Circulating microRNAs May Be Predictive of Degenerative Cervical Myelopathy.

STUDY DESIGN: Basic Science. OBJECTIVE: The objective of this study was to identify a unique serum profile of circulating miRNAs and inflammatory markers in patients with degenerative cervical myelopathy (DCM) compared to healthy controls (HC). SUMMARY OF BACKGROUND DATA: Currently, DCM is diagnosed with a combination of history, physical examination, and close correlation to advanced imaging. To date, no serum marker has been identified to be diagnostic of this condition. METHODS: Whole venous blood was collected from patients with DCM as well as healthy age- and sex-matched controls. miRNA was extracted from venous blood and a screening analysis was initially conducted to identify miRNA dysregulation in DCM patients. RT-qPCR was used to analyze the expression of 2 specific miRNAs based on screening analysis and literature review. Bioinformatics analysis was used to identify gene networks and potential targets of the miRNA. In addition, the serum inflammatory profile of DCM and HC groups was differentiated using a pro-inflammatory panel. RESULTS: Thirty-six patients were enrolled in the DCM group (36.1% male, 61.5±9.5 y) while 35 patients were enrolled in the HC group (31.4% male, 57.5±8.9 y). Of the 15 total miRNAs differentially expressed between DCM and HC groups, two were selected for further analysis: miR-223-3p (upregulated) and miR-451a (downregulated). Functional gene network analysis revealed the highest-ranking gene network was involved in neurological disease, while the most overexpressed miRNA in this network (miR-233-3p) was noted to have over 100 targets including CDKN1B and the insulin receptor. Serum cytokine analysis showed significant upregulation of several pro-inflammatory cytokines in the DCM cohort compared to the HC group. CONCLUSION: DCM patients demonstrated a set of unique circulating miRNAs in addition to a different serum inflammatory profile compared to HC. These miRNAs may potentially serve as targets for future therapeutic intervention or diagnostic/prognostic testing.

The Relationship Between Disc Herniation Morphology and Patient-Reported Outcomes after Microdiscectomy.

OBJECTIVE: Determine if herniation morphology based on the Michigan State University Classification is associated with differences in (1) patient-reported outcome measures (or (2) surgical outcomes after a microdiscectomy. METHODS: Adult patients undergoing single-level microdiscectomy between 2014 and 2021 were identified. Demographics and surgical characteristics were collected through a query search and manual chart review. The Michigan State University classification, which assesses disc herniation laterality (zone A was central, zone B/C was lateral) and degree of extrusion into the central canal (grade 1 was up to 50% of the distance to the intra-facet line, grade >1 was beyond this line), was identified on preoperative MRIs. patient-reported outcome measures were collected at preoperative, 3-month, and 1-year postoperative time points. RESULTS: Of 233 patients, 84 had zone A versus 149 zone B/C herniations while 76 had grade 1 disc extrusion and 157 had >1 grade. There was no difference in surgical outcomes between groups (P > 0.05). Patients with extrusion grade >1 were found to have lower Physical Component Score at baseline. On bivariate and multivariable logistic regression analysis, extrusion grade >1 was a significant independent predictor of greater improvement in Physical Component Score at three months (estimate = 7.957; CI: 4.443-11.471, P < 0.001), but not at 1 year. CONCLUSIONS: Although all patients were found to improve after microdiscectomy, patients with disc herniations extending further posteriorly reported lower preoperative physical function but experienced significantly greater improvement three months after surgery. However, improvement in Visual Analog Scale Leg and back, ODI, and MCS at three and twelve months was unrelated to laterality or depth of disc herniation.

Relating preoperative MCS-12 to microdiscectomy outcomes.

PURPOSE: To determine the impact of poor mental health on patient-reported and surgical outcomes after microdiscectomy. METHODS: 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. RESULTS: Of 210 patients identified, 128 (61%) patients had a preoperative MCS score ≤ 50. There was no difference in 90-day surgical readmissions or spine reoperations within one year. At 3- and 12-month time points, both groups demonstrated improvements in all PROMs (p < 0.05). At three months postoperatively, patients with worse mental health had significantly lower PCS (42.1 vs. 46.4, p = 0.004) and higher ODI (20.5 vs. 13.3, p = 0.006) scores. Lower mental health scores were associated with lower 12-month PCS scores (43.3 vs. 48.8, p < 0.001), but greater improvements in 12-month ODI (- 28.36 vs. - 18.55, p = 0.040). CONCLUSION: While worse preoperative mental health was associated with lower baseline and postoperative PROMs, patients in both groups experienced similar improvements in PROMs. Rates of surgical readmissions and reoperations were similar among patients with varying preoperative mental health status.

The impact of robotic assistance for lumbar fusion surgery on 90-day surgical outcomes and 1-year revisions.

Objectives: To evaluate the (1) 90-day surgical outcomes and (2) 1-year revision rate of robotic versus nonrobotic lumbar fusion surgery. Methods: Patients >18 years of age who underwent primary lumbar fusion surgery at our institution were identified and propensity-matched in a 1:1 fashion based on robotic assistance during surgery. Patient demographics, surgical characteristics, and surgical outcomes, including 90-day surgical complications and 1-year revisions, were collected. Multivariable regression analysis was performed. Significance was set to P < 0.05. Results: Four hundred and fifteen patients were identified as having robotic lumbar fusion and were matched to a control group. Bivariant analysis revealed no significant difference in total 90-day surgical complications (P = 0.193) or 1-year revisions (P = 0.178). The operative duration was longer in robotic surgery (287 + 123 vs. 205 + 88.3, P ≤ 0.001). Multivariable analysis revealed that robotic fusion was not a significant predictor of 90-day surgical complications (odds ratio [OR] = 0.76 [0.32-1.67], P = 0.499) or 1-year revisions (OR = 0.58 [0.28-1.18], P = 0.142). Other variables identified as the positive predictors of 1-year revisions included levels fused (OR = 1.26 [1.08-1.48], P = 0.004) and current smokers (OR = 3.51 [1.46-8.15], P = 0.004). Conclusion: Our study suggests that robotic-assisted and nonrobotic-assisted lumbar fusions are associated with a similar risk of 90-day surgical complications and 1-year revision rates; however, robotic surgery does increase time under anesthesia.

PA and NP burnout in orthopedic surgery.

OBJECTIVE: To quantify the burnout rate among physician associates/assistants (PAs) and NPs in a large orthopedic surgery practice affiliated with an academic institution. METHODS: The Maslach Burnout Inventory (MBI) and original research questions were given to all PAs and NPs in orthopedics at the facility. Burnout was defined as a high level of emotional exhaustion or depersonalization on the MBI subscale. RESULTS: Of the 129 PAs and NPs in orthopedics at our institution, 91 (70.5%) completed all survey items. Nearly 42% of respondents were burned out, as defined by high depersonalization or emotional exhaustion. PAs and NPs who met the burnout criteria were significantly older than those who did not (41.8 ± 10 versus 36.5 ± 7.71 years, P = .007) and spent longer in practice (12.4 ± 6.66 versus 9.35 ± 6.41 years, P = .01). CONCLUSIONS: The prevalence of burnout is high among PAs and NPs in orthopedics who practice in an academic setting.

Impact of Weekday on Short-term Surgical Outcomes After Lumbar Fusion Surgery.

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.

The Inhibitory Effect of NSAIDs and Opioids on Spinal Fusion: An animal model.

STUDY DESIGN: Translational Research. OBJECTIVE: To evaluate the relative effects of NSAIDs, opioids, and a combination of the two on spinal fusion inhibition in a rodent model. SUMMARY OF BACKGROUND DATA: Nonsteroidal anti-inflammatory drugs (NSAIDs) and opioids are common postoperative analgesic agents. Since NSAIDs inhibit the cyclooxygenase (COX) pathway they are seldom prescribed following spinal fusion. Opioids may be given instead, but recent evidence suggests opioids also adversely affect spinal fusion quality and success. METHODS: Eighty male Sprague-Dawley rats underwent L4-5 posterior lumbar fusion and were given one of the following analgesia regimens: saline, morphine (6 mg/kg), ketorolac (4 mg/kg), or morphine (3 mg/kg) and ketorolac (2 mg/kg). Serum samples were drawn to evaluate systemic pro-osteoblastic cytokines and vascular endothelial growth factor-A (VEGF-A) levels, which were measured via enzyme-linked immunosorbent assays (ELISA). After six weeks, the rats were sacrificed and the operated spinal segments underwent manual palpation, microCT, and histological analysis. RESULTS: Manual palpation scores were significantly diminished in the opioid, NSAID, and multimodal groups when compared to control (P<0.001). MicroCT fusion scores (P<0.001) and fusion rates (control: 75% vs. NSAID: 35% vs. opioid: 0% vs. combination: 15%, P<0.001) were significantly diminished in the treatment groups. The bone volume (BV) to tissue volume (TV) ratio (BV/TV) (P<0.001) and bone mineral density (BMD) (P<0.001) were all lower in the treatment groups with the opioid and combined groups having the lowest BMD. Although statistically insignificant (P<0.09), the concentration of VEGF-A was greater in the control group compared to opioids, NSAIDs, and the combined group. CONCLUSION: Opioids and NSAIDs, both independently and combined, inhibited spinal fusion and caused inferior bony callus. Administration of opioids resulted in the lowest rate of spinal fusion. We propose this may be due to the inhibition of VEGF-A, which limits angiogenesis to the burgeoning fusion mass.

The Effect of Muscle Quality on Outcomes after Microdiscectomy.

OBJECTIVES: To investigate the relationship between muscle quality and 1) patient-reported outcomes and 2) surgical outcomes after lumbar microdiscectomy surgery. METHODS: Adult patients (≥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 1-year 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.

Significance of Facet Fluid Index in Anterior Cervical Degenerative Spondylolisthesis.

STUDY DESIGN: Retrospective cohort study. PURPOSE: To correlate cervical facet fluid characteristics to radiographic spondylolisthesis, determine if facet fluid is associated with instability in cervical degenerative spondylolisthesis, and examine whether vertebral levels with certain facet fluid characteristics and spondylolisthesis are more likely to be operated on. OVERVIEW OF LITERATURE: The relationship between facet fluid and lumbar spondylolisthesis is well-documented; however, there is a paucity of literature investigating facet fluid in degenerative cervical spondylolisthesis. METHODS: Patients diagnosed with cervical degenerative spondylolisthesis were identified from a hospital's medical records. Demographic and surgical characteristics were collected through a structured query language search and manual chart review. Radiographic measurements were made on preoperative MRIs for all vertebral levels diagnosed with spondylolisthesis and adjacent undiagnosed levels between C3 and C6. The facet fluid index was calculated by dividing the facet fluid measurement by the width of the facet. Bivariate analysis was conducted to compare facet characteristics based on radiographic spondylolisthesis and spondylolisthesis stability. RESULTS: We included 154 patients, for whom 149 levels were classified as having spondylolisthesis and 206 levels did not. The average facet fluid index was significantly higher in patients with spondylolisthesis (0.26±0.07 vs. 0.23±0.08, p <0.001). In addition, both fluid width and facet width were significantly larger in patients with spondylolisthesis (p <0.001 each). Cervical levels in the fusion construct demonstrated a greater facet fluid index and were more likely to have unstable spondylolisthesis than stable spondylolisthesis (p <0.001 each). CONCLUSIONS: Facet fluid index is associated with cervical spondylolisthesis and an increased facet size and fluid width are associated with unstable spondylolisthesis. While cervical spondylolisthesis continues to be an inconclusive finding, vertebral levels with spondylolisthesis, especially the unstable ones, were more likely to be included in the fusion procedure than those without spondylolisthesis.

Correction of Spinal Sagittal Alignment after Posterior Lumbar Decompression: Does Severity of Central Canal Stenosis Matter?

STUDY DESIGN: This study adopted a retrospective study design. PURPOSE: Our study aimed to investigate the impact of central canal stenosis severity on surgical outcomes and lumbar sagittal correction after lumbar decompression. OVERVIEW OF LITERATURE: Studies have evaluated sagittal correction in patients with central canal stenosis after lumbar decompression and the association of stenosis severity with worse preoperative sagittal alignment. However, none have evaluated the impact of spinal stenosis severity on sagittal correction. METHODS: Patients undergoing posterior lumbar decompression (PLD) of ≤4 levels were divided into severe and non-severe central canal stenosis groups based on the Lee magnetic resonance imaging (MRI) grading system. Patients without preoperative MRI or inadequate visualization on radiographs were excluded. Surgical characteristics, clinical outcomes, and sagittal measurements were compared. Multivariate logistic regression was performed to determine the predictors of pelvic tilt (PT), sacral slope (SS), lumbar lordosis (LL), and pelvic incidence minus lumbar lordosis (PI-LL). RESULTS: Of the 142 patients included, 39 had severe stenosis, and 103 had non-severe stenosis. The mean follow-up duration for the cohort was 4.72 months. Patients with severe stenosis were older, had higher comorbidity indices and levels decompressed, and longer lengths of stay and operative times (p <0.001). Although those with severe stenosis had lower lordosis, lower SS, and higher PI-LL mismatch preoperatively, no differences in Delta LL, SS, PT, or PI-LL were observed between the two groups (p >0.05). On multivariate regression, severe stenosis was a significant predictor of a lower preoperative LL (estimate=-5.243, p =0.045) and a higher preoperative PI-LL mismatch (estimate=6.192, p =0.039). No differences in surgical or clinical outcomes were observed (p >0.05). CONCLUSION: Severe central lumbar stenosis was associated with greater spinopelvic mismatch preoperatively. Sagittal balance improved in both patients with severe and non-severe stenosis after PLD to a similar degree, with differences in sagittal parameters remaining after surgery. We also found no differences in postoperative outcomes associated with stenosis severity.

How Does the Severity of Neuroforaminal Compression in Cervical Radiculopathy Affect Outcomes of Anterior Cervical Discectomy and Fusion.

STUDY DESIGN: This study is a retrospective cohort study. PURPOSE: This study aims to determine whether preoperative neuroforaminal stenosis (FS) severity is associated with motor function patient-reported outcome measures (PROMs) following anterior cervical discectomy and fusion (ACDF). OVERVIEW OF LITERATURE: Cervical FS can significantly contribute to patient symptoms. While magnetic resonance imaging (MRI) has been used to classify FS, there has been limited research into the impact of FS severity on patient outcomes. METHODS: Patients undergoing primary, elective 1-3 level ACDF for radiculopathy at a single academic center between 2015 and 2021 were identified retrospectively. Cervical FS was evaluated using axial T2-weighted MRI images via a validated grading scale. The maximum degree of stenosis was used for multilevel disease. Motor symptoms were classified using encounters at their final preoperative and first postoperative visits, with examinations ≤3/5 indicating weakness. PROMs were obtained preoperatively and at 1-year follow-up. Bivariate analysis was used to compare outcomes based on stenosis severity, followed by multivariable analysis. RESULTS: This study included 354 patients, 157 with moderate stenosis and 197 with severe stenosis. Overall, 58 patients (16.4%) presented with upper extremity weakness ≤3/5. A similar number of patients in both groups presented with baseline motor weakness (13.5% vs. 16.55, p =0.431). Postoperatively, 97.1% and 87.0% of patients with severe and moderate FS, respectively, experienced full motor recovery (p =0.134). At 1-year, patients with severe neuroforaminal stenosis presented with significantly worse 12-item Short Form Survey Physical Component Score (PCS-12) (33.3 vs. 37.3, p =0.049) but demonstrated a greater magnitude of improvement (Δ PCS-12: 5.43 vs. 0.87, p =0.048). Worse stenosis was independently associated with greater ΔPCS-12 at 1-year (ß =5.59, p =0.022). CONCLUSIONS: Patients with severe FS presented with worse preoperative physical health. While ACDF improved outcomes and conferred similar motor recovery in all patients, those with severe FS reported much better improvement in physical function.

Does physical therapy impact clinical outcomes after lumbar decompression surgery?

Objectives: The objectives of our study were to (1) determine if physical therapy (PT) impacts patient-reported outcomes (PROMs) after lumbar decompression surgery and (2) determine if PT impacts postsurgical readmissions or reoperations after lumbar decompression surgery. Methods: Patients >18 years of age who underwent primary one- or two-level lumbar decompression at our institution were identified. Patient demographics, surgical characteristics, surgical outcomes (all-cause 90 days readmissions and 90 days surgical readmissions), and patient-reported outcomes (PROMs) were compared between the groups. Multivariate linear regression was utilized to determine the individual predictors of 90 days readmissions and PROMs at the 1-year postoperative point. Alpha was set at P < 0.05. Results: Of the 1003 patients included, 421 attended PT postoperatively. On univariate analysis, PT attendance did not significantly impact 90-day surgical reoperations (P = 0.225). Although bivariate analysis suggests that attendance of PT is associated with worse improvement in physical function (P = 0.041), increased preoperative Visual Analogue Scale leg pain (0 = 0.004), and disability (P = 0.006), as measured by the Oswestry Disability Index, our multivariate analysis, which accounts for confounding variables found there was no difference in PROM improvement and PT was not an independent predictor of 90-day all-cause readmissions (P = 0.06). Instead, Charlson Comorbidity Index (P = 0.025) and discharge to a skilled nursing facility (P = 0.013) independently predicted greater 90-day all-cause readmissions. Conclusions: Postoperative lumbar decompression PT attendance does not significantly affect clinical improvement, as measured by PROMs or surgical outcomes including all-cause 90 days readmissions and 90-day surgical readmissions.

Radiographic and Patient-Reported Outcomes: Anteriorly Placed Transforaminal Lumbar Interbody Fusion Cage vs. Anterior Lumbar Interbody Fusion with Posterior Instrumentation.

STUDY DESIGN: Retrospective Cohort Study. OBJECTIVE: To compare outcomes in anteriorly placed transforaminal lumbar interbody fusions (TLIFs) and anterior lumbar interbody fusions (ALIFs). SUMMARY OF BACKGROUND DATA: TLIF and ALIF are surgical techniques that have become more prevalent in recent years. Although studies have compared the two, none have considered TLIFs with anteriorly placed cages, which may serve as a better comparison to ALIFs. MATERIALS AND METHODS: Patients undergoing TLIF or ALIF with posterior instrumentation from 2010-2020 at a tertiary care institution were retrospectively identified. TLIF cage position was assessed and those with anterior placement were included. Electronic medical records were reviewed to identify patient characteristics and patient-reported outcomes. Radiographic outcomes included posterior disc height (DH), lumbar lordosis (LL), sacral slope (SS), pelvic incidence (PI) and pelvic tilt (PT). Statistical analysis was performed to compare the two groups. RESULTS: Of the 351 patients, 108 had ALIF with posterior instrumentation and 207 had a TLIF. Preoperatively, TLIF patients had less LL (53.7° vs. 60.6°, P<0.001), SS (38.3° vs. 43.7°, P<0.001), and PI (60.1° vs. 66.1°, P<0.001), all of which remained significant at one-year and long-term follow-up (P<0.001). The TLIF group had less ∆DH (1.51° vs. 5.43°, P<0.001), ∆LL (1.8° vs. 2.97°, P=0.038), and ∆SL (0.18° vs. 4.40°, P<0.001) at one year postoperatively. At two to three years, ∆DH (P<0.001) and ∆SL (P=0.001) remained significant, but ∆LL (P=0.695) did not. Patients in the TLIF group had higher VAS-Back scores one year postoperatively (3.68 vs. 2.16, P=0.008) and experienced less improvement in ODI (-17.1 vs. -28.6, P=0.012) and VAS-Back (-2.67 vs. -4.50, P=0.008) compared to ALIF patients. CONCLUSIONS: Our findings suggest that ALIF with posterior instrumentation performed superiorly in radiographic outcomes and PROMs compared to anteriorly placed TLIFs. Anteriorly placed TLIF cages may not achieve the same results as those of ALIF cages.

Risk Factors for Postoperative Urinary Retention After Lumbar Fusion Surgery: Anesthetics and Surgical Approach.

INTRODUCTION: Postoperative urinary retention (POUR) after lumbar fusion surgery can lead to longer hospital stays and thus increased risk of developing other postoperative complications. Therefore, we aimed to determine the relationship between POUR and (1) surgical approach and (2) anesthetic agents, including sugammadex and glycopyrrolate. METHODS: After institutional review board approval, L4-S1 single-level lumbar fusion surgeries between 2018 and 2021 were identified. A 3:1 propensity match of patients with POUR to those without was conducted, controlling for patient age, sex, diabetes status, body mass index, smoking status, history of benign prostatic hyperplasia, and the number of levels decompressed. POUR was defined as documented straight catheterization yielding >400 mL. We compared patient demographic, surgical, anesthetic, and postoperative characteristics. A bivariant analysis and backward multivariable stepwise logistic regression analysis ( P -value < 0.200) were performed. Significance was set to P < 0.05. RESULTS: Of the 899 patients identified, 51 met the criteria for POUR and were matched to 153 patients. No notable differences were observed between groups based on demographic or surgical characteristics. On bivariant analysis, patients who developed POUR were more likely to have been given succinylcholine (13.7% vs. 3.92%, P = 0.020) as an induction agent. The independent predictors of POUR identified by multivariable analysis included the use of succinylcholine {odds ratio (OR), 4.37 (confidence interval [CI], 1.26 to 16.46), P = 0.022} and reduced postoperative activity (OR, 0.99 [CI, 0.993 to 0.999], P = 0.049). Factors protective against POUR included using sugammadex as a reversal agent (OR, 0.38 [CI, 0.17 to 0.82], P = 0.017). The stepwise regression did not identify an anterior surgical approach as a notable predictor of POUR. CONCLUSION: We demonstrate that sugammadex for anesthesia reversal was protective against POUR while succinylcholine and reduced postoperative activity were associated with the development of POUR. In addition, we found no difference between the anterior or posterior approach to spinal fusion in the development of POUR.

Does the Severity of Foraminal Stenosis Impact Outcomes of Lumbar Decompression Surgery?

OBJECTIVE: To establish the relationship between the magnitude of foraminal stenosis and 1) improvement in patient-reported outcomes, 2) improvement in motor function after lumbar decompression surgery, and 3) difference in surgical outcomes. METHODS: Patients who underwent one-level posterior lumbar decompression for radiculopathy were retrospectively identified. Patient demographics and surgical characteristics were collected through a query search and manual chart review of the electronic medical records. Foraminal stenosis was determined on magnetic resonance imaging and graded using Lee et al.'s validated methodology as none, mild, moderate, or severe. Surgical outcomes, motor function, and patient-reported outcome measures (PROMs) were compared based on the amount of stenosis (mild vs. moderate vs. severe). Bivariant and multivariant analyses were performed. RESULTS: Severe stenosis demonstrated more 90-day readmissions (0.00% vs. 0.00% vs. 8.57%, respectively, P = 0.019), though this effect did not remain significant on multivariate analysis (P = 0.068). There was no association between stenosis severity and the degree of functional impairment or PROMs preoperatively. Patients with moderate or severe preoperative foraminal stenosis showed improvement in all PROMs after surgery (P < 0.05) except the mental component of the Short Form 12 survey. Notably, central stenosis grade was insignificantly different between groups (P = 0.358). Multivariable logistic regression analysis did not identify any significant independent predictors of surgical outcomes or changes in PROMs. CONCLUSIONS: We demonstrated that regardless of foraminal stenosis severity preoperatively, patients have a similar improvement in PROMs, surgical outcomes, and restoration of motor function after lumbar decompression surgery for radiculopathy.

The Sanders Classification and Obesity: Do Obese Kids With AIS Present With More Advanced Skeletal Maturity?

INTRODUCTION: Obese and overweight (OOW) patients with adolescent idiopathic scoliosis (AIS) have been shown to initially present with a more advanced Risser score compared to normal weight (NW) patients. The Sanders Maturity Scale (SMS) is now more commonly used by surgeons to assist with treatment decisions because it more reliably predicts skeletal maturity. However, the relationship between SMS and obesity has not been described. We hypothesize that in patients with AIS, OOW patients will have a higher SMS score on initial presentation when compared to NW patients. METHODS: Billing data from 2 different institutions were used to identify patients with AIS presenting to a pediatric orthopaedic spine surgeon for an initial visit between July 2012 and March 2020. We excluded those without height/weight data, spine radiographs, or left-hand radiographs for measuring SMS stage. Body mass index-for-age percentiles were calculated and used to group patients into NW (<85th percentile) or OOW (85th percentile and above) per Centers for Disease Control guidelines. After collecting preliminary data, a power analysis was performed using average SMS scores between NW and OOW patients with an alpha of 0.5, determining a needed sample size of approximately 300 male and 300 female subjects. RESULTS: Five hundred ninety patients (296 female, 294 male) were identified. The SMS stage at presentation was significantly greater in OOW compared to NW patients for both females (5.9±1.8 vs. 5.2±1.7; P =0.003) and males (4.9±1.9 vs. 4.1±1.8; P =0.002). The major curve magnitude for OOW females was significantly different from NW females (36±16 degrees vs. 30±16 degrees; P =0.004). The major curve magnitude was not different for OOW and NW males ( P =0.3). CONCLUSION: At initial presentation, OOW patients present at a greater skeletal maturity as measured by the SMS compared with NW patients. OOW female patients present with a greater major curve magnitudes than NW female patients. These results highlight negative implications of the pediatric obesity epidemic as it relates to the AIS population. These findings can be used to counsel families and provide anticipatory guidance for the AIS treatment plan. LEVEL OF EVIDENCE: Level III-cross-sectional study.

The Impact of Physical Therapy After Lumbar Fusion Surgery.

STUDY DESIGN: Retrospective Cohort. OBJECTIVE: To determine if outcomes varied between patients based on physical therapy (PT) attendance after lumbar fusion surgery. SUMMARY OF BACKGROUND DATA: The literature has been mixed regarding the efficacy of postoperative PT to improve disability and back pain, as measured by patient-reported outcome measures. Given the prevalence of PT referrals and lack of high-quality evidence, there is a need for additional studies investigating the efficacy of PT after lumbar fusion surgery to aid in developing robust clinical guidelines. METHODS: We retrospectively identified patients receiving lumbar fusion surgery by current procedural terminology codes and separated them into 2 groups based on whether PT was prescribed. Electronic medical records were reviewed for patient and surgical characteristics, PT utilization, and surgical outcomes. Patient-reported outcome measures (PROMs) were identified and compared preoperatively, at 90 days postoperatively and one year postoperatively. RESULTS: The two groups had similar patient characteristics and comorbidities and demonstrated no significant differences between readmission, complication, and revision rates after surgery. Patients that attended PT had significantly more fused levels (1.41 ± 0.64 vs. 1.32 ± 0.54, P =0.027), longer operative durations (234 ± 96.4 vs. 215 ± 86.1 min, P =0.012), and longer postoperative hospital stays (3.35 ± 1.68 vs. 3.00 ± 1.49 days, P =0.004). All groups improved similarly by Oswestry Disability Index, short form-12 physical and mental health subsets, and back and leg pain by Visual Analog Scale at 90-day and 1-year follow-up. CONCLUSION: Our data suggest that physical therapy does not significantly impact PROMs after lumbar fusion surgery. Given the lack of data suggesting clear benefit of PT after lumbar fusion, surgeons should consider more strict criteria when recommending physical therapy to their patients after lumbar fusion surgery. LEVEL OF EVIDENCE: Level-Ⅲ.

The impact of demineralized bone matrix characteristics on pseudarthrosis and surgical outcomes after posterolateral lumbar decompression and fusion.

Objectives: The objectives of our study were to compare the fusion rates and surgical outcomes of lumbar fusion surgery based on the (1) type of demineralized bone matrix (DBM) carrier allograft, (2) the presence/absence of a carrier, and (3) the presence of bone fibers in DBM. Methods: Patients >18 years of age who underwent single-level posterolateral decompression and fusion (PLDF) between L3 and L5 between 2014 and 2021 were retrospectively identified. We assessed bone grafts based on carrier type (no carrier, sodium hyaluronate carrier, and glycerol carrier) and the presence of bone fibers. Fusion status was determined based on a radiographic assessment of bony bridging, screw loosening, or change in segmental lordosis >5°. Analyses were performed to assess fusion rates and surgical outcomes. Results: Fifty-four patients were given DBM with a hyaluronate carrier, 75 had a glycerol carrier, and 94 patients were given DBM without a carrier. DBM carrier type, bone fibers, and carrier presence had no impact on 90-day readmission rates (P = 0.195, P = 0.099, and P = 1.000, respectively) or surgical readmissions (P = 0.562, P = 0.248, and P = 0.640, respectively). Multivariable logistic regression analysis found that type of carrier, presence of fibers (odds ratio [OR] = 1.106 [0.524-2.456], P = 0.797), and presence of a carrier (OR = 0.701 [0.370-1.327], P = 0.274) were also not significantly associated with successful fusion likelihood. Conclusion: Our study found no significant differences between DBM containing glycerol, sodium hyaluronate, or no carrier regarding fusion rates or surgical outcomes after single-level PLDF. Bone particulates versus bone fibers also had no significant differences regarding the likelihood of bony fusion.

Reasons for transfer and subsequent outcomes among patients undergoing elective spine surgery at an orthopedic specialty hospital.

Objective: To evaluate the reasons for transfer as well as the 90-day outcomes of patients who were transferred from a high-volume orthopedic specialty hospital (OSH) following elective spine surgery. Materials and Methods: All patients admitted to a single OSH for elective spine surgery from 2014 to 2021 were retrospectively identified. Ninety-day complications, readmissions, revisions, and mortality events were collected and a 3:1 propensity match was conducted. Results: Thirty-five (1.5%) of 2351 spine patients were transferred, most commonly for arrhythmia (n = 7; 20%). Thirty-three transferred patients were matched to 99 who were not transferred, and groups had similar rates of complications (18.2% vs. 10.1%; P = 0.228), readmissions (3.0% vs. 4.0%; P = 1.000), and mortality (6.1% vs. 0%; P = 0.061). Conclusion: Overall, this study demonstrates a low transfer rate following spine surgery. Risk factors should continue to be optimized in order to decrease patient risks in the postoperative period at an OSH.

The Implication of Preoperative Central Stenosis on Patient-Reported Outcomes After Lumbar Decompression Surgery.

OBJECTIVE: To assess the impact of central stenosis severity on patient-reported outcomes after lumbar decompression. METHODS: Patient diagnosis, demographics, and surgical characteristics were collected via query search and manual chart review of electronic medical records. The inclusion criteria were posterior lumbar decompressions from 2014-2020, with accessible magnetic resonance imaging reports. As previously validated by Lee et al., central stenosis was determined on magnetic resonance imaging and graded as none, mild, moderate, or severe. Patients were dichotomized into 2 groups to improve statistical power for comparisons: none or mild central stenosis and moderate or severe central stenosis. Patient-reported outcome measures (PROMs) were compared between cohorts at 1 year postoperatively. Statistical significance was set at P < 0.05. RESULTS: On bivariate analysis, no significant differences were noted between cohorts with regard to preoperative, 1-year postoperative, and delta PROMs. In addition, no significant difference in the number of patients attaining minimal clinically important difference (MCID) for each PROM was noted between cohorts. With the exception of mental score of the Short Form-12 survey, all intragroup preoperative to postoperative PROMs indicated significant improvement (all P < 0.05) after lumbar decompression surgery. Multivariate regression identified moderate or severe central canal stenosis as a significant independent predictor of improvement in visual analog scale back (estimate = -1.464, P = 0.045). CONCLUSIONS: We demonstrate that patients with moderate or severe central spinal stenosis may have more improvement in back pain than those with mild or no central stenosis after lumbar spine decompression surgery.