were randomly selected from the Hamann-Todd collection. Sagittal and coronal diameters of the atlas, axis, and C3 (when available), and the dens diameter were measured using digital calipers. Correction for modern size and radiographical magnification was performed. Hypoplasia of the atlas was defined as the lowest 2.5% of measurements. The correlation between inner sagittal diameters at C1 and C3 was calculated. RESULTS: The mean C1 inner sagittal diameter was 30.8 ± 2.4 mm (range, 23.5-38.1 mm). We defined C1 hypoplasia as an inner sagittal diameter value representing the smallest 2.5% of subjects. Because the mean was 30.8 mm, hypoplasia was defined as a diameter of ≤26.1 mm or less. Correcting for size and magnification of radiographs, hypoplasia is defined as an inner sagittal diameter of the atlas of 28.9 mm. Approximately 10% of cases had a dens that occupied more than 40% of the spinal canal at C1, thus not following Steel's Rule of Thirds. There was only a moderate correlation between the spinal canal diameter at C1 and at C3 (r = 0.483, N = 345; P < 0.001). CONCLUSION: With an inner sagittal diameter of 26 mm or less, one may describe the atlas as hypoplastic. Ten percent of the specimens had an odontoid process that occupied more than 40% of the spinal canal at C1. There was little correlation between the inner sagittal diameter at C1 and the diameter at C3. LEVEL OF EVIDENCE: N/A.

United States hospital admissions for lumbar spinal stenosis: racial and ethnic differences, 2000 through 2009.

STUDY DESIGN: Retrospective analysis of Nationwide Inpatient Sample and US Census data. OBJECTIVE: To (1) document national trends in surgical hospitalizations with the primary diagnosis of lumbar spinal stenosis from 2000 through 2009; and (2) evaluate how those trends relate to race and ethnicity. SUMMARY OF BACKGROUND DATA: In the United States, the rate of lumbar spinal stenosis surgery is increasing, and understanding how changing demographic trends impact hospitalization rates for this surgery is important. METHODS: Multivariable regression models were used to determine associations between race and ethnicity and the rates of surgical hospitalization for lumbar spinal stenosis. All models were adjusted for age, sex, insurance, income status, geographical location, and comorbidities. RESULTS: From 2000 through 2009, the overall surgical hospitalization rate increased by 30%. Surgical hospitalization rates for lumbar spinal stenosis in the United States varied substantially across racial and ethnic groups. In 2009, white, non-Hispanics had the highest rate (1.074 per 1000) compared with black, non-Hispanics (0.558 per 1000; P< 0.001), and Hispanics (0.339 per 1000; P< 0.001). The relative differences persisted across time. CONCLUSION: There were substantial differences in rates of surgical hospitalization among individuals of different racial and ethnic groups. Possible causes were (1) differences in clinical decision making among spine care providers with regard to offering surgical care to minority populations; (2) differences in access to care because of financial, educational, or geographical barriers; and (3) differences in attitudes toward surgical care among those of different racial and ethnic groups. LEVEL OF EVIDENCE: 3.

Racial disparities in outcomes of spinal surgery for lumbar stenosis.

STUDY DESIGN: A retrospective, cross-sectional study. OBJECTIVE: To evaluate racial disparities in outcomes of lumbar stenosis surgery. SUMMARY OF BACKGROUND DATA: Racial inequalities have been described in the outcomes of cardiovascular and orthopedic procedures. There have been minimal investigation of racial disparities in complications and costs of lumbar laminectomies and fusions. METHODS: We analyzed the Medicaid data set of Thomson Reuter's MarketScan database. African-American and non-Hispanic white patients who underwent laminectomy or fusion for lumbar stenosis with at least 2 years postoperative data were included. We examined the effect of race on the rate of reoperations, complications, and the cost associated with surgery. RESULTS: African-American patients in the Medicaid database were at no higher risk for reoperation in the 2 years after an operation for lumbar stenosis than white patients (7.14% vs. 7.89%, P = 0.7895). However, we did find that African-American patients were more likely to experience postoperative complications of any kind, even after adjusting for length of hospital stay, comorbidities, sex, and age (adjusted odds ratio = 1.819, P = 0.0123 for immediate complication; adjusted odds ratio = 1.746, P = 0.0141 for 30-d complication; and adjusted odds ratio = 1.611, P = 0.0410 for 90-d complication). White patients had a significantly shorter length of stay (3 vs. 5 d, P < 0.007) and accrued fewer hospital-related costs ($16,148 vs. $24,267, P < 0.0007). African-American patients, despite having more comorbidities in our sample, were prescribed significantly fewer medications in the 2 years after index procedures (91 vs. 138 prescriptions, P < 0.0007) and had fewer medication costs during the 2 years after surgery ($5297 vs. $8450, P < 0.0007). CONCLUSION: At the national level, there are several racial disparities in the rate of complications, length of stay, and costs after surgery for lumbar spinal stenosis. LEVEL OF EVIDENCE: 3.

Study protocol- Lumbar Epidural steroid injections for Spinal Stenosis (LESS): a double-blind randomized controlled trial of epidural steroid injections for lumbar spinal stenosis among older adults.

BACKGROUND: Lumbar spinal stenosis is one of the most common causes of low back pain among older adults and can cause significant disability. Despite its prevalence, treatment of spinal stenosis symptoms remains controversial. Epidural steroid injections are used with increasing frequency as a less invasive, potentially safer, and more cost-effective treatment than surgery. However, there is a lack of data to judge the effectiveness and safety of epidural steroid injections for spinal stenosis. We describe our prospective, double-blind, randomized controlled trial that tests the hypothesis that epidural injections with steroids plus local anesthetic are more effective than epidural injections of local anesthetic alone in improving pain and function among older adults with lumbar spinal stenosis. METHODS: We will recruit up to 400 patients with lumbar central canal spinal stenosis from at least 9 clinical sites over 2 years. Patients with spinal instability who require surgical fusion, a history of prior lumbar surgery, or prior epidural steroid injection within the past 6 months are excluded. Participants are randomly assigned to receive either ESI with local anesthetic or the control intervention (epidural injections with local anesthetic alone). Subjects receive up to 2 injections prior to the primary endpoint at 6 weeks, at which time they may choose to crossover to the other intervention.Participants complete validated, standardized measures of pain, functional disability, and health-related quality of life at baseline and at 3 weeks, 6 weeks, and 3, 6, and 12 months after randomization. The primary outcomes are Roland-Morris Disability Questionnaire and a numerical rating scale measure of pain intensity at 6 weeks. In order to better understand their safety, we also measure cortisol, HbA1c, fasting blood glucose, weight, and blood pressure at baseline, and at 3 and 6 weeks post-injection. We also obtain data on resource utilization and costs to assess cost-effectiveness of epidural steroid injection. DISCUSSION: This study is the first multi-center, double-blind RCT to evaluate the effectiveness of epidural steroid injections in improving pain and function among older adults with lumbar spinal stenosis. The study will also yield data on the safety and cost-effectiveness of this procedure for older adults. TRIAL REGISTRATION: Clinicaltrials.gov NCT01238536.

A haplotype at the COL9A2 gene locus contributes to the genetic risk for lumbar spinal stenosis in the Korean population.

STUDY DESIGN: We conducted a cross-sectional, genotyping study in patients with lumbar spinal stenosis (LSS) and controls. OBJECTIVE: To determine the contribution of COL9A2 polymorphisms to LSS development in the Korean population. SUMMARY OF BACKGROUND DATA: Because congenital spinal stenosis is typically associated with chondrodysplasias, which are genetic disorders, genetic factors may also play a role in degenerative LSS. A recent Finnish study reported a splice site mutation in COL9A2, leading to premature translation termination. However, a few studies on the genetic association of single nucleotide polymorphisms (SNPs) or haplotypes with LSS have appeared. METHODS: We studied 205 symptomatic patients with radiographically proven LSS and 101 volunteers with no history of back problems from our institution. Magnetic resonance images were obtained for all the patients and controls. Quantitative image evaluation for LSS was performed to evaluate the severity of LSS. All patients and controls were genotyped for COL9A2 allele variations, using a polymerase chain reaction-based technique. RESULTS: We found no causal SNPs in COL9A2 that were significantly associated with LSS, even after phenotypic subgrouping. Haplotype analysis showed that the "GCAGCG" haplotype (HAP2) was overrepresented in LSS patients (P = 0.023, odds ratio [OR] = 1.86), especially in those with severe stenosis (P = 0.018, OR = 1.98). In addition, the "TCAGCG" haplotype (HAP4) was overrepresented in controls (P = 0.042, OR = 0.52). CONCLUSION: Although no SNPs in COL9A2 were associated with LSS, a COL9A2 haplotype (HAP2) was significantly associated with LSS in the Korean population, whereas another haplotype (HAP4) may play a protective role against LSS development. However, the genetic functions of COL9A2 haplotypes in LSS remain to be determined.

Variation in the human cervical neural canal.

BACKGROUND CONTEXT: The dimensions of the cervical spinal canal can impact the likelihood of an individual suffering longtime effects from a spinal neck injury as well as influence recovery time. Most studies have used radiographic studies to compare differences in the neural canal, but few have examined skeletal populations to determine variation in the neural canal dimensions without the presence of soft tissue. PURPOSE: To analyze variation seen in the cervical neural canal (anterior-posterior and transverse diameters) with respect to sex and ancestry and to define cervical canal narrowing in the sample. STUDY DESIGN: Observational. METHODS: Measurements of the anterior-posterior (sagittal) (CAP) and transverse (CTR) diameters were taken from 321 individual skeletons. Comparisons were made between males and females and individuals belonging to different ancestral (racial) groups. RESULTS: CAP was narrowest at the C4 level for African-Americans and at C6 for Caucasians. CTR was narrowest at the C2/C3 level for all groups. Statistical analyses indicated that significant differences in cervical canal dimensions are due first to sexual dimorphism and then to ancestry. CONCLUSIONS: Significant variation in cervical canal dimensions precludes usage of universal definitions to determine spinal stenosis in individuals; definitions should be according to sex and ancestry.

Variation of the cervical spinal Torg ratio with gender and ethnicity.

BACKGROUND CONTEXT: The Torg ratio is used as a universal indicator of cervical canal stenosis despite reports of differences between gender and race. Normal values of this ratio have been established for subjects of different ethnicity, but the differences between genders and race have not been critically compared. PURPOSE: To establish normal cervical spinal dimensions and analyze the differences observed between men and women, and between reports using subjects of different ethnicity. STUDY DESIGN/SETTING: Observational. PATIENT SAMPLE: Forty men and 40 women of Chinese descent with no history or symptoms of neck pathology selected from patients presenting to the Emergency Department for foreign body ingestion. OUTCOME MEASURES: Measurements of the sagittal developmental diameter (SDD) and vertebral body diameter (VB) on the lateral cervical radiograph with calculation of SDD/VB (Torg ratio). METHODS: Lateral radiographs of the cervical spine were taken in a standardized manner with a 180-cm film-to-tube distance. Comparison was made between genders in the study population and with previous reports on subjects of different ethnicity. RESULTS: The SDD was narrowest at the C4 level in both men and women. Women had smaller SDDs at all levels of the cervical spine. Female VBs were of sizes similar to their corresponding SDDs, whereas men had larger VBs. This resulted in small Torg ratios in men averaging 0.87. Comparison with previous reports demonstrated consistent variation in the SDD, which increased serially from Japanese, through Chinese and Indian, to white subjects. The relationship of VB to the corresponding SDD displayed wide variation between reports. This resulted in Torg ratios differing not only between subjects of different ethnicity but also between genders within the same population. CONCLUSIONS: The Torg ratio is not a consistent indicator of the SDD and may not be used to reliably identify the presence of cervical canal stenosis.

Epidemiology of spinal stenosis.

Although spinal stenosis has been recognized for nearly 190 years, no exact definition has yet been agreed on, a fact that has made incidence and prevalence studies all but impossible to interpret. The age at onset clearly correlates with the underlying pathomechanics. The disease appears to affect more men than women, except for degenerative spondylolisthesis, which affects more women. Occupation and somatotype do not appear to correlate with the development of symptomatic spinal stenosis. Although they are statistically more likely to have a smaller canal diameter, the black population does not seem to have a high incidence of symptomatic stenosis. Finally, although many syndromes have been reported to be associated with the development of spinal stenosis, the concomitant presence of degenerative changes appears to be a prerequisite to the development of symptomatic spinal stenosis.