OBJECTIVE:Magnetic resonance-guided focused ultrasound (MRgFUS) thalamotomy has become a popular tool in the neurosurgical armamentarium for managing tremor in patients with essential tremor (ET) and Parkinson's disease (PD). METHODS:Given the recent exponential growth in the use of this technology, the American Society for Stereotactic and Functional Neurosurgery, which acts as the joint section representing the field of stereotactic and functional neurosurgery on behalf of the Congress of Neurological Surgeons and the American Association of Neurological Surgeons, provides an update on treatment indications and the efficacy and safety of MRgFUS for the treatment of tremor. RESULTS:In ET, the efficacy of MRgFUS thalamotomy is supported by several open-label and 1 prospective, double-blind, sham-controlled randomized clinical trial (RCT) that showed a 47% improvement in hand tremor in the short term. Follow-up studies demonstrated that the benefits of MRgFUS for ET are sustained in the long term. Studies investigating the effects of bilateral staged MRgFUS thalamotomy in patients with ET have shown that tremor improvement on the second side was as significant as that observed after the first procedure. The efficacy of MRgFUS thalamotomy for PD tremor is supported by a systematic meta-analysis that consisted predominantly of smaller, nonrandomized studies; 1 RCT; and 1 prospective cohort study. Despite a significant short-term improvement in PD tremor, the long-term effects of this therapy remain unknown. Common early adverse effects of MRgFUS thalamotomy include gait disturbance and paresthesias. These, however, tend to subside over time. Other reported side effects are dysarthria, ataxia, taste disturbance, motor deficits, and speech difficulty. CONCLUSIONS:MRgFUS thalamotomy is a safe, effective, and durable intervention for refractory ET in appropriately selected patients. The procedure appears to be safe and effective for PD tremor, although the long-term durability of the technique remains a concern. Early experience with bilateral staged lesions for ET suggests the procedure to be safe and effective.

Since its US Food and Drug Administration approval in 2016, magnetic resonance-guided focused ultrasound (MRgFUS) thalamotomy has grown into one of the procedures of choice among patients with essential tremor (ET). Approved applications for the procedure have expanded over time from unilateral thalamotomy to treat ET and Parkinson disease tremor to bilateral staged thalamotomy for ET. As the procedure expands to healthcare environments beyond large academic centers, guidance is required to ensure that the responsible clinicians are appropriately trained to undertake this operative procedure. Although multidisciplinary movement disorder teams are important for the optimal management of patients, MRgFUS lesions are inherently surgical interventions. Neurosurgeons are trained to evaluate these patients, consider surgical alternatives and conduct these operations, particularly after completing a fellowship in the subspecialty of stereotactic and functional neurosurgery. At present, all high-level evidence regarding the safety and efficacy of MRgFUS lesions to treat movement disorders derives from procedures performed by neurosurgeons, so those results may not be generalizable to other physicians. Based on these considerations and potential liability issues, the American Society for Stereotactic and Functional Neurosurgery, which acts as the joint section representing the field of stereotactic and functional neurosurgery on behalf of the Congress of Neurological Surgeons and the American Association of Neurological Surgeons, puts forth this position statement that only neurosurgeons appropriately trained to conduct functional neurosurgery procedures should conduct MRgFUS surgical lesions.

BACKGROUND AND OBJECTIVES:Although axial neck pain and radicular arm pain are often associated with cervical spondylotic myelopathy (CSM), some patients present or are discovered to have CSM without pain. Little is known regarding the surgical outcomes in these patients. Our objective is to describe the outcomes of decompressive spine surgery in a cohort of patients treated for painless CSM. METHODS:This is a retrospective study of data from the Michigan Spine Surgery Improvement Collaborative registry. A total of 407 patients undergoing spine surgery for painless CSM between March 2014 and May 2022 were analyzed. Patient-reported outcomes (PROs), including minimal clinically important difference (MCID) in Modified Japanese Orthopedic Association, EuroQol-5 Dimension (EQ-5D), and Patient-Reported Outcomes Measurement Information System Physical Function (PROMIS PF) scores, were assessed at baseline, and at 90 days, 1 year, and 2 years postoperatively. All analyses were conducted with a P -value of < .05 being considered significant. RESULTS:After surgery, the number of patients experiencing a clinically significant improvement in PROs was greatest at 1 year (49% PROMIS PF MCID, 36% Modified Japanese Orthopedic Association MCID, 42% EQ-5D MCID). When stratifying by preoperative CSM severity, patients with severe myelopathy were significantly more likely to have a poorer discharge disposition and readmission at 90 days compared with mild myelopathy patients. PROs also significantly varied by CSM severity, including patient satisfaction at 2 years (95% mild vs 80% moderate vs 74% severe, P < .05), PROMIS PF MCID at 90 days (26% mild vs 53% moderate vs 45% severe, P = .02), and mean EQ-5D at 90 days (0.84 mild vs 0.80 moderate vs 0.69 severe, P < .01), 1 year (0.85 mild vs 0.79 moderate vs 0.82 severe, P < .01), and 2 years (0.85 mild vs 0.75 moderate vs 0.76 severe, P < .01). CONCLUSION:After surgery, a clinically significant improvement was seen in a modest number of patients. In addition to halting the progression of myelopathy, surgery may enhance functional status and quality of life in some with painless CSM.

Enhanced recovery after surgery (ERAS) protocols have been utilized in various surgical specialties to facilitate decreased post-operative complication rates and length of stay, while improving patient satisfaction. However, there is a paucity of literature analyzing the effects of a multi-institutional ERAS protocol in spine surgery. The Michigan Spine Surgery Improvement Collaborative (MSSIC) database was queried for patients across 29 hospitals undergoing elective lumbar spine surgery from January 2017 to December 2019 and from January 2022 to July 2023 when the ERAS protocol was implemented. Multivariate analysis was conducted to compare outcomes of patients in this cohort who underwent the standardized ERAS protocol with those who did not. Outcomes measured include adverse events, timing and disposition of discharge, readmissions, and patient reported outcomes. 5,188 patients were included in this analysis. Patients who underwent the ERAS protocol were more likely to be discharged home (RR = 1.06; CI: 1.03-1.09, p < 0.001) and trended towards being less likely to have a length of stay greater or equal to 3 days (RR = 0.85, CI: 0.71-1.0, p = 0.055). In addition, patients who underwent the ERAS protocol were more likely to achieve a minimal clinically important difference (MCID) in their PROMIS functional score at 90-days (RR 1.14; CI: 1.01-1.29, p = 0.034). There was a trend towards a lower risk of any complications for the ERAS group (RR = 0.80; CI: 0.62-1.03, p = 0.077). Our statewide multi-institutional ERAS protocol demonstrates potential for cost-saving and improved patient reported outcomes by utilizing an ERAS protocol in elective lumbar spine surgery.

INTRODUCTION: In an effort to minimize costs, there has been an increased shift in performing elective surgical procedures at ambulatory surgery centers (ASC), and spine surgery is no exception. There is a paucity of literature with direct comparisons between hospital outpatient department (HOPD) and ASC spine procedures within a multi-center study. METHODS: The Michigan Spine Surgery Improvement Collaborative (MSSIC) database was queried for patients who underwent outpatient lumbar decompression surgery from January 2021 to June 2023. Patients in the HOPD and ASC cohorts underwent propensity score matching based on BMI, ASA, and number of levels. Subsequent multivariate analysis was then performed to further control for confounding variables. Outcomes measured included adverse events, timing and disposition of discharge, readmissions, and ED presentations. RESULTS: A total of 3,333 patients were included in the multivariate analysis. Compared to HOPDs, ASCs had a higher risk of any complication (IRR = 1.50; CI: 1.17-1.92, p=0.001) which was driven primarily by an increased risk in return to OR (IRR = 2.30; CI: 1.44-3.68, p < 0.001). Differences in risk of re-operation were driven by an increased rate of recurrent disc herniations in the ASC setting (3.27% versus 1.01% in HOPD). There was no significant difference in the risk of surgical site infection, post-operative ED visit, or 30- and 90-day readmission. CONCLUSIONS: Patients undergoing surgery at ASCs may endure a higher risk of complications and reoperations when compared to an outpatient surgery performed in a hospital setting.

BACKGROUND AND OBJECTIVES:Given the current opioid epidemic and its impact on public health, long-term opioid use after elective spine surgery is a significant concern. Identifying risk factors of long-term opioid use after spine surgery is crucial for developing effective interventions to reduce opioid dependence in this patient population. The objective of this study was to identify risk factors associated with long-term opioid use after elective lumbar and cervical spine surgeries. METHODS:A retrospective analysis of patient data was conducted using the Michigan Spine Surgery Improvement Collaborative data registry. Patients who underwent elective lumbar or cervical spine surgery between March 2018 and September 2021 were included. Poisson generalized estimating equation models were used for multivariate analyses. RESULTS:A total of 5301 and 3992 lumbar surgery patients at 1 and 2 years, respectively, and a total of 2074 and 1451 cervical surgery patients at 1 and 2 years, respectively, were included for analysis. Preoperative opioid use, opioid use at 90 days postoperatively, and poor functional status were the strongest predictors of long-term opioid use. Among all patients, preoperative opioid use most strongly predicted long-term use at 1 and 2 years for lumbar and cervical patients. Among opioid-naïve patients (preoperative nonusers), opioid use at 90 days postoperatively strongly predicted continued use at 1 and 2 years in both lumbar and cervical patients. The inability to achieve a minimal clinically important difference in Patient-Reported Outcomes Measurement Information System physical function was also associated with opioid use at 1-year and 2-year follow-up in lumbar and cervical patients. CONCLUSION:Preoperative opioid use, opioid use at 90 days postoperatively, and failure to reach minimal clinically important difference of Patient-Reported Outcomes Measurement Information System Physical Function were the strongest predictors of long-term opioid use after elective lumbar and cervical spine surgeries.

OBJECTIVE:Patients undergoing anterior/posterior lumbar fusion surgery can undergo either a single-stage or multistage operation, depending on surgeon preference. The goal of this study was to assess different patient outcomes between single-stage and multistage lumbar fusion procedures in a multicenter setting. METHODS:The Michigan Spine Surgery Improvement Collaborative database was queried for anterior/posterior lumbar fusion surgeries between July 2018 and January 2022. Patients who underwent either single-stage or multistage procedures were included. For multistage procedures, the first surgery included both anterior lumbar interbody fusions and lateral lumbar interbody fusions. Primary outcomes included postoperative complications and improvement in patient-reported outcomes: Patient-Reported Outcomes Measurement Information System Physical Function, EQ-5D, and satisfaction. The two cohorts were propensity score matched, while Poisson generalized estimating equation models were used for multivariate analyses. RESULTS:After one-to-one propensity score matching, 355 patients were identified in the single-stage and multistage cohorts. Single-stage procedures were associated with a lower risk of complications (p = 0.024), fewer emergency department visits (p = 0.029), and higher patient satisfaction after 1 year (p = 0.026) and 2 years (p = 0.007), compared with multistage procedures. After adjusting for baseline patient and operative characteristics, patients undergoing multistage procedures had a higher risk of complications (relative risk [RR] 1.17, 95% CI 1.02-1.34; p = 0.026), were less likely to be satisfied after 1 year (RR 0.83, 95% CI 0.74-0.93; p < 0.001), and were less likely to experience improvement in back pain after 90 days (RR 0.86, 95% CI 0.75-0.99; p = 0.039) and 2 years (RR 0.76, 95% CI 0.60-0.96; p = 0.023). CONCLUSIONS:The authors observed that patients who undergo lumbar fusion surgery using a multistage approach have higher postoperative complication rates and are less likely to report satisfaction compared with a matched, single-stage procedure cohort.

OBJECTIVE Patient-perceived functional improvement is a core metric in lumbar surgery for degenerative disease. It is important to identify both modifiable and nonmodifiable risk factors that can be evaluated and possibly optimized prior to elective surgery. This case -control study was designed to study risk factors for not achieving the minimal clinically important difference (MCID) in Patient-Reported Outcomes Measurement Information System Function 4 -item Short Form (PROMIS PF) score. METHODS The authors queried the Michigan Spine Surgery Improvement Collaborative database to identify patients who underwent elective lumbar surgical procedures with PROMIS PF scores. Cases were divided into two cohorts based on whether patients achieved MCID at 90 days and 1 year after surgery. Patient characteristics and operative details were analyzed as potential risk factors. RESULTS The authors captured 10,922 patients for 90 -day follow-up and 4453 patients (40.8%) did not reach MCID. At the 1-year follow-up period, 7780 patients were identified and 2941 patients (37.8%) did not achieve MCID. The significant demographic characteristic-adjusted relative risks (RRs) for both groups (RR 90 day, RR 1 year) included the following: symptom duration > 1 year (1.34, 1.41); previous spine surgery (1.25, 1.30); African American descent (1.25, 1.20); chronic opiate use (1.23, 1.25); and less than high school education (1.20, 1.34). Independent ambulatory status (0.83, 0.88) and private insurance (0.91, 0.85) were associated with higher likelihood of reaching MCID at 90 days and 1 year, respectively. CONCLUSIONS Several key unique demographic risk factors were identified in this cohort study that precluded optimal postoperative functional outcomes after elective lumbar spine surgery. With this information, appropriate preoperative counseling can be administered to assist in shaping patient expectations.

BACKGROUND CONTEXT Serum albumin, a marker of nutritional status, has been identified as a significant predictor of postoperative outcomes across various surgical fields. Patients with serum albumin levels < 3.5, indicative of poor nutritional status, are traditionally nutritionally optimized prior to undergoing operative intervention. However, there is a paucity of data regarding the outcomes of patients with albumin levels ranging between 3.5 to 4. PURPOSE This study aims to determine if there is an association between albumin levels between 3.5 and 4 g/dL and postoperative outcomes in cervical spine surgery, and to determine if these patients may benefit from preoperative optimization. STUDY DESIGN/SETTING N/A PATIENT SAMPLE N/A OUTCOME MEASURES N/A METHODS A Michigan Spine Surgery Improvement Collaborative (MSSIC) database search was performed for cervical spine fusion surgeries between January 2020 and December 2022. 6,826 patients were analyzed retrospectively. Patients were grouped by preoperative serum albumin level: < 3.5 g/dL, 3.5–3.7 g/dL, 3.8–4 g/dL, and >4 g/dL. Measured postoperative outcomes included urinary retention, readmission within 30 and 90 days, surgical site infection (SSI), return to the operating room, dysphagia, and length of stay (LOS) ≥ 4 days. RESULTS A total of 6,826 cervical fusion cases were included in the analysis. Multivariate analysis used cases with albumin >4 g/dL as the reference group. Urinary retention rates among albumin levels did not vary significantly from the reference group. Albumin < 3.5 g/dL was associated with increased readmission at 90 days (incidence rate ratio 1.72, CI [1.06-2.77], p=0.027), increased LOS > 4 days (IRR 1.39, CI [1.29-1.51], p< 0.001) and higher levels of dysphagia (IRR 1.78, CI [1.24-2.56], p = 0.002). Albumin 3.5-3.7 g/dL was associated with increased readmission at 90 days (IRR 1.92, CI [1.47-2.52], p< 0.001), increased readmission at 30 days (IRR 1.97, CI [1.28-3.03], p=0.002), and increased LOS > 4 days (IRR 1.31, CI [1.23-1.40], p< 0.001). Albumin 3.8-4 g/dL was associated with increased readmission at 90 days (IRR 1.35, CI [1.13-1.61], p=0.001), increased readmission at 30 days (IRR 1.40, CI [1.08-1.83], p=0.012), and increased LOS > 4 days (IRR 1.14, CI [1.09-1.20], p< 0.001). CONCLUSIONS Albumin levels < 3.5 g/dL is the traditional cutoff for preoperative nutritional optimization. Albumin 3.5-3.7 g/dL and 3.8-4 g/dL had an increased risk of readmission at 90 days and increased LOS similar to albumin < 3.5 g/dL. This study suggests a higher albumin cutoff than 3.5 g/dL may be beneficial in limiting poor postoperative outcomes in cervical spine surgery. FDA Device/Drug Status This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT Serum albumin has been identified as a significant predictor of postoperative complications. Traditionally, patients with serum albumin levels < 3.5 g/dL are considered malnourished and are nutritionally optimized prior to surgery. However, there is a paucity of data regarding the outcomes of patients with albumin levels greater than 3.5 g/dL but less than 4.0 g/dL. PURPOSE This study aims to examine whether patients with albumin levels between 3.5-4g/dL have an increased risk of complications and could benefit from nutritional optimization prior to lumbar spine surgery. STUDY DESIGN/SETTING N/A PATIENT SAMPLE N/A OUTCOME MEASURES N/A METHODS The Michigan Spine Surgery Improvement Collaborative (MSSIC) database contained 15,629 lumbar fusion surgeries between January, 2020 and December, 2022. Patients were grouped based on serum albumin levels: < 3.5g/dL, 3.5-3.7g/dL, 3.8-4g/dL, and >4g/dL. Outcomes measured included urinary retention, surgical site infection (SSI), wound dehiscence, readmission within 30 and 90 days, return to OR, and length of stay (LOS) ≥4 days. Patients with albumin levels >4g/dL comprised the reference group. RESULTS This study included a total of 15,393 lumbar cases. Albumin of < 3.5 g/dL was associated with an increased risk of urinary retention (Incidence Rate Ratio 1.40, CI [1.08-1.83], p=0.012), Surgical Site Infection (2.35 [1.71-3.23], p< 0.001), readmission at 30 days (1.87 [1.49-2.34], p< 0.001) and 90 days (1.95 [1.58-2.40], p< 0.001), return to OR (2.13 [1.65-2.75], p< 0.001), and LOS ≥4 days (1.32 [1.21-1.44], p< 0.001). Albumin of 3.5– 3.7 g/dL was associated with increased risk of readmission at 30 days (1.21 [1.001-1.45], p=0.048) and 90 days (1.28 [1.08-1.52], p=0.005), and LOS ≥4 days (1.22 [1.16-1.29], p< 0.001). Albumin of 3.8–4.0 g/dL was associated with an increased risk of LOS ≥4 days (1.08 [1.04-1.11], p< 0.001). CONCLUSIONS Serum albumin of < 3.5 g/dL was strongly associated with increased complications and increased return to OR, length of stay, and 30- and 90-day readmissions in elective lumbar spine procedures. Levels of 3.5-3.7 g/dL had increased risk of readmission and LOS, whereas levels of 3.8-4.0 g/dL did not show increased risk. These findings suggest that a goal albumin of >3.7 g/dL may improve postoperative outcomes in elective lumbar spine surgery. FDA Device/Drug Status This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND AND OBJECTIVES: Diabetes mellitus is associated with increased risk of postoperative adverse outcomes. Previous studies have emphasized the role of glycemic control in postoperative complications. This study aims to ascertain whether controlling hemoglobin A1c (HbA1c) lower than 8% preoperatively results in meaningful risk reduction or improved outcomes. METHODS: We used patient-level data from the Michigan Spine Surgery Improvement Collaborative registry, focusing on patients who underwent elective lumbar spine surgery between 2018 and 2021. The primary outcomes were length of stay and the occurrence of postoperative adverse events. Secondary outcomes included patient satisfaction, achievement of a minimum clinically important difference (MCID) of Patient-Reported Outcomes Measurement Information System-Physical Function, the EuroQol-5D and NRS of leg and back pain, and return to work. RESULTS: A total of 11 348 patients were included in this analysis. Patients with HbA1c above the thresholds before surgery had significantly higher risks of urinary retention for all 3 possible threshold values (incidence rate ratio [IRR] = 1.30, P = .015; IRR = 1.35, P = .001; IRR = 1.25, P = .011 for the HbA1c cutoffs of 8%, 7.5%, and 7%, respectively). They also had longer hospital stay (IRR = 1.04, P = .002; IRR = 1.03, P = .001; IRR = 1.03, P < .001 for the HbA1c cutoffs of 8%, 7.5%, and 7%, respectively) and had higher risks of developing any complication with HbA1c cutoff of 7.5% (IRR = 1.09, P = .010) and 7% (IRR = 1.12, P = .001). Diabetics with preoperative HbA1c above all 3 thresholds were less likely to achieve Patient-Reported Outcomes Measurement Information System MCID at the 90-day follow-up (IRR = .81, P < .001; IRR = .86, P < .001; IRR = .90, P = .007 for the HbA1c cutoffs of 8%, 7.5%, and 7%, respectively) and less likely to achieve EuroQol-5D MCID at the 2-year follow-up (IRR = .87, P = .027; IRR = .84, P = .005 for the HbA1c cutoffs of 7.5% and 7%, respectively). CONCLUSION: Our study suggests that reducing HbA1c below 8% may have diminishing returns regarding reducing complications after spine surgery.

INTRODUCTION: Long-term opioid use after elective lumbar spine surgery is a significant concern, given the current opioid epidemic and its impact on public health. Identifying risk factors for long-term opioid use after spine surgery is crucial in developing effective interventions to reduce the incidence of opioid dependence in this patient population. METHODS: A retrospective analysis of patient data was conducted using the Michigan Spine Surgery Improvement Collaborative (MSSIC) registry. Patients who underwent elective lumbar spine surgery between March 2018, and September 2021, were included, resulting in a total of 3599 patients at one year and 966 patients at two years follow-up. Poisson generalized estimating equation models were used for multivariate analyses. RESULTS: A total of 493 (13.7%) and 137 (14.2%) patients were still using opiates at one-year and two-years post-surgery respectively. Discharge morphine milligram equivalents (MMEs), baseline PROMIS PF functional scores, baseline pain scores, age, gender, education level, pre-operative opioid use, and not achieving the minimal clinically important difference (MCID) in PROMIS PF scores at follow-up were significantly associated with long-term opioid use. Specifically, pre-operative opioid use had the strongest association with opioid use at one year (IRR = 2.83, CI: 2.40-3.34, p < 0.001) and two years (IRR = 3.79, CI: 2.53-5.68, p < 0.001). Additionally, not achieving MCID in PROMIS scores at follow-up was strongly associated (IRR = 2.00, CI: 1.72-2.32, p < 0.001 and IRR = 2.18, CI: 1.64-2.91, p < 0.001) with opioid use at both time points (1-year and 2-year respectively). CONCLUSIONS: Pre-operative opioid use and not achieving MCID in PROMIS scores at follow-up were the strongest predictors of long-term opioid use after elective lumbar spine surgery. Identifying these risk factors can help clinicians target interventions to reduce opioid use in at-risk patients and improve postoperative outcomes.

INTRODUCTION: Electrical stimulation of the vagus nerve activates the inflammatory reflex to inhibit cytokines and decrease clinical signs and symptoms of chronic inflammatory disease such as rheumatoid arthritis (RA) (Genovese et al. Lancet Rheum 2020). METHODS: The device system consists of two implanted components: a miniature integrated pulse generator and a silicon sleeve positioning device that holds the generator in apposition to the nerve. There are two external components: a wireless charger and an iPad application for programming the pulse generator. Subjects were randomly assigned (1:1) after device implantation on the left vagus nerve to receive active or sham stimulation. The risks of the surgical procedure, device, and stimulation were blindly assessed after 12 weeks of stimulation therapy in the first 60 subjects enrolled in the study. RESULTS: All implant procedures were completed without intraoperative complications, infections, or surgical revisions. No unanticipated adverse events (AEs) were reported during the perioperative period and at the end of 12 weeks of follow-up. No serious AEs related to the device, stimulation, or explant procedures were reported. Vocal cord paresis and prolonged hoarseness were reported in two subjects. The former resolved following vocal cord augmentation with injectable filler; the latter is ongoing and improving with speech therapy. CONCLUSIONS: Initial results demonstrated that implantation and programming of the novel neuroimmune modulation device were safe, and the surgical procedure and device were well tolerated.

OBJECTIVE Emergency department visits 90 days after elective spinal surgery are relatively common, with rates ranging from 9% to 29%. Emergency visits are very costly, so their reduction is of importance. This study's objective was to evaluate the reasons for emergency department visits and determine potentially modifiable risk factors. METHODS This study retrospectively reviewed data queried from the Michigan Spine Surgery Improvement Collaborative (MSSIC) registry from July 2020 to November 2021. MSSIC is a multicenter (28 -hospital) registry of patients undergoing cervical and lumbar degenerative spinal surgery. Adult patients treated for elective cervical and/or lumbar spine surgery for degenerative pathology (spondylosis, intervertebral disc disease, low-grade spondylolisthesis) were included. Emergency department visits within 90 days of surgery (outcome measure) were analyzed utilizing univariate and multivariate regression analyses. RESULTS Of 16,224 patients, 2024 (12.5%) presented to the emergency department during the study period, most commonly for pain related to spinal surgery (31.5%), abdominal problems (15.8%), and pain unrelated to the spinal surgery (12.8%). On multivariate analysis, age (per 5 -year increase) (relative risk [RR] 0.94, 95% CI 0.92-0.95), college education (RR 0.82, 95% CI 0.69-0.96), private insurance (RR 0.79, 95% CI 0.70-0.89), and preoperative ambulation status (RR 0.88, 95% CI 0.79-0.97) were associated with decreased emergency visits. Conversely, Black race (RR 1.30, 95% CI 1.13-1.51), current diabetes (RR 1.13, 95% CI 1.01-1.26), history of deep venous thromboembolism (RR 1.28, 95% CI 1.16-1.43), history of depression (RR 1.13, 95% CI 1.03-1.25), history of anxiety (RR 1.32, 95% CI 1.19-1.46), history of osteoporosis (RR 1.21, 95% CI 1.09-1.34), history of chronic obstructive pulmonary disease (RR 1.19, 95% CI 1.06-1.34), American Society of Anesthesiologists class > II (RR 1.18, 95% CI 1.08-1.29), and length of stay > 3 days (RR 1.29, 95% CI 1.16-1.44) were associated with increased emergency visits. CONCLUSIONS The most common reasons for emergency department visits were surgical pain, abdominal dysfunction, and pain unrelated to index spinal surgery. Increased focus on postoperative pain management and bowel regimen can potentially reduce emergency visits. The risks of diabetes, history of osteoporosis, depression, and anxiety are areas for additional preoperative screening.

Objective: The multicenter, randomized, double-blinded, active-sham controlled trial (high-freQUEncy nerve block for poST amputation pain [QUEST]) was conducted to show the safety and efficacy of a novel, peripherally placed high-frequency nerve block (HFNB) system in treating chronic postamputation pain (PAP) in patients with lower limb amputations. The primary outcomes from QUEST were reported previously. This study presents the long-term, single-cross-over, secondary outcomes of on-demand HFNB treatment for chronic PAP. Materials and Methods: After the three-month randomized period, subjects in the active-sham group were crossed over to receive therapy for 12 months. Subjects self-administered HFNB therapy as needed and reported their pain (numerical rating scale [NRS]; range, 1-10) before and 30 and 120 minutes after each treatment. Pain medication use was reported throughout the study. Pain-days per week and quality of life (QOL) were assessed using the Brief Pain Inventory (BPI). Adverse events (AEs) were recorded for all subjects implanted for 12 months. Results: Of 180 subjects implanted in QUEST, 164 (91%) were included in the cross-over period, and 146 (82%) completed follow-up. By month 12, average NRS pain in the combined cohort was reduced by 2.3 +/- 2.2 points (95% CI, 1.7-2.8; p < 0.0001) 30 minutes after treatment and 2.9 +/- 2.4 points (95% CI, 2.2-3.6; p < 0.0001) 120 minutes after treatment. Mean pain-days per week were significantly reduced (-3.5 +/- 2.7 days; p < 0.001), and subject daily opioid use was reduced by 6.7 +/- 29.0 morphine equivalent dose from baseline to month 12 (p = 0.013). Mean BPI-interference scores (QOL) improved by 2.7 +/- 2.7 points from baseline (p < 0.001). The incidence of nonserious AEs and serious AEs was 72% (130/180) and 42% (76/180), respectively; serious device-related AEs occurred in 15 of 180 subjects (8%). Conclusion: Overall, HFNB delivered directly to the damaged peripheral nerve provided sustained, on-demand relief of acute PAP exacerbations, reduced opioid utilization, and improved QOL for patients with lower limb amputations with chronic PAP.

OBJECTIVE Patients with serum albumin levels < 3.5 g/dL are considered malnourished, but there is a paucity of data regarding the outcomes of patients with albumin levels > 3.5 g/dL. The objective of this study was to evaluate the effect of albumin on postoperative outcome in patients undergoing elective cervical and lumbar spine procedures. METHODS The Michigan Spine Surgery Improvement Collaborative database was queried for lumbar and cervical fusion surgeries between January 2020 and December 2022. Patients were grouped by preoperative serum albumin levels: < 3.5 g/dL, 3.5–3.7 g/dL, 3.8–4.0 g/dL, and > 4.0 g/dL. Primary outcomes included urinary retention, ileus, dysphagia, surgical site infection (SSI), readmission within 30 and 90 days, return to the operating room, and length of stay (LOS) ≥ 4 days. Multivariate analysis was conducted to adjust for potential confounders. RESULTS This study included 15,629 lumbar cases and 6889 cervical cases. Within the lumbar cohort, an albumin level of 3.5–3.7 g/dL was associated with an increased risk of readmission at 30 days (p = 0.048) and 90 days (p = 0.005) and an LOS ≥ 4 days (p < 0.001). An albumin level of 3.8–4.0 g/dL was associated with an increased risk of an LOS ≥ 4 days (p < 0.001). Within the cervical cohort, an albumin level of 3.5–3.7 g/dL was associated with an increased risk of SSI (p = 0.023), readmission at 30 days (p < 0.002) and 90 days (p < 0.001), return to the operating room (p = 0.002), and an LOS ≥ 4 days (p < 0.001). An albumin level of 3.8–4.0 g/dL was associated with an increased risk of readmission at 30 days (p = 0.012) and 90 days (p = 0.001) and an LOS ≥ 4 days (p < 0.001). CONCLUSIONS This study maintains that patients with hypoalbunemia undergoing spine surgery are at risk for postoperative adverse events. However, there also exist significant associations between borderline serum albumin levels of 3.5–4.0 g/dL and increased risk of postoperative adverse events.