Do Hounsfield Units From Intraoperative CT Scans Correlate With Preoperative Values?

BACKGROUND: There is increasing interest in forecasting postoperative complications using bone density metrics. Vertebral Hounsfield unit measurements obtained from CT scans performed for surgical planning or other purposes, known as opportunistic CTs, have shown promise for their ease of measurement and the ability to target density measurement to a particular region of interest. Concomitant with the rising interest in prognostic bone density measurement use has been the increasing adoption of intraoperative advanced imaging techniques. Despite the interest in both outcome prognostication and intraoperative advanced imaging, there is little information regarding the use of CT-based intraoperative imaging as a means to measure bone density. QUESTIONS/PURPOSES: (1) Can vertebral Hounsfield units be reliably measured by physician reviewers from CT scans obtained intraoperatively? (2) Do Hounsfield units measured from intraoperative studies correlate with values measured from preoperative CT scans? METHODS: To be eligible for this retrospective study, patients had to have been treated with the use of an intraoperative CT scan for instrumented spinal fusion for either degenerative conditions or traumatic injuries between January 2015 and December 2022. Importantly, patients without a preoperative CT scan of the fused levels within 180 days before surgery or who were indicated for surgery because of infection, metastatic disease, or who were having revision surgery after prior instrumentation were excluded from the query. Of the 285 patients meeting these inclusion criteria, 53% (151) were initially excluded for the following reasons: 36% (102) had intraoperative CT scans obtained after placement of instrumentation, 16% (47) had undergone intraoperative CT scans but the studies were not accessible for Hounsfield unit measurement, and 0.7% (2) had prior kyphoplasty wherein the cement prevented Hounsfield unit measurement. Finally, an additional 19% (53) of patients were excluded because the preoperative CT and intraoperative CT were obtained at different peak voltages, which can influence Hounsfield unit measurement. This yielded a final population of 81 patients from whom 276 preoperative and 276 intraoperative vertebral Hounsfield unit measurements were taken. Hounsfield unit data were abstracted from the same vertebra(e) from both preoperative and intraoperative studies by two physician reviewers (one PGY3 and one PGY5 orthopaedic surgery resident, both pursuing spine surgery fellowships). For a small, representative subset of patients, measurements were taken by both reviewers. The feasibility and reliability of Hounsfield unit measurement were then assessed with interrater reliability of values measured from the same vertebra by the two different reviewers. To compare Hounsfield unit values from intraoperative CT scans with preoperative CT studies, an intraclass correlation using a two-way random effects, absolute agreement testing technique was employed. Because the data were formatted as multiple measurements from the same vertebra at different times, a repeated measures correlation was used to assess the relationship between preoperative and intraoperative Hounsfield unit values. Finally, a linear mixed model with patients handled as a random effect was used to control for different patient and clinical factors (age, BMI, use of bone density modifying agents, American Society of Anesthesiologists [ASA] classification, smoking status, and total Charlson comorbidity index [CCI] score). RESULTS: We found that Hounsfield units can be reliably measured from intraoperative CT scans by human raters with good concordance. Hounsfield unit measurements of 31 vertebrae from a representative sample of 10 patients, measured by both reviewers, demonstrated a correlation value of 0.82 (95% CI 0.66 to 0.91), indicating good correlation. With regard to the relationship between preoperative and intraoperative measurements of the same vertebra, repeated measures correlation testing demonstrated no correlation between preoperative and intraoperative measurements (r = 0.01 [95% CI -0.13 to 0.15]; p = 0.84). When controlling for patient and clinical factors, we continued to observe no relationship between preoperative and intraoperative Hounsfield unit measurements. CONCLUSION: As intraoperative CT and measurement of vertebral Hounsfield units both become increasingly popular, it would be a natural extension for spine surgeons to try to extract Hounsfield unit data from intraoperative CTs. However, we found that although it is feasible to measure Hounsfield data from intraoperative CT scans, the obtained values do not have any predictable relationship with values obtained from preoperative studies, and thus, these values should not be used interchangeably. With this knowledge, future studies should explore the prognostic value of intraoperative Hounsfield unit measurements as a distinct entity from preoperative measurements. LEVEL OF EVIDENCE: Level III, diagnostic study.

What Happens to Sagittal Alignment Following Laminoplasty Versus Laminectomy and Fusion?

OBJECTIVE: Laminectomy and fusion (LF) and laminoplasty (LP) are 2 sucessful posterior decompression techniques for cervical myelo-radiculopathy. There is also a growing body of evidence describing the importance of cervical sagittal alignment (CSA) and its importance in outcomes. We investigated the difference between pre- and postoperative CSA parameters in and between LF or LP. Furthermore, we studied predictive variables associated with change in cervical mismatch (CM). METHODS: This is a retrospective cohort study of adults with cervical myeloradiculopathy in a single healthcare system. The primary outcomes are intra- and inter-cohort comparison of LF versus LP radiographic parameters at pre- and postoperative time points. A secondary multivariable analysis of predictive factors was performed evaluating factors predicting postoperative CM. RESULTS: Eighty nine patients were included; 38 (43%) had LF and 51 (57%) underwent LP. Both groups decreased in lordosis (LF 11.4° vs. 4.9°, P = 0.01; LP 15.2° vs. 9.1°, P < 0.001), increased in cSVA (LF 3.4 vs. 4.2 cm, P = 0.01; LP 3.2 vs. 4.2 cm, P < 0.001), and increased in CM (LF 22.0° vs. 28.5°, P = 0.02; LP 16.8° vs. 22.3°, P = 0.002). There were no significant differences in the postoperative CSA between groups. No significant predictors of change in pre- and postoperative CM were found. CONSLUSIONS: There were no significant pre-or postoperative differences following the 2 procedures, suggesting radiographic equipoise in well indicated patients. Across all groups, lordosis decreased, cSVA increased, and cervical mismatch increased. There were no predictive factors that led to change in cervical mismatch.

OrthoPass: Long-term Outcomes following Implementation of an Orthopaedic Patient Handoff Template.

Standardized handoff tools improve communication and patient care; however, their widespread use in surgical fields is lacking. OrthoPass, an orthopaedic adaptation of I-PASS, was developed in 2019 to address handoff concerns and demonstrated sustained improvements across multiple handoff domains over an 18-month period. We sought to characterize the longitudinal effect and sustainability of OrthoPass within a single large residency program 3.5 years after its implementation. This mixed methods study involved electronic handoff review for quality domains in addition to survey distribution and evaluation. We conducted comparative analyses of handoff adherence and survey questions as well as a thematic analysis of provider-free responses. We evaluated 146 electronic handoffs orthopaedic residents, fellows, and advanced practice providers 3.5 years after OrthoPass implementation. Compared with 18-month levels, adherence was sustained across five of nine handoff domains and was markedly improved in two domains. Furthermore, provider valuations of OrthoPass improved regarding promoting communication and patient safety (83% versus 70%) and avoiding patient errors and near misses (72% versus 60%). These improvements were further substantiated by positive trends in Agency for Healthcare Research and Quality Surveys on Patient Safety Culture hospital survey data. Thematic analysis of free responses shared by 37 providers (42%) generated favorable, unfavorable, and balanced themes further contextualized by subthemes. At 3.5 years after its introduction, OrthoPass continues to improve patient handoff quality and to support provider notions of patient safety. Although providers acknowledged the benefits of this electronic handoff tool, they also shared unique insights into several drawbacks. This feedback will inform ongoing efforts to improve OrthoPass.

Inpatient opioid use varies by construct length among laminoplasty versus laminectomy and fusion patients.

Background: Laminoplasty (LP) and laminectomy and fusion (LF) are utilized to achieve decompression in patients with symptomatic degenerative cervical myelopathy (DCM). Comparative analyses aimed at determining outcomes and clarifying indications between these procedures represent an area of active research. Accordingly, we sought to compare inpatient opioid use between LP and LF patients and to determine if opioid use correlated with length of stay. Methods: Sociodemographic information, surgical and hospitalization data, and medication administration records were abstracted for patients >18 years of age who underwent LP or LF for DCM in the Mass General Brigham (MGB) health system between 2017 and 2019. Specifically, morphine milligram equivalents (MME) of oral and parenteral pain medication given after arrival in the recovery area until discharge from the hospital were collected. Categorical variables were analyzed using chi-squared analysis or Fisher exact test when appropriate. Continuous variables were compared using Independent samples t tests and Mann-Whitney U tests. Results: One hundred eight patients underwent LF, while 138 patients underwent LP. Total inpatient opioid use was significantly higher in the LF group (312 vs. 260 MME, p=.03); this difference was primarily driven by higher postoperative day 0 pain medication requirements. Furthermore, more LF patients required high dose (>80 MME/day) regimens. While length of stay was significantly different between groups, with LF patients staying approximately 1 additional day, postoperative day 0 MME was not a significant predictor of this difference. When operative levels including C2, T1, and T2 were excluded, the differences in total opioid use and average length of stay lost significance. Conclusions: Inpatient opioid use and length of stay were significantly greater in LF patients compared to LP patients; however, when constructs including C2, T1, T2 were excluded from analysis, these differences lost significance. Such findings highlight the impact of operative extent between these procedures. Future studies incorporating patient reported outcomes and evaluating long-term pain needs will provide a more complete understanding of postoperative outcomes between these 2 procedures.

Projected Lifetime Cancer Risk Associated With Intraoperative Computed Tomography for Lumbar Spine Surgery.

STUDY DESIGN: Retrospective cross-sectional study. OBJECTIVE: (1) To determine the incremental increase in intraoperative ionizing radiation conferred by computed tomography (CT) as compared with conventional radiography; and (2) to model different lifetime cancer risks contextualized by the intersection between age, sex, and intraoperative imaging modality. SUMMARY OF BACKGROUND DATA: Emerging technologies in spine surgery, like navigation, automation, and augmented reality, commonly utilize intraoperative CT. Although much has been written about the benefits of such imaging modalities, the inherent risk profile of increasing intraoperative CT has not been well evaluated. MATERIALS AND METHODS: Effective doses of intraoperative ionizing radiation were extracted from 610 adult patients who underwent single-level instrumented fusion for lumbar degenerative or isthmic spondylolisthesis from January 2015 through January 2022. Patients were divided into those who received intraoperative CT (n=138) and those who underwent conventional intraoperative radiography (n=472). Generalized linear modeling was utilized with intraoperative CT use as a primary predictor and patient demographics, disease characteristics, and preference-sensitive intraoperative considerations ( e.g. surgical approach and surgical invasiveness) as covariates. The adjusted risk difference in radiation dose calculated from our regression analysis was used to prognosticate the associated cancer risk across age and sex strata. RESULTS: (1) After adjusting for covariates, intraoperative CT was associated with 7.6 mSv (interquartile range: 6.8-8.4 mSv; P <0.001) more radiation than conventional radiography. (2) For the median patient in our population (a 62-year-old female), intraoperative CT use increased lifetime cancer risk by 2.3 incidents (interquartile range: 2.1-2.6) per 10,000. Similar projections for other age and sex strata were also appreciated. CONCLUSIONS: Intraoperative CT use significantly increases cancer risk compared with conventional intraoperative radiography for patients undergoing lumbar spinal fusions. As emerging technologies in spine surgery continue to proliferate and leverage intraoperative CT for cross-sectional imaging data, strategies must be developed by surgeons, institutions, and medical technology companies to mitigate long-term cancer risks.

Intraoperative CT for lumbar fusion is not associated with improved short- or long-term complication profiles.

BACKGROUND CONTEXT: The use of intraoperative CT has continued to grow in recent years, as various techniques leverage the promise of improved instrumentation accuracy and the hope for decreased complications. Nonetheless, the literature regarding the short- and long-term complications associated with such techniques remains scant and/or confounded by indication and selection bias. PURPOSE: To use causal inference techniques to determine whether intraoperative CT use is associated with an improved complication profile as compared to conventional radiography for single-level lumbar fusions, an increasingly commonplace application for this technology. STUDY DESIGN/SETTING: Inverse probability weighted retrospective cohort study carried out within a large integrated health care network. PATIENT SAMPLE: Adult patients who underwent surgical treatment of spondylolisthesis via lumbar fusion from January 2016 to December 2021. OUTCOME MEASURES: Our primary outcome was the incidence rate of revision surgery. Our secondary outcome was the incidence of composite 90-day complications (deep and superficial surgical site infection, venous thromboembolic events, and unplanned readmissions). METHODS: Demographics, intraoperative information, and postoperative complications were abstracted from electronic health records. A propensity score was developed utilizing a parsimonious model to account for covariate interaction with our primary predictor, intraoperative imaging technique. This propensity score was utilized in the creation of inverse probability weights to adjust for indication and selection bias. The rate of revisions within 3 years as well as the rate of revisions at any time-point were compared between cohorts using Cox regression analysis. The incidence of composite 90-day complications were compared using negative binomial regression. RESULTS: Our patient population consisted of 583 patients, with 132 who underwent intraoperative CT and 451 who underwent conventional radiographic techniques. There were no significant differences between cohorts following inverse probability weighting. No significant differences were detected in 3-year revision rates (HR, 0.74 [95% CI 0.29, 1.92]; p=.5), overall revision rates (HR, 0.54 [95% CI 0.20, 1.46]; p=.2), or 90-day complications (RC -0.24 [95% CI -1.35, 0.87]; p=.7). CONCLUSIONS: Intraoperative CT use was not associated with an improved complication profile in either the short- or long-term for patients undergoing single-level instrumented fusion. This observed clinical equipoise should be weighed against resource and radiation-related costs when considering intraoperative CT for low complexity fusions.

Development of a machine learning algorithm to identify surgical candidates for hip and knee arthroplasty without in-person evaluation.

INTRODUCTION: Arthroplasty care delivery is facing a growing supply-demand mismatch. To meet future demand for joint arthroplasty, systems will need to identify potential surgical candidates prior to evaluation by orthopaedic surgeons. MATERIALS AND METHODS: Retrospective review was conducted at two academic medical centers and three community hospitals from March 1 to July 31, 2020 to identify new patient telemedicine encounters (without prior in-person evaluation) for consideration of hip or knee arthroplasty. The primary outcome was surgical indication for joint replacement. Five machine learning algorithms were developed to predict likelihood of surgical indication and assessed by discrimination, calibration, overall performance, and decision curve analysis. RESULTS: Overall, 158 patients underwent new patient telemedicine evaluation for consideration of THA, TKA, or UKA and 65.2% (n = 103) were indicated for operative intervention prior to in-person evaluation. The median age was 65 (interquartile range 59-70) and 60.8% were women. Variables found to be associated with operative intervention were radiographic degree of arthritis, prior trial of intra-articular injection, trial of physical therapy, opioid use, and tobacco use. In the independent testing set (n = 46) not used for algorithm development, the stochastic gradient boosting algorithm achieved the best performance with AUC 0.83, calibration intercept 0.13, calibration slope 1.03, Brier score 0.15 relative to a null model Brier score of 0.23, and higher net benefit than the default alternatives on decision curve analysis. CONCLUSION: We developed a machine learning algorithm to identify potential surgical candidates for joint arthroplasty in the setting of osteoarthritis without an in-person evaluation or physical examination. If externally validated, this algorithm could be deployed by various stakeholders, including patients, providers, and health systems, to direct appropriate next steps in patients with osteoarthritis and improve efficiency in identifying surgical candidates. LEVEL OF EVIDENCE: III.

Projected lifetime cancer risk for patients undergoing spine surgery for isthmic spondylolisthesis.

BACKGROUND CONTEXT: Radiographs, fluoroscopy, and computed tomography (CT) are increasingly utilized in the diagnosis and management of various spine pathologies. Such modalities utilize ionizing radiation, a known cause of carcinogenesis. While the radiation doses such studies confer has been investigated previously, it is less clear how such doses translate to projected cancer risks, which may be a more interpretable metric. PURPOSE: (1) Calculate the lifetime cancer risk and the relative contributions of preference-sensitive selection of imaging modalities associated with the surgical management of a common spine pathology, isthmic spondylolisthesis (IS); (2) Investigate whether the use of intraoperative CT, which is being more pervasively adopted, increases the risk of cancer. STUDY DESIGN/SETTING: Retrospective cross-sectional study carried out within a large integrated health care network. PATIENT SAMPLE: Adult patients who underwent surgical treatment of IS via lumbar fusion from January 2016 through December 2021. OUTCOME MEASURES: (1) Effective radiation dose and lifetime cancer risk associated with each exposure to ionizing radiation; (2) Difference in effective radiation dose (and lifetime cancer risk) among patients who received intraoperative CT compared to other intraoperative imaging techniques. METHODS: Baseline demographics and differences in surgical techniques were characterized. Radiation exposure data were collected from the 2-year period centered on the operative date. Projected risk of cancer from this radiation was calculated utilizing each patient's effective radiation dose in combination with age and sex. Generalized linear modeling was used to adjust for covariates when determining the comparative risk of intraoperative CT as compared to alternative imaging modalities. RESULTS: We included 151 patients in this cohort. The range in calculated cancer risk exclusively from IS management was 1.3-13 cases of cancer per 1,000 patients. During the intraoperative period, CT imaging was found to significantly increase radiation exposure as compared to alternate imaging modalities (adjusted risk difference (ARD) 12.33mSv; IQR 10.04, 14.63mSv; p<.001). For a standardized 40 to 49-year-old female, this projects to an additional 0.72 cases of cancer per 1,000. For the entire 2-year perioperative care episode, intraoperative CT as compared to other intraoperative imaging techniques was not found to increase total ionizing radiation exposure (ARD 9.49mSv; IQR -0.83, 19.81mSv; p=.072). The effect of intraoperative imaging choice was mitigated in part due to preoperative (ARD 13.1mSv, p<.001) and postoperative CTs (ARD 22.7mSv, p<.001). CONCLUSIONS: Preference-sensitive imaging decisions in the treatment of IS impart substantial cancer risk. Important drivers of radiation exposure exist in each phase of care, including intraoperative CT and/or CT scans during the perioperative period. Knowledge of these data warrant re-evaluation of current imaging protocols and suggest a need for the development of radiation-sensitive approaches to perioperative imaging.

The Variability and Contributions to Cost of Anterior Cervical Discectomy and Fusion Constructs.

STUDY DESIGN: This was a retrospective cohort study. OBJECTIVE: To characterize the variability in cost for anterior cervical discectomy and fusion (ACDF) constructs and to identify key predictors of procedural cost. SUMMARY OF BACKGROUND DATA: ACDF is commonly performed for surgical treatment of cervical radiculopathy and myelopathy. Numerous biomechanical constructs and graft/biological options are available, with most demonstrating relatively equivalent clinical results. Despite the substantial focus on value in spine care, the differences and contributions to procedural cost in ACDF have not been well defined. MATERIALS AND METHODS: We evaluated the records of patients who underwent a single level ACDF from 2016 to 2020 at 4 hospitals in a major metropolitan area. We abstracted demographics, insurance status, operative time, diagnosis, surgeon, institution, and components of procedural costs. Costs based on construct were compared using multivariable adjusted analyses using negative binomial regression. The primary outcome measures were cost differences between ACDF techniques. RESULTS: Two hundred sixty-four patients were included, with procedures by 13 surgeons across 4 institutions. The total procedural cost for ACDF had a mean of US$2317 with wide variation (range, US$967-US$7370). Multivariable analysis revealed body mass index and use of polyether ether ketone to be correlated with increased cost while carbon fiber and autograft correlated with decreased cost. When comparing standalone device constructs to cases with anterior instrumentation (plate/screws), the total cost was significantly higher in the plate/screw group (US$2686±US$921 vs. US$1466±US$878, P <0.001). CONCLUSIONS: We encountered wide variation in procedural costs associated with ACDF, including as much as an 8-fold difference in the cost of constructs. The most important drivers included instrumentation type and implant materials. Here, we identify potential targets of opportunity for health care organizations that are looking to reduce variance in procedural expenditures to improve health care savings associated with the performance of ACDF.

Magnetic Resonance Imaging Is Inadequate to Assess Cervical Sagittal Alignment Parameters.

STUDY DESIGN: Retrospective radiographic study. OBJECTIVE: To evaluate cervical sagittal alignment measurement reliability and correlation between upright radiographs and magnetic resonance imaging (MRI). SUMMARY OF BACKGROUND DATA: Cervical sagittal alignment (CSA) helps determine the surgical technique employed to treat cervical spondylotic myelopathy. Traditionally, upright lateral radiographs are used to measure CSA, but obtaining adequate imaging can be challenging. Utilizing MRI to evaluate sagittal parameters has been explored; however, the impact of positional change on these parameters has not been determined. METHODS: One hundred seventeen adult patients were identified who underwent laminoplasty or laminectomy and fusion for cervical spondylotic myelopathy from 2017 to 2019. Two clinicians independently measured the C2-C7 sagittal angle, C2-C7 sagittal vertical axis (SVA), and the T1 tilt. Interobserver and intraobserver reliability were assessed by intraclass correlation coefficient. RESULTS: Intraobserver and interobserver reliabilities were highly correlated, with correlations greater than 0.85 across all permutations; intraclass correlation coefficients were highest with MRI measurements. The C2-C7 sagittal angle was highly correlated between x-ray and MRI at 0.76 with no significant difference ( P =0.46). There was a weaker correlation with regard to C2-C7 SVA (0.48) and T1 tilt (0.62) with significant differences observed in the mean values between the 2 modalities ( P <0.01). CONCLUSIONS: The C2-C7 sagittal angle is highly correlated and not significantly different between upright x-ray and supine MRIs. However, cervical SVA and T1 tilt change with patient position. Since MRI does not accurately reflect the CSA in the upright position, upright lateral radiographs should be obtained to assess global sagittal alignment when planning a posterior-based cervical procedure.

C-reactive Protein-to-albumin Ratio in Spinal Epidural Abscess: Association with Post-treatment Complications.

INTRODUCTION: Spinal epidural abscess (SEA) is a complex medical condition with high morbidity and healthcare costs. Clinical presentation and laboratory data may have prognostic value in forecasting morbidity and mortality. C-reactive protein-to-albumin ratio (CAR) demonstrates promise for the prediction of adverse events in multiple orthopaedic and nonorthopaedic surgical conditions. We investigated the relationship between CAR and outcomes after treatment of SEA. METHODS: We retrospectively evaluated adult patients treated within a single healthcare system for a diagnosis of SEA (2005 to 2017). Laboratory and clinical data included age at diagnosis, sex, race, body mass index, smoking status, history of intravenous drug use, Charlson Comorbidity Index, and CAR. The primary outcome was the occurrence of any complication; mortality and readmissions were considered secondarily. We used logistic regression to determine the association between baseline CAR and outcomes, adjusting for confounders. RESULTS: We included 362 patients with a 90-day mortality rate of 13.3% and a 90-day complication rate of 47.8%. A reduced complication rate was observed in the lowest decile of CAR values compared with the remaining 90% of patients, a threshold value of 2.5 (27.0% versus 50.2%; odds ratio [OR] 2.66, 95% confidence interval [CI] 1.22 to 5.81). CAR values in the highest two deciles experienced significantly increased odds of complications compared with the lowest decile (80th: OR 3.44; 95% CI 1.25 to 9.42; 90th: OR 3.28; 95% CI 1.19 to 9.04). DISCUSSION: We found elevated CAR to be associated with an increased likelihood of major morbidity in SEA. We suggest using a CAR value of 2.5 as a threshold for enhanced surveillance and recognizing patients with values above 73.7 as being at exceptional risk of morbidity. LEVEL OF EVIDENCE: Level III observational cohort study.

Microendoscopic Decompression for Lumbar Disc Herniations: An Analysis of Short and Long Term Patient Reported Outcome Measures.

INTRODUCTION: Endoscopic spine surgery is increasingly being used, and techniques, platforms, and applications are rapidly evolving. Despite substantial enthusiasm surrounding these techniques, there is a dearth of longer term patient-reported clinical outcomes. Within the United States in particular, there are yet to be reported large cohort studies with a notable follow-up. We sought to characterize the clinical outcomes of patients undergoing microendoscopic decompression (MED) for lumbar disk herniations. METHODS: The records of patients with symptomatic lumbar disk herniations who underwent MED from May 2018 to February 2021 within a single practice were reviewed. Paired outcomes scores were evaluated using Patient-Reported Outcomes Measurement Information System parameters. Basic perioperative data including length of stay, estimated blood loss, mean opioid use, complication rate, and rate of revision were tabulated. Paired sample Student t-tests and paired Wilcoxon sign tests were used to compare normally distributed and nonparametric data, respectively. RESULTS: Thirty-five patients with complete paired patient-reported outcome measures data and a minimum 6-month follow-up were included; 65.7% of the patients were male with a mean age of 47.1 years (SE 1.8). The mean follow-up was 590.6 days (SE 47.7). In total, 34 of the 35 patients (97.1%) were discharged on the day of their procedure. The estimated blood loss was <25 mL for each procedure. The mean opioid use after extubation and before discharge was 10.4 morphine milligram equivalents. At the 2-week follow-up, there were notable improvements in pain metrics and global health components. At the final follow-up, nearly all parameters showed notable improvement that exceeded minimally clinical important difference values. For most parameters, preoperative values outside of the "normal" range were within normal limits on postoperative testing. DISCUSSION: MED resulted in sustained notable improvement in patient-reported outcome measures that exceeded minimally clinical important difference values at the average follow-up approximating 2 years. These findings substantiate the utility of this technique and additional investment in endoscopic spine technology. DATA AVAILABILITY: Not publicly available; available upon request.

Microendoscopic decompression of conjoined lumbosacral nerve roots.

Nerve root morphological variability is often incompletely appreciated on preoperative imaging and can complicate intraoperative decision-making. This case demonstrates the utility of spinal endoscopy in the visualisation and manipulation of conjoined nerve roots and includes procedural images to promote better understanding and awareness of this anatomical anomaly. A woman in her 50s presented with 1 year of progressive left S1 radiculopathy refractory to non-operative modalities. History and examination were notable for S1 dermatomal paresthesias, positive ipsilateral straight leg raise and grade 4/5 gastrocnemius strength. MRI demonstrated an L5-S1 left paracentral disc herniation causing severe lateral recess stenosis. Endoscopic decompression revealed conjoined lumbosacral nerve roots. Laminotomies and discectomy provided circumferential decompression. The patient experienced immediate and sustained relief of her preoperative radiculopathy as manifested in patient-reported outcome measures. Evolving endoscopic spine platforms provide novel visualisation of nerve root anomalies yielding new insight on safe and effective decompressive techniques.

Insurance Type is Associated with Baseline Patient-Reported Outcome Measures in Patients with Lumbar Stenosis.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To determine if insurance type is associated with differences in baseline patient-reported outcome measures (PROMs) among patients with lumbar spinal stenosis (LSS). SUMMARY OF BACKGROUND DATA: PROMs are increasingly used as means to convey value. Prior research suggests that sociodemographic factors, including insurance type may influence these metrics, with patients who are more socioeconomi-cally disadvantaged reporting poorer baseline PROMs. Nonetheless, this association is yet to be evaluated among patients with spinal stenosis. METHODS: Six-hundred-eight patients with LSS were identified within a major academic health system. Their baseline Patient-Reported Outcomes Measurement Information System for physical function, pain, anxiety and depression, and visual analogue scale for low back and leg pain were analyzed. Wilcoxon rank-sum testing and chi-squared testing were utilized for descriptive nonadjusted comparisons. Negative binomial regression modeling was performed with PROMs considered as dependent variables, insurance type as the primary predictor, and all other factors (e.g., Charlson Comorbidity Index, age, gender, race, ethnicity, language spoken, and median geospatial household income) considered as covariates. RESULTS: The mean age of the cohort was 62.6 ± 14years with a female majority (50.7%). Patients with Medicaid insurance were younger, more likely to be Hispanic, and less likely to be English-speaking than those with commercial insurance or Medicare. Overall, patients with Medicaid insurance were found to have worse baseline PROMs across almost all domains, with the worst performance in Patient-Reported Outcomes Measurement Information System 10 physical global (incidence rate ration 0.88, 95% confidence interval 0.82-0.95) and mental function (incidence rate ration 0.85, 95% confidence interval 0.80-0.92). CONCLUSION: LSS patients insured through Medicaid have systematically worse baseline PROMs across almost all domains as compared to those with commercial insurance and Medicare, even after adjusting for confounders. These findings have broad ranging implications for research and healthcare policy, especially when using PROMs as measures of value.

ALIF Versus TLIF for L5-S1 Isthmic Spondylolisthesis: ALIF Demonstrates Superior Segmental and Regional Radiographic Outcomes and Clinical Improvements Across More Patient-reported Outcome Measures Domains.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The purpose of this study was to compare segmental and regional radiographic parameters between anterior interbody fusion (ALIF) and posterior interbody fusion (TLIF) for treatment of L5-S1 isthmic spondylolisthesis, and to assess for changes in these parameters over time. Secondarily, we sought to compare clinical outcomes via patient-reported outcome measures (PROMs) between techniques and within groups over time. SUMMARY OF BACKGROUND DATA: Isthmic spondylolistheses are frequently treated with interbody fusion via ALIF or TLIF approaches. Robust comparisons of radiographic and clinical outcomes are lacking. METHODS: We reviewed pre- and postoperative radiographs as well as Patient-Reported Outcomes Measurement Information System (PROMIS) elements for patients who received L5-S1 interbody fusions for isthmic spondylolisthesis in the Mass General Brigham (MGB) health system (2016-2020). Intraclass correlation testing was used for reliability assessments; Mann-Whitney U tests and Sign tests were employed for intercohort and intracohort comparative analyses, respectively. RESULTS: ALIFs generated greater segmental and L4-S1 lordosis than TLIF, both at first postoperative visit (mean 26 days [SE = 4]; 11.3° vs. 1.3°, P  < 0.001; 6.2° vs. 0.3°, P  = 0.005) and at final follow-up (mean 410days [SE = 45]; 9.6° vs. 0.2°, P < 0.001; 7.9° vs. 2.1°, P = 0.005). ALIF also demonstrated greater increase in disc height than TLIF at first (9.6 vs. 5.5 mm, P < 0.001) and final follow-up (8.7 vs. 3.6 mm, P < 0.001). Disc height was maintained in the ALIF group but decreased over time in the TLIF cohort (ALIF 9.6 vs. 8.7 mm, P = 0.1; TLIF 5.5 vs. 3.6 mm, P < 0.001). Both groups demonstrated improvements in Pain Intensity and Pain Interference scores; ALIF patients also improved in Physical Function and Global Health - Physical domains. CONCLUSION: ALIF generates greater segmental lordosis, regional lordosis, and restoration of disc height compared to TLIF for treatment of isthmic spondylolisthesis. Additionally, ALIF patients demonstrate significant improvements across more PROMs domains relative to TLIF patients.Level of Evidence: 3.

Spinal endoscopy: evidence, techniques, global trends, and future projections.

The utilization of indirect visualization during procedures has been increasingly replacing traditional forms of direct visualization across many different surgical specialties. The adoption of arthroscopy, using small cameras placed inside joints, has transformed musculoskeletal care over the last several decades, allowing surgeons to provide the same anatomic solutions with less tissue dissection, resulting in lower requirements for inpatient care, reduced costs, and expedited recovery.  For a variety of reasons, spine surgery has lagged behind other specialties in the adoption of indirect visualization.  Nonetheless, patient demand for less invasive spine procedures and surgeon drive to provide these solutions and improve care quality has driven global adoption of spinal endoscopy.  There are numerous endoscopic platforms and techniques currently utilized, and these systems are rapidly evolving.  Additionally, the variance in technology and health system incentives across the globe has generated tremendous regional heterogeneity in the utilization of spinal endoscopic procedures.  We present a consolidated review, including the background, evidence, techniques, and trends in spinal endoscopy, so that clinicians can gain a deeper understanding of this rapidly evolving domain of spinal healthcare.

Patient Experiences of Telemedicine in Spine Care: A Mixed Methods Study.

STUDY DESIGN: Survey-based study. OBJECTIVE: We performed a mixed methods study involving patients using telemedicine for spine care. We sought to understand factors influencing the utilization and evaluation of this modality. SUMMARY OF BACKGROUND DATA: Telemedicine has been integrated into routine spine care; its long-term viability will depend not only on optimizing its safety, efficiency, and cost-effectiveness, but also on understanding patient valuation of its benefits and limitations. METHODS: We used a clinical registry to identify spine patients seen virtually by providers at our tertiary academic medical center between March and September of 2020. We distributed an online survey that queried patients' experiences with telemedicine. We performed statistical analyses of Likert-scale questions and a thematic analysis of free-form responses. Sociodemographic data were abstracted and analyzed. RESULTS: Overall, we evaluated 139 patient surveys. High levels of patient-rated care and patient-rated experience were observed for both in-person and telemedicine visits; however, in-person visits were rated significantly higher in both respects (9.3/10 vs. 8.7/10 for patient-rated care, P < 0.001; 9.0/10 vs. 8.4/10 for patient-rated experience, P = 0.006). A preference for in-person first-time visits was observed which was not maintained for follow up appointments. Both patient and clinical factors influenced perceptions of telemedicine. Thematic analysis of free-form responses provided by 113 patients (81%) generated favorable, unfavorable, and reflective themes, each further contextualized by subthemes. Responders were not significantly different from nonresponders across sociodemographic characteristics. CONCLUSION: Our quantitative and qualitative findings yield insight into the patient experience of telemedicine in spine care. A preference for in-person visits was notable, particularly for new patient evaluations. This preference was not maintained for follow-up care. Patients acknowledged the benefits of telemedicine and reflected on its effective integration with in-person care. These results may guide best practices to improve access and patient satisfaction in the future.Level of Evidence: 4.

Trends and Complications in Spinopelvic Fixation for Deformity for Spinal Surgeons in Early Independent Practice.

STUDY DESIGN: Retrospective case series study. OBJECTIVE: Evaluate trends and complications following posterior spinal instrumented fusion for deformity with/without pelvic fixation using the American Board of Orthopaedic Surgery Part II Oral Examination Candidate Case List data from 2008 to 2017. SUMMARY OF BACKGROUND DATA: Complication rates for cases with pelvic fixation are widely reported in spine deformity literature but are typically derived from practices of senior surgeons. As surgical experience and clinical volume are shown to decrease complication rates, spine surgeons newly in practice may have higher risks of such events. MATERIALS AND METHODS: Surgical cases submitted by candidates taking the American Board of Orthopaedic Surgery Part II Oral Examination between 2008 and 2017 with a self-designated sub-specialty of spine surgery were retrospectively reviewed. Mortality, readmission/reoperation data, and complications as reported by candidates were tracked over time. Bivariate testing and multivariable Poisson analyses, respectively, were used to assess complication rates and time-related trends. RESULTS: A total of 37,539 cases were submitted between 2008 and 2017. Four hundred sixty-one cases (1.2%) were for deformity; of these, 60 cases included pelvic fixation (13% of deformity cases). For all deformity cases, we noted medical, surgical, and overall complication rates to be 17%, 22.3%, and 31.5%. Multivariable analyses demonstrated no difference in surgical/overall complication rates between spinopelvic and nonspinopelvic instrumented groups, but showed a consistently low number of cases using spinopelvic fixation over time. CONCLUSIONS: Newly practicing spinal surgeons consistently performed low numbers of deformity cases with relatively high complication rates which remained stable over time.

Telemedicine visits generate accurate surgical plans across orthopaedic subspecialties.

INTRODUCTION: The role of telemedicine is rapidly evolving across medical specialties and orthopaedics. The utility of telemedicine to identify operative candidates and determine surgical plans has yet to be demonstrated. We sought to assess whether surgical plans proposed following telemedicine visits changed after subsequent in-person interaction across orthopaedic subspecialties. MATERIALS AND METHODS: We identified all elective telemedicine encounters across two academic institutions from March 1, 2020 to July 31, 2020. We identified patients indicated for surgery with a specific surgical plan during the virtual visit. The surgical plans delineated during the telemedicine encounter were then compared to final pre-operative plans documented following subsequent in-person evaluation. Changes in the surgical plan between telemedicine and in-person encounters were defined using a standardised schema. Regression analysis was used to evaluate factors associated with a change in surgical plan between visits across specialties, including the number of virtual examination manoeuvres performed. RESULTS: We identified 303 instances of a patient being indicated for orthopaedic surgery during a telemedicine encounter. In 11 cases (4%), the plan was changed between telemedicine and subsequent in-person encounter. No plans were changed amongst patients indicated for joint arthroplasty and foot and ankle surgery, whilst 4% of plans were changed amongst sports surgery and upper extremity/shoulder surgery. Surgical plans had the highest rate of change amongst spine surgery patients (8%). There was notable variability in the conduct of virtual examinations across subspecialties. CONCLUSION: Our results demonstrate the capability of telemedicine to support development of accurate surgical plans for orthopaedic patients across several subspecialties. Our findings also highlight the substantial variation in the utilisation of physical examination manoeuvres conducted via telemedicine across institutions, subspecialties, and providers. DESCRIPTION OF STUDY TYPE: Level IV, retrospective cohort study.