Pearls and pitfalls of posterior superior iliac spine reference frame placement for spinal navigation: cadaveric series.

BACKGROUND: Navigation and robotics are important tools in the spine surgeon's armamentarium and use of these tools requires placement of a reference frame. The posterior superior iliac spine (PSIS) is a commonly used site for reference frame placement, due to its location away from the surgical corridor and its ability to provide solid fixation. Placement of a reference frame requires not only familiarity with proper technique, but also command of the relevant anatomy. OBSERVATIONS: Cadaveric analysis demonstrates a significant difference in PSIS location in males versus females, and additionally provides average thickness for accurate placement. LESSONS: In this technical note, the authors describe the precise technique for PSIS frame placement in addition to relevant anatomy and offer solutions to commonly encountered problems.

Laser Interstitial Thermal Therapy for First-Line Treatment of Surgically Accessible Recurrent Glioblastoma: Outcomes Compared With a Surgical Cohort.

BACKGROUND: Laser interstitial thermal therapy (LITT) for glioblastoma (GBM) has been reserved for poor surgical candidates and deep "inoperable" lesions. We present the first reported series of LITT for surgically accessible recurrent GBM (rGBM) that would otherwise be treated with surgical resection. OBJECTIVE: To evaluate the use of LITT for unifocal, lobar, first-time rGBM compared with a similar surgical cohort. METHODS: A retrospective institutional database was used to identify patients with unifocal, lobar, first-time rGBM who underwent LITT or resection between 2013 and 2020. Clinical and volumetric lesional characteristics were compared between cohorts. Subgroup analysis of patients with lesions ≤20 cm 3 was also completed. Primary outcomes were overall survival and progression-free survival. RESULTS: Of the 744 patients with rGBM treated from 2013 to 2020, a LITT cohort of 17 patients were compared with 23 similar surgical patients. There were no differences in baseline characteristics, although lesions were larger in the surgical cohort (7.54 vs 4.37 cm 3 , P = .017). Despite differences in lesion size, both cohorts had similar extents of ablation/resection (90.7% vs 95.1%, P = .739). Overall survival (14.1 vs 13.8 months, P = .578) and progression-free survival (3.7 vs 3.3 months, P = 0. 495) were similar. LITT patients had significantly shorter hospital stays (2.2 vs 3.0 days, P = .004). Subgroup analysis of patients with lesions ≤20 cm 3 showed similar outcomes, with LITT allowing for significantly shorter hospital stays. CONCLUSION: We found no difference in survival outcomes or morbidity between LITT and repeat surgery for surgically accessible rGBM while LITT resulted in shorter hospital stays and more efficient postoperative care.

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.

Learning curves in robot-assisted spine surgery: a systematic review and proposal of application to residency curricula.

OBJECTIVE: Spine robots have seen increased utilization over the past half decade with the introduction of multiple new systems. Market research expects this expansion to continue over the next half decade at an annual rate of 20%. However, because of the novelty of these devices, there is limited literature on their learning curves and how they should be integrated into residency curricula. With the present review, the authors aimed to address these two points. METHODS: A systematic review of the published English-language literature on PubMed, Ovid, Scopus, and Web of Science was conducted to identify studies describing the learning curve in spine robotics. Included articles described clinical results in patients using one of the following endpoints: operative time, screw placement time, fluoroscopy usage, and instrumentation accuracy. Systems examined included the Mazor series, the ExcelsiusGPS, and the TiRobot. Learning curves were reported in a qualitative synthesis, given as the mean improvement in the endpoint per case performed or screw placed where possible. All studies were level IV case series with a high risk of reporting bias. RESULTS: Of 1579 unique articles, 97 underwent full-text review and 21 met the inclusion and exclusion criteria; 62 articles were excluded for not presenting primary data for one of the above-described endpoints. Of the 21 articles, 18 noted the presence of a learning curve in spine robots, which ranged from 3 to 30 cases or 15 to 62 screws. Only 12 articles performed regressions of one of the endpoints (most commonly operative time) as a function of screws placed or cases performed. Among these, increasing experience was associated with a 0.24- to 4.6-minute decrease in operative time per case performed. All but one series described the experience of attending surgeons, not residents. CONCLUSIONS: Most studies of learning curves with spine robots have found them to be present, with the most common threshold being 20 to 30 cases performed. Unfortunately, all available evidence is level IV data, limited to case series. Given the ability of residency to allow trainees to safely perform these cases under the supervision of experienced senior surgeons, it is argued that a curriculum should be developed for senior-level residents specializing in spine comprising a minimum of 30 performed cases.

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.

Spine Image Guidance and Robotics: Exposure, Education, Training, and the Learning Curve.

The use of intraoperative robotics and imaging for spine surgery has been shown to be safe, efficacious, and beneficial to patients, offering accurate placement of instrumentation, decreased operative time and blood loss, and improved postoperative outcomes. Despite these proven benefits, it has yet to be uniformly adopted. One of the major barriers for universal adoption of intraoperative robotics is the learning curve for this complex technology, in conjunction with a lack of formalized training. These same obstacles for universal adoption were faced in the introduction of surgical technology in other disciplines, and the use of this technology has become the standard of care in some of those specialties. Part of the success and widespread implementation of prior novel technology was the introduction of formalized training systems, which are currently lacking in advanced spine surgical technology. Therefore, the future success of intraoperative robotics and imaging for spine surgery depends on the creation of a formalized training system. We detail the best techniques for surgical pedagogy, as well as propose a comprehensive curriculum.

Augmented Reality in Spine Surgery: A Narrative Review.

Augmented reality (AR) navigation refers to novel technologies that superimpose images, such as radiographs and navigation pathways, onto a view of the operative field. The development of AR navigation has focused on improving the safety and efficacy of neurosurgical and orthopedic procedures. In this review, the authors focus on 3 types of AR technology used in spine surgery: AR surgical navigation, microscope-mediated heads-up display, and AR head-mounted displays. Microscope AR and head-mounted displays offer the advantage of reducing attention shift and line-of-sight interruptions inherent in traditional navigation systems. With the U.S. Food and Drug Administration's recent clearance of the XVision AR system (Augmedics, Arlington Heights, IL), the adoption and refinement of AR technology by spine surgeons will only accelerate.

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.

Bone Marrow Aspirate in Spine Surgery: Case Series and Review of the Literature.

Background With the modernization of biotechnology, there has been a concerted effort to create novel biomaterials to promote arthrodesis for spine surgery. The novel use of the stem cells from bone marrow aspirate (BMA) to augment spine surgery is a burgeoning field because these cells are considered to be both osteoinductive and osteogenic. We sought to review the evidence behind the use of BMAs in spinal fusions and report the results of our own case series. Methods PubMed and EMBASE databases were searched for studies that investigated the use of stem cells for spine surgery. For our own case series, the medical records of 150 consecutive patients who underwent a lumbar spinal fusion with BMA were retrospectively reviewed for adverse events (AEs) for up to two years after surgery. Results In our case series, there were no AEs identified in 49% of our patients. Of the identified AEs, 61% were unrelated to the use of BMA (e.g., UTI and heart failure), with the remaining 39% likely unrelated to its use (e.g., back pain and anemia). There was a 92.8% arthrodesis rate with the use of BMA. Conclusions We reviewed the rationale, basic science, and clinical science for BMA usage in spine surgery and concluded that BMA is safe for use in spine surgery and is associated with a high rate of arthrodesis.

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.

Introducing the Rupture Criticality Index to Compare Risk Factor Combinations Associated With Aneurysmal Rupture.

BACKGROUND: Relative risk is insufficient to guide treatment decision-making for unruptured intracranial aneurysms. Our objective was to introduce a novel risk assessment methodology called the Rupture Criticality Index (RCI), which allows for concurrent evaluation of groups of risk factors (RFs). METHODS: From a retrospective database of saccular aneurysms, we identify 915 patients and delineate 50 potential RFs for aneurysms in 11 unique locations. RF combinations for multivariable analysis were defined by aneurysm size, location, and a third variable from the study design. Data analysis was performed by applying frequency distribution methods to define the RCI of each RF combination. RESULTS: RF combinations at greatest risk were small (4.8-8.2 mm) or medium (8.3-14.5 mm) anterior communicating aneurysms (ACoA) in male individuals (RCI 9.87-10), small ACoA in those ≤37 years or 38-55 years (RCI 8.67-8.99), medium basilar tip aneurysms (BTAs) in male individuals (RCI 10), and large (14.6-22.5 mm) BTA in Caucasians or those aged 38-55 years (RCI 9.25, 9.35, respectively). CONCLUSIONS: We introduce the concept of RCI and compare how RF combinations are associated with aneurysmal rupture. This novel approach to aneurysmal rupture identifies high-risk clinical presentations and can be used to guide clinical decision-making in patients with non-traditional risks.

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.

Surgical Treatment of Intracranial Anterior Ethmoidal Aneurysm: Case Report, Literature Review, and Surgical Video.

BACKGROUND: Anterior ethmoid aneurysms are rare with 5 cases of intracranial rupture and 3 cases of life-threatening epistaxis described in recent literature. We present a case of an intracranial ruptured anterior ethmoid aneurysm treated surgically with a favorable outcome. CASE DESCRIPTION: A 64-year-old male presenting with a headache was found to have a right frontal intracranial hemorrhage with an associated 1.5 cm length × 1.8 cm maximal width anterior ethmoidal artery aneurysm. No definitive etiology of the aneurysm was identified. The aneurysm was treated using a bifrontal craniotomy with interhemispheric microdissection, clip ligation, and resection of the aneurysm dome for pathologic analysis, which ruled out a mycotic etiology. He recovered uneventfully and returned to work with no identifiable neurologic deficit. CONCLUSIONS: Consistent with prior reports, an intracranial, anterior ethmoidal artery aneurysm can occur in isolation without an associated vascular malformation. On the basis of a literature review and this case, surgical ligation is considered effective and possibly superior over endovascular treatment due to the risk of injury to the orbital vascular supply with transarterial treatment.

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.