Schober test is not a valid assessment tool for lumbar mobility.

The Schober test is considered reliable in evaluating lumbar mobility and its impairment. Especially in patients with chronic low back pain (cLBP) identification of functional restriction is important. We aimed to investigate whether the 5 cm Schober cut-off provides a valid distinction between unrestricted and restricted mobility in participants with and without cLBP (18-65 years). cLBP is defined as LBP persisting for ≥ 12 weeks. We analyzed agreement between the Schober test with two measurement devices (Epionics SPINE®; Idiag M360®) and the influence of lumbar lordosis (LL) on their agreement. Also, the sensitivity and specificity of the Schober test was evaluated. For 187 participants (49.6%) Epionics SPINE® RoF and Schober test matched (either ≥ 5 cm; > 40.8° RoF or ≤ 5 cm; < 40.8° RoF), for 190 participants (50.4%) the two measurements did not. Idiag M360® RoF of 190 participants (50.4%) showed corresponding results (either ≥ 5 cm; > 46.0° RoF or ≤ 5 cm; < 46.0° RoF). Non-agreement was seen in 187 participants (49.6%). LL differed significantly in the Epionics SPINE® cohort (p < 0.001). Regarding the Epionics SPINE® cohort, Schober test showed a sensitivity of 79.6% with a specificity of 36.1%. For the Idiag M360® cohort, Schober test showed a sensitivity of 68.2% and a specificity of 46.6%. Our results do not establish a consistent matching between Schober test and the device measurements. Therefore, Schober test may not be valid to predict impairment of lumbar mobility. We recommend Schober test as an add-on in monitoring of an individual relative to its case.

Dynamic assessment of spine movement patterns using an RGB-D camera and deep learning.

In clinical practice, functional limitations in patients with low back pain are subjectively assessed, potentially leading to misdiagnosis and prolonged pain. This paper proposes an objective deep learning (DL) markerless motion capture system that uses a red-green-blue-depth (RGB-D) camera to measure the kinematics of the spine during flexion-extension (FE) through: 1) the development and validation of a DL semantic segmentation algorithm that segments the back into four anatomical classes and 2) the development and validation of a framework that uses these segmentations to measure spine kinematics during FE. Twenty participants performed ten cycles of FE with drawn-on point markers while being recorded with an RGB-D camera. Five of these participants also performed an additional trial where they were recorded with an optical motion capture (OPT) system. The DL algorithm was trained to segment the back and pelvis into four anatomical classes: upper back, lower back, spine, and pelvis. A kinematic framework was then developed to refine these segmentations into upper spine, lower spine, and pelvis masks, which were used to measure spine kinematics after obtaining 3D global coordinates of the mask corners. The segmentation algorithm achieved high accuracy, and the root mean square error (RMSE) between ground truth and predicted lumbar kinematics was < 4°. When comparing markerless and OPT kinematics, RMSE values were < 6°. This work demonstrates the feasibility of using markerless motion capture to assess FE spine movement in clinical settings. Future work will expand the studied movement directions and test on different demographics.

Radiologic Assessment of Interbody Fusion: A Systematic Review on the Use, Reliability, and Accuracy of Current Fusion Criteria.

BACKGROUND: Lumbar interbody fusion (IF) is a common procedure to fuse the anterior spine. However, a lack of consensus on image-based fusion assessment limits the validity and comparison of IF studies. This systematic review aims to (1) report on IF assessment strategies and definitions and (2) summarize available literature on the diagnostic reliability and accuracy of these assessments. METHODS: Two searches were performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Search 1 identified studies on adult lumbar IF that provided a detailed description of image-based fusion assessment. Search 2 analyzed studies on the reliability of specific fusion criteria/classifications and the accuracy assessed with surgical exploration. RESULTS: A total of 442 studies were included for search 1 and 8 studies for search 2. Fusion assessment throughout the literature was highly variable. Eighteen definitions and more than 250 unique fusion assessment methods were identified. The criteria that showed most consistent use were continuity of bony bridging, radiolucency around the cage, and angular motion <5°. However, reliability and accuracy studies were scarce. CONCLUSION: This review highlights the challenges in reaching consensus on IF assessment. The variability in IF assessment is very high, which limits the translatability of studies. Accuracy studies are needed to guide innovations of assessment. Future IF assessment strategies should focus on the standardization of computed tomography-based continuity of bony bridging. Knowledge from preclinical and imaging studies can add valuable information to this ongoing discussion. LEVEL OF EVIDENCE: Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

The assessment of paraspinal muscle epimuscular fat in participants with and without low back pain: A case-control study.

It remains unclear whether paraspinal muscle fatty infiltration in low back pain (LBP) is i) solely intramuscular, ii) is lying outside the epimysium between the muscle and fascial plane (epimuscular) or iii) or combination of both, as imaging studies often use different segmentation protocols that are not thoroughly described. Epimuscular fat possibly disturbs force generation of paraspinal muscles, but is seldomly explored. This project aimed to 1) compare epimuscular fat in participants with and without chronic LBP, and 2) determine whether epimuscular fat is different across lumbar spinal levels and associated with BMI, age, sex and LBP status, duration or intensity. Fat and water lumbosacral MRIs of 50 chronic LBP participants and 41 healthy controls were used. The presence and extent of epimuscular fat for the paraspinal muscle group (erector spinae and multifidus) was assessed using a qualitative score (0-5 scale; 0 = no epimuscular fat and 5 = epimuscular fat present along the entire muscle) and quantitative manual segmentation method. Chi-squared tests evaluated associations between qualitative epimuscular fat ratings and LBP status at each lumbar level. Bivariate and partial spearman's rho correlation assessed relationships between quantitative and qualitative epimuscular fat with participants' characteristics. Epimuscular fat was more frequent at the L4-L5 (X2 = 13.781, p = 0.017) and L5-S1 level (X2 = 27.825, p < 0.001) in participants with LBP compared to controls, which was not found for the higher lumbar levels. The total qualitative score (combined from all levels) showed a significant positive correlation with BMI, age, sex (female) and LBP status (r = 0.23-0.55; p < 0.05). Similarly, the total area of epimuscular fat (quantitative measure) was significantly correlated with BMI, age and LBP status (r = 0.26-0.57; p < 0.05). No correlations were found between epimuscular fat and LBP duration or intensity. Paraspinal muscle epimuscular fat is more common in chronic LBP patients. The functional implications of epimuscular fat should be further explored.

Correlations among Cervical, Thoracic, and lumbar Hounsfield Unit measurements for assessment of bone mineral density.

OBJECTIVE: Bone mineral density assessment using Hounsfield Unit (HU) currently depends upon the availability of computed tomography (CT) of the lumbar spine. The primary aim of this study was to evaluate the associations among HU measurements of the cervical (CHU), thoracic (THU), and lumbar (LHU) spine. The secondary aim of this study was to analyze the influence of patient demographic and anthropometric characteristics on HU measurements. METHODS: Radiographic records of 165 patients who underwent CT of the cervical, thoracic, and lumbar spine were retrieved. The CHU, THU, and LHU were calculated by obtaining the mean signal intensity from the medullary portions of C3-C7, T8-T12, and L1-L4 vertebral bodies. RESULTS: Mean CHU, THU, and LHU values were 266.26 ± 88.69, 165.57 ± 55.06, and 166.45 ± 51.38. Significant differences of 100.69, 99.81, and 0.88 were observed between CHU and THU (p <.001), CHU and LHU (p <.001), and THU and LHU (p =.023). Correlations of 0.574, 0.488, and 0.686 were observed between CHU and THU (p <.001), CHU and LHU (p <.001), and THU and LHU (p <.001). No differences in HU based on sex, age, height, weight, or ethnicity were observed. Multivariate regression models demonstrated R2 values of 0.770 - 0.790 (p <.001) in prediction of LHU. CONCLUSIONS: Hounsfield Unit measurements derived from the cervical and thoracic spine correlate with the validated lumbar Hounsfield Unit. Hounsfield Unit measurements do not vary based on sex, ethnicity, age, height, or weight.

Assessment of the External Validity of Dialogue Support for Predicting Lumbar Spine Surgery Outcomes in a US Cohort.

STUDY DESIGN: External validation using prospectively collected data. OBJECTIVES: To determine the model performance of "Dialogue Support" (DS) in predicting outcomes after lumbar spine surgery. SUMMARY OF BACKGROUND DATA: To help clinicians discuss risk versus benefit with patients considering lumbar fusion surgery, DS has been made available online. As DS was created using a Swedish sample, there is a need to study how well DS performs in alternative populations. PATIENTS AND METHODS: Preoperative data from patients enrolled in the Quality Outcomes Database were entered into DS. The probability for each patient to report satisfaction, achieve success (leg pain improvement ≥3), or have no leg pain 12 months after surgery was extracted and compared with their actual 12-month postoperative data. The ability of DS to identify patients in the Quality Outcomes Database who report satisfaction, achieve success, or have no leg pain 12 months after surgery was determined using Receiver operating characteristic curve analysis, goodness-of-fit tests, and calibration plots. RESULTS: There was a significant improvement in all outcomes in 23,928 cases included in the analysis from baseline to 12 months postoperative. Most (84%) reported satisfaction, 67% achieved success, and 44% were pain-free 12 months postoperative. Receiver operating characteristic analysis showed that DS had a low ability to predict satisfaction [area under the curve (AUC) = 0.606], success (AUC = 0.546), and being pain-free (AUC = 0.578) at 12 months postoperative; poor fit for satisfaction (<0.001) and being pain-free ( P = 0.004), but acceptable fit for success ( P = 0.052). Calibration plots showed underestimation for satisfaction and success, but acceptable estimates for being pain-free. CONCLUSION: DS is not directly transferable to predict satisfaction and success after lumbar surgery in a US population. This may be due to differences in patient characteristics, weights of the variables included, or the exclusion of unknown variables associated with outcomes. Future studies to better understand and improve the transferability of these models are needed.

Quantitative multi-parameter assessment of age- and gender-related variation of back extensor muscles in healthy adults using Dixon MR imaging.

OBJECTIVES: Investigate sex differences in age-related back extensor muscle degeneration using Dixon MRI and analyze the relationship between quantitative muscle parameters and back muscle strength in healthy adults. METHODS: 105 healthy subjects underwent lumbar Dixon MRI. Fat fraction (FF), cross-sectional area (CSA), functional CSA (FCSA), and relative FCSA (RFCSA) of multifidus muscle (MF) and erector spinae (ES) were quantified. Back extension muscle strength was measured using an external fixation dynamometer. ANOVA with post hoc Tukey correction was used for age group comparisons. Partial and Spearman's correlation analyzed relationships between age, muscle parameters, and muscle strength. RESULTS: MF and ES FF significantly increased with age in both genders (r = 0.55-0.85; p < 0.001). Muscle FF increased prominently for females (40-49 years, MF and 50-59 years, ES) and males (60-73 years, MF and ES). In females, total ES FCSA and RFCSA (r = - 0.42, - 0.37; p < 0.01) correlated with age. While in males, all MF and ES muscle size parameters, except total MF CSA, correlated with age (r = - 0.30 to - 0.58; p < 0.05). Back extension muscle strength correlated with mean FF, total CSA, and total FCAS for MF and ES individually (p < 0.001). The combined MF + ES FCSA correlation coefficient (r = 0.63) was higher than FF (r = - 0.51) and CSA (r = 0.59) (p < 0.001). CONCLUSIONS: Age-related back extensor muscle degeneration varies by muscle type and sex. FCSA has the highest association with back muscle strength compared to FF and CSA. CLINICAL RELEVANCE STATEMENT: The investigation of sex differences in age-related back extensor muscle degeneration utilizing Dixon imaging may hold significant implications for evaluating spine health and enabling earlier intervention. Muscles' FCSA could contribute to acquiring additional evidence for reflecting muscle function change. KEY POINTS: • The multifidus muscle (MF) and erector spinae (ES) fat fraction (FF) increased with age at all lumbar disc levels in females and males. • Age-related changes in muscle morphological quantitative parameters of healthy adults were specific by muscle type and gender. • The muscle functional cross-sectional area (FCSA) measured by Dixon imaging may better monitor back extensor muscle strength changes than muscle FF and cross-sectional area (CSA).

Assessment of Muscle Coordination Changes Caused by the Use of an Occupational Passive Lumbar Exoskeleton in Laboratory Conditions.

The introduction of exoskeletons in industry has focused on improving worker safety. Exoskeletons have the objective of decreasing the risk of injury or fatigue when performing physically demanding tasks. Exoskeletons' effect on the muscles is one of the most common focuses of their assessment. The present study aimed to analyze the muscle interactions generated during load-handling tasks in laboratory conditions with and without a passive lumbar exoskeleton. The electromyographic data of the muscles involved in the task were recorded from twelve participants performing load-handling tasks. The correlation coefficient, coherence coefficient, mutual information, and multivariate sample entropy were calculated to determine if there were significant differences in muscle interactions between the two test conditions. The results showed that muscle coordination was affected by the use of the exoskeleton. In some cases, the exoskeleton prevented changes in muscle coordination throughout the execution of the task, suggesting a more stable strategy. Additionally, according to the directed Granger causality, a trend of increasing bottom-up activation was found throughout the task when the participant was not using the exoskeleton. Among the different variables analyzed for coordination, the most sensitive to changes was the multivariate sample entropy.

Reliability of panoramic ultrasound imaging and agreement with magnetic resonance imaging for the assessment of lumbar multifidus anatomical cross-sectional area.

The aim of this study was to investigate the reliability of panoramic ultrasound (US) imaging and agreement with magnetic resonance imaging (MRI) for assessing the average lumbar multifidus anatomical cross-sectional area between the lumbar vertebral bodies L3-L5 (i.e., LMF ACSAL3-L5). US and MRI scans of 20 male youth competitive alpine skiers were collected. To test the intra- and interrater reliability of US, transversal panoramic scans were analyzed on two different days by the same rater and the analysis of the first day was compared with the analysis of a second rater. To examine the agreement between US and MRI, Bland-Altman analysis was performed. Intrarater reliability was excellent, and interrater reliability was weak to good for both sides. The bias between MRI and US was - 0.19 ± 0.90 cm2 (2.68 ± 12.30%) for the left side and - 0.04 ± 0.98 cm2 (- 1.11 ± 12.93%) for the right side (i.e., for both sides US slightly overestimated LMF ACSAL3-L5 on average). The limits of agreement were - 1.95 to 1.57 cm2 (- 26.70 to 21.30%) for the left side and - 1.95 to 1.88 cm2 (- 26.46 to 24.24%) for the right side. Panoramic US imaging may be considered a method with excellent intrarater and weak to good interrater reliability for assessing LMF ACSAL3-L5. Comparison with MRI showed large individual differences in some cases, but an acceptable bias between the two imaging modalities.

Combinations of two imaging parameters to improve bone mineral density (BMD) assessment in patients with lumbar degenerative diseases.

PURPOSE: To explore whether combining the Hounsfield unit (HU) values and vertebral bone quality (VBQ) scores can improve the BMD assessment in patients with lumbar degenerative diseases. METHODS: The HU values were measured by CT image, and VBQ scores were calculated by lumbar MRI image. The correlations of the opportunistic imaging parameters to the lowest T-scores were analyzed. Receiver-operating characteristic curve (ROC) analysis was used to evaluate the accuracy in detecting osteoporosis. Finally, the specificity and sensitivity of different combined methods of the HU values and VBQ scores in the diagnosis of osteoporosis were compared. RESULTS: Patients with osteoporosis had the lowest HU values and the highest VBQ scores. The correlation coefficients between the VBQ scores and the T-scores were smaller than HU values (L1 HU value: 0.702; average HU value:0.700; L1 VBQ score: -0.413; VBQ score: -0.386). The areas under the curve (AUCs) of the HU values were greater than those of the VBQ scores, and the AUCs of the L1 VBQ score were similar to the VBQ score (L1 HU value: 0.850; average HU value:0.857; L1 VBQ score: 0.704; VBQ score: 0.673). When combining the two imaging parameters in series, the specificity of the detection of osteoporosis was improved (L1 HU value and L1 VBQ score: 87.3%; Average HU value and VBQ score: 85.9%). When combining the two imaging parameters in parallel, the sensitivity of the detection of osteoporosis was improved (L1 HU value or L1 VBQ score: 88.1%; Average HU value or VBQ score: 91.5%). CONCLUSIONS: Combinations of the HU values and VBQ scores could improve the diagnostic performance of osteoporosis. In addition, considering the same diagnostic performance but easier measurement, parameters at the single-segment level were recommended to assist in the diagnosis of osteoporosis.

Variable flip angle T1 mapping and multi-echo T2 and T2* mapping magnetic resonance imaging sequences allow quantitative assessment of canine lumbar disc degeneration.

Magnetic resonance imaging is the gold standard for diagnosing intervertebral disc (IVD) degeneration in dogs. However, published methods for quantifying severity or progression of IVD degeneration are currently limited. Mapping MRI sequences are used in humans for quantifying IVD degeneration but have rarely been applied in dogs. The objective of this prospective, method comparison study was to evaluate variable flip angle T1 mapping and multiecho T2 and T2* mapping as methods for quantifying canine lumbar IVD degeneration in twenty canine patients without clinical signs of spinal disease. Ventral and dorsal lumbar IVD widths were measured on radiographs, and lumbar IVDs were assigned a qualitative Pfirrmann grade based on standard T2-weighted sequences. T1, T2, and T2* relaxation times of the nucleus pulposus (NP) were measured on corresponding maps using manual-drawn ROIs. Strong intra- and interrater agreements were found (P < 0.01) for NP relaxation times. Radiographic IVD widths and T1, T2, and T2* mapping NP relaxation times were negatively correlated with Pfirrmann grading (P < 0.01). Significant differences in T1 NP relaxation times were found between Pfirrmann grade I and the other grades (P < 0.01). Significant differences in T2 and T2* NP relaxation times were found between grade I and the other grades and between grades II and III (P < 0.01). Findings indicated that T1, T2, and T2* MRI mapping sequences are feasible in dogs. Measured NP relaxation times were repeatable and decreased when Pfirrmann grades increased. These methods may be useful for quantifying the effects of regenerative treatment interventions in future longitudinal studies.

Incidence of spine surgery in the South African private healthcare sector: ten-year trends within a large open medical scheme.

PURPOSE: Studies from developed countries suggest a dramatic increase in the utilization of spine surgery in recent decades, however less is known about spine surgery rates in the developing world. The aim of this study was to investigate ten-year trends in the incidence of spine surgery within South Africa's largest open medical scheme. METHODS: This retrospective review included adult inpatient spine surgeries funded by the scheme between 2008 and 2017. The incidence of spine surgery was investigated by age group-overall and for degenerative pathologies, fusion and instrumentation. Surgeons per 100,000 members were determined. Trends were evaluated by linear regression and by crude 10-year change in incidence. RESULTS: A total of 49,575 spine surgeries were included. The incidence of surgery for lumbar degenerative pathology showed a significant upward trend among 60-79 year olds but declined among 40-59 year olds. The incidence of lumbar fusion and lumbar instrumentation declined significantly among 40-59 year olds with little change among 60-79 year olds. The ratio of orthopaedic spinal surgeons decreased from 10.2 to 6.3 per 100,000 members whereas the ratio of neurosurgeons decreased from 7.6 to 6.5 per 100,000. CONCLUSION: Spine surgery in the South African private healthcare sector bears some similarity to developed countries in that it is dominated by elective procedures for degenerative pathology. However, the findings did not reflect the marked increases in the utilization of spine surgery reported elsewhere. It is hypothesized that this may be partly related to differences in the supply of spinal surgery.

Procedures employing interbody devices and multi-level fusion require target price adjustment to build a sustainable lumbar fusion bundled payment model.

BACKGROUND CONTEXT: Bundled payment models require risk adjustment to ensure appropriate targets are set. While this may be standardized for many services, spine fusions demonstrate significant variability in approach, invasiveness, and use of implants, that may require further risk adjustment. PURPOSE: To evaluate variability in costs of spinal fusion episodes in a private insurer bundle payment program and identify whether current procedural terminology (CPT) code modifications are necessary for sustainable implementation. STUDY DESIGN/SETTING: Retrospective single-institution cohort study. PATIENT SAMPLE: A total of 542 lumbar fusion episodes in a private insurer bundled payment program from October 2018 to December 2020. OUTCOME MEASURES: A total of 120-day episode of care net surplus/deficit, 90-day readmissions, discharge disposition, and length of hospital stay. METHODS: A review was conducted of all lumbar fusions in a single institution's payer database. Surgical characteristics (approach [posterior lumbar decompression and fusion (PLDF), transforaminal lumbar interbody fusion (TLIF), and circumferential fusion], levels fused, and primary vs revision) were collected from manual chart review. Episode of care cost data were collected as net surplus or deficit with respect to target prices. A multivariate linear regression model was constructed to measure the independent effects of primary versus revision, levels fused, and approach on the net cost savings. RESULTS: Most procedures were PLDFs (N=312, 57.6%), single-level (N=416, 76.8%) and primary fusions (N=477, 88.0%). Overall, 197 (36.3%) resulted in a deficit, and were more likely to be three levels (7.11% vs 2.03%, p=.005), revisions (18.8% vs 8.12%, p<.001), and TLIF (47.7% vs 35.1%, p<.001) or circumferential fusions (p<.001). One-level PLDFs resulted in the greatest cost savings per episode ($6,883). Across both PLDFs and TLIFs, 3-level procedures resulted in significant deficit of -$23,040 and -$18,887, respectively. For circumferential fusions, 1-level fusions resulted in deficit of -$17,169 per case which rose to -$64,485 and -$49,222 for 2- and 3-level fusions. All 2- and 3-level circumferential spinal fusions resulted in a deficit. On multivariable regression, TLIF and circumferential fusions were independently associated with a deficit of -$7,378 (p=.004) and -$42,185 (p<.001), respectively. Three-level fusions were independently associated with an additional -$26,003 deficit compared to single-level fusions (p<.001). CONCLUSIONS: Interbody fusions, especially circumferential fusions, and multi-level procedures are not adequately risk adjusted by current bundled payment models. Health systems may not be able to financially support these alternative payment models with improved procedure-specific risk adjustment.

The role of socioeconomic factors as barriers to patient reported outcome measure completion following lumbar spine fusion.

BACKGROUND CONTEXT: Although incorporating patient reported outcomes (PROMs) into practice allows healthcare systems to evaluate the value of care provided, research and policy reflecting PROMs can only be valid if they represent all patients. Few studies have evaluated socioeconomic barriers to PROM completion, and none have done so in a spine patient population. PURPOSE: To identify patient barriers to PROM completion one year following lumbar spine fusion. STUDY DESIGN/SETTING: Retrospective single-institution cohort study. PATIENT SAMPLE: A total of 2,984 patients undergoing lumbar fusion between 2014 and 2020 OUTCOME MEASURES: Completion of Mental Component Score (MCS-12) and Physical Component Score (PCS-12) of Short Form-12 questionnaire 1 year postoperatively. METHODS: A retrospective review was conducted of all patients undergoing 1-3-level lumbar fusion at a single urban tertiary center. PROMs were queried from our prospectively managed electronic outcomes database. Patients were considered to have complete PROMs if 1-year outcomes were available. Community-level characteristics were collected from patients' zip codes using the Economic Innovation Group Distressed Communities Index. Bivariate analyses were performed to assess factors associated with PROM incompletion along with multivariate logistic regression to control for confounders. RESULTS: A total of 1,968 (66.0%) had incomplete 1-year PROMs. Patients with incomplete PROMs were more likely to be Black (14.5% vs 9.3%, p<.001), Hispanic (2.9% vs 1.6%, p=.027), reside in a distressed community (14.7% vs 8.5%, p<.001), and be active smokers (22.4% vs 15.5%, p<.001). On multivariate regression, Black race (OR: 1.46, p=.014, Hispanic ethnicity (OR: 2.19, p=.027), distressed community status (OR: 1.47, p=.024), workers' compensation status (OR: 2.82, p=.001), and active smoking (OR:1.31, p=.034) all were independently associated with PROM incompletion. Surgical characteristics, including primary surgeon, revision status, approach, and levels fused were not associated with PROM incompletion. CONCLUSIONS: Social determinants of health impact completion of PROMs. Patients completing PROMs are overwhelmingly White, non-Hispanic, and reside in wealthier communities. Efforts should be taken to provide better education regarding PROMs and ensure closer follow-up of certain subgroups of patients to avoid furthering disparities in PROM research.

Cost consequence analysis of waiting for lumbar disc herniation surgery.

The economic repercussions of waiting for lumbar disc surgery have not been well studied. The primary goal of this study was to perform a cost-consequence analysis of patients receiving early vs late surgery for symptomatic disc herniation from a societal perspective. Secondarily, we compared patient factors and patient-reported outcomes. This is a retrospective analysis of prospectively collected data from the CSORN registry. A cost-consequence analysis was performed where direct and indirect costs were compared, and different outcomes were listed separately. Comparisons were made on an observational cohort of patients receiving surgery less than 60 days after consent (short wait) or 60 days or more after consent (long wait). This study included 493 patients with surgery between January 2015 and October 2021 with 272 patients (55.2%) in the short wait group and 221 patients (44.8%) classified as long wait. There was no difference in proportions of patients who returned to work at 3 and 12-months. Time from surgery to return to work was similar between both groups (34.0 vs 34.9 days, p = 0.804). Time from consent to return to work was longer in the longer wait group corresponding to an additional $11,753.10 mean indirect cost per patient. The short wait group showed increased healthcare usage at 3 months with more emergency department visits (52.6% vs 25.0%, p < 0.032), more physiotherapy (84.6% vs 72.0%, p < 0.001) and more MRI (65.2% vs 41.4%, p < 0.043). This corresponded to an additional direct cost of $518.21 per patient. Secondarily, the short wait group had higher baseline NRS leg, ODI, and lower EQ5D and PCS. The long wait group had more patients with symptoms over 2 years duration (57.6% vs 34.1%, p < 0.001). A higher proportion of patients reached MCID in terms of NRS leg pain at 3-month follow up in the short wait group (84.0% vs 75.9%, p < 0.040). This cost-consequence analysis of an observational cohort showed decreased costs associated with early surgery of $11,234.89 per patient when compared to late surgery for lumbar disc herniation. The early surgery group had more severe symptoms with higher healthcare utilization. This is counterbalanced by the additional productivity loss in the long wait group, which likely have a more chronic disease. From a societal economic perspective, early surgery seems beneficial and should be promoted.

CT-guided vs. fluoroscopically guided transforaminal epidural steroid injections for lumbar radiculopathy: a comparison of efficacy, safety and cost.

INTRODUCTION: There are no formal guidelines for whether CT-guided or fluoroscopy-guided TFESI should be undertaken for patients with symptoms of lumbar nerve root irritation and corresponding nerve impingement. Here, we sought to compare the efficacy, safety and cost of computer tomography (CT)-guided and fluoroscopically guided transforaminal epidural steroid injection (TFESI). MATERIALS AND METHODS: All patients who underwent lumbar TFESI at our institution between June 2016 and June 2018 were identified. Six-week follow-up outcomes were categorised. The radiation doses and associated cost was retrieved from our institution's costing system. RESULTS: One hundred and sixteen patients were included (CT-50; fluoroscopy-56). There were no complications. More patients were discharged 6 weeks after CT-guided lumbar TFESI when compared with fluoroscopically guided TFESI (CT-23, fluoroscopy-14 (P = 0.027)). There was no difference in the number of patients who were referred to surgery (P = 0.18), for further pain management (P = 0.45), or for further TFESI (P = 0.43). The effective radiation dose was significantly higher for CT-guided TFESI (CT-5.73 mSv (3.87 to 7.76); fluoroscopy-0.55 mSv (0.11 to 1.4) (P < 0.01)). The total cost for CT-guided lumbar TFESI was £237.50 (£235 to £337), over £800 less than under fluoroscopic guidance (£1052 (£892.80 to £1298.00), P < 0.01)). Removing cost associated with staff and theatre use (staffing, theatre, medical indemnity and overheads) revealed CT-guided lumbar TFESI to be less expensive than if the procedure was fluoroscopy-guided-CT-guided: £132.6 (130.8 to 197.5); fluoroscopy: £237.4 (£209.2 to £271.9) (P = 0.019). CONCLUSIONS: CT-guided TFESI was associated with a higher discharge rate, a lower cost, but a ten times higher radiation dose when compared with fluoroscopically guided TFESI. Prospective studies are required to compare the efficacy of these procedures and to investigate how the radiation dose of CT-guided TFESI can be reduced without jeopardising efficacy or safety.

Assessment of Posterolateral Lumbar Fusion: A Systematic Review of Imaging-Based Fusion Criteria.

BACKGROUND: Noninvasive assessment of osseous fusion after spinal fusion surgery is essential for timely diagnosis of patients with symptomatic pseudarthrosis and for evaluation of the performance of spinal fusion procedures. There is, however, no consensus on the definition and assessment of successful posterolateral fusion (PLF) of the lumbar spine. This systematic review aimed to (1) summarize the criteria used for imaging-based fusion assessment after instrumented PLF and (2) evaluate their diagnostic accuracy and reliability. METHODS: First, a search of the literature was conducted in November 2018 to identify reproducible criteria for imaging-based fusion assessment after primary instrumented PLF between T10 and S1 in adult patients, and to determine their frequency of use. A second search in July 2021 was directed at primary studies on the diagnostic accuracy (with surgical exploration as the reference) and/or reliability (interobserver and intraobserver agreement) of these criteria. Article selection and data extraction were performed by at least 2 reviewers independently. The methodological quality of validation studies was assessed with the QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies 2) and QAREL (Quality Appraisal of Reliability Studies). RESULTS: Of the 187 articles included from the first search, 47% used a classification system and 63% used ≥1 descriptive criterion related to osseous bridging (104 articles), absence of motion (78 articles), and/or absence of static signs of nonunion (39 articles). A great variation in terminology, cutoff values, and assessed anatomical locations was observed. While the use of computed tomography (CT) increased over time, radiographs remained predominant. The second search yielded 11 articles with considerable variation in outcomes and quality concerns. Agreement between imaging-based assessment and surgical exploration with regard to demonstration of fusion ranged between 55% and 80%, while reliability ranged from poor to excellent. CONCLUSIONS: None of the available criteria for noninvasive assessment of fusion status after instrumented PLF were demonstrated to have both sufficient accuracy and reliability. Further elaboration and validation of a well-defined systematic CT-based assessment method that allows grading of the intertransverse and interfacet fusion mass at each side of each fusion level and includes signs of nonunion is recommended. LEVEL OF EVIDENCE: Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.