Vascular Myelopathy Secondary to Compression of the Artery of Adamkiewicz From an Intrathecal Catheter: A Technical Case Report.

BACKGROUND AND IMPORTANCE: Although catheter-related complications in intrathecal drug delivery systems are relatively common, vascular myelopathy secondary to occlusion of the artery of Adamkiewicz (AoA) from an abutting intrathecal catheter has not yet been reported. In this study, we present a case of this extremely rare presentation, which resolved after decompression of the artery. CLINICAL PRESENTATION: A 39-year-old woman presented with lower extremity weakness and paresthesia. She had a 20-year history of severe chronic back pain and stable sensory disturbances below T8 as sequelae of multiple injuries after a motor vehicle accident. Three years before presentation in our clinic, she underwent baclofen pump placement because of neuropathic pain refractory to oral medication. After pump placement, she gradually developed myelopathic symptoms and dysautonomia. All medications through the pump were discontinued, but her symptoms continued to progress. Workup included a spinal angiogram that showed that her intrathecal catheter was abutting the left side of the AoA at the T12 level. After interdisciplinary evaluation, it was believed that her clinical presentation was attributable to vascular compression, and she underwent surgical removal of the catheter. Three years later, her symptoms have improved and her neurological examination returned to baseline before the catheter placement. CONCLUSION: Meticulous, multidisciplinary neurological and radiological evaluations were essential to diagnose the compression of the AoA as the cause of this patient's myelopathy. Although exceedingly rare, direct compression of the AoA by an intrathecal catheter should be on the differential diagnosis when evaluating for causes of vascular myelopathy.

The association of patient education level with outcomes after elective lumbar surgery: a Michigan Spine Surgery Improvement Collaborative study.

OBJECTIVE: Socioeconomic factors have been shown to impact a host of healthcare-related outcomes. Level of education is a marker of socioeconomic status. This study aimed to investigate the relationship between patient education level and outcomes after elective lumbar surgery and to characterize any education-related disparities. METHODS: The Michigan Spine Surgery Improvement Collaborative registry was queried for all lumbar spine operations. Primary outcomes included patient satisfaction determined by the North American Spine Society patient satisfaction index, and reaching the minimum clinically important difference of Patient-Reported Outcomes Measurement Information System Physical Function score and return to work up to 2 years after surgery. Multivariate Poisson generalized estimating equation models reported adjusted risk ratios. RESULTS: A total of 26,229 lumbar spine patients had data available for inclusion in this study. On multivariate generalized estimating equation analysis all comparisons were done versus the high school (HS)/general equivalency development (GED)-level cohort. For North American Spine Society satisfaction scores after surgery the authors observed the following: at 90 days the likelihood of satisfaction significantly decreased by 11% (p < 0.001) among < HS, but increased by 1% (p = 0.52) among college-educated and 3% (p = 0.011) among postcollege-educated cohorts compared to the HS/GED cohort; at 1 year there was a decrease of 9% (p = 0.02) among < HS and increases of 3% (p = 0.02) among college-educated and 9% (p < 0.001) among postcollege-educated patients; and at 2 years, there was an increase of 5% (p = 0.001) among postcollege-educated patients compared to the < HS group. The likelihood of reaching a minimum clinically important difference of Patient-Reported Outcomes Measurement Information System Physical Function score at 90 days increased by 5% (p = 0.005) among college-educated and 9% (p < 0.001) among postcollege-educated cohorts; at 1 year, all comparison cohorts demonstrated significance, with a decrease of 12% (p = 0.007) among < HS, but an increase by 6% (p < 0.001) among college-educated patients and 14% (p < 0.001) among postcollege-educated compared to the HS/GED cohort; at 2 years, there was a significant decrease by 19% (p = 0.003) among the < HS cohort, an increase by 8% (p = 0.001) among the college-educated group, and an increase by 16% (p < 0.001) among the postcollege-educated group. For return to work, a significant increase was demonstrated at 90 days and 1 year when comparing the HS or less group with college or postcollege cohorts. CONCLUSIONS: This study demonstrated negative associations on all primary outcomes with lower levels of education. This finding suggests a potential disparity linked to education in elective spine surgery.

Disparities in outcomes after spine surgery: a Michigan Spine Surgery Improvement Collaborative study.

OBJECTIVE: Most studies on racial disparities in spine surgery lack data granularity to control for both comorbidities and self-assessment metrics. Analyses from large, multicenter surgical registries can provide an enhanced platform for understanding different factors that influence outcome. In this study, the authors aimed to determine the effects of race on outcomes after lumbar surgery, using patient-reported outcomes (PROs) in 3 areas: the North American Spine Society patient satisfaction index, the minimal clinically important difference (MCID) on the Oswestry Disability Index (ODI) for low-back pain, and return to work. METHODS: The Michigan Spine Surgery Improvement Collaborative was queried for all elective lumbar operations. Patient race/ethnicity was categorized as Caucasian, African American, and "other." Measures of association between race and PROs were calculated with generalized estimating equations (GEEs) to report adjusted risk ratios. RESULTS: The African American cohort consisted of a greater proportion of women with the highest comorbidity burden. Among the 7980 and 4222 patients followed up at 1 and 2 years postoperatively, respectively, African American patients experienced the lowest rates of satisfaction, MCID on ODI, and return to work. Following a GEE, African American race decreased the probability of satisfaction at both 1 and 2 years postoperatively. Race did not affect return to work or achieving MCID on the ODI. The variable of greatest association with all 3 PROs at both follow-up times was postoperative depression. CONCLUSIONS: While a complex myriad of socioeconomic factors interplay between race and surgical success, the authors identified modifiable risk factors, specifically depression, that may improve PROs among African American patients after elective lumbar spine surgery.

The influence of sagittal spinopelvic alignment on patient discharge disposition following minimally invasive lumbar interbody fusion.

BACKGROUND: The aim of this study was to investigate the changes to spinopelvic sagittal alignment following minimally invasive (MIS) lumbar interbody fusion, and the influence of such changes on postoperative discharge disposition. METHODS: The Michigan Spine Surgery Improvement Collaborative was queried for all patients who underwent transforaminal lumbar interbody fusion (TLIF)or lateral lumbar interbody fusion (LLIF) procedures for degenerative spine disease. Several spinopelvic sagittal alignment parameters were measured, including sagittal vertical axis (SVA), lumbar lordosis, pelvic tilt, pelvic incidence, and pelvic incidence-lumbar lordosis mismatch. Primary outcome measure-discharge to a rehabilitation facility-was expressed as adjusted odds ratio (ORadj) following a multivariable logistical regression. RESULTS: Of the 83 patients in the study population, 11 (13.2%) were discharged to a rehabilitation facility. Preoperative SVA was equivalent. Postoperative SVA increased to 8.0 cm in the discharge-to-rehabilitation division versus a decrease to 3.6 cm in the discharge-to-home division (P<0.001). The odds of discharge to a rehabilitation facility increased by 25% for every 1-cm increase in postoperative sagittal balance (ORadj =1.27, P=0.014). The strongest predictor of discharge to rehabilitation was increasing decade of life (ORadj =3.13, P=0.201). CONCLUSIONS: Correction of sagittal balance is associated with greater odds of discharge to home. These findings, coupled with the recognized implications of admission to a rehabilitation facility, will emphasize the importance of spine surgeons accounting for SVA into their surgical planning of MIS lumbar interbody fusions.

Traumatic sacral dermoid cyst rupture with intracranial subarachnoid seeding of lipid particles: illustrative case.

BACKGROUND: Intracranial deposits of fat droplets are an unusual presentation of a spinal dermoid cyst after spontaneous rupture and are even more uncommon after trauma. Here, the authors present a case with this rare clinical presentation, along with a systematic review of the literature to guide decision making in these patients. OBSERVATIONS: A 54-year-old woman with Lynch syndrome presented with severe headache and sacrococcygeal pain after a traumatic fall. Computed tomography of the head revealed multifocal intraventricular and intracisternal fat deposits, which were confirmed by magnetic resonance imaging (MRI) of the neuroaxis; in addition, a ruptured multiloculated cyst was identified within the sacral canal with proteinaceous/hemorrhagic debris, most consistent with a sacral dermoid cyst with rupture into the cerebrospinal fluid (CSF) space. An unruptured sacral cyst was later noted on numerous previous MRI scans. In our systematic review, we identified 20 similar cases, most of which favored surgical treatment. LESSONS: Rupture of an intraspinal dermoid cyst must be considered when intracranial fat deposits are found in the context of cauda equina syndrome, meningism, or hydrocephalus. Complete tumor removal with close postoperative follow-up is recommended to decrease the risk of complications. CSF diversion must be prioritized if life-threatening hydrocephalus is present.

The Effect of Physical Therapy on Time to Discharge After Lumbar Interbody Fusion.

BACKGROUND: With a lesser degree of tissue destruction, patients undergoing minimally-invasive spine surgery are primed to benefit from early mobilization, which can further enhance recovery and hasten rehabilitation. We aimed to determine the role of physical therapy on earlier discharge after minimally-invasive transforaminal lumbar interbody fusion (TLIF). METHODS: Michigan Spine Surgery Improvement Collaborative (MSSIC) provided patients undergoing one- and two-level minimally-invasive TLIF for degenerative lumbar disease. The study population was divided into patients with a one-day length of stay (LOS 1), two days (LOS 2), and three or more days (LOS ≥ 3) to maintain three equal-time cohorts. On POD 0, physical therapy (or, in very rare circumstances, a spine-care-specialized nurse in patients arriving to the in-patient floors late after hours) must evaluate capacity to ambulate. RESULTS: Of the 101 patients, the median day of first ambulation statistically significantly increased from the LOS 1 to LOS ≥ 3 cohort (P = 0.007). Mean distance ambulated decreased from 156.5 ±â€¯123.1 feet in the LOS 1 group, 108.9 ±â€¯83.9 feet in the LOS 2 group, to 69.2 ±â€¯58.3 feet in the LOS ≥ 3 group (P = 0.002). Patient-reported outcomes did not differ among the three cohorts. Following a multivariable ordinal logistical regression controlling for disposition to rehab over home (ORadj = 5.47, P = 0.045), the odds of longer LOS decreased by 39% for every 50-feet ambulated (P = 0.002). CONCLUSIONS: Time to first ambulation independently increases the odds of earlier discharge, regardless of comorbidity burden and surgical determinants.

Sarcopenia as a Prognostic Factor for 90-Day and Overall Mortality in Patients Undergoing Spine Surgery for Metastatic Tumors: A Multicenter Retrospective Cohort Study.

BACKGROUND: Novel methods in predicting survival in patients with spinal metastases may help guide clinical decision-making and stratify treatments regarding surgery vs palliative care. OBJECTIVE: To evaluate whether the frailty/sarcopenia paradigm is predictive of survival and morbidity in patients undergoing surgery for spinal metastasis. METHODS: A total of 271 patients from 4 tertiary care centers who had undergone surgery for spinal metastasis were identified. Frailty/sarcopenia was defined by psoas muscle size. Survival hazard ratios were calculated using multivariate analysis, with variables from demographic, functional, oncological, and surgical factors. Secondary outcomes included improvement of neurological function and postoperative morbidity. RESULTS: Patients in the smallest psoas tertile had shorter overall survival compared to the middle and largest tertile. Psoas size (PS) predicted overall mortality more strongly than Tokuhashi score, Tomita score, and Karnofsky Performance Status (KPS). PS predicted 90-d mortality more strongly than Tokuhashi score, Tomita score, and KPS. Patients with a larger PS were more likely to have an improvement in deficit compared to the middle tertile. PS was not predictive of 30-d morbidity. CONCLUSION: In patients undergoing surgery for spine metastases, PS as a surrogate for frailty/sarcopenia predicts 90-d and overall mortality, independent of demographic, functional, oncological, and surgical characteristics. The frailty/sarcopenia paradigm is a stronger predictor of survival at these time points than other standards. PS can be used in clinical decision-making to select which patients with metastatic spine tumors are appropriate surgical candidates.

The Preoperative Risks and Two-Year Sequelae of Postoperative Urinary Retention: Analysis of the Michigan Spine Surgery Improvement Collaborative (MSSIC).

OBJECTIVE: Although postoperative urinary retention (POUR) is common after spine surgery, the association of this adverse event with other morbidities and patient-reported outcomes is not fully understood. We sought to examine the sequelae of POUR after lumbar spine surgery. METHODS: The Michigan Spine Surgery Improvement Collaborative (MSSIC) is a large prospective multicenter registry. MSSIC was queried with multivariate analysis for factors that are associated with POUR, the association of POUR with 90-day adverse events, and the effect of POUR on 2-year patient-reported outcomes and satisfaction. RESULTS: Multivariate analysis identified hardware revision (odds ratio [OR], 0.61), 1 operative level (OR, 0.74), and ambulation on postoperative day zero (OR, 0.65) to be protective for POUR. Factors associated with POUR included age (OR, 1.19), male gender (OR, 1.58), body mass index <25 (OR, 1.22), diabetes (OR, 1.28), coronary artery disease (OR, 1.20), fusion surgery (OR, 1.27), and longer surgery (OR, 1.11). Patients who had POUR were more likely to be readmitted, develop a urinary tract infection, and develop an infection (P < 0.001). POUR was associated with decreased likelihood of achieving Oswestry Disability Index minimal clinically important difference at 90 days (P < 0.001), but not at 1 year after surgery. POUR was associated with dissatisfaction with surgery at 90 days (P < 0.001), 1 year (P = 0.004), and 2 years after surgery (P = 0.011). CONCLUSIONS: POUR is common after lumbar spine surgery, and the demographic, diagnostic, and surgical factors that are associated with POUR are identified. POUR is associated with several adverse events, and patients who have POUR were less likely to be satisfied with surgery up to 2 years after surgery.

The Association of Preoperative Opioid Usage With Patient-Reported Outcomes, Adverse Events, and Return to Work After Lumbar Fusion: Analysis From the Michigan Spine Surgery Improvement Collaborative (MSSIC).

BACKGROUND: It is important to delineate the relationship between opioid use and spine surgery outcomes. OBJECTIVE: To determine the association between preoperative opioid usage and postoperative adverse events, patient satisfaction, return to work, and improvement in Oswestry Disability Index (ODI) in patients undergoing lumbar fusion procedures by using 2-yr data from a prospective spine registry. METHODS: Preoperative opioid chronicity from 8693 lumbar fusion patients was defined as opioid-naïve (no usage), new users (<6 wk), short-term users (6 wk-3 mo), intermediate-term users (3-6 mo), and chronic users (>6 mo). Multivariate generalized estimating equation models were constructed. RESULTS: All comparisons were to opioid-naïve patients. Chronic opioid users showed less satisfaction with their procedure at 90 d (Relative Risk (RR) 0.95, P = .001), 1 yr (RR 0.89, P = .001), and 2 yr (RR 0.89, P = .005). New opioid users were more likely to show improvement in ODI at 90 d (RR 1.25, P < .001), 1 yr (RR 1.17, P < .001), and 2 yr (RR 1.19, P = .002). Short-term opioid users were more likely to show ODI improvement at 90 d (RR 1.25, P < .001). Chronic opioid users were less likely to show ODI improvement at 90 d (RR 0.90, P = .004), 1 yr (RR 0.85, P < .001), and 2 yr (RR 0.80, P = .003). Chronic opioid users were less likely to return to work at 90 d (RR 0.80, P < .001). CONCLUSION: In lumbar fusion patients and when compared to opioid-naïve patients, new opioid users were more likely and chronic opioid users less likely to have improved ODI scores 2 yr after surgery. Chronic opioid users are less likely to be satisfied with their procedure 2 yr after surgery and less likely to return to work at 90 d. Preoperative opioid counseling is advised.

Sarcopenia Predicts Overall Survival in Patients with Lung, Breast, Prostate, or Myeloma Spine Metastases Undergoing Stereotactic Body Radiation Therapy (SBRT), Independent of Histology.

BACKGROUND: Predicting survival of patients with spinal metastases would help stratify treatments from aggressive to palliation. OBJECTIVE: To evaluate whether sarcopenia predicts survival in patients with lung, breast, prostate, or multiple myeloma spinal metastases. METHODS: Psoas muscle measurements in patients with spinal metastasis were taken from computed tomography scans at 2 time points: at first episode of stereotactic body radiation therapy (SBRT) and from the most recent scan available. Overall survival and hazard ratios were calculated with multivariate cox proportional hazards regression analyses. RESULTS: In 417 patients with spinal metastases, 40% had lung cancer, 27% breast, 21% prostate, and 11% myeloma. Overall survival was not associated with age, sex, ethnicity, levels treated, or SBRT volume. Multivariate analysis showed patients in the lowest psoas tertile had shorter survival (222 d, 95% CI = 185-323 d) as compared to the largest tertile (579 d, 95% CI = 405-815 d), (HR1.54, P = .005). Median psoas size as a cutoff value was also strongly predictive for survival (HR1.48, P = .002). Survival was independent of tumor histology. The psoas/vertebral body ratio was also successful in predicting overall survival independent of tumor histology and gender (HR1.52, P < .01). Kaplan-Meier survival curves visually represent survival (P = .0005). CONCLUSION: In patients with spine metastases, psoas muscle size as a hallmark of frailty/sarcopenia is an objective, simple, and effective way to identify patients who are at risk for shorter survival, regardless of tumor histology. This information can be used to help with surgical decision making in patients with advanced cancer, as patients with small psoas sizes are at higher risk of death.

Ambulation on Postoperative Day #0 Is Associated With Decreased Morbidity and Adverse Events After Elective Lumbar Spine Surgery: Analysis From the Michigan Spine Surgery Improvement Collaborative (MSSIC).

BACKGROUND: While consistently recommended, the significance of early ambulation after surgery has not been definitively studied. OBJECTIVE: To identify the relationship between ambulation on the day of surgery (postoperative day (POD)#0) and 90-d adverse events after lumbar surgery. METHODS: The Michigan Spine Surgery Improvement Collaborative (MSSIC) is a prospective multicenter registry of spine surgery patients. As part of routine postoperative care, patients either ambulated on POD#0 or did not. The 90-d adverse events of length of stay (LOS), urinary retention (UR), urinary tract infection (UTI), ileus, readmission, surgical site infection (SSI), pulmonary embolism/deep vein thrombosis (PE/DVT), and disposition to a rehab facility were measured. RESULTS: A total of 23 295 lumbar surgery patients were analyzed. POD#0 ambulation was associated with decreased LOS (relative LOS 0.83, P < .001), rehab discharge (odds ratio [OR] 0.52, P < .001), 30-d (OR 0.85, P = .044) and 90-d (OR 0.86, P = .014) readmission, UR (OR 0.73, P = 10), UTI (OR 73, P = .001), and ileus (OR 0.52, P < .001) for all patients. Significant improvements in LOS, rehab discharge, readmission, UR, UTI, and ileus were observed in subset analysis of single-level decompressions (4698 pts), multilevel decompressions (4079 pts), single-level fusions (4846 pts), and multilevel fusions (4413 pts). No change in rate of SSI or DVT/PE was observed for patients who ambulated POD#0. CONCLUSION: POD#0 ambulation is associated with a significantly decreased risk for several key adverse events after lumbar spine surgery. Decreasing the incidence of these outcomes would be associated with significant cost savings. As ambulation POD#0 is a modifiable factor in any patient's postoperative care following most spine surgery, it should be encouraged and incorporated into spine-related, enhanced-recovery-after-surgery programs.

Use of Patient Health Questionnaire-2 scoring to predict patient satisfaction and return to work up to 1 year after lumbar fusion: a 2-year analysis from the Michigan Spine Surgery Improvement Collaborative.

OBJECTIVE: The Michigan Spine Surgery Improvement Collaborative (MSSIC) is a prospective, longitudinal, multicenter, quality-improvement collaborative. Using MSSIC, the authors sought to identify the relationship between a positive Patient Health Questionnaire-2 (PHQ-2) screening, which is predictive of depression, and patient satisfaction, return to work, and achieving Oswestry Disability Index (ODI) minimal clinically important difference (MCID) scores up to 2 years after lumbar fusion. METHODS: Data from a total of 8585 lumbar fusion patients were analyzed. Patient satisfaction was measured by the North American Spine Society patient satisfaction index. A positive PHQ-2 score is one that is ≥ 3, which has an 82.9% sensitivity and 90.0% specificity in detecting major depressive disorder. Generalized estimating equation models were constructed; variables tested include age, sex, race, past medical history, severity of surgery, and preoperative opioid usage. RESULTS: Multivariate analysis was performed. Patients with a positive PHQ-2 score (i.e., ≥ 3) were less likely to be satisfied after lumbar fusion at 90 days (relative risk [RR] 0.93, p < 0.001), 1 year (RR 0.92, p = 0.001), and 2 years (RR 0.92, p = 0.028). A positive PHQ-2 score was also associated with decreased likelihood of returning to work at 90 days (RR 0.76, p < 0.001), 1 year (RR 0.85, p = 0.001), and 2 years (RR 0.82, p = 0.031). A positive PHQ-2 score was predictive of failure to achieve an ODI MCID at 90 days (RR 1.07, p = 0.005) but not at 1 year or 2 years after lumbar fusion. CONCLUSIONS: A multivariate analysis based on information from a large, multicenter, prospective database on lumbar fusion patients was performed. The authors found that a positive score (≥ 3) on the PHQ-2, which is a simple and accurate screening tool for depression, predicts an inability to return to work and worse satisfaction up to 2 years after lumbar fusion. Depression is a treatable condition, and so in the same way that patients are medically optimized before surgery to decrease postoperative morbidity, perhaps patients should have preoperative psychiatric optimization to improve postoperative functional outcomes.

Patient Demographic and Surgical Factors that Affect Completion of Patient-Reported Outcomes 90 Days and 1 Year After Spine Surgery: Analysis from the Michigan Spine Surgery Improvement Collaborative (MSSIC).

BACKGROUND: The Michigan Spine Surgery Improvement Collaborative is a statewide multicenter quality improvement registry. Because missing data can affect registry results, we used MSSIC to find demographic and surgical characteristics that affect the completion of patient-reported outcomes (PROs) at 90 days and 1 year. METHODS: A total of 24,404 patients who had lumbar surgery (17,813 patients) or cervical surgery (6591 patients) were included. Multivariate logistic regression models of patient disease were constructed to identify risk factors for failure to complete scheduled PRO surveys. RESULTS: Patients ≥65 years old and female patients were both more likely to respond at 90 days and 1 year. Increasing education was associated with greater response rate at 90 days and 1 year. Whites and African Americans had no differences in response rates. Calling provided the highest response rate at 90 days and 1 year. For cervical spine patients, only discharge to rehabilitation increased completion rates, at 90 days but not 1 year. For lumbar spine patients, spondylolisthesis or stenosis (vs. herniated disc) had a greater response rate at 1 year. Patients with leg (vs. back) pain had a greater response only at 1 year. Patients with multilevel surgery had an increased response at 1 year. Patients who underwent fusion were more likely to respond at 90 days, but not 1 year. Discharge to rehabilitation increased response at 90 days and 1 year. CONCLUSIONS: A multivariate analysis from a multicenter prospective database identified surgical factors that affect PRO follow-up, up to 1 year. This information can be helpful for imputing missing PRO data and could be used to strengthen data derived from large prospective databases.

Malignant Transformation of a Filum Terminale Dermoid Tumor into Adenocarcinoma.

BACKGROUND: Intraspinal dermoid tumors are usually rare benign growths that occur as a result of defects during neural tube formation. They make up less than 1% of tumors in the spine and are associated with spinal dysraphisms or sinus tracts. Although rare, malignant transformation into squamous cell carcinoma has been previously reported. Malignant transformation into adenocarcinoma, however, represents a novel phenotypic differentiation pattern that is hitherto undescribed. CASE DESCRIPTION: A 45-year-old woman presented with acute symptoms of cauda equina syndrome. Imaging of the spine revealed a large intradural sacral mass. The lesion was surgically resected with pathology revealing a dermoid tumor with malignant transformation into adenocarcinoma. Metastatic workup revealed no other suspicious lesions. The patient had an uneventful postoperative course, gradually regaining micturition control. CONCLUSIONS: Dermoid tumors, also known as benign cystic teratoma or mature teratoma, are usually benign congenital tumors comprising epithelial cells that arise from displaced embryonic ectoderm and mesoderm during neural tube formation. Although extremely rare, malignant transformation into squamous cell carcinoma has been reported. This case represents the first report of an intraspinal dermoid tumor transforming into adenocarcinoma. A comprehensive histopathologic analysis is key to identifying the lesion and guiding postsurgical management.

Adverse events and their risk factors 90 days after cervical spine surgery: analysis from the Michigan Spine Surgery Improvement Collaborative.

OBJECTIVEThe Michigan Spine Surgery Improvement Collaborative (MSSIC) is a statewide, multicenter quality improvement initiative. Using MSSIC data, the authors sought to identify 90-day adverse events and their associated risk factors (RFs) after cervical spine surgery.METHODSA total of 8236 cervical spine surgery cases were analyzed. Multivariable generalized estimating equation regression models were constructed to identify RFs for adverse events; variables tested included age, sex, diabetes mellitus, disc herniation, foraminal stenosis, central stenosis, American Society of Anesthesiologists Physical Classification System (ASA) class > II, myelopathy, private insurance, anterior versus posterior approach, revision procedures, number of surgical levels, length of procedure, blood loss, preoperative ambulation, ambulation day of surgery, length of hospital stay, and discharge disposition.RESULTSNinety days after cervical spine surgery, adverse events identified included radicular findings (11.6%), readmission (7.7%), dysphagia requiring dietary modification (feeding tube or nothing by mouth [NPO]) (6.4%), urinary retention (4.7%), urinary tract infection (2.2%), surgical site hematoma (1.1%), surgical site infection (0.9%), deep vein thrombosis (0.7%), pulmonary embolism (0.5%), neurogenic bowel/bladder (0.4%), myelopathy (0.4%), myocardial infarction (0.4%), wound dehiscence (0.2%), claudication (0.2%), and ileus (0.2%). RFs for dysphagia included anterior approach (p < 0.001), fusion procedures (p = 0.030), multiple-level surgery when considering anterior procedures only (p = 0.037), and surgery duration (p = 0.002). RFs for readmission included ASA class > II (p < 0.001), while preoperative ambulation (p = 0.001) and private insurance (p < 0.001) were protective. RFs for urinary retention included increasing age (p < 0.001) and male sex (p < 0.001), while anterior-approach surgery (p < 0.001), preoperative ambulation (p = 0.001), and ambulation day of surgery (p = 0.001) were protective. Preoperative ambulation (p = 0.010) and anterior approach (p = 0.002) were protective of radicular findings.CONCLUSIONSA multivariate analysis from a large, multicenter, prospective database identified the common adverse events after cervical spine surgery, along with their associated RFs. This information can lead to more informed surgeons and patients. The authors found that early mobilization after cervical spine surgery has the potential to significantly decrease adverse events.

Morphometrics predicts overall survival in patients with multiple myeloma spine metastasis: A retrospective cohort study.

Background: Treatment strategies for spinal metastases for myeloma range from conservative measures (radiation and chemotherapy) to invasive (surgical). Identifying better predictors of overall survival (OS) would help in surgical decision making. Analytic morphometrics has been shown to predict survival in oncologic patients, and our study evaluates whether morphometrics is predictive of survival in patients with multiple myeloma (MM) spinal metastases. Methods: For this observational retrospective cohort study, we identified 46 patients with MM spinal metastases who had undergone stereotactic body radiation therapy. OS was the primary outcome measure. Morphometric analysis of the psoas muscle was performed using computed tomography scans of the lumbar spine. Results: OS was statistically correlated with age (P = 0.025), tumor burden (P = 0.023), and number of levels radiated (P = 0.029), but not with gender. Patients in the lowest tertile of average psoas size had significantly shorter survival compared to the highest tertile, hazard ratio (HZ) 6.87 (95% CI = 1.65-28.5, P = 0.008). When calculating the psoas size to vertebral body ratio and correlating this measure to OS, the lowest tertile again had significantly shorter OS compared to the highest tertile, HZ 6.87 (95% CI = 1.57-29.89, P = 0.010); the middle tertile also showed significantly shorter OS compared to the highest tertile, HZ 5.07 (95% CI = 1.34-19.10, P = 0.016). Kaplan-Meier survival curves were used to visually illustrate the differences in survival between different tertiles (Log-rank test P = 0.006). Conclusions: Morphometric analysis successfully predicts long-term survival in patients with MM. More research is needed to validate these results and to see if these methodologies can be applied to other cancer histologies.

Mechanomyography for Intraoperative Assessment of Cortical Breach During Instrumented Spine Surgery.

OBJECTIVE: We sought to determine the utility of mechanomyography (MMG) in detecting and preventing pedicle breach in instrumented lumbar spine surgery. METHODS: In a prospective nonrandomized trial without controls, we selected consecutive patients to undergo intraoperative MMG during instrumented lumbar spine surgery. MMG testing was performed at the original pilot hole, after tapping, and after screw placement, with the minimum current to elicit a recorded MMG response. All patients underwent a postoperative computed tomography scan, and a single radiologist interpreted each pedicle to identify breach. Chi-square test was used to compare patients with and without breaches. Two sample Student's t-tests were used to compare changes in functional outcomes. Sensitivity and specificity of MMG were computed using receiver operating characteristic curve analysis. RESULTS: There were 122 consecutive instrumented lumbar surgery patients enrolled, with a total of 890 lumbar pedicle screws tested with MMG. The medial or inferior breach rate was 2.25%, with no statistically significant difference in Oswestry Disability Index or visual analog scale between patients who breached and who did not. For the MMG measurement from the original pilot hole, the area under the receiver operating characteristic was 0.835; the maximum combination of sensitivity (80.42%) and specificity (80.6%) was found using MMG current ≤12 mA. We found that an MMG cutoff of >12 mA resulted in a 99.5% likelihood of no medial or inferior breach. CONCLUSIONS: MMG can be safely used during instrumented lumbar spine surgery. A cutoff value of >12 mA for MMG can accurately predict and prevent medial and inferior pedicle screw breach.

Application of Morphometrics as a Predictor for Survival in Patients with Prostate Cancer Metastasis to the Spine.

BACKGROUND: Surgery for spinal metastases can improve survival but has high morbidity that can potentially diminish benefits. New objective methods of predicting overall survival would be beneficial for surgical decision making. Morphometrics quantifies patient frailty and has been successfully used to predict overall survival in patients with lung cancer spinal metastases. This study evaluated whether morphometrics can predict survival in patients with prostate cancer spinal metastases. METHODS: Using a retrospective registry of patients with spinal metastases who underwent stereotactic body radiation therapy, we identified patients with primary prostate cancer. Morphometric measurements of the psoas muscle were taken from most recent lumbar spine computed tomography. Patients were stratified into lowest, middle, and highest tertiles based on psoas muscle area. Primary outcome measure was overall survival from the date of computed tomography scan. RESULTS: We identified 92 patients. Median survival for all patients was 124 days (95% confidence interval, 98-197 days). Patients in the smallest third for average psoas size had significantly shorter survival compared with patients in the largest third: 117 days versus 302 days (hazard ratio 2.42; 95% confidence interval, 1.32-4.43; P = 0.004). Patients in the middle third for average psoas size also had shorter survival compared with patients in the largest third: 113 days versus 302 days (hazard ratio 2.31; 95% confidence interval, 1.25-4.25; P = 0.007). CONCLUSIONS: In patients with prostate cancer spinal metastases, morphometric analysis of psoas muscle size can identify patients at risk for shorter survival. This technique can aid in surgical decision making by weighing expected survival and fitness versus potential morbidity of intervention.

Application of morphometrics as a predictor for survival in female patients with breast cancer spinal metastasis: a retrospective cohort study.

BACKGROUND CONTEXT: The current standard of care for prediction of survival of cancer staging is based on TNM staging. However, for patients with spinal metastasis, who all have identical stage IV disease, identifying accurate prognostic markers of survival would allow better treatment stratification between more aggressive treatment strategies or palliation. Analytical morphometrics enables physicians to quantify patient frailty by measuring lean muscle mass. Morphometrics also predicts survival in patients with lung cancer metastases to the spine. PURPOSE: Our study evaluates whether morphometrics is predictive of survival in patients with breast cancer spinal metastasis. DESIGN: This is an observational retrospective cohort study. PATIENT SAMPLE: This study includes female patients with breast cancer spinal metastases and patients who have undergone stereotactic body radiation therapy. OUTCOME MEASURES: Overall survival was the primary outcome measure. METHODS: Morphometric measurements of the psoas muscle were taken using computed tomography scans of the lumbar spine. We then stratified patients into tertiles based on the psoas muscle area. RESULTS: We identified 118 patients, with a median survival of 104 days (95% confidence interval [CI]=73-157 days). Overall survival was not associated with age, chemotherapy, or number of levels radiated. Patients in the lowest tertile of psoas size had significantly shorter survival compared with the highest tertile (68 days versus 148 days, hazard ratio 1.76 [95% CI=1.08-2.89], p=.024). The shorter survival was also true for the lowest tertile versus the middle tertile (68 days versus 167 days, hazard ratio 1.95 [95% CI=1.19-3.19], p=.007). Kaplan-Meier survival curves were used to visually illustrate the differences in survival between different tertiles. CONCLUSIONS: Morphometric analysis of the psoas muscle size in patients with breast cancer metastases to the spine was effective in identifying patients at risk of shorter survival. Further research is needed to validate these results, as well as to see if these methodologies can be applied to other cancer histologies.

The reliability of identifying the Omega sign using axial T2-weighted magnetic resonance imaging.

Preoperative identification of the eloquent brain is important for neurosurgical planning. One common method of finding the motor cortex is by localizing "the Omega sign." No studies have tested the reliability of imaging to identify the Omega sign. We identified 40 recent and consecutive patients who had undergone preoperative functional magnetic resonance imaging for identification of the hand motor area prior to tumor resection. We recruited 11 neurosurgical residents of various levels of training and one board-certified neurosurgeon to identify the hand motor cortex Omega. Testees were given axial images of T2-weighted MRI and placed marks where they expected to find the Omega. Two board-certified radiologists graded and quantified the localization attempts. Inter-rater reliability was assessed using the kappa statistic, and Rao-Scott chi-square tests were used to examine the relationship between clinical factors and testees' experience with correct identification of the Omega sign. The overall correct identification rate was 69.9% (95% CI = 63.4-75.7), ranging from 36.6% to 92.7% among all raters for the tumor side and from 46.2% to 97.4% for the non-tumor side. Anatomic distortion greatly affected correct identification ( p < 0.005). Senior residents had a significantly higher rate of identification of the Omega than junior residents ( p < 0.001). Overall, inter-rater reliability for the Omega sign is poor, with a Fleiss kappa of 0.23. We concluded that correct identification of the Omega sign is affected by tumor distortion and experience but overall is not reliable. This underscores the limitations of anatomic landmarks and the importance of utilizing multiple scanning planes and preoperative fMRI for appropriate localization.