Faculty Bibliography

BACKGROUND CONTEXT:Posterior cervical foraminotomy (PCF) is a relatively safe procedure for the treatment of cervical radiculopathy. Though most often performed as an inpatient procedure, there is an increasing number of patients treated in an outpatient setting. PURPOSE:This study aimed to compare the perioperative complication rates associated with inpatient and outpatient single-level PCF. STUDY DESIGN/SETTING:Retrospective database study. PATIENT SAMPLE:Patients with cervical radiculopathy who underwent inpatient or outpatient single-level PCF between 2007 to the first quarter of 2016. OUTCOME MEASURES:Charlson Comorbidity Index (CCI) was used as a broad measure of comorbidity. Surgical complications included cervical nerve root injury, dural tear, wound complications, infection, dysphagia, cervicalgia, and revision surgery. Medical complications included pulmonary embolism and lower limb deep vein thrombosis, acute myocardial infarction, acute respiratory failure, pneumonia, sepsis, and urinary complications. METHODS:This study was a retrospective review of patients who received single-level PCF from 2007 to the first quarter of 2016 as either outpatients or inpatients using the Humana subset of the PearlDiver Patient Record Database. The incidence of perioperative medical and surgical complications was queried using relevant International Classification of Diseases (ICD-9-CM and ICD-10-CM) and Current Procedural Terminology codes. Multivariate logistic regression analysis, adjusted for age, gender, and CCI, was performed to calculate odds ratios (ORs) of complications among inpatients relative to outpatients treated with PCF. Propensity score matching was done, and comparisons were made for postoperative complications. RESULTS:Throughout the time period, 1,469 and 1,192 patients received inpatient and outpatient single-level PCF, respectively. The mean CCIs±standard deviation of inpatient and outpatient groups undergoing PCF were 2.83±3.11 and 1.46±2.21, respectively (p<.001). After propensity score matching, patients who received PCF in an inpatient setting showed significantly higher rates of wound complications (OR=1.53, 95% confidence interval [CI]=1.04-2.23; p=.029), infection (OR=1.91, CI=1.15-3.15; p=.012), acute respiratory failure (OR=2.50, CI=1.23-5.08; p=.011), and urinary tract infections and incontinence (OR=2.11, CI=1.32-3.38; p=.002). CONCLUSIONS:Outpatient single-level PCF was associated with a lower rate of perioperative medical and surgical complications. The PCF in the outpatient setting can potentially be a safe procedure for the treatment of cervical radiculopathy with appropriate patient selection.

PURPOSE/OBJECTIVE:To evaluate which cervical level is the most appropriate level to measure occipitocervical inclination (OCI). METHODS:Sixty-two patients with multi-positional MRI: 24 males and 38 females, who had cervical lordosis and had a disk degeneration grade of 3 or less were included. We measured patient's OCI at C3, C4, and C5, occipitocervical angle (OCA), occipitocervical distance (OCD), C2-7 angle, and cervical sagittal vertical axis (cSVA) in neutral, flexion, and extension position. The correlation between OCI and OCA, OCD, C2-7 angle, and cSVA on each cervical level in all three positions was tested using Pearson's correlation coefficient test. The difference between OCIs at each cervical level was tested by Wilcoxon signed-rank test. p value of less than 0.05 was set as a statistically significant level. RESULTS:C5 OCI showed statistically significant correlation with OCA, OCD, C2-7 angle, and cSVA in all three positions (p < 0.05, r = 0.214-0.525). C3 OCI in flexion (p = 0.393, r = 0.081) and C4 OCI in neutral and flexion (neutral p = 0.275, r 0.104; flexion p = 0.987, r = 0.002) did not show significant correlation with C2-7 angle. There was a statistically significant difference between C3, C4, and C5 OCIs in neutral and extension position (p < 0.05). At the same time, OCI showed statistically strong correlation between adjacent cervical levels (p < 0.001, r = 0.627-0.822). CONCLUSION/CONCLUSIONS:C5 cervical level is the most appropriate level for OCI measurement. OCI should be measured at the same cervical level at all time. C4 OCI can reliably substitute C5 OCI in case C5 which is invisible on radiographic image. These slides can be retrieved under Electronic Supplementary Material.

PURPOSE/OBJECTIVE:As the population continues to age, the number of lumbar spine surgeries continues to increase. While there are many complications associated with lumbar surgeries, a myocardial infarction (MI) is a particularly devastating one. This complication is of considerable importance with mortality rates of postoperative MI documented between 26.5 and 70%. This study aimed to determine the relationship between lumbar surgeries, preoperative diagnoses (risk factors), and myocardial infarction. METHODS:Data from the Humana database (PearlDiver) were analyzed from 2007 to 2016. Patients undergoing lumbar spine surgeries were identified and stratified based on procedural approach, patient demographics, and preoperative risk factors. Each group was analyzed to determine the incidence and relative risk. Chi-square analysis was used to determine the significance. RESULTS:A total of 105,505 patients who fit inclusion criteria were identified in the PearlDiver database between 2007 and 2016. A total of 644 patients (0.63%) experienced a postoperative myocardial infarction within 30 days of surgery. Patients undergoing fusion and non-fusion procedures showed significantly different rates of postoperative myocardial infarction (0.08% vs. 0.05%, p < 0.01). Male patients, older patients, and patients with a Charlson comorbidity index > 3 showed a considerable increase in incidence (p < 0.01). Furthermore, patients with preoperative risk factors (high cholesterol, obesity, depression, congestive heart failure, hypertension, and hypotension) exhibited risk ratios from 0.01 to 1.85 (p < 0.01). CONCLUSION/CONCLUSIONS:Preoperative risk factors, patient demographics, and procedure type had a significant effect on the incidence of postoperative myocardial infarction. These slides can be retrieved under Electronic Supplementary Material.

Study Design/UNASSIGNED:Case-control study. Objectives/UNASSIGNED:Cervical spondylotic myelopathy (CSM) is the most common cause of spinal cord injury in adults aged over 55 years. However, since the onset is typically insidious, accurately diagnosing CSM can be challenging, often requiring referral to a subspecialist and advanced imaging. To help identify patients at risk for CSM, this case-control study compared responses to a series of 4 questions (DOWN questionnaire) in myelopathic and non-myelopathic patients. Methods/UNASSIGNED:Ninety-two patients, 46 with and 46 without myelopathy, were recruited for the study. Each patient answered 4 questions encompassing common symptoms associated with CSM. Responses between patient groups were compared, and Cohen's κ was used to assess for agreement between responses and the diagnosis of myelopathy. Results/UNASSIGNED:We found a sensitivity of 91% and a κ of 0.54 to 3 positive responses and a sensitivity of 72% and a κ of 0.61 to 4 positive responses. Conclusions/UNASSIGNED:Positive responses to 3 or more DOWN questions has high sensitivity and moderate agreement with the diagnosis of myelopathy based on history, physical exam, and review of advanced imaging by an orthopedic or neurological surgeon. The DOWN questionnaire is a potentially useful screening tool to identify patients at risk for CSM.

BACKGROUND:Whiplash is a common traumatic cervical injury which is most often a consequence of rear-end motor vehicle accidents. It has been estimated that up to 50% of the whiplash patients suffer from chronic symptoms, resulting in extensive individual and societal burden. Several measurement instruments are used for initial assessment of whiplash and evaluation of response to treatment. However, a comprehensive assessment of the performance of these measures is lacking. Furthermore, there is no consensus on the most relevant outcome domains and their corresponding measurement instruments of choice. This systematic review aims to identify, describe, and critically appraise the performance properties of health-related measurement instruments in whiplash population. METHODS:The following literature databases will be searched from their date of establishment: PubMed, Embase®, MEDLINE, CINAHL Complete, PsycINFO, and HAPI. All original articles evaluating the reliability, validity, responsiveness, and feasibility of health-related measurement instruments in whiplash will be included, without additional restriction on their intended use, source of data, and structure. Risk of bias will be assessed using the COSMIN Risk of Bias checklist. Findings of the studies will be judged against the criteria for good measurement properties, and results from all studies will be qualitatively summarized to generate an overall quality of findings. Overall quality of evidence will be determined using a modified GRADE approach, which will be used in conjunction with the overall quality of results for generation of recommendations. Two reviewers will perform all steps of the review independently. Discrepancies will be discussed between the reviewers, and in case of remaining disagreement, the senior reviewer will make the final decision. DISCUSSION:This systematic review will summarize the body of literature on health-related measurement instruments in whiplash, aiming to facilitate the selection of high-quality measurement instrument for researchers and physicians. Findings of this study will guide the ongoing efforts for development of a core outcome set. SYSTEMATIC REVIEW REGISTRATION:PROSPERO reference number CRD42018070901.

The aim of this study was to evaluate disc degeneration and kinematic changes in translation and angular motion of the thoracic spine using kinematic MRI (kMRI). 105 thoracic spine kMRI were analyzed from T4-5 to T11-12 using MRAnalyzer3. Translational and angular motion were evaluated in neutral, flexion, and extension positions. Thoracic disc height and disc degeneration grading were measured in the neutral position. Intraclass Correlation Coefficients were used to analyze agreement among three observers. The Friedman's test was used to analyze the difference in disc height, disc degeneration, translational motion, and angular motion. The Wilcoxon-signed rank test was used for post-hoc analysis with a Bonferroni correction. A p-value of 0.00625 was used to establish a statistically significant difference. Analysis using the Friedman's test revealed that translational motion, disc height, and disc degeneration were significantly different from T4-5 to T11-12 (p < 0.001). The T4-5 level showed the least translational motion, while the T10-11 showed the most translational motion. The lower thoracic level (T8-12) showed significantly more translational motion, more advanced disc degeneration, and greater disc height than the upper thoracic level (T4-8, p < 0.001). T11-12 showed the most advanced disc degeneration. There was a significant negative correlation between disc degeneration and translational motion at the upper thoracic level (p = 0.013). The lower thoracic region (below T8) had significantly more translational motion, more advanced disc degeneration, and greater disc height. This information is crucial in further understanding thoracic spinal kinematics and may contribute to determining the stopping level in fusion surgeries involving the thoracic spine.

The correlation between BMP-2 and osteosarcoma growth has gained increased interest in the recent years, however, there is still no consensus. In this study, we tested the effects of BMP-2 on osteosarcoma cells through both in vitro and in vivo experiments. The effect of BMP-2 on the proliferation, migration and invasion of osteosarcoma cells was tested in vitro. Subcutaneous and intratibial tumor models were used for the in vivo experiments in nude mice. The effects of BMP-2 on EMT of osteosarcoma cells and the Wnt/β-catenin signaling pathway were also tested using a variety of biochemical methods. In vitro tests did not show a significant effect of BMP-2 on tumor cell proliferation. However, BMP-2 increased the mobility of tumor cells and the invasion assay demonstrated that BMP-2 promoted invasion of osteosarcoma cells in vitro. In vivo animal study showed that BMP-2 dramatically enhanced tumor growth. We also found that BMP-2 induced EMT of osteosarcoma cells. The expression levels of Axin2 and Dkk-1 were both down regulated by BMP-2 treatment, while β-catenin, c-myc and Cyclin-D1 were all upregulated. The expression of Wnt3α and p-GSK-3β were also significantly upregulated indicating that the Wnt/β-catenin signaling pathway was activated during the EMT of osteosarcoma driven by BMP-2. From this study, we can conclude that BMP-2 significantly promotes growth of osteosarcoma cells (143B, MG63), and enhances mobility and invasiveness of tumor cells as demonstrated in vitro. The underlying mechanism might be that BMP-2 promotes EMT of osteosarcoma through the Wnt/β-catenin signaling pathway. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1638-1648, 2019.