STUDY DESIGN:Retrospective cohort study. OBJECTIVE:The purpose of this study was to investigate how inpatient physical therapy variables impact (1) inpatient complications, (2) 90-day readmissions, (3) 1-year reoperation rates, and (4) length of stay after posterior lumbar decompression and fusion. SUMMARY OF BACKGROUND DATA:Previous studies have emphasized the role of early ambulation in postoperative spine patients as an effective method for improving pain and decreasing length of stay, but few studies have evaluated the efficacy of inpatient physical therapy. METHODS:Patients 18 years of age or older who underwent primary 1-level or 2-level posterior lumbar decompression and fusion from 2019 to 2020 were retrospectively identified. Physical therapy data, including time to first inpatient PT session, gait trial distance achieved, post-treatment pain rating, and Activity Measure for Post-Acute Care (Activity Measure for Post-Acute Care [AM-PAC]) scores were collected using manual chart review. Surgical outcome variables included length of stay, inpatient complications, 90-day readmissions, and reoperations within 1 year of primary surgery. RESULTS:Overall, 425 patients were identified. There was no difference in hours to PT or total gait trial distance achieved between patients who experienced a complication and those that did not. Patients in the noncomplication group had higher AM-PAC scores than patients in the complication group. There was no difference with regards to time to PT, AM-PAC score, or gait trial distance achieved between readmitted patients and nonreadmitted patients or revision patients and nonrevision patients. Stepwise logistic regression showed that having a physical therapy session within 6 hours of surgery was predictive of a decreased length of stay both in all patients. CONCLUSIONS:While inpatient physical therapy within 6 hours of surgery does not appear to impact readmissions, complications, or reoperations, surgeons should encourage early ambulation postoperatively to decrease extended hospital stays. Future investigation should seek to identify factors that delay inpatient PT in the 6 hours after surgery.

Post-surgical spinal infection occurs in up to 20 % of patients, despite aggressive peri-operative antibiotic treatments. To improve prophylaxis, we have designed and evaluated an ultrasound-activated prophylactic antibiotic release system to combat post-surgical bacterial survival. Polylactic acid (PLA) clips (1 cm3) were 3D-printed with an interior reservoir (0.8 cm3) for carrying drug payload, specifically vancomycin (VAN). Under IACUC approval, clips were surgically implanted into the spines of sheep (n = 9) and swine (n = 2) by removing the spinous process at several levels of the lumbar spine. In the sheep, clips were insonated and the interstitial wound fluid was collected to quantify the ultrasound-triggered VAN release. Uninsonated control sheep exhibited an average VAN concentration of 6.32 ± 5.99 µg/mL after 72 h, while ultrasound-triggered clips released significantly higher VAN concentrations at 72 h (22.98 ± 11.22 µg/mL, p = 0.033). In the swine, device efficacy against Staphylococcus aureus was evaluated. Insonated sites saw significant reduction in colony forming units (CFU) to 4.3 ± 3.2 CFU in the activated clips, compared to uninsonated controls where bacterial colonization was higher (2898 ± 1214 CFU, p = 0.017). Overall, these results demonstrate the ability to non-invasively release VAN from an implanted reservoir in vivo, and that this VAN release is effective in mitigating invading microbes in the wound site

Study Design.Retrospective cohort study.Objective.The objective of this study was to determine if a baseline prognostic nutritional index (PNI) score could be used to predict outcomes in patients with native spine infections, including the need for operative intervention.Summary of Background Data.Nutritional status is an important, potentially modifiable risk factor to consider in the native spine population. The PNI score is a tool that has demonstrated utility as a marker of preoperative nutritional status in patients undergoing surgery; however, it has not yet been studied in the context of native spine infection.Methods.Adult patients (>= 18 y) with a diagnosis of spine infection from 2017 to 2022 were retrospectively identified. Native spine infection was defined as a diagnosis of spinal infection in the absence of prior spine surgery within 3 months of diagnosis. PNI was calculated using the equation: PNI=10xserum albumin (g/dL)+0.005 total lymphocyte count (/mu L). Patients were stratified into high or low PNI groups based on their PNI being above or below the average, respectively.Results.There were 45 patients in the low PNI group and 56 patients in the high PNI group. Patients in the low PNI group were more likely to require surgery (P=0.046), had more levels decompressed (P=0.012), and were more likely to undergo two or more irrigation and debridement procedures (P=0.016). Patients in the low PNI group were also less likely to be discharged home (P=0.016). There was no difference in length of stay, inpatient complications, 90-day readmissions, 90-day ED visits, or 1-year reoperations between groups.Conclusion.While postadmission outcomes and inpatient complications were similar across PNI groups, PNI on admission provides useful insight into the severity of infection and predicts the need for operative intervention in patients presenting with native spine infection.

STUDY DESIGN:Retrospective cohort study. OBJECTIVE:The purpose of this study is to characterize the relationship between preoperative MCS and surgical outcomes after lumbar spine surgery including inpatient complications, length of stay, readmissions, and reoperations. SUMMARY OF BACKGROUND DATA:As the prevalence of mental health disorders in the United States increases, it is important to identify risks associated with poor mental health status in the surgical spine patient. The mental health component summary (MCS) of the Short Form-12 has been used extensively as an indication of a patient's mental health status and psychological well-being. PATIENTS AND METHODS:Adult patients older than or equal to 18 years who underwent primary one to three level lumbar fusion surgery at our academic medical institution from 2017 to 2021 were retrospectively identified. Preoperative MCS score was used to analyze outcomes in patients based on a cutoff (<45.6). A score >45.6 indicated better preoperative mental health and a score ≤45.6 indicated worse preoperative mental health. RESULTS:Patients with lower preoperative MCS scores had longer hospital stays (3.86±2.16 vs. 3.55±1.42 d, P =0.010) and were more likely to have inpatient renal complications (3.09% vs. 7.19%, P =0.006). Patients with lower preoperative MCS scores also had lower activity measure for post-acute care (AM-PAC) scores (17.1±2.85 vs. 17.6±2.49, P =0.030). Ninety-day surgical readmissions, medical readmissions, and reoperations were not significantly different between groups ( P >0.05). CONCLUSION:Our study suggests that patients with lower preoperative mental health scores (MCS ≤45.6) were independently more likely to experience more renal complications and longer length of stay after primary lumbar fusion. In addition, higher MCS scores may correlate with better postoperative mobility and daily activity scores. Nevertheless, long-term outcomes are not significantly different between patients of better or worse preoperative mental health. LEVEL OF EVIDENCE:Level IV.

STUDY DESIGN:Retrospective cohort. OBJECTIVE:To investigate the impact of cervical paraspinal muscle mass and quality on the rate of pseudarthrosis and patient-reported outcome measures (PROMs) after anterior cervical discectomy and fusion (ACDF). SUMMARY OF BACKGROUND DATA:Poor muscle quality has been shown to correlate with inferior outcomes in spine surgery. However, few studies have investigated the impact of paraspinal sarcopenia on pseudoarthrosis following cervical spine surgery. MATERIALS AND METHODS:Adult patients who underwent primary, elective one-to-four level ACDF with preoperative magnetic resonance imaging (MRI) and postoperative radiographs were included. MRIs were reviewed to assess sternocleidomastoid (SCM) cross-sectional area (CSA) and Goutallier grade at the C5-C6 disc space. Pseudarthrosis was diagnosed on 1-year postoperative flexion-extension radiographs as <1 mm of interspinous motion between each instrumented level. Patient demographic and surgical variables and 1-year patient-reported outcome measures (PROMs) were compared between those with and without pseudoarthrosis on bivariate and multivariate analyses. RESULTS:A total of 205 patients were included (33.7% with pseudoarthrosis). The pseudoarthrosis group had a higher percentage of patients with 4-level (7.25% vs . 1.47%) and 3-level (30.4% vs . 17.6%, P =0.01) ACDF. The groups were similar in terms of demographics, surgical variables, and SCM area normalized to BMI. After controlling for the SCM CSA group, age, sex, BMI, and number of levels fused, a higher Goutallier grade independently increased the odds of pseudoarthrosis [odds ratio (OR): 3.46, P =0.009]. Patients with greater SCM fatty infiltration experienced greater improvement in PCS scores ( P =0.023), but there were no other differences in PROM scores between groups. CONCLUSION:Although this analysis did not show an association between SCM muscle size and pseudoarthrosis, even mild fatty infiltration appears to be independently predictive of pseudoarthrosis. In contrast, PROMs were not associated with SCM size or fatty infiltration. Further work is needed to confirm these findings and explore their clinical implications.

Study Design.Retrospective cohort study. Objective.The objective of this study was to explore the impact of different hospital-based ambulation protocols on mobility and surgical outcomes after lumbar fusion surgery. Summary of Background Data.Previous research has highlighted the value of early ambulation after surgery; still some hospitals choose to adopt a more conservative ambulation approach due to concern for patient safety. Methods.Adult patients >= 18 years of age who underwent primary posterior lumbar decompression and fusion (PLDF) surgery at a hospital with restricted ambulation and a hospital with a liberal ambulation protocol within the same health system from 2021 to 2022 were identified and matched based on patient demographic characteristics. Surgical outcomes included inpatient complications, length of stay, readmissions, reoperations, and discharge disposition. Mobility outcomes included Activity Measure for Post-Acute Care (AM-PAC) daily activity score, post-therapy session pain rating, and gait trial distance from the first inpatient physical therapy session. Results.Patients within the liberal ambulation protocol cohort had shorter hospital stays (P<0.001) and were less likely to require reoperation within 1 year of surgery (P=0.013). Patients within the restricted ambulation protocol were more likely to experience a complication (P=0.005) and were less likely to be discharged home after surgery (P=0.020). Patients at the liberal ambulation hospital had higher AM-PAC basic mobility scores (P<0.001) and achieved further gait distances (P<0.001). On multivariable regression analysis, a further gait distance at the first inpatient PT session was a significant predictor of decreased odds of inpatient complications (P=0.010), decreased length of stay (P=0.005), and increased odds of discharge to home (P<0.001). Conclusions.Liberal ambulation protocols are safe and effective postoperative management strategies after PLDF to decrease inpatient complications, length of stay and discharge to a rehabilitation facility. These findings highlight the role that such protocols can play in helping patients to achieve early mobilization and favorable short-term outcomes.

BACKGROUND CONTEXT: Previous research has demonstrated an association between socioeconomic status (SES) and patient health, specifically noting that patients of lower SES have poor health outcomes. Understanding how social factors, including socioeconomic status (SES), relate to disparities in health outcomes is critical to closing gaps in equitable care to patients. While several studies have examined the effect of SES on postoperative spine outcomes, there is limited spine literature evaluating SES in the context of barriers to spine care. PURPOSE: The primary objective of this study was to determine if socioeconomic status is associated with resource utilization prior to spine surgery consultation. As part of a subanalysis, this paper also explores the effect of other social factors on previsit resource utilization. STUDY DESIGN: Retrospective cohort study. PATIENT SAMPLE: Adult patients who underwent elective cervical or lumbar spinal fusion between 2020 and 2021. OUTCOME MEASURES: Previsit resource utilization including 1) epidural steroid injection, 2) opioid use, 3) physical therapy, 4) prior spine surgeon, and 5) prior spine surgery. METHODS: Each patient was assigned a "distressed score" using the Distressed Communities Index (DCI) and a socioeconomic status (SES) score using the Social Vulnerability Index (SVI) based on their zip code. Patient charts were manually reviewed to collect data regarding previsit resource utilization. The cohort was analyzed based on DCI quintile and SVI quartile. Additional analyses were conducted based on marital status and race. RESULTS: Our study included 996 patients in the final analysis. Based on DCI, patients from prosperous communities were more likely to have previously visited a spine surgeon (13.2% (prosperous) vs 7.58% vs 6.92% vs 9.09% vs 3.70% (distressed), p=.015) and to have had prior spine surgery (11.1% (prosperous) vs 9.57% vs 9.09% vs 2.52% vs 6.36% (distressed), p=.015). Similarly, when evaluated based on SES SVI, patients who lived in a low-risk community were more likely to have previously visited a spine surgeon (13.0% low-risk vs 7.26% low-medium risk vs 16.9% medium-high risk vs 10.6% high risk, p=.049) and to have had prior spine surgery (13.0% low-risk vs 7.26% vs 16.9% vs 10.6% high risk, p=.030). When evaluated based on marital status, there was no difference in any resource utilization. Non-Black and non-White patients were more likely to have tried physical therapy compared to their black and white counterparts (76.9% (other) vs 60.9% (Black) vs 54.3% (White), p=.026). CONCLUSION: This study examined the relationship between socioeconomic status and resource utilization and found a positive correlation between higher social standing and access to spine surgery and spine surgeons. These findings demonstrate a propensity for earlier evaluation of spine- related conditions among patients from prosperous communities compared to patients from less prosperous communities. (c) 2024 Published by Elsevier Inc.

BACKGROUND CONTEXT:As the incidence of de novo spinal infections has risen with increasing global medical complexity and intravenous drug use, so has the uncertainty around standard of care and surgical decision making. Nonoperative management has increased in popularity albeit with frequent failure rates in up to one-third of patients. Although clinical decision making has largely been guided by clinician experience and institutional preference, two recent scoring system-the Spinal Instability Spondylodiscitis Score (SISS) and the Spinal Infection Treatment Evaluation score (SITE) provide a promising potential avenue towards evidence-based pathways. PURPOSE:The aim of the current study was to compare external performance of the SITE and the SISS score in predicting operative decision making in patients with de novo spinal infections seen at a tertiary urban referral center, using real-world clinical decision making as a comparison. A secondary aim was to elucidate areas with low reliability or floor or ceiling effects as possible targets for score improvement. STUDY DESIGN/SETTING:Retrospective external validation study utilizing consecutive cases from an academic tertiary referral center. PATIENT SAMPLE:Adult patients undergoing treatment for spondylodiscitis or spinal epidural abscess. OUTCOME MEASURES:Using the surgical intervention as the ground truth, the primary outcomes were performance metrics of the SITE and SISS score including receiver operating characteristic curves, specificity, sensitivity, and interrater reliability for both score and classification. Of note, the SITE score increases in severity with lower scores, whereas the SISS score increases in severity with higher scores. METHODS:A panel of three blinded raters scored the clinical data. RESULTS:Two-hundred thirteen patients were included, of which 62% (144/213) underwent nonoperative medical management and 38% (80/213) underwent operative management. Mean SITE numerical scores were lower (more severe) in the operative group (5.63 vs 7.45, p<.001). The most frequent categorical group for the SITE score was "severe" in both the operative group (93%, 74/80, mean score 5.63) and the nonoperative group (68%, 90/133, mean score 7.45). The mean SISS score did not differ between operative and nonoperative groups (6.73 vs 6.25, p=.2). ICC agreement was "almost perfect" for the SITE score (0.86, 95% CI 0.82-0.89) and "substantial" for the SISS score (0.68, 95% CI 0.56-0.76). Performance metrics for the SITE score were "good" (AUC 0.743, 95% CI 0.67-0.81), and for the SISS score were "poor" (AUC 0.557, 95% CI 0.47-0.64). ROC analysis for SITE identified a cutoff score of 6.5 to optimize sensitivity and specificity at 0.692 and 0.700, respectively. If using the established cutoff of 8 for "severe" infection as described in the original scoring system, the sensitivity was 0.813, specificity, 0.504, positive predictive value (PPV) 0.496, and negative predictive value (NPV) 0.817. ROC analysis for SISS similarly proposed a cutoff score of 8.0 which yielded a sensitivity and specificity of 0.350 and 0.797, respectively. If using the established cutoff of 10 for "unstable lesion" as described in the original scoring system, the sensitivity was 0.125, specificity 0.917, PPV 0.476, and NPV 0.635. CONCLUSIONS:This study reports external performance metrics for the SITE and SISS score, demonstrating good performance for SITE and poor performance for SISS in predicting operative intervention with almost perfect SITE and substantial SISS agreement among raters. Ceiling effects may limit clinical utility of the SITE score. Subscales which require raters to determine percent vertebral body involvement or posterolateral involvement performed worse. Future work can focus on further discrimination within the "severe" infection group and improvement of low-performing subscales to improve clinical impact.

STUDY DESIGN:Retrospective Cohort Study.OBJECTIVE:The purpose of this study was to determine if muscle mass and quality of the lumbar paraspinal muscles was associated with improvements in lumbar lordosis and other sagittal parameters after isolated posterior lumbar decompression surgery for lumbar spinal stenosis.SUMMARY OF BACKGROUND DATA:Over time, either due to degenerative changes or other spinal conditions, individuals may develop sagittal imbalance. In patients with lumbar spinal stenosis, sagittal imbalance can further exacerbate symptoms of pain and radiculopathy. Sarcopenia of paraspinal muscles has been implicated in previous spine research as a variable with influence on surgical outcomes.METHODS:Sagittal parameters were measured on preoperative and postoperative lateral lumbar radiographs and included lumbar lordosis (LL), sacral slope (SS), and pelvic tilt (PT). Preoperative MRI images were evaluated at the base of the L4 vertebral body to assess muscles mass of the psoas muscle and paravertebral muscles (PVM) and Goutallier grade of the PVM. Patients were divided into 3 muscle size groups based on PVM normalized for body size (PVM/BMI): Group A (smallest), Group B, and Group C (largest).RESULTS:Patients in Group C had greater LL preoperatively (51.5° vs. 47.9° vs. 43.2, P=0.005) and postoperatively (52.2° vs. 48.9° vs. 45.7°, P=0.043). There was no significant difference in the ∆LL values between groups (P>0.05). Patients in Group C had larger SS preoperatively (35.2° vs. 32.1° vs. 30.0°, P=0.010) and postoperatively (36.1° vs. 33.0° vs. 31.7°, P=0.030). Regression analysis showed that PVM/BMI was a significant predictor of LL preoperatively (P=0.039) and postoperatively (P=0.031), as well as SS preoperatively (P=0.001) and postoperatively (P<0.001).CONCLUSION:Muscle mass of the paravertebral muscles significantly impacts lumbar lordosis and sacral slope in patients with lumbar spinal stenosis before and after posterior lumbar decompression. These findings highlight a need to address risk factors for poor muscle quality in patients with sagittal imbalance.

BACKGROUND CONTEXT:Given the relatively low cell density in degenerative discs, strategies intended to bolster disc cellularity through stem cell injections have come into clinical use. Stem cell therapy is meant to provide a source of viable disc cells that can promote a healthy disc phenotype. Nevertheless, there is a limited understanding of the mechanisms through which stem cell therapy impacts degeneration. PURPOSE:The objectives of this pilot study were: 1) to evaluate gene expression changes associated with an in vitro induced degenerative phenotype in human nucleus pulposus (NP) cells, 2) to co-culture these degenerative NP cells with human mesenchymal stem cells (hMSCs) and investigate the impact this has on gene expression, 3) to investigate possible mechanisms by which hMSCs may impact the degenerative phenotype. STUDY DESIGN:Laboratory study. METHODS:NP cells were isolated and cultured from patients undergoing anterior lumbar interbody fusion for degenerative disc disease. A degenerative phenotype was induced in cultured NP cells by treatment with an inflammatory protocol (10pg/ml IL-1β and 100pg/ml TNF-α) for 7 days. Gene expression of Treated NP cells was compared to Untreated NP cells via reverse transcriptase polymerase chain reaction. NP cells were then co-cultured with hMSCs in vitro and treated with the inflammatory protocol. Gene expression of Treated NP cells co-cultured with hMSCs was compared to Treated NP cells alone. Preliminary co-culture data demonstrated that IL-10 was uniquely and dramatically upregulated. Therefore, gene expression of Treated NP cells exposed to IL-10 for 24 hours was compared to Treated NP cells alone. RESULTS:Treated NP cells compared to Control NP cells showed upregulation of numerous pro-inflammatory cytokines, including CXCL5, IL-8, and IL-6 and downregulation of several antiinflammatory cytokines, including IL-10. After co-culture of Treated NP cells with hMSCs, a significant increase in gene expression was identified in IL-10 (+15.34 fold), BMP-6 (+2.32 fold), and LIF (+2.14 fold). A significant decrease in gene expression (p<.05) was seen in CCL7 (-2.03) and CXCL12 (-1.67). Exposure of Treated NP cells to IL-10 resulted in upregulation of COL-2 (+1.55 fold, p=.013) and downregulation of IL-8 (-1.4 fold), CXCL-5 (-1.58 fold,), and MMP-3 (-2.02 fold). CONCLUSION:This in vitro pilot study shows that co-culture of degenerative phenotype NP cells with hMSCs produces multiple gene regulatory changes associated with an antiinflammatory phenotype. Additionally, exposure of degenerative phenotype NP cells to IL-10 produces gene regulation associated with both antiinflammatory and pro-extracellular matrix effects. CLINICAL SIGNIFICANCE:These findings provide mechanistic support for the use of stem cell therapy as a strategy to decrease the pro-inflammatory molecular environment associated with disc degeneration. Additionally, given the challenges with the viability of hMSCs in the disc microenvironment, IL-10 may be another potential candidate for future targeted therapies for disc degeneration.

OBJECTIVES: To investigate the relationship between muscle quality and 1) patient-reported outcomes and 2) surgical outcomes after lumbar microdiscectomy surgery. METHODS: Adult patients ( double dagger 18 years) who underwent lumbar microdiscectomy from 2014 to 2021 at a single academic institution were identified. Outcomes were collected during the preoperative, 3-month, 6-month, and 1year postoperative periods. Those included were the Oswestry Disability Index (ODI), Visual Analog Scale Back and Leg (VAS -Back and VAS -Leg, respectively), and the mental and physical component of the short -form 12 survey (MCS and PCS). Muscle quality was determined by 2 systems: the normalized total psoas area (NTPA) and a paralumbar-based grading system. Surgical outcomes including 90-day surgical readmissions and 1 -year reoperations were also collected. - RESULTS: Of the 218 patients identified, 150 had good paralumbar muscle quality and 165 had good psoas muscle quality. Bivariant analysis demonstrated no difference between groups regarding surgical outcomes ( P > 0.05). Multivariable analysis demonstrated that better paralumbar muscle quality was not associated with any consistent changes in patient reported outcomes. Higher NTPA was associated with improved PCS at 6 months (est. = 6.703, [95% CI: 0.759-12.646], P = 0.030) and 12 months (est. = 6.625, [95% CI: 0.845-12.405], P = 0.027). There was no association between muscle quality and surgical readmissions or reoperations. CONCLUSIONS: Our analysis demonstrated that higher psoas muscle quality was associated with greater physical improvement postoperatively. Muscle quality did not affect surgical readmissions or reoperations. Additional studies are needed for further assessment of the implications of muscle quality on postoperative outcomes.

Objectives:The purpose of this study is to identify if construct length affects the rate of surgical complications and instrumentation revision following surgical fixation of subaxial and thoracolumbar Type B and C fractures. This study evaluates the effect of ankylosing spondylitis/diffuse idiopathic skeletal hyperostosis (AS/DISH) within this population on outcomes. Methods:Retrospective review of 91 cervical and 89 thoracolumbar Type B and C fractures. Groups were divided by construct length for analysis: short-segment (constructs spanning two or less segments adjacent to the fracture) and long-segment (constructs spanning more than two segments adjacent to the vertebral fracture). Results:For cervical fractures, construct length did not impact surgical complications (P = 0.641), surgical hardware revision (P = 0.167), or kyphotic change (P = 0.994). For thoracolumbar fractures, construct length did not impact surgical complications (P = 0.508), surgical hardware revision (P = 0.224), and kyphotic change (P = 0.278). Cervical Type B fractures were nonsignificantly more likely to have worsened kyphosis (P = 0.058) than Type C fractures. Assessing all regions of the spine, a diagnosis of AS/DISH was associated with an increase in kyphosis (P = 0.030) and a diagnosis of osteoporosis was associated with surgical hardware failure (P = 0.006). Conclusion:Patients with short-segment instrumentation have similar surgical outcomes and changes in kyphosis compared to those with long-segment instrumentation. A diagnosis of AS/DISH or osteoporosis was associated with worse surgical outcomes.

STUDY DESIGN:Retrospective cohort study. OBJECTIVE:The purpose of this study is to investigate whether weekday lumbar spine fusion surgery has an impact on surgical and inpatient physical therapy (PT) outcomes. SUMMARY OF BACKGROUND DATA:Timing of surgery has been implicated as a factor that may impact outcomes after spine surgery. Previous literature suggests that there may be an adverse effect to having surgery on the weekend. METHODS:All patients ≥18 years who underwent primary lumbar spinal fusion from 2014 to 2020 were retrospectively identified. Patients were subdivided into an early subgroup (surgery between Monday and Wednesday) and a late subgroup (surgery between Thursday and Friday). Surgical outcome variables included inpatient complications, 90-day readmissions, and 1-year revisions. PT data from the first inpatient PT session included hours to PT session, AM-PAC Daily Activity or Basic Mobility scores, and total gait trial distance achieved. RESULTS:Of the 1239 patients identified, 839 had surgery between Monday and Wednesday and 400 had surgery between Thursday and Friday. Patients in the later surgery subgroup were more likely to experience a nonsurgical neurologic complication (3.08% vs. 0.86%, P =0.008); however, there was no difference in total complications. Patients in the early surgery subgroup had their first inpatient PT session earlier than patients in the late subgroup (15.7 vs. 18.9 h, P <0.001). However, patients in the late subgroup achieved a farther total gait distance (98.2 vs. 75.4, P =0.011). Late surgery was a significant predictor of more hours of PT (est.=0.256, P =0.016) and longer length of stay (est.=2.277, P =0.001). There were no significant differences in readmission and revision rates. CONCLUSIONS:Patients who undergo surgery later in the week may experience more nonsurgical neurologic complications, longer wait times for inpatient PT appointments, and longer lengths of stay. This analysis showed no adverse effect of later weekday surgery as it relates to total complications, readmissions, and reoperations. LEVEL OF EVIDENCE:Level III.

BACKGROUND CONTEXT Degenerative spondylolisthesis (DS), which affects up to 25% of the adult U.S population, is defined by the anterior slippage of one vertebra with respect to the underlying vertebra. Although many patients remain asymptomatic or have symptoms that respond well to conservative treatment, other patients have refractory symptoms, such as radiculopathy, claudication, and back pain, necessitating surgical intervention. Despite this significant prevalence and high disease burden of degenerative spondylolisthesis, there is currently no consensus on proper surgical management. The two most common approaches to managing degenerative spondylolisthesis are posterior lumbar decompression and fusion (PLDF) and transforaminal lumbar decompression and fusion (TLIF) with concomitant PLDF. PURPOSE The present study aims to compare clinical outcomes for patients undergoing spinal fusion via PLDF and TLIF and clarify whether specific radiographic characteristics might influence optimal fusion technique, in order to help develop clinical guidelines that encompass the entire breadth of degenerative spondylolisthesis pathology. STUDY DESIGN/SETTING Retrospective cohort study. PATIENT SAMPLE Adult patients (> 18 years old) who underwent primary elective single level PLDF or combined TLIF/PLDF for degenerative spondylolisthesis from 2010 to 2020 at a single academic institution were identified. OUTCOME MEASURES N/A METHODS PROMs were collected preoperatively and 1 year after surgery and included: Oswestry Disability Index (ODI), the mental and physical component of the short-form-12 survey (MCS-12 and PCS-12), and the Visual Analog Scale Back and Leg (VAS Back and VAS Leg, respectively). Preoperative flexion-extension standing lumbar radiographs were reviewed by at least 2 independent reviewers for classification of DS. DS was classified using the Meyerding grading system as well as the Clinical and Radiographic Degenerative Spondylolisthesis (CARDS) classification system. Meyerding grade is determined by measuring the degree of slip on lateral lumbar radiographs. The CARDS classification system divides DS into 4 classes and accounts for “bone on bone” apposition, anterior translation, and kyphotic alignment. Patients were grouped for analysis by Meyerding grade and separately by CARDS subtype. PROM outcomes were compared between procedure types (PLDF and TLIF) within each group. Delta PROM values were calculated by subtracting preoperative scores from 1-year postoperative scores. Multivariable linear regression analyses were used to further assess the independent effect of procedure type on delta PROM scores for each Meyerding grade and CARDS class. RESULTS A total of 594 patients were identified. There were 260 patients (55.4% female) who underwent PLDF and 334 patients (54.5% female) who underwent TLIF. Patients in the PLDF group were older (65.9 vs 61.5, p<0.001), had higher Charlson comorbidity indices (2.79 vs 2.15, p=0.001), and were more likely to have a Meyerding grade of 1 (90.8% vs 81.4%, p=0.002). Patients with CARDS class A spondylolisthesis experienced greater improvement in ODI (-11.02 vs -3.06, p=0.005) when they underwent TLIF; however, patients with CARDS class B experienced greater ODI improvement after a PLDF (-14.33 vs -5.45, p<0.001). Patients with Meyerding grade 1 spondylolisthesis experienced greater improvement in ODI (-10.15 vs -6.27, p=0.006) and MCS (5.68 vs 2.87, p=0.011) when they underwent PLDF compared to TLIF. There were no other differences in PROM improvement between approaches for other grades and classes. After controlling for patient characteristics, these differences persisted on linear regression analysis. CONCLUSIONS While there are several factors to consider, these results show that PLDF may be the optimal approach for DS patients with milder degrees of disc slippage. Patients with advanced disc collapse and endplate apposition may benefit more from TLIF. In patients with more severe spondylolisthesis +/- kyphosis, we observed no difference in clinical outcomes 1 year after surgery. FDA Device/Drug Status This abstract does not discuss or include any applicable devices or drugs.

To determine the impact of poor mental health on patient-reported and surgical outcomes after microdiscectomy. Patients ≥ 18 years who underwent a single-level lumbar microdiscectomy from 2014 to 2021 at a single academic institution were retrospectively identified. Patient-reported outcomes (PROMs) were collected at preoperative, three-month, and one-year postoperative time points. PROMs included the Oswestry Disability Index (ODI), Visual Analog Scale Back and Leg (VAS Back and VAS Leg, respectively), and the mental and physical component of the short form-12 survey (MCS and PCS). The minimum clinically important differences (MCID) were employed to compare scores for each PROM. Patients were categorized as having worse mental health or better mental health based on a MCS threshold of 50. Of 210 patients identified, 128 (61

Background:The North American Spine Society (NASS) assembled the first ever comprehensive naming system for describing lumbar disc disease, including lumbar disc herniation. The objectives of this study were (1) to determine which NASS descriptors are most predictive of independent patient-reported outcomes after microdiscectomy and (2) to identify the inter-rater reliability of each NASS descriptor. Methods:Adult patients (≥18 years) who underwent a lumbar microdiscectomy from 2014-2021 were retrospectively identified. Patient-reported outcome measures (PROMs) were collected at preoperative, 3-month, and 1-year postoperative time points. Lumbar disc herniations were evaluated and classified on preoperative MRI using the NASS lumbar disc nomenclature specific to disc herniation. Results:About 213 microdiscectomy patients were included in the final analysis. Herniation descriptors exhibiting the greatest reliability included sequestration status (κ=0.83), axial disc herniation area (κ=0.83), and laterality (κ=0.83). The descriptor with the lowest inter-rater reliability was direction of migration (κ=0.53). At 3 months, a sequestered herniation was associated with lower odds of achieving the minimal clinically important difference (MCID) for ODI (p=.004) and MCS (p=.032). At 12 months, a similar trend was observed for Oswestry Disability Index (ODI) MCID achievement (p=.001). At 3 months, a herniation with larger axial area was a predictor of MCID achievement in ODI (p=.004) and the mental component summary (MCS) (p=.009). Neither association persisted at 12 months; however, larger axial disc herniation area was able to predict MCID achievement in the Visual Analogue Scale (VAS) leg (p=.031) at 12 months. Conclusions:The utility of the NASS nomenclature system in predicting postoperative outcomes after microdiscectomy has yet to be studied. We showed that sequestration status and disc area are both reliable and able to predict the odds of achieving MCID in certain clinical outcomes at 3 months and 12 months after surgery. Hence, preoperative imaging analysis of lumbar disc herniations may be useful in accurately setting patient expectations.

STUDY DESIGN:Retrospective cohort study. OBJECTIVE:The purpose of this study is to determine which demographic, surgical, and radiographic preoperative characteristics are most associated with the need for subsequent fusion after decompression lumbar spinal surgery. SUMMARY OF BACKGROUND DATA:There is a relatively high rate of the need for repeat decompression or fusion after an index decompression procedure for degenerative spine disease. Nevertheless, there is a dearth of literature identifying risk factors for lumbar fusion following decompression surgery. METHODS:Patients 18 years or older receiving a primary lumbar decompression surgery within the levels of L3-S1 between 2011 and 2020 were identified. All patients had preoperative radiographs and 2 years of follow-up data. Chart review was performed for surgical characteristics and demographics. The sagittal parameters included lumbar lordosis (LL), segmental lordosis (SL), anterior disk height (aDH), posterior disk height (pDH), sacral slope (SS), and pelvic tilt (PT). Pelvic incidence (PI=PT+SS) and pelvic incidence minus lumbar lordosis (PI-LL) were calculated. In addition, the Roussouly classification was determined for each patient. Bivariant and multivariant analyses were performed. RESULTS:Of the 363 patients identified in this study, 96 patients had a fusion after their index decompression surgery. Multivariable analysis identified involvement of L4-L5 level in the decompression [odds ratio (OR)=1.83 (1.09-3.14), P =0.026], increased L5-S1 segmental lordosis [OR=1.08 (1.03-1.13), P =0.001], decreased SS [OR=0.96 (0.93-0.99), P =0.023], and decreased endplate obliquity [OR=0.88 (0.77-0.99), P =0.040] as significant independent predictors of fusion after decompression surgery. CONCLUSIONS:This is one of the first studies to assess preoperative sagittal parameters in conjunction with demographic variables to determine predictors of the need for fusion after index decompression. We demonstrated that decompression at L4-L5, greater L5-S1 segmental lordosis, decreased sacral slope, and decreased endplate obliquity were associated with higher rates of fusion after decompression surgery.

Introduction: Given the increasing incidence of traumatic thoracolumbar injuries in recent years, studies have sought to investigate potential risk factors for outcomes in these patients. Research question: The aim of this study was to investigate trends and risk factors for in-hospital mortality after fusion for traumatic thoracolumbar injury. Materials and methods: Patients undergoing thoracolumbar fusion after traumatic injury were queried from the National Inpatient Sample (NIS) from 2012 to 2017. Analysis was performed to identify risk factors for inpatient mortality after surgery. Results: Patients in 2017 were on average older (51.0 vs. 48.5, P = 0.004), had more admitting diagnoses (15.5 vs. 10.7, p < 0.001), were less likely to be White (75.8% vs. 81.2%, p = 0.006), were from a ZIP code with a higher median income quartile (Quartile 1: 31.4% vs. 28.6%, p = 0.011), and were more likely to have Medicare as a primary payer (22.9% vs. 30.1%, p < 0.001). Bivariate analysis of demographics and surgical characteristics demonstrated that patients in the in-hospital mortality group (n = 90) were older (70.2 vs. 49.6, p < 0.001), more likely to be male (74.4% vs. 62.8%, p = 0.031), had a great number of admitted diagnoses (21.3 vs. 12.7, p < 0.001), and were more likely to be insured by Medicare (70.0% vs. 27.0%, p < 0.001). Multivariate regression analysis found age (OR 1.06, p < 0.001) and Black race (OR 3.71, p = 0.007) were independently associated with in-hospital mortality. Conclusion: Our study of nationwide, traumatic thoracolumbar fusion procedures from 2012 to 2017 in the NIS database found older, black patients were at increased risk for in-hospital mortality after surgery.