Preoperative Electrodiagnostic Study Findings Differ Between Patients With Double-crush Syndrome and Carpal Tunnel Syndrome: A Propensity Matched Analysis.

INTRODUCTION: Double-crush syndrome (DCS) represents a condition that involves peripheral nerve compression in combination with spinal nerve root impingement. The purpose of this study was to compare electrodiagnostic study (EDS) results in patients undergoing carpal tunnel release (CTR) for carpal tunnel syndrome with those undergoing both CTR and anterior cervical diskectomy and fusion for DCS. METHODS: Patients receiving an isolated CTR were compared with those undergoing CTR and anterior cervical diskectomy and fusion within two years of CTR. The latter group was defined as our DCS cohort. Electrodiagnostic study results were collected which included sensory and motor nerve conduction data as well as electromyogram (EMG) findings. All electrodiagnostic studies were done before CTR in both sets of patients. RESULTS: Fifty-four patients with DCS and 137 CTR-only patients were included. Patients with DCS were found to have decreased sensory onset latency (3.51 vs 4.01; P = 0.015) and peak latency (4.25 vs 5.17; P = 0.004) compared with the CTR-only patients. Patients with DCS had slower wrist motor velocity (30.5 vs 47.7; P = 0.012), decreased elbow motor latency (9.62 vs 10.6; P = 0.015), and faster elbow motor velocity (56.0 vs 49.4; P = 0.031). EMG results showed that patients with DCS were more likely to have positive findings in the biceps (31.9% vs 1.96%; P < 0.001) and triceps (24.4% vs 2.97%; P < 0.001), but not abductor pollicis brevis (APB) (45.7% vs 37.9%; P = 0.459). CONCLUSION: We identified changes on EDS between patients with and without DCS. In patients with DCS, sensory nerve studies showed shorter peak and onset latency than in CTR-only patients. Interestingly, DCS and CTR-only patients had different patterns of wrist and elbow motor nerve conduction. Providers observing positive EMG findings proximal to the APB should raise their suspicion for possible cervical radiculopathy and when present with carpal tunnel syndrome-like symptoms, should also consider DCS in their diagnostic differential.

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

OBJECTIVE: Determine if herniation morphology based on the Michigan State University (MSU) Classification is associated with differences in (1) patient-reported outcome measures (PROMs) or (2) surgical outcomes after a microdiscectomy. METHODS: Adult patients undergoing single-level microdiscectomy between 2014 - 2021 were identified. Demographics and surgical characteristics were collected through a query search and manual chart review. The MSU 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. PROMs were collected at preoperative, three-month, and one-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 PCS at baseline. On bivariate and multivariable logistic regression analysis, extrusion grade >1 was a significant independent predictor of greater improvement in PCS at three months (estimate=7.957; CI: 4.443 - 11.471, p<0.001), but not at one 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 VAS 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.

Radiology Reports Do Not Accurately Portray the Severity of Cervical Neural Foraminal Stenosis.

STUDY DESIGN: Retrospective study. OBJECTIVE: (1) To compare cervical magnetic resonance imaging (MRI) radiology reports to a validated grading system for cervical foraminal stenosis (FS) and (2) to evaluate whether the severity of cervical neural FS on MRI correlates to motor weakness or patient-reported outcomes. BACKGROUND: Radiology reports of cervical spine MRI are often reviewed to assess the degree of neural FS. However, research looking at the association between these reports and objective MRI findings, as well as clinical symptoms, is lacking. PATIENTS AND METHODS: We retrospectively identified all adult patients undergoing primary 1 or 2-level anterior cervical discectomy and fusion at a single academic center for an indication of cervical radiculopathy. Preoperative MRI was assessed for neural FS severity using the grading system described by Kim and colleagues for each level of fusion, as well as adjacent levels. Neural FS severity was recorded from diagnostic radiologist MRI reports. Motor weakness was defined as an examination grade <4/5 on the final preoperative encounter. Regression analysis was conducted to evaluate whether the degree of FS by either classification was related to patient-reported outcome measure severity. RESULTS: A total of 283 patients were included in the study, and 998 total levels were assessed. There were significant differences between the MRI grading system and the assessment by radio-logists (P< 0.001). In levels with moderate stenosis, 28.9% were classified as having no stenosis by radiology. In levels with severe stenosis, 29.7% were classified as having mild-moderate stenosis or less. Motor weakness was found similarly often in levels of moderate or severe stenosis (6.9% and 9.2%, respectively). On regression analysis, no associations were found between baseline patient-reported outcome measures and stenosis severity assessed by radiologists or MRI grading systems. CONCLUSION: Radiology reports on the severity of cervical neural FS are not consistent with a validated MRI grading system. These radiology reports underestimated the severity of neural foraminal compression and may be inappropriate when used for clinical decision-making. LEVEL OF EVIDENCE: Level III.

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.

Reimbursement of Lumbar Fusion at an Orthopaedic Specialty Hospital Versus Tertiary Referral Center.

STUDY DESIGN: Retrospective Cohort Study. OBJECTIVE: To explore the differences in Medicare reimbursement for lumbar fusion performed at an orthopaedic specialty hospital (OSH) and a tertiary referral center and to elucidate drivers of Medicare reimbursement differences. SUMMARY OF BACKGROUND DATA: To provide more cost-efficient care, appropriately selected patients are increasingly being transitioned to OSHs for lumbar fusion procedures. There are no studies directly comparing reimbursement of lumbar fusion between tertiary referral centers (TRC) and OSHs. METHODS: Reimbursement data for a tertiary referral center and an orthopaedic specialty hospital were compiled through the Centers for Medicare and Medicaid Services. Any patient with lumbar fusions between January 2014 and December 2018 were identified. OSH patients were matched to TRC patients by demographic and surgical variables. Outcomes analyzed were reimbursement data, procedure data, 90-day complications and readmissions, operating room times, and length of stay (LOS). RESULTS: A total of 114 patients were included in the final cohort. The tertiary referral center had higher post-trigger ($13,554 vs. $8,541, P<0.001) and total episode ($49,973 vs. $43,512, P<0.010) reimbursements. Lumbar fusion performed at an OSH was predictive of shorter OR time (ß=0.77, P<0.001), shorter procedure time (ß=0.71, P<0.001), and shorter LOS (ß=0.53, P<0.001). There were no significant differences in complications (9.21% vs. 15.8%, P=0.353) or readmission rates (3.95% vs. 7.89%, P=0.374) between the 2 hospitals; however, our study is underpowered for complications and readmissions. CONCLUSION: Lumbar fusion performed at an OSH, compared with a tertiary referral center, is associated with significant Medicare cost savings, shorter perioperative times, decreased LOS, and decreased utilization of post-acute resources. LEVEL OF EVIDENCE: 3.

Utilization of In-Hospital Orthopaedic Spine Consultations: Evaluating the Impact of Health Care Policy.

Access to specialty and private practice providers has been a divisive policy issue over the last decade, complicated by the conflict between a reduction in government-funded health care reimbursement and the need for health care providers to sustain a financially sound practice. This study evaluates the orthopedic spine consult service at an academic tertiary care center at 2 separate time points over a 5-year period to better understand the impact of decreasing orthopedic reimbursement rates and the increasing prevalence of federally supported medical insurance on the access to specialty care. In total 500 patients in 2017 and 480 patients in 2021 were included for the final analysis. A higher percentage of consults in 2021 came from the emergency department (74.0% versus 60.4%, P < 0.001); however, the emergency department saw fewer spinal cord injuries (11.9% versus 21.4%, P < 0.001), and the spinal cord injuries were less severe (3.1% versus 6.2% Association Impairment Scale A or B, P = 0.034). A smaller percentage of patients in 2021 went on to receive orthopedic spine surgery following consultation (35.2% versus 43.8%, P = 0.007), and those receiving surgery had an operation performed farther out from the initial consultation (4.73 versus 4.09 days, P < 0.001). Additionally, fewer patients with Medicare insurance (23.5% versus 30.8%) and more patients with Medicaid insurance (20.2% versus 12.4%) were seen in 2021 compared with 2017 (P = 0.003). Overall, this study found an increased proportion of Medicaid patients seen by the spine consult service but a decrease in the acuity of consults. Measures to improve access to health insurance under the Affordable Care Act have revealed the complexity of this issue in health care. This study's findings have demonstrated that while more patients did have insurance coverage following the Affordable Care Act, they still face a barrier to accessing outpatient orthopedic spine providers.

Lateral approach to the lumbar spine: The utility of an access surgeon.

Background: Lateral lumbar interbody fusions (LLIFs) utilize a retroperitoneal approach that avoids the intraperitoneal organs and manipulation of the anterior vasculature encountered in anterior approaches to the lumbar spine. The approach was championed by spinal surgeons; however, general/vasculature surgeons may be more comfortable with the approach. Objective: The objective of this study was to compare short-term outcomes following LLIF procedures based on whether a spine surgeon or access surgeon performed the approach. Materials and Methods: We retrospectively identified all one- to two-level LLIFs at a tertiary care center from 2011 to 2021 for degenerative spine disease. Patients were divided into groups based on whether a spine surgeon or general surgeon performed the surgical approach. The electronic medical record was reviewed for hospital readmissions and complication rates. Results: We identified 239 patients; of which 177 had approaches performed by spine surgeons and 62 by general surgeons. The spine surgeon group had fewer levels with posterior instrumentation (1.40 vs. 2.00; P < 0.001) and decompressed (0.94 vs. 1.25, P = 0.046); however, the two groups had a similar amount of two-level LLIFs (29.9% vs. 27.4%, P = 0.831). This spine surgeon approach group was found to have shorter surgeries (281 vs. 328 min, P = 0.002) and shorter hospital stays Length of Stay (LOS) (3.1 vs. 3.6 days, P = 0.019); however, these differences were largely attributed to the shorter posterior fusion construct. On regression analysis, there was no statistical difference in postoperative complication rates whether or not an access surgeon was utilized (P = 0.226). Conclusion: Similar outcomes may be seen regardless of whether a spine or access surgeon performs the approach for an LLIF.

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.

The Impact of Unexpected Billing in Spine Surgery and How the Price Calculator Can Improve Patient Care.

STUDY DESIGN: Survey study. OBJECTIVE: The objective of this study was to determine the impact of unexpected in-network billing on the patient experience after spinal surgery. SUMMARY OF BACKGROUND DATA: The average American household faces difficulty paying unexpected medical bills. Although legislative efforts have targeted price transparency and rising costs, elective surgical costs continue to rise significantly. Patients are therefore sometimes still responsible for unexpected medical costs, the impact of which is unknown in spine surgery. METHODS: Patients who underwent elective spine surgery patients from January 2021 to January 2022 at a single institution were surveyed regarding their experience with the billing process. Demographic characteristics associated with unexpected billing situations, patient satisfaction, and financial distress, along with utilization and evaluation of the online price estimator, were collected. RESULTS: Of 818 survey participants, 183 (22.4%) received an unexpected in-network bill, and these patients were younger (56.7 vs. 63.4 y, P <0.001). Patients who received an unexpected bill were more likely to feel uninformed about billing (41.2% vs. 21.7%, P <0.001) and to report that billing impacted surgical satisfaction (53.8% vs. 19.1%, P <0.001). However, both groups reported similar satisfaction postoperatively (Likert >3/5: 86.0% vs. 85.5%, P =0.856). Only 35 (4.3%) patients knew of the price estimator's existence. The price estimator was reported to be very easy or easy (N=18, 78.2%) to understand and very accurate (N=6, 35.3%) or somewhat accurate (N=8, 47.1%) in predicting costs. CONCLUSIONS: Despite new regulations, a significant portion of patients received unexpected bills leading to financial distress and affecting their surgical experience. Although most patients were unaware of the price estimator, almost all patients who did know of it found it to be easy to use and accurate in cost prediction. Patients may benefit from targeted education efforts, including information on the price estimator to alleviate unexpected financial burden.

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.

Early Experience With Uniplanar Versus Biplanar Expandable Interbody Fusion Devices in Single-Level Minimally Invasive Transforaminal Lumbar Interbody Fusion.

OBJECTIVE: To compare the early radiographic and clinical outcomes of expandable uniplanar versus biplanar interbody cages used for single-level minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF). METHODS: A retrospective review of 1-level MIS-TLIFs performed with uniplanar and biplanar polyetheretherketone cages was performed. Radiographic measurements were performed on radiographs taken preoperatively, at 6-week follow-up, and 1-year follow-up. Oswestry Disability Index (ODI) and visual analogue scale (VAS) for back and leg at 3-month and 1-year follow-up. RESULTS: A total of 93 patients (41 uniplanar, 52 biplanar) were included. Both cage types provided significant postoperative improvements in anterior disc height, posterior disc height, and segmental lordosis at 1 year. No significant differences in cage subsidence rates were found between uniplanar (21.9%) and biplanar devices (32.7%) at 6 weeks (odds ratio, 2.015; 95% confidence interval, 0.651-6.235; p = 0.249) with no additional instances of subsidence at 1 year. No significant differences in the magnitude of improvements based on ODI, VAS back, or VAS leg at 3-month or 1-year follow-up between groups and the proportion of patients achieving the minimal clinically important difference in ODI, VAS back, or VAS leg at 1 year were not statistically significantly different (p > 0.05). Finally, there were no significant differences in complication rates (p = 0.283), 90-day readmission rates (p = 1.00), revision surgical procedures (p = 0.423), or fusion rates at 1 year (p = 0.457) between groups. CONCLUSION: Biplanar and uniplanar expandable cages offer a safe and effective means of improving anterior disc height, posterior disc height, segmental lordosis, and patient-reported outcome measures at 1 year postoperatively. No significant differences in radiographic outcomes, subsidence rates, mean subsidence distance, 1-year patient-reported outcomes, and postoperative complications were noted between groups.

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.

The Effect of Preoperative Exposure to Benzodiazepines on Opioid Consumption After One and Two-level Anterior Cervical Discectomy and Fusion.

STUDY DESIGN: Retrospective cohort. OBJECTIVE: Investigate the relationship between preoperative benzodiazepine exposure and postoperative opioid use in patients undergoing primary 1 or 2-level anterior cervical discectomy and fusion (ACDF). BACKGROUND: Little is known about the effect of preoperative benzodiazepine exposure on postoperative opioid use in spine surgery. PATIENTS AND METHODS: Patients undergoing primary 1 or 2-level ACDF at a single institution from February 2020 to November 2021 were identified through electronic medical records. The prescription drug monitoring program was utilized to record the name, dosage, and quantity of preoperative benzodiazepines/opioids filled within 60 days before surgery and postoperative opioids 6 months after surgery. Patients were classified as benzodiazepine naïve or exposed according to preoperative usage, and postoperative opioid dose and duration were compared between groups. Regression analysis was performed for outcomes that demonstrated statistical significance, adjusting for preoperative opioid use, age, sex, and body mass index. RESULTS: Sixty-seven patients comprised the benzodiazepine-exposed group whereas 90 comprised the benzodiazepine-naïve group. There was no significant difference in average daily morphine milligram equivalents between groups (median: 96.0 vs 65.0, P = 0.11). The benzodiazepine-exposed group received postoperative opioids for a longer duration (median: 32.0 d vs 12.0 d, P = 0.004) with more prescriptions (median: 2.0 vs 1.0, P = 0.004) and a greater number of pills (median: 110.0 vs 59.0, P = 0.007). On regression analysis, preoperative benzodiazepine use was not significantly associated with postoperative opioid duration [incidence rate ratio (IRR): 0.93, P = 0.74], number of prescriptions (IRR: 1.21, P = 0.16), or number of pills (IRR: 0.89, P = 0.58). CONCLUSIONS: While preoperative benzodiazepine users undergoing primary 1 or 2-level ACDF received postoperative opioids for a longer duration compared with a benzodiazepine naïve cohort, preoperative benzodiazepine use did not independently contribute to this observation. These findings provide insight into the relationship between preoperative benzodiazepine use and postoperative opioid consumption. LEVEL OF EVIDENCE: Level III.

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.

The severity of preoperative anemia escalates risk of poor short-term outcomes after lumbar spine fusion.

OBJECTIVE: To evaluate how preoperative anemia severity affects 90-day outcomes of spinal fusion surgery. METHODS: A retrospective cohort study was conducted on adult lumbar fusion patients at a tertiary medical center. Patients were classified by World Health Organization anemia severity definitions for comparisons. Multivariate regression models were created to control for confounding variables, for all primary outcomes of transfusion requirements, non-home discharge, readmissions, complications, and length of stay. RESULTS: A total of 2582 patients were included: 2.7% with moderate-severe anemia, 11.0% with mild anemia, and 86.3% without anemia. Moderate-severe patients had the longest hospital stay (5.03 days vs 4.14 and 3.59 days, p < 0.001) and highest risk of transfusion (52.2% vs 13.0% vs 2.69%, p < 0.001), non-home discharge (39.1% vs 27.8% vs 15.4%, p < 0.001), readmission (7.25% vs 5.99% vs 3.36%, p = 0.023), and complications (13.0% vs 9.51% vs 6.20%, p = 0.012). On multivariable logistic regression, both patients with mild and moderate-severe anemia had an increased risk of transfusion (OR: 37.3, p < 0.001; OR: 5.25, p < 0.001, respectively) and non-home discharge (OR: 2.00, p = 0.021; OR: 1.71, p = 0.001, respectively) compared to patients without anemia. Anemia severity was not independently associated with complications or 90-day readmission. On multivariable linear regression, mild anemia (ß: 0.37, p = 0.001) and moderate-severe anemia (ß: 1.07, p < 0.001) were independently associated with length of hospital stay. CONCLUSION: Patients with moderate-severe preoperative anemia are at increased risk for longer length of stay, transfusions, and non-home discharge. Improved optimization of preoperative anemia may significantly reduce healthcare utilization, and surgeons should consider these risks in preoperative planning. LEVEL OF EVIDENCE: III.

Predictors of Blood Transfusion in Patients Undergoing Lumbar Spinal Fusion.

OBJECTIVE: To determine risk factors for perioperative blood transfusion after lumbar fusion surgery. METHODS: After institutional review board approval, a retrospective cohort study of adult patients who underwent lumbar fusion at a single, urban tertiary academic center was retrospectively retrieved. Our primary outcome, blood transfusion, was collected via chart query. A receiver operating characteristic curve was used to evaluate the regression model. A P-value < 0.05 was considered statistically significant. RESULTS: Of the 3,842 patients, 282 (7.3%) required a blood transfusion. For patients undergoing posterolateral decompression and fusion, predictors of transfusion included age (P < 0.001) and more levels fused (P < 0.001). A higher preoperative hemoglobin level (P < 0.001) and revision surgery (P = 0.005) were protective of blood transfusion. For patients undergoing transforaminal lumbar interbody fusion, greater Elixhauser comorbidity index (P < 0.001), longer operative time (P = 0.040), and more levels fused (P = 0.030) were independent predictors of the need for blood transfusion. Patients with a higher body mass index (P = 0.012) and preoperative hemoglobin level (P < 0.001) had a reduced likelihood of receiving a transfusion. For circumferential fusion, greater age (P = 0.006) and longer operative times (P = 0.015) were independent predictors of blood transfusion, while a higher preoperative hemoglobin level (P < 0.001) and male sex (P = 0.002) were protective. CONCLUSIONS: Our analysis identified older age, lower body mass index, greater Elixhauser comorbidity index, longer operative duration, more levels fused, and lower preoperative hemoglobin levels as independent predictors of requiring a blood transfusion following lumbar spinal fusion. Different surgical approaches were not found to be associated with transfusion.

Comparing Posterior Lumbar Decompression and Fusion and Transforaminal Lumbar Interbody Fusion in Lumbar Degenerative Spondylolisthesis as Assessed by the CARDS Classification System.

OBJECTIVE: In a retrospective cohort study, we compared the outcomes among clinical and radiographic degenerative spondylolisthesis (CARDS) subtypes for patients undergoing posterior lumbar decompression and fusion (PLDF) or transforaminal lumbar interbody fusion (TLIF) and evaluated the CARDS system as a tool to guide clinical decisions regarding the treatment of degenerative spondylolisthesis (DS). METHODS: Patients undergoing PLDF or TLIF for DS from 2010 to 2020 were identified. The patients were grouped by the preoperative CARDS classification. Multivariate analysis was used to determine the effects of the treatment approach on the 1-year patient-reported outcome measures (PROMs) and 90-day surgical outcomes. RESULTS: A total of 1056 patients were included: 148 patients with type A DS, 323 with type B, 525 with type C, and 60 with type D. Patients with CARDS types A and C who underwent PLDF experienced a longer length of stay and were less likely to be discharged home. No differences were found in the incidence of revisions, complications, or readmissions between the surgical approaches. Patients with CARDS type A undergoing PLDF were less likely to achieve a minimal clinically important difference for back pain (36.8% vs. 76.7%; P = 0.013). No other significant differences were found in the PROMs among the CARDS subtypes. TLIF independently predicted for better leg pain improvement using the visual analog scale at 1 year of follow-up (ß = -2.92; P = 0.017) for patients with CARDS type A. Multivariable analysis demonstrated no significant differences in PROMs by surgical approach among the other CARDS subtypes. CONCLUSIONS: Patients with disc space collapse and endplate apposition (CARDS type A) appear to benefit from TLIF. However, patients with lumbar spondylolisthesis without disc space collapse or kyphotic angulation (CARDS types B and C) showed no benefit from additional interbody placement.