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Study Design: Retrospective review of prospectively collected data.Objective: To investigate if zero profile devices offer an advantage over traditional plate/cage constructs for dysphagia rates in single level anterior cervical discectomy and fusion (ACDF).Summary Of Background Data: Dysphagia rates following ACDF have been reported to be as high as 83%, most cases are self-limiting, but chronic dysphagia can continue in up to 35% of patients. Zero profile devices were developed to limit dysphagia, and other plate specific complications, however the literature is currently divided regarding their efficacy.Methods: Dysphagia was assessed by swallowing quality of life (SWAL-QOL) scores preoperatively, at 6 weeks and 12 weeks. Patient reported outcome measures (PROMs) including visual analog scale (VAS) and Neck Disability Index (NDI) were collected preoperatively, at 6 weeks and at 6 months. Univariate and multivariate regression analysis was conducted with SWAL-QOL score as the dependent variable.Results: Sixty-four patients were included, 41 received a zero profile device, and 23 received plate-graft construct. Both groups were similar regarding patient demographics, except operative time, with the zero-profile group having a shorter procedure time than the cage-plate group (44.88 ± 6.54 vs. 54.43 ± 14.71 min, P = 0.001). At all timepoints dysphagia rates were similar between the groups. Regression analysis confirmed preoperative SWAL-QOL and operative time were the only significant variables. PROMs were also similar between groups at all time points, except VAS neck at 6 months, which was lower in the plate-graft group (1.05 ± 1.48 vs. 3.43 ± 3.21, P = 0.007).Conclusion: Operative time and preoperative SWAL-QOL scores are predictive of dysphagia in single level ACDF. Zero profile devices had a significantly shorter operative time, and may provide a benefit in dysphagia rates in this regard.Level Of Evidence: 3. [ABSTRACT FROM AUTHOR]

Over the last decades, spine surgery has advanced from conventional fluoroscopy to navigation and now to robotics. Although numerous studies have demonstrated the benefits of navigation and robotics, literature on the comparison of the two modalities is scarce. To compare robotics and navigation for minimally invasive lumbar fusion in terms of operative variables and clinical outcomes. Retrospective cohort. Consecutive patients who underwent elective single-level minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) by a single surgeon using robotics (ExcelsiusGPS, Globus Medical Inc, Audubon, PA) or navigation (Stryker SpineMask, Stryker Corp., Kalamazoo, MI) and had a minimum of 1-year followup. 1) operative time 2) radiation exposure 3) pedicle screw accuracy 4) pedicle screw size 5) screw-related complications and 6) patient-reported outcomes (PROs) at the preoperative and early (6 months) postoperative timepoints (Oswestry Disability Index, ODI; Visual Analog Scale (VAS) back and leg; 12-Item Short Form Survey Physical Component Score, SF-12 PCS). Pedicle screw accuracy was assessed according to the CT-based Gertzbein-Robbins Scale (grade A to E) and Simplified Screw Grading System (good, acceptable, poor). The robotics and navigation cohorts were compared using Chi square test and Fisher's exact test for categorical variables, and student t-test and Mann Whitney u-test for normally and non-normally distributed continuous variables respectively. A total of 183 patients (81 robotics, 102 navigation) were included. There were no significant differences between the two cohorts in terms of age, gender, BMI, Charlson Comorbidity Index, ASA class, number of primary/revision surgeries and level of surgery. Total fluoroscopy time, total radiation dose, and % of radiation for surgical procedure were significantly less with robotics compared to navigation (20 vs. 25s, p < 0.001; 38 vs. 42mGy, p=0.005; 58 vs. 65%, p=0.021). Although time for setup and image capture was significantly less with robotics (22 vs. 25 min, p < 0.001) and operative time was significantly greater with robotics (103 vs. 93 min, p < 0.001), there was no significant difference in the total operating room (OR) time (145 vs. 141 min, p=0.25). Although pedicle screw accuracy with robotics was higher compared to navigation (96.6 vs. 93.3%), there was no significant difference between the two groups in terms of proximal level violation (2% robotics vs. 1.4% navigation), poor screw placement rates (4% robotics, 4.2% navigation), and return to the OR for screw revision (1 case with robotics vs. 0 with navigation). The robotics group had significantly greater screw diameter (7.4 vs. 6.5 mm, p < 0.0001) and length (47.5 mm vs. 45 mm, p < 0.0001). Although there were significant improvements in all PROs in both cohorts at both the early and late postoperative timepoints compared to the preoperative values, there was no significant difference in the magnitude of improvement in any PRO at any timepoint between the two cohorts. Radiation exposure was significantly less with robotics compared to navigation. Although the use of robotics led to a higher pedicle screw accuracy and screws with greater diameter and length, it did not translate into a significant difference in clinical outcomes compared to navigation. This abstract does not discuss or include any applicable devices or drugs. [ABSTRACT FROM AUTHOR]

Assessing postoperative system inefficiencies and implementing process-improvement measures are vital to increase the feasibility of ambulatory lumbar fusion. Primary objective was to identify patients who would have been eligible for same-day discharge following minimally invasive elective lumbar fusion and then analyze the limiting factors in their postoperative pathway that led to a delay in discharge. Secondary objective was to assess if patient characteristics and operative variables had an impact on postoperative parameters influencing discharge. Retrospective review of prospectively collected data. Consecutive patients undergoing primary single-level minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) for degenerative conditions of the lumbar spine who would have been eligible for ambulatory lumbar fusion. Postoperative in-hospital variables including 1) length of stay (LOS), 2) time in post-anesthesia recovery unit (PACU), 3) alertness check, neurological exam and pain scores at 3 hours and 6 hours, 4) type of analgesia, 5) time to physical therapy (PT) visit and clearance, 6) reasons for PT non-clearance, 7) time to per-oral (PO) intake, 8) time to voiding, 9) time to readiness for discharge, and 10) complications. Eligibility criteria for ambulatory lumbar fusion and discharge criteria were determined a priori based on a review of the literature and the authors' experience. Preoperative, surgical and postoperative in-hospital data were analyzed. Time taken to meet each discharge criterion was calculated. Time of discharge readiness was taken as the point when the patient had fulfilled all the criteria. The percentage of patients meeting each discharge criterion at 3 hours and 6 hours post-surgery was calculated. Correlation and regression analyses were performed to study the effect of postoperative variables on LOS. Multiple linear and logistic regression analyses were performed to study the effect of preoperative and operative variables on postoperative parameters influencing discharge. A total of 71 patients were included of which only 4% were discharged on the same day. Most (69%) patients were discharged on postoperative day one. PT clearance, voiding and PO intake were the last-met discharge criterion in 93%, 6% and 1% of patients respectively. A total of 66% of patients did not get a PT evaluation on the day of surgery. Intravenous (IV) opioids for pain control (average of 2 doses) were required for 76% of patients. Less than 60% of patients had adequate pain control at 3 hours and 6 hours after the surgery. Orthostatic intolerance was seen in 27% of patients. The median postoperative LOS was 26.9 hours, time in PACU was 4.2 hours, time to PO intake was 6.5 hours, time to first void was 6.3 hours, time to first PT visit was 17.7 hours, time to PT clearance was 21.8 hours, and time to discharge readiness was 21.9 hours. Regression analyses showed that postoperative variables (time to PT clearance, time to PO intake, time to voiding, time in PACU, and pain score at 3 hours) had a significant effect on LOS. There was no effect of preoperative and operative variables on postoperative parameters influencing discharge. Unavailability of PT, orthostatic intolerance, inadequate pain control, prolonged PACU stay, and long feeding and voiding times were identified as modifiable factors preventing same-day discharge in patients eligible for ambulatory lumbar fusion. This abstract does not discuss or include any applicable devices or drugs. [ABSTRACT FROM AUTHOR]

Purpose: To determine the optimal level for the measurement of psoas cross-sectional area and examine the correlation with short-term functional outcomes of posterior lumbar surgery. Methods: Patients who underwent minimally invasive posterior lumbar surgery were included in this study. The cross-sectional area of psoas muscle was measured at each intervertebral level on T2-weighted axial images of preoperative MRI. Normalized total psoas area (NTPA) (mm2/m2) was calculated as total psoas area normalized to patient height. Intraclass Correlation Coefficient (ICC) was calculated for the analysis of inter-rater reliability. Patient reported outcome measures including Oswestry disability index (ODI), visual analog scale (VAS), short form health survey (SF-12) and patient-reported outcomes measurement information system were collected. A multivariate analysis was performed to elucidate independent predictors associated with failure to reach minimal clinically important difference (MCID) in each functional outcome at 6 months. Results: The total of 212 patients were included in this study. ICC was highest at L3/4 [0.992 (95% CI: 0.987–0.994)] compared to the other levels [L1/2 0.983 (0.973–0.989), L2/3 0.991 (0.986–0.994), L4/5 0.928 (0.893–0.952)]. Postoperative PROMs were significantly worse in patients with low NTPA. Low NTPA was an independent predictor of failure to reach MCID in ODI (OR = 2.68; 95% CI: 1.26–5.67; p = 0.010) and VAS leg (OR = 2.43; 95% CI: 1.13–5.20; p = 0.022). Conclusion: Decreased psoas cross-sectional area on preoperative MRI correlated with functional outcomes after posterior lumbar surgery. NTPA was highly reliable, especially at L3/4. [ABSTRACT FROM AUTHOR]

Despite the role of vitamin D3 endocrine system in prevention of mammary gland transformation in animal models, use of 1,25(OH)2D3 in clinical settings is precluded due to its toxicity in vivo. Therefore much effort has been placed in developing relatively non-toxic vitamin D analogs. Recently, with the discovery of the expression of 25-hydroxy vitamin D3 1α-hydroxylase (CYP27B1) in multiple extrarenal organs, the functional role of prohormone, 25-hydroxyvitamin D3 [25(OH)D3], has been redefined. Since 25(OH)D3 does not cause hypercalcemia and maintains relative high concentration in serum, it is possible that the prohormone can be converted to active hormone in mammary epithelial cells to provide chemopreventive effects. In the present study, we evaluated its functional significance using mouse mammary organ culture (MMOC) system. We first showed that 25(OH)D3 1α-hydroxylase is extensively expressed in mammary ductal epithelial cells at both protein and mRNA levels, which is a prerequisite for 25(OH)D3 to function in an autocrine/paracrine manner. However, we also observed that clotrimazol (1α-hydroxylase inhibitor) enhanced 25(OH)D3 -induced CYP24 expression in breast cancer cells. In mammary glands derived from 1α-hydroxylase knockout mice, 25(OH)D3 treatment in organ culture significantly induced CYP24 expression, indicating a potential direct effect of 25(OH)D3. In MMOC, 100–250 nM 25(OH)D3 suppressed both ovarian hormone-dependent and -independent mammary precancerous lesions (induced by DMBA) by more than 50%, while the active hormone 1,25(OH)2D3 (positive control) at 100 nM suppressed alveolar lesions by more than 80%. The inactive vitamin D3 (negative control) at 100 nM suppressed alveolar lesions by only 20% ( P > 0.05). We found that 25(OH)D3 inhibits DMBA-induced mammary alveolar lesions (MAL) in a stage-specific manner: 25(OH)D3 mainly inhibits the promotion stage of lesion formation. We conclude that 25(OH)D3 could serve as a non-toxic natural chemopreventive agent for further development for breast cancer prevention. [ABSTRACT FROM AUTHOR]

Visual impairment refers to any kind of vision loss ranging from complete blindness to the partial loss of vision. Studies have shown that social understanding can be severely affected due to visual impairment. This paper tries to address this gap by presenting a socially assistive application for the visually impaired. The study develops the application using deep learning and app development technologies. A transfer learning Facial Expression Recognition (FER) model is embedded in a mobile application to recognize facial expressions. Guided by haptic feedback, the application developed in this study helps users perceive expressions of the person(s) they are interacting with. The practical value of this work lies in assisting and enhancing the social understanding of visually impaired individuals. On the other hand, the research value of the current study lies in the development of a novel application which is faster, lighter, implementable on low-end devices, and achieves better accuracy, on par with state-of-the-art models. [ABSTRACT FROM AUTHOR]

Study Design. Retrospective review of prospectively collected data. Objective. To identify the risk factors associated with failure to respond to erector spinae plane (ESP) block following minimally invasive transforaminal lumbar interbody fusion (MI-TLIF). Summary of Background Data. ESP block is an emerging opioid-sparing regional anesthetic that has been shown to reduce immediate postoperative pain and opioid demand following MI-TLIF--however, not all patients who receive ESP blocks perioperatively experience a reduction in immediate postoperative pain. Methods. This was a retrospective review of consecutive patients undergoing one-level MI-TLIF who received ESP blocks by a single anesthesiologist perioperatively at a single institution. ESP blocks were administered in the OR following induction. Failure to respond to ESP block was defined as patients with a first numerical rating scale (NRS) score postsurgery of >5.7 (mean immediate postoperative NRS score of control cohort undergoing MI TLIF without ESP block). Multivariable logistic regressions were performed to identify predictors for failure to respond to ESP block. Results. A total of 134 patients were included (mean age 60.6 yr, 43.3% females). The median and interquartile range (IQR) first pain score postsurgery was 2.5 (0.0-7.5). Forty-nine (36.6%) patients failed to respond to ESP block. In the multivariable regression analysis, several independent predictors for failure to respond to ESP block following MI TLIF were identified: female sex (OR 2.33, 95% CI 1.04-5.98, P= 0.040), preoperative opioid use (OR 2.75, 95% CI 1.03-7.30, P= 0.043), anxiety requiring medication (OR 3.83, 95% CI 1.27-11.49, P= 0.017), and hyperlipidemia (OR 3.15, 95% CI 1.31-7.55, P= 0.010). Conclusions. Our study identified several predictors for failure to respond to ESP block following MI TLIF, including female gender, preoperative opioid pain medication use, anxiety, and hyperlipidemia. These findings may help inform the approach to counseling patients on perioperative outcomes and pain expectations following MI-TLIF with ESP block. Level of Evidence. 3 [ABSTRACT FROM AUTHOR]

Study Design: Single-center, multisurgeon, retrospective review.Objective: To evaluate the timing of return to commonly performed activities following minimally invasive spine surgery. Identify preoperative factors associated with these outcomes.Summary Of Background Data: Studies have reported return to activities with open techniques, but the precise timing of when patients return to these activities after minimally invasive surgery remains uncertain.Materials and Methods: Patients who underwent either minimally invasive lumbar laminectomy (MI-L) or minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) were included. Patient-reported outcome measures, return to drive, return to work, and discontinuation of opioids data were reviewed. Regression was conducted to identify factors associated with return to driving by 15 days, return to work by 30 days, and for discontinuing opioids by 15 days. A composite group analysis was also performed for patients who returned to all three activities by 30 days.Results: In total, 123 MI-L patients and 107 MI-TLIF patients were included. Overall, 88.8% of MI-L patients and 96.4% of MI-TLIF patients returned to driving in 11 and 18.5 days, respectively. In all, 91.9% of MI-L patients and 85.7% of MI-TLIF patients returned to work in 14 and 25 days. In all, 88.7% of MI-L patients and 92.6% of MI-TLIF patients discontinued opioids in a median of seven and 11 days. Overall, 96.2% of MI-L patients and 100% of MI-TLIF patients returned to all three activities, with a median of 27 and 31 days, respectively. Male sex [odds ratio (OR)=3.57] and preoperative 12-Item Short Form Physical Component Score (OR=1.08) are associated with return to driving by 15 days. Male sex (OR=3.23) and preoperative 12-Item Short Form Physical Component Score (OR=1.07) are associated with return to work by 30 days. Preoperative Visual Analog Scale back was associated with decreased odds of discontinuing opioids by 15 days (OR=0.84).Conclusion: Most patients return to activity following MI-L and MI-TLIF. These findings serve as an important compass for preoperative counseling. [ABSTRACT FROM AUTHOR]

Study Design.: Retrospective review of prospectively collected data. Objective.: To analyze temporal trends in improvement after minimally invasive transforaminal lumbar interbody fusion (MIS TLIF). Summary of Background Data.: Although several studies have shown that patients improve significantly after MIS TLIF, evidence regarding the temporal trends in improvement is still largely lacking. Methods.: Patients who underwent primary single-level MIS TLIF for degenerative conditions of the lumbar spine and had a minimum of 2-year follow-up were included. Outcome measures were: 1) patient reported outcome measures (PROMs) (Oswestry Disability Index, ODI; Visual Analog Scale, VAS back and leg; 12-Item Short Form Survey Physical Component Score, SF-12 PCS); 2) global rating change (GRC); 3) minimal clinically important difference (MCID); and 4) return to activities. Timepoints analyzed were preoperative, 2 weeks, 6 weeks, 3 months, 6 months, 1 year, and 2 years. Trends across these timepoints were plotted on graphs. Results.: 236 patients were included. VAS back and VAS leg were found to have statistically significant improvement compared to the previous timepoint up to 3 months after surgery. ODI and SF-12 PCS were found to have statistically significant improvement compared to the previous timepoint up to 6 months after surgery. Beyond these timepoints, there was no significant improvement in PROMs. 80% of patients reported feeling better compared to preoperative by 3 months. >50% of patients achieved MCID in all PROMs by 3 months. Most patients returned to driving, returned to work, and discontinued narcotics at an average of 21, 20, and 10 days, respectively. Conclusions.: Patients are expected to improve up to 6 months after MIS TLIF. Back pain and leg pain improve up to 3 months and disability and physical function improve up to 6 months. Beyond these timepoints, the trends in improvement tend to reach a plateau. 80% of patients feel better compared to preoperative by 3 months after surgery. [ABSTRACT FROM AUTHOR]

Background Context: Patients undergoing minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) frequently present with lower extremity neurologic symptoms with or without associated lower back pain. While symptomatic improvement of leg and back pain has been reported, the resolution of back pain when it is a predominant presenting symptom remains underreported following MI-TLIF.Purpose: The purpose of this study was to compare clinical outcomes at 1 year of patients undergoing MI-TLIF with lower extremity neurologic symptoms with and without a significant component of back pain.Study Design: A retrospective review of prospectively collected data from a single surgeon surgical database from 2017 to 2019 was performed.Patient Sample: Fifty one patients undergoing MI-TLIF.Outcome Measures: Self-reported measures included the Oswestry Disability Index (ODI), Visual analog scale back pain (VAS-back), and VAS leg pain (VAS-leg).Methods: Patients were divided into two groups: Leg Pain Predominant (patients reported greater than 50% leg pain upon presentation) and Back Pain Predominant (patients reported 50% or greater back pain). Multivariate analysis was performed to determine differences between groups based upon any significantly baseline characteristics.Results: Preoperative demographic and radiographic outcomes were similar between the two groups. Both groups demonstrated significant improvement in ODI, VAS-Back and VAS-leg at 1-year postoperatively. On multivariate analysis, there were differences in ODI at 1-year, 1-year back pain, and 1-year leg pain between groups with those who initially presented with leg pain having a lower ODI, VAS Back, and VAS leg. Patients who presented with predominantly leg pain were more likely to meet minimal clinically important difference (MCID) criteria for ODI and VAS-back compared to those with predominantly back pain.Conclusion: Following MI-TLIF, patients with lower extremity neurologic symptoms with and without a significant component of back pain have improvements in back pain, leg pain, and ODI regardless of their primary presenting pain complaint; however, patients who presented with predominantly leg pain were more likely to meet MCID criteria for improvement in their back pain and ODI score. [ABSTRACT FROM AUTHOR]

Case: A 47-year-old healthy man underwent cervical disc arthroplasty (CDA) for a C6 radiculopathy. Two-week radiographs showed a well-positioned implant. At the 6-week postoperative visit, the inferior portion of the implant had displaced ventrally, with C6 anterior vertebral body collapse. The next day, the implant was removed and converted to a C5/6 anterior cervical discectomy and fusion. Bone biopsy was unremarkable. Conclusions: This is the first reported case of early catastrophic failure of a well-positioned CDA in a healthy patient with good bone quality. Possible contributing mechanisms include hypermobility and anterior bone loss, factors previously associated with CDA. [ABSTRACT FROM AUTHOR]

Study design: Matched cohort comparison. Objective: To determine perioperative outcomes of erector spinae plane (ESP) block for minimally invasive transforaminal lumbar interbody fusion (MI-TLIF). Summary of background data: There is a paucity of data on the impact of lumbar ESP block on perioperative outcomes and its safety in MI-TLIF. Materials and methods: Patients who underwent 1-level MI-TLIF and received the ESP block (group E) were included. An age and sex-matched control group was selected from a historical cohort that received the standard-of-care (group NE). The primary outcome of this study was 24-hour opioid consumption in morphine milligram equivalents. Secondary outcomes were pain severity measured by a numeric rating scale, opioid-related side effects, and hospital length of stay. Outcomes were compared between the two groups. Results: Ninety-eight and 55 patients were included in the E and NE groups, respectively. There were no significant differences between the two cohorts in patient demographics. Group E had lower 24-hour postoperative opioid consumption (P = 0.117, not significant), reduced opioid consumption on a postoperative day (POD) 0 (P = 0.016), and lower first pain scores postsurgery (P < 0.001). Group E had lower intraoperative opioid requirements (P < 0.001), and significantly lower average numeric rating scale pain scores on POD 0 (P = 0.034). Group E reported fewer opioid-related side effects as compared with group NE, although this was not statistically significant. The average highest postoperative pain score within 3 hours postprocedurally was 6.9 and 7.7 in the E and NE cohorts, respectively (P = 0.029). The median length of stay was comparable between groups with the majority of patients in both groups being discharged on POD 1. Conclusions: In our retrospective matched cohort, ESP blocks resulted in reduced opioid consumption and decreased pain scores on POD 0 in patients undergoing MI-TLIF. [ABSTRACT FROM AUTHOR]

Study Design. Retrospective review of prospectively collected multisurgeon data. Objective. Examine the rate, clinical impact, and predictors of subsidence after expandable minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) cage. Summary of Background Data. Expandable cage technology has been adopted in MI-TLIF to reduce the risks and optimize outcomes. Although subsidence is of particular concern when using expandable technology as the force required to expand the cage can weaken the endplates, its rates, predictors, and outcomes lack evidence. Materials and Methods. Patients who underwent 1 or 2-level MI-TLIF using expandable cages for degenerative lumbar conditions and had a follow-up of >1 year were included. Preoperative and immediate, early, and late postoperative radiographs were reviewed. Subsidence was determined if the average anterior/posterior disc height decreased by >25% compared with the immediate postoperative value. Patient-reported outcomes were collected and analyzed for differences at the early (< 6 mo) and late (>6 mo) time points. Fusion was assessed by 1-year postoperative computed tomography. Results. One hundred forty-eight patients were included (mean age, 61 yr, 86% 1-level, 14% 2-level). Twenty-two (14.9%) demonstrated subsidence. Although statistically not significant, patients with subsidence were older, had lower bone mineral density, and had higher body mass index and comorbidity burden. Operative time was significantly higher (P = 0.02) and implant width was lower (P < 0.01) for subsided patients. Visual analog scale-leg was significantly lower for subsided patients compared with nonsubsided patients at a > 6 months time point. Long-term (>6 mo) patient-acceptable symptom state achievement rate was lower for subsided patients (53% vs. 77%), although statistically not significant (P = 0.065). No differences existed in complication, reoperation, or fusion rates. Conclusions. Of the patients, 14.9% experienced subsidence predicted by narrower implants. Although subsidence did not have a significant impact on most patient-reported outcome measures and complication, reoperation, or fusion rates, patients had lower visual analog scale-leg and patient-acceptable symptom state achievement rates at the > 6-month time point. [ABSTRACT FROM AUTHOR]

While cervical disc replacement (CDR) has been emerging as a reliable and efficacious treatment option for degenerative cervical spine pathology, not all patients undergoing CDR will achieve minimal clinically important difference (MCID) in patient-reported outcome measures (PROMs) postoperatively—risk factors for failure to achieve MCID in PROMs following CDR have not been established. To identify risk factors for failure to achieve MCID in Neck Disability Index (NDI, Visual Analog Scale (VAS) neck and arm following primary 1- or 2-level CDRs in the early and late postoperative periods. Retrospective review of prospectively collected data. Patients who had undergone primary 1- or 2-level CDR for the treatment of degenerative cervical pathology at a single institution with a minimum follow-up of 6 weeks between 2017 and 2022. Patient-reported outcomes: Neck disability index (NDI), Visual analog scale (VAS) neck and arm, MCID. Minimal clinically important difference achievement rates for NDI, VAS-Neck, and VAS-Arm within early (within 3 months) and late (6 months to 2 years) postoperative periods were assessed based on previously established thresholds. Multivariate logistic regressions were performed for each PROM and evaluation period, with failure to achieve MCID assigned as the outcome variable, to establish models to identify risk factors for failure to achieve MCID and predictors for achievement of MCID. Predictor variables included in the analyses featured demographics, comorbidities, diagnoses/symptoms, and perioperative characteristics. A total of 154 patients met the inclusion criteria. The majority of patients achieved MCID for NDI, VAS-Neck, and VAS-Arm for both early and late postoperative periods—79% achieved MCID for at least one of the PROMs in the early postoperative period, while 80% achieved MCID for at least one of the PROMs in the late postoperative period. Predominant neck pain was identified as a risk factor for failure to achieve MCID for NDI in the early (OR: 3.13 [1.10–8.87], p-value:.032) and late (OR: 5.01 [1.31–19.12], p-value:.018) postoperative periods, and VAS-Arm for the late postoperative period (OR: 36.63 [3.78–354.56], p-value:.002). Myelopathy was identified as a risk factor for failure to achieve MCID for VAS-Neck in the early postoperative period (OR: 3.40 [1.08–10.66], p-value:.036). Anxiety was identified as a risk factor for failure to achieve MCID for VAS-Neck in the late postoperative period (OR: 6.51 [1.91–22.18], p-value:.003). CDR at levels C5C7 was identified as a risk factor for failure to achieve MCID in NDI for the late postoperative period (OR: 9.74 [1.43–66.34], p-value:.020). Our study identified several risk factors for failure to achieve MCID in common PROMs following CDR including predominant neck pain, myelopathy, anxiety, and CDR at levels C5−C7. These findings may help inform the approach to counseling patients on outcomes of CDR as the evidence suggests that those with the risk factors above may not improve as reliably after CDR. [ABSTRACT FROM AUTHOR]

Study Design. Retrospective review of prospectively collected data. Objective. To analyze the learning curves of three spine surgeons for robotic minimally invasive transforaminal lumbar interbody fusion (MI-TLIF). Summary of Background Data. Although the learning curve for robotic MI-TLIF has been described, the current evidence is of low quality with most studies being single-surgeon series. Materials and Methods. Patients who underwent single-level MI-TLIF with three spine surgeons (years in practice: surgeon 1: 4, surgeon 2: 16, and surgeon 3: two) using a floor-mounted robot were included. Outcome measures were operative time, fluoroscopy time, intraoperative complications, screw revision, and patientreported outcome measures. Each surgeon's cases were divided into successive groups of 10 patients and compared for differences. Linear regression and cumulative sum (CuSum) analyses were performed to analyze the trend and learning curve, respectively. Results. A total of 187 patients were included (surgeon 1: 45, surgeon 2: 122, and surgeon 3: 20). For surgeon 1, CuSum analysis showed a learning curve of 21 cases with the attainment of mastery at case 31. Linear regression plots showed negative slopes for operative and fluoroscopy time. Both learning phase and postlearning phase groups showed significant improvement in patient-reported outcome measures. For surgeon 2, CuSum analysis demonstrated no discernible learning curve. There was no significant difference between successive patient groups in either operative time or fluoroscopy time. For surgeon 3, CuSum analysis demonstrated no discernible learning curve. Even though the difference between successive patient groups was not significant, cases 11 to 20 had an average operative time of 26 minutes less than cases 1-10), suggesting an ongoing learning curve. Conclusions. Surgeons who are well-experienced can be expected to have no or minimal learning curve for robotic MI-TLIF. Early attendings are likely to have a learning curve of around 21 cases with the attainment of mastery at case 31. Learning curve does not seem to impact clinical outcomes after surgery. [ABSTRACT FROM AUTHOR]

Postoperative recovery is a common discussion topic during their preoperative counseling. Studies have reported return to activities with open techniques, with recent literature focusing on minimally invasive techniques. However, the precise timing of when patients return to these activities after certain procedures remains uncertain. The purpose of this study was to evaluate the timing of return to commonly performed activities, including driving, working and discontinuing opioids, as well as to identify preoperative factors associated with these outcomes. This was a single-center, multi-surgeon, retrospective review. Patients in this study had lumbar stenosis and underwent either minimally invasive lumbar laminectomy (MIS-L) or minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) between 7/2018 and 10/2021. In addition to time to return to drive, return to work and discontinuation of opioids, patient reported outcome measures (PROMs) including Oswestry Disability Index (ODI), Visual Analog Scale (VAS) for back and leg pain, Short Form-12 physical and mental score components (SF-12 PCS and SF-12 MCS), and Patient-Reported Outcomes Measurement Information System Physical Function (PROMIS-PF) were collected preoperatively. Descriptive statistics were calculated for demographic variables, PROMs and return-to-activity measures. Logistic regression was conducted to identify factors associated with return to driving by 15, work by 30 days and for discontinuing opioids by 15 days. A composite group was also created for patients who returned to all three activities, and regression was performed for return to all activities by 30 days. Seventy-one patients (88.8%) (Median 11 days; IQR 5-25) in the MIS-L group and 80 (96.4%) (Median 18.5 days; IQR 14-30) in the MIS-TLIF group returned to driving. Fifty-seven patients (91.9%) (Median 14 days; IQR 4.5-32) in the MIS-L group and 54 (85.7%) (Median 25 days; IQR 14-49.75) in the MIS-TLIF returned to work. Sixty-three patients (88.7%) (Median 7 days; IQR 4-17) in the MIS-L group and 87 (92.6%) (Median 11 days; IQR 5-18) in the MIS-TLIF group discontinued opioids. Twenty-five (96.2%) subjects in the MIS-L group and 45 (100%) of the MIS-TLIF group returned to all three activities, with a median of 27 days [IQR 14-53.5] and 31 days [IQR 18.5-49], respectively. Male gender (OR 3.57, 95 CI [1.64, 7.69], p=0.001) and a higher preoperative SF-12 PCS score (OR 1.08, 95 CI [1.02, 1.12], p=0.004) predicted return to driving by 15 days. Male gender (OR 3.23, 95 CI [1.27, 8.2], p=0.014) and a higher preoperative SF-12 PCS score (OR 1.07, 95 CI [1.01, 1.13], p=0.029) predicted return to work by 30 days. A higher preoperative VAS back was correlated with decreased odds of discontinuing opioids by 15 days (OR 0.84, 95 CI [0.73, 0.96], p=0.011). Minimally invasive techniques seem to narrow the gap in postoperative recovery between a laminectomy and TLIF in this relatively homogenous patient population. While our data do not provide guidance on surgical indication, they do suggest that patients undergoing MIS TLIF are highly likely to return to work, driving and discontinue opioids. Additionally, the difference between the two procedures is less than 2 weeks for most activities and similar when examining composite success. These findings serve as an important compass for preoperative counseling. This abstract does not discuss or include any applicable devices or drugs. [ABSTRACT FROM AUTHOR]

Degenerative grade 1 spondylolisthesis is associated with lumbar instability, typically addressed with decompression and fusion to prevent iatrogenic instability. The SLIP trial indicated that decompression-only patients benefit significantly from early reoperation for instability. Yet, it's unclear how these revision patients' outcomes compare to those undergoing primary fusion. To evaluate whether outcomes were inferior among patients receiving revision transforaminal lumbar interbody fusion (TLIF) after prior decompression in the setting of degenerative, grade 1 spondylolisthesis when compared to those undergoing primary TLIF for grade 1 spondylolisthesis. Retrospective cohort study. Patients with grade 1 spondylolisthesis at L4-L5 or L5-S1 who underwent TLIF between 2018-2023 and had complete 1Y clinical follow-up and 6-month (6M) patient reported outcomes (PROs) were included. PROs (ODI, PROMIS, SF-12, VAS Pain) and Clinical (readmission and reoperation at 6-week [6W], 6M, and 1Y). No predictors for missing data were identified. Comparisons were made between primary fusion patients and those with prior decompression now undergoing revision TLIF. Bias was minimized via 2:1 propensity score matching (PSM) for age, comorbidities (CCI), slip percentage, slip translation, angular change, anterior and posterior disc height (ADH and PDH respectively), facet diastasis and cysts, and facet orientation—termed spondylolisthesis characteristics. Unmatched PROs and clinical outcomes were analyzed with a mixed-effects (ME) model and Chi-Squared test, while matched PROs and clinical outcomes employed an ME model and conditional logistic regression. A total of 285 patients (55.4% female, mean age 60.80 ± 0.73, CCI of 2.10 ± 0.09, and 35.1% current/former smokers) were included. Spondylolisthesis slip was 13.11% ± 0.99% with mean translation in flexion/extension of 1.60 ± 0.19 mm. Compared to revision patients (N=42, 14.7%), primary fusion patients (N=243, 85.3%) were younger (59.70 ± 0.77 vs 67.20 ± 1.76) and had a lower prevalence of active smoking (2.48% vs 11.90%), but showed no differences in slip percentage (p=0.480), translation in flexion/extension (p=0.778), ADH(p=0.578), PDH(p=0.991), facet diastasis (p=0.132), facet cysts (p=0.550), or angular change across L3-S1. Preoperatively, PROs were comparable across all domains. At one-year postop, no differences were observed in back pain (p=0.430), leg pain (p=0.346), SF-12 PCS(p=0.976), MCS(p=0.737), PROMIS Score (p=0.063), or ODI(p=0.362). The PSM cohort, matched for age, CCI, and spondylolisthesis characteristics, showed standardized differences of less than 0.10 for all demographics, baseline PROs, and spondylolisthesis characteristics, aside angular change at L5-S1 (3.05 vs 7.08, p=0.062). At one-year postop, there were no differences in back pain (2.62 vs 2.10, p=0.414), leg pain (2.15 vs 1.48, p=0.270), SF-12 PCS (43.02 vs 43.38, p=0.888), SF-12 MCS (51.31 vs 52.80, p=0.553), PROMIS Score (45.69 vs 44.81, p=0.630), and ODI (18.66 vs 15.26, p=0.375). Finally, no significant differences were found in early (6W) or long-term (6M to 1Y) complications, with 98.1% primary and 90.5% revision patients complication-free at 6W, and 93.6% vs 100.0%, respectively, from 6M to 1Y. Following decompression alone for grade 1 spondylolisthesis, patients having revision TLIF after decompression exhibit patient-reported and clinical outcomes similar to those undergoing primary TLIF. This abstract does not discuss or include any applicable devices or drugs. [ABSTRACT FROM AUTHOR]

Cervical disc replacement (CDR) has emerged as a reliable and efficacious treatment option for appropriately indicated degenerative cervical spine pathologies. While previous studies have demonstrated a strong association between prolonged preoperative symptom duration and poor outcomes following ACDF, the relationship between preoperative symptom duration and postoperative clinical outcomes in CDR for radiculopathy is not well established. To determine the impact of prolonged preoperative symptom duration on postoperative functional outcomes and disability following CDR for radiculopathy. Retrospective review of a prospectively maintained database. Primary 1- or 2-level CDRs in patients with radiculopathy without myelopathy performed by 4 surgeons between 2018-2023. Neck Disability Index (NDI), Visual Analog Scale (VAS) Neck and Arm, change in patient reported outcome measure (PROM) scores, minimal clinically important difference (MCID) rates, and predictors for failure to achieve MCID. Patients were divided into two cohorts (shorter: <6 months; prolonged: ≥6 months) based on preoperative symptom duration. Change in PROM scores and MCID rates were calculated. Analyses were conducted on the early (within 3 months) and late (6 months to 2 years) postoperative periods. Student's t-test and Mann-Whitney U test were used to compare continuous variables. Chi-Square test was used to compare categorical variables. Multivariable logistic regressions were used to identify predictors for failure to achieve MCID for PROMs at the latest follow-up timepoint. A total of 201 patients (43.6±8.7 years, 33.3% female) were included. There were no significant differences in baseline characteristics or preoperative PROM scores between the shorter (<6 months) and prolonged (≥6 months) preoperative symptom duration cohorts. In both early and late postoperative periods, the shorter preoperative symptom duration cohort experienced significantly greater change from preoperative PROM scores compared to the prolonged symptom duration cohort for NDI (early: 31.4±16.6 vs 19.6±22.4, P<0.001; late: 34.2±17.2 vs 25.1±22.3, P-0.016), VAS-Neck (early: 5.2±2.6 vs 2.9±2.9, P<0.001; late: 5.3±2.6 vs 3.4±3.3, P<0.001), and VAS-Arm (early: 5.6±2.8 vs 3.4±3.5, P<0.001; late: 5.5±2.8 vs 3.5±3.6, P<0.001). The shorter symptom duration cohort achieved MCID in the early postoperative period at a significantly higher rate for NDI (78.9% vs 54.9%, P=0.001), VAS-Neck (87.0% vs 56.0%, P<0.001), and VAS-Arm (90.5% vs 70.7%, P=0.002). In the late postoperative period, the shorter symptom duration cohort achieved MCID at a significantly higher rate for VAS-Neck (94.1% vs 65.2%, P<0.001) and VAS-Arm (91.8% vs 71.2%, P=0.007). Prolonged preoperative symptom duration (≥6 months) was identified as an independent risk factor for failure to achieve MCID at the latest timepoint for NDI (OR: 2.9, 95% CI: 1.2-6.9, P=0.016), VAS-Neck (OR: 9.8, 95% CI: 3.7-26.0, P<0.001), and VAS-Arm (OR: 7.5, 95% CI: 2.5-22.5, P<0.001). Our study demonstrates improved clinical outcomes for patients with shorter preoperative symptom duration undergoing CDR for radiculopathy, suggesting delayed surgical intervention may result in poorer outcomes and greater postoperative disability. As such, these patients may benefit from earlier surgical intervention. These findings may help inform the approach to counseling patients on postoperative expectations and outcomes based on their preoperative symptom duration. This abstract does not discuss or include any applicable devices or drugs. [ABSTRACT FROM AUTHOR]

Background Context: Opioid utilization has been well studied for inpatient ACDF. However, the amount and type of opioids prescribed following ambulatory ACDF and the associated risk of persistent use are largely unknown.Purpose: To characterize opioid prescription filling following single-level ambulatory anterior cervical discectomy and fusion (ACDF) compared to inpatient procedures.Study Design/setting: Retrospective cohort study.Patient Sample: Opioid-naive patients who underwent ambulatory (no overnight stay) or inpatient single-level ACDF from 2011 to 2019 were identified from a national insurance database.Outcome Measures: Rate, amount, and type of perioperative opioid prescription.Methods: Opioid-naive patients who underwent ambulatory (no overnight stay) or inpatient single-level ACDF from 2011 to 2019 were identified from a national insurance database. Perioperative opioids were defined as opioid prescriptions 30 days prior to and 14 days after the procedure. Rate, amount, and type of opioid prescription were characterized. Multivariable analyses controlling for any differences in demographics and comorbidities between the two treatment groups were utilized to determine any association between surgical setting and persistent opioid use (defined as the patient still filling new opioid prescriptions >90 days postoperatively).Results: A total of 42,521 opioid-naive patients were identified, of which 2,850 were ambulatory and 39,671 were inpatient. Ambulatory ACDF was associated with slightly increased perioperative opioid prescription filling (52.7% versus 47.3% for inpatient procedures; p < 0.001). Among the 20,280 patients (47.7%) who filled perioperative opioid prescriptions, the average amount of opioids prescribed (in morphine milligram equivalents) was similar between ambulatory and inpatient procedures (550 versus 540, p=0.413). There was no association between surgical setting and persistent opioid use in patients who filled a perioperative opioid prescription, even after controlling for comorbidities, (adjusted odds ratio, 1.15, p=0.066).Conclusions: Ambulatory ACDF patients who filled perioperative opioid prescriptions were prescribed a similar amount of opioids as those undergoing inpatient procedures. Further, ambulatory ACDF does not appear to be a risk factor for persistent opioid use. These findings are important for patient counseling as well as support the safety profile of this new surgical pathway. [ABSTRACT FROM AUTHOR]

Study Design/Setting.: Systematic review. Objective.: The primary purpose was to propose patient selection criteria and perioperative best practices that can serve as a starting point for an ambulatory lumbar fusion program. The secondary purpose was to review patient-reported outcomes (PROs) after ambulatory lumbar fusion. Summary of Background.: As healthcare costs rise, there is an increasing emphasis on cost saving strategies (i.e. outpatient/ambulatory surgeries). Lumbar fusion procedures remain a largely inpatient surgery. Early studies have shown that fusion procedures can be safely preformed in an outpatient setting but no review has summarized these findings and best practices. Materials and Methods.: This study was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. PubMed/MEDLINE, The Cochrane Library, and Embase were searched. The following data were collected: (1) study design; (2) number of participants; (3) patient population; (4) procedure types; (5) procedure setting; (6) inclusion criteria; (7) protocols; (8) adverse events; (9) PROs; and (10) associations between patient/surgical factors, setting, and outcomes. Results.: The search yielded 20 publications. The following selection criteria for ambulatory lumbar fusion were identified: age below 70, minimal comorbidities, low/normal body mass index, no tobacco use, and no opioid use. The perioperative protocol can include a multimodal analgesic regimen. The patient should be observed for at least three hours after surgery. The patient should not be discharged without an alertness check and a neurological examination. Patients experienced significant improvements in PROs after ambulatory lumbar fusion; similarly, when compared to an inpatient group, ambulatory lumbar fusion patients experienced a comparable or superior improvement in PROs. Conclusion.: There are two critical issues surrounding ambulatory lumbar fusion: (1) Who is the ideal patient, and (2) What needs to be done to enable expedited discharge? We believe this review will provide a foundation to assist surgeons in making decisions regarding the performance of lumbar fusion on an ambulatory basis. Level of Evidence.: Level III. [ABSTRACT FROM AUTHOR]

Background Context: Published rates for disc reherniation following primary discectomy are around 6%, but the ultimate reoperation outcomes in patients after receiving revision discectomy are not well understood. Additionally, any disparity in the outcomes of subsequent revision discectomy (SRD) versus subsequent lumbar fusion (SLF) following primary/revision discectomy remains poorly studied.Purpose: To determine the 8-year SRD/SLF rates and time until SRD/SLF after primary/revision discectomy respectively.Study Design: Retrospective cohort study.Patient Sample: Patients undergoing primary or revision discectomy, with records in the PearlDiver Patient Records Database from the years 2010 to 2019.Outcome Measures: Subsequent surgery type and time to subsequent surgery.Methods: Patients were grouped into primary or revision discectomy cohorts based off of the nature of "index" procedure (primary or revision discectomy) using ICD9/10 and CPT procedure codes from 2010 to 19 insurance data sets in the PearlDiver Patient Records Database. Preoperative demographic data was collected. Outcome measures such as subsequent surgery type (fusion or discectomy) and time to subsequent surgery were collected prospectively in PearlDiver Mariner database. Statistical analysis was performed using BellWeather statistical software. A Kaplan-Meier survival analysis of time to SLF/SRD was performed on each cohort, and log-rank test was used to compare the rates of SLF/SRD between cohorts.Results: A total of 20,147 patients were identified (17,849 primary discectomy, 2,298 revision discectomy). The 8-year rates of SRD (6.1% in revision cohort, 4.8% in primary cohort, p<.01) and SLF (10.4% in revision cohort, 6.2% in primary cohort, p<.01) were higher after revision versus primary discectomy. Time to SLF was shorter after revision versus primary discectomy (709 vs. 886 days, p<.01). After both primary and revision discectomy, the 8-year rate of SLF (10.4% in revision cohort, 6.2% in primary cohort, p<.01) is greater than SRD (6.1% in revision cohort, 4.8% in primary cohort, p<.01).Conclusions: Compared to primary discectomy, revision discectomy has higher rates of SLF (10.4% vs. 6.2%), and faster time to SLF (2.4 vs. 1.9 years) at 8-year follow up. [ABSTRACT FROM AUTHOR]

Study Design: A retrospective cohort comparison study.Objective: To compare perioperative outcomes, radiographic parameters, and patient-reported outcome measures (PROMs) between minimally invasive unilateral laminotomy with bilateral decompression (MIS-ULBD) versus MIS transforaminal lumbar interbody fusion (MIS-TLIF) for treatment of low-grade lumbar degenerative spondylolisthesis.Summary Of Background Data: While lumbar degenerative spondylolisthesis is a common condition, optimal surgical treatment remains controversial. Newer MIS techniques, which preserve bone, paraspinal musculature, and posterior midline stabilizers, are thought to reduce the risk of iatrogenic instability and may obviate the need for fusion. However, few comparative studies of MIS techniques for low-grade lumbar degenerative spondylolisthesis currently exist.Materials and Methods: Consecutive patients with low-grade (Meyerding grade I or II) lumbar degenerative spondylolisthesis treated with single-level MIS-ULBD or MIS-TLIF were identified retrospectively from a prospectively collected spine surgery registry from April 2017 to November 2021. Perioperative outcomes, radiographic data, and PROMs were assessed.Results: A total of 188 patients underwent either MIS-ULBD or MIS-TLIF (79 MIS-ULBD and 109 MIS-TLIF). Patients who underwent MIS-ULBD tended to be older, had higher Charlson Comorbidity Index, lower mean percentage back pain, higher percentage of L4/L5 pathology, shorter operative time, lower estimated blood loss, and lower postoperative pain ( P <0.05). In both groups, there were statistically significant improvements at one year for five of the six PROMs studied: Oswestry Disability Index (ODI), visual analog scale (VAS)-back pain, VAS-leg pain, Short Form 12 Physical Component Score (SF12-PCS), and Patient-Reported Outcomes Measurement Information System (PROMIS) ( P <0.05). On multivariate analysis controlling for confounders, there were no associations between procedure type and achieving minimal clinically important difference at one year in any of the PROMs studied.Conclusions: The current study suggests that both MIS-ULBD and MIS-TLIF result in significant improvements in pain and physical function for patients with low-grade lumbar degenerative spondylolisthesis.Level Of Evidences: 3. [ABSTRACT FROM AUTHOR]

Background: Degenerative spondylolisthesis (DS) is one of the most common pathologies spine surgeons treat. While a number of potential factors have been identified, there is no current consensus on which variables most impact the decision to fuse vs. decompress alone in this population.Purpose: The purpose of this study was to describe current DS treatment practices and identify both the radiographic and clinical factors leading to the decision to fuse segments for one level DS.Study Design/setting: Descriptive cross-sectional survey.Patient Sample: Surveys were administered to members of Lumbar Spine Research Society and Society of Minimally Invasive Spine Surgery.Outcome Measures: Surgeon demographics and treatment practices were reported. Radiographic and clinical parameters were ranked by each surgeon with regards to their importance.Methods: The primary analysis was limited to completed surveys. Baseline characteristics were summarized. Clinical and radiographic parameters were ranked and compared. Ranking of each clinical and radiographic parameters was reported using best and worst rank, mean rank position, and percentiles. The most important, top 3 most important, and top 5 most important parameters were ordered given each parameter's ranking frequency.Results: 381 surveys were returned completed. With regards to fusion vs. decompression, 19.9% fuse all cases, 39.1% fuse > 75%, 17.8% fuse 50%-75%, and 23.2% fuse <25%. The most common decompressive technique was a partial laminotomy (51.4%), followed by full laminectomy (28.9%). 82.2% of respondents instrument all fusion cases. Instability (93.2%), spondylolisthesis grade (59.8%), and laterolisthesis (37.3%) were the most common radiographic factors impacting the decision to fuse. With regards to the clinical factors leading to fusion, mechanical low back pain (83.2%), activity level (58.3%), and neurogenic claudication (42.8%) were the top 3 clinical parameters.Conclusions: There is little consensus on the treatment of DS, with society members showing substantial variation in treatment patterns with the majority utilizing fusion for treatment. The most common radiographic parameters impacting treatment are instability, spondylolisthesis grade, and laterolisthesis while mechanical low back pain, activity level, and neurogenic claudication are the most common clinical parameters. [ABSTRACT FROM AUTHOR]

Several experiments have shown that delivery of BMP-2 in a delayed fashion from initial surgery may be superior for optimal bone growth. Studies of posterolateral spinal fusion in rabbits have shown that BMP-2 expression physiologically peaks from 4-6 weeks out from surgery. The hypothesis of this experiment was that delayed delivery of ACS/BMP-2 would augment bone growth in a rabbit spine fusion model. By percutaneously delivering ACS/BMP-2 we would be able to deliver osteoinductive material at an optimal time point away from the typical time of surgery application. To determine if controlled delivery of morselized absorbable collagen sponge (ACS) Rh-BMP2 in a delayed manner postsurgery would allow for increased fusion mass in a rabbit spine fusion model. A nicotine-impaired spinal fusion rabbit model. Sixteen male one-year-old rabbits. Histologic, radiologic (radiographic, CT scans) and palpation examinations were performed to determine fusion status and the volume of bone formed. Sixteen male one-year-old rabbits underwent a posterolateral spinal fusion with iliac crest bone graft at L5-L6 while being given nicotine to prevent spinal fusion as previously published. Eight were controls while 8 had morselized RhBMP-2 (4.2mg) injected at the fusion site at 4 weeks postoperatively. At 12 weeks, the rabbits were sacrificed. Histologic, radiologic (radiographic, CT scans) and palpation examinations were performed to determine fusion status and the volume of bone formed. Hematoxylin and eosin (H&E) stain were used for histology. There were 4 of 8 rabbits in the control cohort with bilateral fusion and 6 of 8 rabbits in the BMP-DDC that had bilateral fusion based on CT scan analysis. A student's t-test was used to compare the CT scan measured volume of bone created between control (CC) and RhBMP-2 delayed delivery cohorts (BMP-DDC). Seven of 8 rabbits in the BMP-DDC and 5 of 8 rabbits in the CC formed definitive fusion with a positive palpation exam, bridging bone between transverse processes on CT scan and an x-ray showing fusion. Histologic analysis revealed new remodeled bone within the BMP-DDC. There was increased average volume of bone formed within the BMP-DDC vs the CC (22.6±13.1 vs 11.1±3.6 cm^3, p=0.04) Our study shows that injectable morselized ACS/RhBMP-2 can create twice as much bone within a nicotine-impaired rabbit spine fusion model when delivered 4 weeks out from time of surgery. This abstract does not discuss or include any applicable devices or drugs. [ABSTRACT FROM AUTHOR]

High body mass index (BMI) is an important factor impacting surgical outcomes. However, no previous study has analyzed the impact of class 2/3 obesity (BMI > 35) on outcomes following minimally invasive lumbar fusion. To study the impact of class 2/3 obesity on clinical and radiological outcomes following minimally invasive lumbar fusion. Retrospective cohort. Patients who underwent primary single-level minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) for degenerative conditions of the lumbar spine by multiple surgeons at a single academic institution and had a minimum of 1-year follow-up. 1) Intraoperative variables: operative time, estimated blood loss (EBL); 2) Patient reported outcome measures (PROMs) (Oswestry Disability Index, ODI; Visual Analog Scale, VAS back and leg; 12-Item Short Form Survey Physical Component Score, SF-12 PCS); 3) Global rating change (GRC), minimal clinically important difference (MCID), and patient acceptable symptom state (PASS) achievement rates; 4) return to activities; and 5) complication and reoperation rates. Patients were divided into 4 cohorts based on their BMI: normal (BMI 18.5 to <25), overweight (25 to <30), class 1 obesity (30 to <35), and class 2/3 obesity (BMI > 35). Two postoperative timepoints were defined – early (<6 months) and late (> 6 months). MCID and PASS thresholds were utilized as previously described by Copay et al. (2008) and Shahi et al. (2023), respectively. Fusion was assessed on 1-year CT scan done as standard of care. Outcome measures were compared between the groups for differences with univariate analyses. In total, 390 patients were included (119 normal, 160 overweight, 67 class 1 obesity, 44 class 2/3 obesity). Class 2/3 obesity group had a significantly higher number of patients with American Society of Anesthesiologists (ASA) class 3 (27% vs <12% in other groups, p<0.001). There was no difference between the groups in age, gender, age-adjusted Charlson Comorbidity Index (CCI), smoking, and intraoperative variables (operative time, EBL). On comparison of PROMs, class 2/3 obesity patients had significantly worse ODI, VAS back, VAS leg, and SF-12 PCS at the late postoperative timepoint (> 6 months). Class 2/3 obesity group had significantly lower PASS achievement rates (43% vs >67% in other groups, p=0.01) and significantly lower MCID achievement rates in VAS leg (41% vs >61% in other groups, p=0.04) and SF-12 PCS (41% vs >65% in other groups, p=0.04) at > 6 months. There was no significant difference between the groups in fusion rates. On comparison of recovery kinetics, class 2/3 obesity group had significantly higher postoperative length of stay (LOS) (62 hours vs <50 hours in other groups, p=0.006) and took significantly greater number of days to return to driving (74 days vs <40 days in other groups, p=0.015). No significant difference was found in return to work and discontinuation of narcotics. The groups had similar complication and reoperation rates. Class 2/3 obesity (BMI > 35) patients undergoing MIS TLIF had significantly worse ODI, VAS back and leg, and SF-12 PCS at > 6 months. They had significantly lower MCID and PASS achievement rates and took longer to be discharged from the hospital and return to driving following surgery. This abstract does not discuss or include any applicable devices or drugs. [ABSTRACT FROM AUTHOR]

Percutaneous transforaminal endoscopic discectomy (PTED) has emerged as a reliable and efficacious treatment option for appropriately indicated lumbar disc herniations. While previous studies have demonstrated a strong association between prolonged preoperative symptom duration and poor functional and pain outcomes following other lumbar surgeries, the relationship between preoperative symptom duration and postoperative clinical outcomes in endoscopic lumbar discectomy is not well established. The purpose of this study is to determine the impact of prolonged preoperative symptom duration on postoperative functional outcomes and disability following PTED. Retrospective review of a prospectively maintained registry. Primary 1- or 2-level PTEDs for lumbar disc herniation with a single surgeon between 2020-2023. Oswestry Disability Index (ODI), Visual Analog Scale (VAS) Back and Leg, change in patient reported outcome measure (PROM) scores, and minimal clinically important difference (MCID) rates. Included patients were divided into two cohorts (shorter: <6 and prolonged: ≥6 months) based on preoperative symptom duration. Outcomes include ODI, VAS Back and Leg, change in PROM scores, and MCID rates. Analyses were conducted on the early (within 3 months) and late (6 months to 2 years) postoperative periods. Student's t-test and Mann-Whitney U test were used to compare continuous variables. Chi-Square test was used to compare categorical variables. Multivariable logistic regressions were used to identify risk factors for failure to achieve MCID for PROMs at the latest follow-up timepoint. A total of 83 patients (63.3±15.5 years, 44.6% female) were included. There were no significant differences in demographics, baseline characteristics, perioperative factors, or preoperative PROM scores (ODI, VAS-Back, or VAS-Leg) between the preoperative symptom duration <6 months and ≥6 months cohorts. ODI for the shorter preoperative symptom duration cohort was significantly lower in the early postoperative period (median: 12.7 [IQR: 6.5 – 34.2] vs median: 27.8 [IQR: 14.0 – 40.0], P=0.005), and VAS-Back was significantly lower for the shorter symptom duration cohort in the last postoperative period (median: 0.0 [IQR: 0.0 – 2.0] vs median: 2.0 [IQR: 0.0 – 5.0], P=0.024). Changes in ODI in the early and late postoperative periods was significantly greater for the shorter symptom duration cohort (<6 months) (early: 32.4±18.7 vs 11.1±17.8, P<0.001; late: 35.9±24.1 vs 16.9±16.5, P=0.002). The shorter symptom duration cohort achieved MCID for ODI at a significantly greater rate in the early postoperative period (85.2% vs 44.4%, P<0.001). Prolonged preoperative symptom duration (≥6 months) was identified as an independent risk factor for failure to achieve MCID at the latest timepoint for ODI (OR: 10.1, 95% CI: 2.6 – 39.8, P<0.001) and VAS-Leg (OR: 5.9, 95% CI: 1.1 – 31.2, P=0.037). Our study demonstrates improved clinical outcomes for patients with shorter preoperative symptom duration undergoing endoscopic lumbar discectomy, suggesting delayed surgical intervention may result in poorer outcomes and greater postoperative disability. As such, these patients may benefit from earlier surgical intervention. These findings may help inform the approach to counseling patients on postoperative expectations and outcomes based on their preoperative symptom duration. This abstract does not discuss or include any applicable devices or drugs. [ABSTRACT FROM AUTHOR]

Purpose: There are data underlining the relationship between muscle health and spine related pathology, but little data regarding changes in paralumbar muscle associated with lumbar spondylolisthesis. We aimed to define changes in paralumbar muscle health associated with spondylolisthesis. Methods: A retrospective review was performed on consecutive patients with lumbar spine pathology requiring an operation. A pre-operative lumbar MRI was analysed for muscle health measurements including lumbar indentation value (LIV), paralumbar cross-sectional area divided by body mass index (PL-CSA/BMI), and Goutallier classification of fatty atrophy. All measurements were taken from an axial slice of a T2-weighted image at lumbar disc spaces. Baseline health-related quality of life scores (HRQOLs), narcotic use and areas of stenosis were tracked. We performed Chi-square analyses and student's t test to determine statistically significant differences between cohorts. Results: There were 307 patients (average age 56.1 ± 16.7 years, 141 females) included within our analysis. 112 patients had spondylolisthesis. There were no differences in baseline HRQOLs between the spondylolisthesis cohort (SC) and non-spondylolisthesis cohort (non-SC). There were significantly worse PL-CSA/BMI at L2-L3 (p = 0.03), L3-L4 (p = 0.04) and L4-L5 (p = 0.02) for the SC. Goutallier classification of paralumbar muscle was worse for SC at L1-L2 (p = 0.04) and at L4-L5 (p < 0.001). Increased grade of spondylolisthesis was associated with worse PL-CSA at L1-L2 (p = 0.02), L2-L3 (p = 0.03) and L3-L4 (p = 0.05). Similarly, there were worse Goutallier classification scores associated with higher-grade spondylolisthesis at all levels (p < 0.05). Conclusion: There are significant detrimental changes to paralumbar muscle health throughout the lumbar spine associated with spondylolisthesis. [ABSTRACT FROM AUTHOR]

Study Design: Retrospective cross-sectional cohort.Objective: The aim of this sudy was to determine whether muscle health measurements are associated with health-related quality of life scores (HRQOLs) for patients with lumbar spine pathology.Summary Of Background Data: Poor muscle health has been implicated as a source of pain/dysfunction for patients with lumbar spine pathology. Our aim was to quantify the relationship using muscle health measurements and HRQOLs.Methods: Three hundred and eight patients were included (mean age 57.7 ± standard deviation 18.2 years' old). We randomly selected patients into a derivation cohort (200) and validation cohort (108) to create our muscle health grade. We measured muscle health by the lumbar indentation value (LIV), goutallier classification (GC), and ratio of paralumbar muscle cross-sectional area over body mass index (PL-CSA/BMI). A muscle health grade was derived based on whether a measurement showed a statistically significant impact on visual analog scale back and leg pain (VAS-leg and VAS-leg), Oswestry Disability Index (ODI), short-form 12 physical health score (SF-12 PHS), short-form 12 mental health score (SF-12 MHS) and Patient-reported Outcomes Measurement Information System (PROMIS). A variety of statistical tools were used to determine whether there was a relationship between a measurement and HRQOLs.Results: In the derivation cohort, a muscle health grade was created based on the GC and PL-CSA/BMI ratio. For patients with a GC ≤2, one point was given. For patients with a PL-CSA/BMI ≥130, one point was given. Patients with 2 points were graded as "A" and 0 or 1 point were graded "B." Within the validation cohort of patients, there was a statistically significant higher PROMIS (mean 34.5 ± standard deviation 12.6 vs. 27.6 ± 14.0, P = 0.002), ODI (38.8 ± 18.3 vs. 45.8 ± 18.1, P = 0.05) and SF-12 PHS (34.7 ± 11.3 vs. 29.1 ± 6.3, P = 0.002) for patients with a good muscle health grade of "A."Conclusion: This study offers an objective measurement of muscle health that correlates with HRQOLs for patients with lumbar spine pathology.Level of Evidence: 3. [ABSTRACT FROM AUTHOR]

Background: Lateral lumbar interbody fusion (LLIF) is used to treat multiple conditions, including spondylolisthesis, degenerative disc disorders, adjacent segment disease, and degenerative scoliosis. Although many advocate for posterior fixation with LLIF, stand-alone LLIF is increasingly being performed. Yet the fusion rate for stand-alone LLIF is unknown.Purpose: Determine the fusion rate for stand-alone LLIF.Study Design: Systematic review.Methods: We queried Cochrane, EMBASE, and MEDLINE for literature on stand-alone LLIF fusion rate with a publication cutoff of April 2020. LLIF surgery was considered stand-alone when not paired with supplemental posterior fixation. Cohort fusion rate differences were calculated and tested for significance (p<0.05). All reported means were pooled.Results: A total of 2,735 publications were assessed. Twenty-two studies met inclusion criteria, including 736 patients and 1,103 vertebral levels. Mean age was 61.7 years with BMI 26.5 kg/m2. Mean fusion rate was 85.6% (range, 53.0%-100.0%), which did not differ significantly by number of levels fused (1-level, 2-level, and ≥3-level). Use of rhBMP-2 was reported in 39.3% of subjects, with no difference in fusion rates between studies using rhBMP-2 (87.7%) and those in which rhBMP-2 was not used (83.9%, odds ratio=1.37, p=0.448). Fusion rate did not differ with the addition of a lateral plate, or by underlying diagnosis. All-complication rate was 42.2% and mean reoperation rate was 11.1%, with 2.3% reoperation due to pseudarthrosis. Of the studies comparing stand-alone to circumferential fusion, pooled fusion rate was found to be 80.4% versus 91.0% (p=0.637).Conclusions: Stand-alone LLIF yields high fusion rates overall. The wide range of reported fusion rates and lower fusion rates in studies involving subsequent surgical reoperation highlights the importance of proper training in this technique and employing a rigorous algorithm when indicating patients for stand-alone LLIF. Future research should focus on examining risk factors and patient-reported outcomes in stand-alone LLIF. [ABSTRACT FROM AUTHOR]

Background/context: Although decompression without fusion is a reasonable surgical treatment option for some patients with lumbar spinal stenosis (LSS) secondary to spondylolisthesis, some of these patients will require secondary surgery for subsequent fusion. Long-term outcome and need for subsequent fusion in patients treated with decompression alone in the setting of lumbar spondylolisthesis remains controversial.Purpose: The aim of this study was to examine the rate, timing, and risk factors of subsequent fusion for patients after decompression alone for LSS with spondylolisthesis.Study Design/setting: A retrospective cohort study.Patient Sample: Patients who had LSS with spondylolisthesis and underwent decompression alone at 1 or 2 levels as a primary lumbar surgery with more than 5 year follow-up.Outcome Measures: The rate, timing, and risk factors for subsequent fusion.Methods: Subjects were extracted from both public and private insurance resources in a nationwide insurer database. Risk factors for subsequent fusion were evaluated by multivariate cox proportion-hazard regression controlling for age, gender, comorbidities and the presence or absence of claudication.Results: Five thousand eight hundred and seventy-five patients in the public insurance population (PI population) and 1,456 patients in the private insurance population (PrI population) were included in this study. The rates of patients who needed subsequent fusion were 1.9% at 1 year, 3.5% at 2 years, and 6.7% at 5 years in the PI population, whereas they were 4.3% at 1 year, 8.9% at 2 years, 14.6% at 5 years in the PrI population. The time to subsequent fusion was 730 (365-1234) days in the PI population and 588 (300-998) days in the PrI population. Age less than 70 years, presence of neurogenic claudication and rheumatoid arthritis (RA)/collagen vascular diseases (CVD) were independent risk factors for subsequent fusion in both populations.Conclusions: Decompression surgery alone can demonstrate good outcomes in some patients with LSS with spondylolisthesis. It is important for surgeons to recognize, however, that patient age less than 70 years, symptomatic neurogenic claudication, and presence of RA and/or CVD are significant independent factors associated with greater likelihood of needing secondary fusion surgery. [ABSTRACT FROM AUTHOR]