Varenicline Mitigates the Increased Risk of Pseudoarthrosis Associated with Nicotine

BACKGROUND CONTEXT

High serum nicotine levels increase the risk of non-union after spinal fusion. Varenicline, a pharmaceutical adjunct for smoking cessation, is a partial agonist designed to displace and outcompete nicotine at its receptor binding site, thereby limiting downstream activation. Given its mechanism, varenicline may have therapeutic benefits in mitigating non-union for active smokers undergoing spinal fusion.

PURPOSE

To compare fusion rate and fusion mass characteristics between cohorts receiving nicotine, varenicline, or concurrent nicotine and varenicline after lumbar fusion.

STUDY DESIGN

Rodent non-instrumented spinal fusion model.

METHODS

Sixty eight-week-old male Sprague-Dawley rats weighing approximately 300 grams underwent L4-5 posterolateral fusion (PLF) surgery. Four experimental groups (control: C, nicotine: N, varenicline: V, and combined: NV [nicotine and varenicline]) were included for analysis. Treatment groups received nicotine, varenicline, or a combination of nicotine and varenicline delivered through subcutaneous osmotic pumps beginning two weeks before surgery until the time of sacrifice at age 14 weeks. Manual palpation testing, microCT imaging, bone histomorphometry, and biomechanical testing were performed on harvested spinal fusion segments.

RESULTS

Control (p=0.016) and combined (p=0.032) groups, when compared directly to the nicotine group, demonstrated significantly greater manual palpation scores. The fusion rate in the control (93.3%) and combined (93.3%) groups were significantly greater than that of the nicotine group (33.3%) (p=0.007, both). Biomechanical testing demonstrated greater Young's modulus of the fusion segment in the control (17.1 MPa) and combined groups (34.5 MPa) compared to the nicotine group (8.07 MPa) (p<0.001, both). MicroCT analysis demonstrated greater bone volume fraction (C:0.35 vs N:0.26 vs NV:0.33) (p<0.001, all) and bone mineral density (C:335 vs N:262 vs NV:328 mg Ha/cm³) (p<0.001, all) in the control and combined groups compared to the nicotine group. Histomorphometry demonstrated a greater mineral apposition rate in the combined group compared to the nicotine group (0.34 vs 0.24 μm/day, p=0.025).

CONCLUSION

In a rodent spinal fusion model, varenicline mitigates the adverse effects of high nicotine serum levels on the rate and quality of spinal fusion.

CLINICAL SIGNIFICANCE

These findings have the potential to significantly impact clinical practice guidelines and the use of pharmacotherapy for active nicotine users undergoing fusion surgery.

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

STUDY DESIGN

Retrospective cohort study OBJECTIVE: To compare outcomes among Clinical and Radiographic Degenerative Spondylolisthesis (CARDS) subtypes in patients undergoing posterior lumbar decompression and fusion (PLDF) or transforaminal lumbar interbody fusion (TLIF) and evaluate 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 2010-2020 were identified. Patients were grouped by preoperative CARDS classification. Multivariate analysis was utilized to determine the effects of treatment approach on one-year PROMs and 90-day surgical outcomes.

RESULTS

A total of 1,056 patients were included:148 patients with Type A DS, 323 Type B, 525 Type C, and 60 Type D. Patients with CARDS Types A and C who underwent PLDF experienced longer length of stay and were less likely to be discharged home. There were no differences in revisions, complications, or readmissions between surgical approaches. CARDS Type A patients undergoing PLDF were less likely to achieve MCID for VAS Back (36.8% vs 76.7%, p=0.013). There were no other significant differences in PROMs among CARDS subtypes. TLIF independently predicted better VAS Leg pain improvement at one-year follow-up (β=-2.92, p=0.017) among CARDS Type A patients. Multivariable analysis demonstrated no significant difference in PROMs by surgical approach among other CARDS subtypes.

CONCLUSION

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 Type B and C) showed no benefit from additional interbody placement.

Patient-Reported Outcomes Following Anterior and Posterior Surgical Approaches for Multilevel Cervical Myelopathy

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

To compare health-related quality of life (HRQoL) outcomes between approach techniques for the treatment of multilevel degenerative cervical myelopathy (DCM).

SUMMARY OF BACKGROUND DATA

Both anterior and posterior approaches for the surgical treatment of cervical myelopathy are successful techniques in the treatment of myelopathy. However, the optimal treatment has yet to be determined, especially for multilevel disease, as the different approaches have separate complication profiles and potentially different impacts on HRQoL metrics.

MATERIALS AND METHODS

Retrospective review of a prospectively managed single institution database of patient-reported outcome measures after 3 and 4-level anterior cervical discectomy and fusion (ACDF) and posterior cervical decompression and fusion (PCDF) for DCM. The electronic medical record was reviewed for patient baseline characteristics and surgical outcomes whereas preoperative radiographs were analyzed for baseline cervical lordosis and sagittal balance. Bivariate and multivariate statistical analyses were performed to compare the two groups.

RESULTS

We identified 153 patients treated by ACDF and 43 patients treated by PCDF. Patients in the ACDF cohort were younger (60.1 ± 9.8 vs . 65.8 ± 6.9 yr; P < 0.001), had a lower overall comorbidity burden (Charlson Comorbidity Index: 2.25 ± 1.61 vs . 3.07 ± 1.64; P = 0.002), and were more likely to have a 3-level fusion (79.7% vs . 30.2%; P < 0.001), myeloradiculopathy (42.5% vs . 23.3%; P = 0.034), and cervical kyphosis (25.7% vs . 7.69%; P = 0.027). Patients undergoing an ACDF had significantly more improvement in their neck disability index after surgery (-14.28 vs . -3.02; P = 0.001), and this relationship was maintained on multivariate analysis with PCDF being independently associated with a worse neck disability index (+8.83; P = 0.025). Patients undergoing an ACDF also experienced more improvement in visual analog score neck pain after surgery (-2.94 vs . -1.47; P = 0.025) by bivariate analysis.

CONCLUSIONS

Our data suggest that patients undergoing an ACDF or PCDF for multilevel DCM have similar outcomes after surgery.

Creation of a Risk Calculator for Predicting New-Onset Cardiac Arrhythmias in Patients Undergoing Lumbar Fusion

INTRODUCTION

As an increasing number of lumbar fusion procedures are being conducted at specialty hospitals and surgery centers, appropriate patient selection and risk stratification is critical to minimizing patient transfers. Postoperative cardiac arrhythmia has been linked to worse patient outcomes and is a common cause of patient transfer. Therefore, we created a risk calculator to predict a patient's likelihood of developing a new-onset postoperative cardiac arrhythmia after lumbar spinal fusion, which may improve preoperative facility selection.

METHODS

A retrospective review was conducted of patients who undergoing lumbar fusion from 2017 to 2021 at a single academic center. Patients were excluded if they had any medical history of a cardiac arrhythmia. Multivariable regression was conducted to determine independent predictors of inpatient arrhythmias. The final regression was applied to a bootstrap to validate an arrhythmia prediction model. A risk calculator was created to determine a patient's risk of new-onset cardiac arrhythmia.

RESULTS

A total of 1,622 patients were included, with 45 patients developing a new-onset postoperative arrhythmia. Age (OR = 1.05; 95% CI, 1.02 to 1.09; P = 0.003), history of beta-blocker use (OR = 2.01; 95% CI, 1.08 to 3.72; P = 0.027), and levels fused (OR = 1.59; 95% CI, 1.20 to 2.00; P = 0.001) were all independent predictors of having a new-onset inpatient arrhythmia. This multivariable regression produced an area under the curve of 0.742. The final regression was applied to a bootstrap prediction modeling technique to create a risk calculator including the male sex, age, body mass index, beta-blocker use, and levels fused (OR = 1.04, [CI = 1.03 to 1.06]) that produced an area under the curve of 0.733.

CONCLUSION

A patient's likelihood of developing postoperative cardiac arrhythmias may be predicted by comorbid conditions and demographic factors including age, sex, body mass index, and beta-blocker use. Knowledge of these risk factors may improve appropriate selection of an outpatient surgical center or orthopaedic specialty hospital versus an inpatient hospital for lumbar fusions.

A Multi-Disciplinary Review of Time-Driven Activity-Based Costing: Practical Considerations for Spine Surgery

STUDY DESIGN

A multi-disciplinary review.

OBJECTIVES

To provide a roadmap for implementing time-driven activity-based costing (TDABC) for spine surgery. This is achieved by organizing and scrutinizing publications in the spine, neurosurgical, and orthopedic literature which utilize TDABC and related methodologies.

METHODS

PubMed and Google Scholar were searched for relevant articles. The articles were selected by two independent researchers. After article selection, data was extracted and summarized into research domains. Preferred reporting items for systematic reviews and meta-analyses (PRISMA) systematic review process was followed.

RESULTS

Of the 524 articles screened, thirty-five articles met the inclusion criteria. Each included article was examined and reviewed to define the primary research question and objective. Comparing different procedures was the most common primary objective. Direct observation along with one other strategy (surveys, interviews, surgical database, or EMR) was most commonly employed during process map development. Across all surgical subspecialties (spine, neurologic, and orthopedic surgery), costs were divided into direct cost, indirect cost, cost to patient, and total costs. The most commonly calculated direct costs included personnel and supply costs. Facility costs, hospital overhead costs, and utilities were the most commonly calculated indirect costs. Transportation costs and parental lost wages were considered when calculating cost to patient. The total cost was a sum of direct costs, indirect costs, and costs to the patient.

CONCLUSION

TDABC provides a common platform to accurately estimate costs of care delivery. Institutions embarking on TDABC for spine surgery should consider the breadth of methodologies highlighted in this review to determine which type of calculations are appropriate for their practice.

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

Objective

To evaluate the reasons for transfer as well as the 90-day outcomes of patients who were transferred from a high-volume orthopedic specialty hospital (OSH) following elective spine surgery.

Materials and Methods

All patients admitted to a single OSH for elective spine surgery from 2014 to 2021 were retrospectively identified. Ninety-day complications, readmissions, revisions, and mortality events were collected and a 3:1 propensity match was conducted.

Results

Thirty-five (1.5%) of 2351 spine patients were transferred, most commonly for arrhythmia (n = 7; 20%). Thirty-three transferred patients were matched to 99 who were not transferred, and groups had similar rates of complications (18.2% vs. 10.1%; P = 0.228), readmissions (3.0% vs. 4.0%; P = 1.000), and mortality (6.1% vs. 0%; P = 0.061).

Conclusion

Overall, this study demonstrates a low transfer rate following spine surgery. Risk factors should continue to be optimized in order to decrease patient risks in the postoperative period at an OSH.

A Proposal for a Standardized Imaging Algorithm to Improve the Accuracy and Reliability for the Diagnosis of Thoracolumbar Posterior Ligamentous Complex Injury in Computed Tomography and Magnetic Resonance Imaging

STUDY DESIGN

Systematic Literature Review.

OBJECTIVE

To propose a systematic imaging algorithm for diagnosing posterior ligamentous complex (PLC) injury in computed tomography (CT) and magnetic resonance imaging (MRI) to improve the reliability of PLC assessment.

METHODS

A systematic review was conducted following PRISMA guidelines. The Scopus database was searched from its inception until July 21, 2022, for studies evaluating CT or MRI assessment of the PLC injury following thoracolumbar trauma. The studies extracted key findings, objectives, injury definitions, and radiographic modalities.

RESULTS

Twenty-three studies were included in this systematic review, encompassing 2021 patients. Five studies evaluated the accuracy of MRI in detecting thoracolumbar PLC injury using intraoperative findings as a reference. These studies indicate that black stripe discontinuity due to supraspinous or ligamentum flavum rupture is a more specific criterion of PLC injury than high-signal intensity. Thirteen papers evaluated the accuracy or reliability of CT in detecting thoracolumbar PLC injury using MRI or intraoperative findings as a reference. The overall accuracy rate of CT in detecting PLC injury was 68-90%. Two studies evaluate the accuracy of combined CT findings, showing that ≥2 CT findings are associated with a positive predictive value of 88-91 %. Vertebral translation, facet joint malalignment, spinous process fracture, horizontal laminar fracture, and interspinous widening were independent predictors of PLC injury.

CONCLUSION

We provided a comprehensive imaging algorithm for diagnosing PLC in CT and MRI based on available literature and our experience. The algorithm will potentially improve the accuracy and reliability of PLC assessment, however it needs multicentre prospective validation.

Does Facet Distraction Affect Patient Outcomes After ACDF?

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The aim of this study is to determine if there is a correlation between the amount of facet distraction and postoperative patient-reported outcomes after ACDF.

METHODS

A retrospective cohort analysis of patients undergoing 1 to 3 level ACDF for degenerative pathologies at a single academic center was performed. Each patient received upright, lateral cervical spine x-rays at the immediate postoperative time point from which interfacet distance (facet distraction) was measured. Patient-reported outcome measures including NDI, PCS-12, MCS-12, VAS Neck, and VAS Arm pain scores were obtained preoperatively and at short-term (<3 months) and long-term (>1 year) follow-up. Receiver operating curves were generated to evaluate the possibility of a critical interfacet distraction distance. Univariate and multivariate analysis were performed to compare outcomes between groups based on the degree of facet distraction.

RESULTS

A total of 229 patients met the inclusion criteria. Receiver operating curves failed to yield a critical interfacet distraction distance associated with worse post-operative outcomes. Patients were instead grouped based on facet distraction distance below and above the third quartile (0.8mm-2.0 mm, 2.0mm-3.7 mm), with 173 and 56 patients in each respective group. Univariate analysis did not detect any statistically significant differences in outcome measures, recovery ratio, or % MCID achievement at short- and long-term follow-up between groups. Multivariate analysis also failed to demonstrate any significant differences between the facet distraction groups.

CONCLUSION

Increased interfacet distance did not correlate with increased neck pain or disability after an ACDF.

Linking Patterns of Intraoperative Neuromonitoring (IONM) Alerts to the Odds of a New Postoperative Neurological Deficit: Analysis of 27,808 Cervical Spine Procedures From a National Multi-institutional Database

STUDY DESIGN/SETTING

Retrospective review of a national multi-institutional database of 27,808 extradural cervical spine procedures performed between January 2017 and May 2021.

OBJECTIVE

Characterize intraoperative neuromonitoring alerts by the patterns of modalities and nerves/muscles involved and quantify risk of new-onset neurological deficit for patients with a primary diagnosis of myelopathy, stenosis, or radiculopathy.

SUMMARY OF BACKGROUND DATA

Phenotyping alert patterns and linking those patterns with risk is needed to facilitate clinical decision-making.

METHODS

Cases with alerts were categorized by patterns of modalities or nerves/muscles involved, and alert status at closure. Unadjusted odds ratios (ORs) for new-onset neurological deficit were calculated. A mixed-effects logistic regression model controlling for demographic and operative factors, with random intercepts to account for clustering in outcomes by surgeon and surgical neurophysiologist was also used to calculate ORs and probabilities of neurological deficit.

RESULTS

There was significantly increased risk of a new neurological deficit for procedures involving posterior compared with anterior approaches (OR: 1.82, P=0.001) and procedures involving three levels compared with one (OR: 2.17, P=0.001). Odds of a deficit were lower for patients with radiculopathy compared with myelopathy (OR: 0.69, P=0.058). Compared with cases with no alerts, those with unresolved Spinal Cord alerts were associated with the greatest elevation in risk (OR: 289.05) followed by unresolved C5-6 Nerve Root (OR: 172.7), C5-T1 Nerve Root/Arm (OR: 162.89), C7 Nerve Root (OR:84.2), and C8-T1 Nerve Root alerts (OR:75.49, all P<0.001). Significant reductions in risk were seen for resolved Spinal Cord, C5-6 Nerve Root, and C8-T1 nerve alerts. Overall, unresolved motor evoked potential and somatosensory evoked potential alerts were associated with the greatest elevation in risk (OR:340.92) followed by unresolved motor evoked potential-only (OR:140.6) and unresolved somatosensory evoked potential-Only alerts (OR:78.3, all P<0.001). These relationships were similar across diagnostic cohorts.

CONCLUSIONS

Risk elevation and risk mitigation after an intraoperative neuromonitoring alert during surgery is dependent on the type and pattern of alert.

Cellular Bone Matrix Leading to Disseminated Tuberculosis After Spinal Fusion: A Report of 2 Cases

CASE

Although implanted tuberculosis (TB) is rare, a single lot of cellular bone matrix was found to be infected with TB, leading to devastating outcomes. We present 2 cases referred to our institution because of instrumentation failure caused by TB inoculation of cellular bone matrix.

CONCLUSION

Irrespective of spinal region of implanted TB infection, excision of infected bone, extensive irrigation and debridement, and instrumented stabilization are of primary importance to ensure TB eradication and adequate stabilization.

Six-Year Follow-up of a Randomized Controlled Trial of i-FACTOR Peptide-Enhanced Bone Graft Versus Local Autograft in Single-Level Anterior Cervical Discectomy and Fusion

BACKGROUND

Previous analyses of the US Food and Drug Administration (FDA) Investigational Device Exemption study demonstrated the superiority of i-FACTOR compared with local autograft bone in single-level anterior cervical discectomy and fusion (ACDF) at 12 and 24 months postoperatively in a composite end point of overall success.

OBJECTIVE

To report the final, 6-year clinical and radiological outcomes of the FDA postapproval study.

METHODS

Of the original 319 subjects enrolled in the Investigational Device Exemption study, 220 participated in the postapproval study (106 i-FACTOR and 114 control).

RESULTS

The study met statistical noninferiority success for all 4 coprimary end points. Radiographic fusion was achieved in 99% (103/104) and 98.2% (109/111) in i-FACTOR and local autograft subjects, mean Neck Disability Index improvement from baseline was 28.6 (24.8, 32.3) in the i-FACTOR and 29.2 (25.6, 32.9) in the control group, respectively (noninferiority P < .0001). The neurological success rate at 6 years was 95.9% (70/73) in i-FACTOR subjects and 93.7% (70/75) in local autograft subjects (noninferiority P < .0001). Safety outcomes were similar between the 2 groups. Secondary surgery on the same or different cervical levels occurred in 20/106 (18.9%) i-FACTOR subjects and 23/114 (20.2%) local autograft subjects ( P = .866). Secondary outcomes (pain, SF-36 physical component score and mental component score) in i-FACTOR subjects were similar to those in local autograft subjects.

CONCLUSION

i-FACTOR met all 4 FDA-mandated noninferiority success criteria and demonstrated safety and efficacy in single-level anterior cervical discectomy and fusion for cervical radiculopathy through 6 years postoperatively. Safety outcomes are acceptable, and the clinical and functional outcomes observed at 12 and 24 months remained at 72 months.

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.

Development of a comprehensive assessment tool to measure the quality of care for individuals with traumatic spinal cord injuries

OBJECTIVE

To develop a comprehensive assessment tool to evaluate the Quality of Care (QoC) in managing individuals with traumatic spinal cord injuries (TSCI).

METHOD

At first, the concepts of QoC for TSCI were identified by conducting a qualitative interview along with re-evaluation of the results of a published scoping review (conceptualization). After operationalization of indicators, they were valued by using the expert panel method. Afterward, the content validity index (CVI) and content validity ratio (CVR) were calculated and served as cut-offs for indicator selection. Then specific questions were developed for each indicator and classified into three categories: pre-hospital, in-hospital, and post-hospital. Data availability of the National Spinal Cord Injury Registry of Iran (NSCIR-IR) was subsequently used to design questions that represent indicators in an assessment tool format. The comprehensiveness of the tool was evaluated using a 4-item Likert scale by the expert panel.

RESULT

Twelve experts participated in conceptualization and 11 experts participated in operationalization phase. Overall, 94 concepts for QoC were identified from published scoping review (87 items) and qualitative interviews (7 items). The process of operationalization and indicator selection led to the development of 27 indicators with acceptable content validity. Finally, the assessment tool contained three pre-hospital, twelve in-hospital, nine post-hospital, and three mixed indicators. Ninety-one percent of experts evaluated the entire tool as comprehensive.

CONCLUSION

Our study presents a health-related QoC tool that contains a comprehensive set of indicators to assess the QoC for individuals with TSCI. However, this tool should be used in various situations to establish construct validity further.

Predictors of Academic Productivity Among Spine Surgeons

INTRODUCTION

The relationship between research productivity in training and future productivity as an attending spine surgeon is not well-established in the literature nor has the effect of geographic location of training institutions on future academic success been investigated. The aim of our study was to (1) summarize characteristics of academically productive spine surgeons, (2) assess predictors of long-term academic productivity, and (3) establish the effect of geographic location on long-term academic productivity.

METHODS

A query was conducted of the 2021 to 2022 North American Spine Society Spine Fellowship Directory of all orthopaedic and neurosurgical spine fellowship selection committee members for each institution participating in the spine fellowship match. The attending publication rate and h-index were determined. A multivariate linear regression model was developed. P value was set to <0.05.

RESULTS

We identified 310 orthopaedic and neurosurgical spine surgeons, representing 76 fellowship programs. Multivariate linear regression analysis identified that the publications during residency (P < 0.001) and during fellowship (P < 0.001) were significant predictors of an increased publication rate as an attending surgeon. By contrast, the preresidency publication rate (P = 0.729) was not significantly predictive of the attending publication rate. Multivariate analysis of h-index found that residency publication rate had a positive correlation (P = 0.031) compared with preresidency (P = 0.579) or fellowship (P = 0.257) rates. Attendings who had attended residency in the Northeast and currently practicing in the Northeast had a higher publication rate (P < 0.001 and P = 0.004, respectively).

DISCUSSION

A higher number of publications in residency and fellowship were markedly predictive of an increased publication rate as an attending spine surgeon. By contrast, preresidency publications may not be indicative of future academic productivity as an attending. Location may also contribute to attending publication rate and favor those who undergo residency training and ultimately practice in the Northeast.

Trends in Short Construct Lumbar Fusions Over the Past Decade at a Single Institution

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

(1) To compare the rates of fusion techniques over the last decade; (2) to identify whether surgeon experience affects a surgeon's preferred fusion technique; (3) to evaluate differences in complications, readmissions, mortality, and patient-reported outcomes measures (PROMs) based on fusion technique.

SUMMARY OF BACKGROUND DATA

Database studies indicate the number of lumbar fusions have been steadily increasing over the last two decades; however, insufficient granularity exists to detect if surgeons' preferences are altered based on additive surgical experience.

METHODS

A retrospective review of continuously collected patients undergoing lumbar fusion at a single urban academic center was performed. Rates of lumbar fusion technique: posterolateral decompression fusion (PLDF), transforaminal lumbar interbody fusion (TLIF), anterior lumbar interbody fusion + PLDF (ALIF), and lateral lumbar interbody fusion + PLDF (LLIF) were recorded. Inpatient complications, 90-day readmission, and inpatient mortality were compared with χ 2 test and Bonferroni correction. The Δ 1-year PROMs were compared with the analysis of variance.

RESULTS

Of 3938 lumbar fusions, 1647 (41.8%) were PLDFs, 1356 (34.4%) were TLIFs, 885 (21.7%) were ALIFs, and 80 (2.0%) were lateral lumbar interbody fusions. Lumbar fusion rates increased but interbody fusion rates (2012: 57.3%; 2019: 57.6%) were stable across the study period. Surgeons with <10 years of experience performed more PLDFs and less ALIFs, whereas surgeons with >10 years' experience used ALIFs, TLIFs, and PLDFs at similar rates. Patients were more likely to be discharged home over the course of the decade (2012: 78.4%; 2019: 83.8%, P <0.001). No differences were observed between the techniques in regard to inpatient mortality ( P =0.441) or Δ (postoperative minus preoperative) PROMs.

CONCLUSIONS

Preferred lumbar fusion technique varies by surgeon preference, but typically remains stable over the course of a decade. The preferred fusion technique did not correlate with differences in PROMs, inpatient mortality, and patient complication rates.

LEVELS OF EVIDENCE

3-treatment.

Facet Distraction and Dysphagia: A Prospective Evaluation of This Common Postoperative Issue Following Anterior Cervical Spine Surgery

STUDY DESIGN

Prospective cohort study.

OBJECTIVE

Our primary study was to investigate whether the degree of postoperative facet and disk space distraction following anterior cervical discectomy and fusion (ACDF) affects the rate of postoperative dysphagia.

SUMMARY OF BACKGROUND DATA

Although ACDF is safe and well tolerated, postoperative dysphagia remains a common complication. Intervertebral disk space distraction is necessary in ACDF to visualize the operative field, prepare the endplates for fusion, and facilitate graft insertion. However, the degree of distraction tolerated, before onset of dysphagia, is not well characterized ACDF.

MATERIALS AND METHODS

A prospective cohort study was conducted of 70 patients who underwent ACDF between June 2018 and January 2019. Two independent reviewers measured all preoperative and postoperative radiographs measured for interfacet distraction distance and intervertebral distraction distance, with intrareviewer reproducibility measurements after one month. For multilevel surgery, the level with the greatest distraction was measured. Primary outcomes were numerical dysphagia (0-10), Eating Assessment Tool 10, and Dysphagia Symptom Questionnaire score collected at initial visit and two, six, 12, and 24 weeks postoperatively.

RESULTS

A total of 70 patients were prospectively enrolled, 59 of whom had adequate radiographs. An average of 1.71 (SD: 0.70) levels were included in the ACDF construct. Preoperatively, 13.4% of patients reported symptoms of dysphagia, which subsequently increased in the postoperative period at through 12 weeks postoperatively, before returning to baseline at 24 weeks. Intrareviewer and interreviewer reliability analysis demonstrated strong agreement. There was no relationship between interfacet distraction distance/intervertebral distraction distance and dysphagia prevalence, numerical rating, Eating Assessment Tool 10, or Dysphagia Symptom Questionnaire.

CONCLUSIONS

Patients who had an ACDF have an increased risk of dysphagia in the short term, however, this resolved without intervention by six months. Our data suggests increased facet and intervertebral disk distraction does not influence postoperative dysphagia rates.

LEVEL OF EVIDENCE

3.

Do On-Table Radiographs Predict Postoperative Sagittal Alignment after Posterior Lumbar Fusion?

STUDY DESIGN

Retrospective Cohort Study OBJECTIVE: To determine if intraoperative on-table lumbar lordosis and segmental lordosis correlate with postoperative lordosis following single-level posterolateral decompression and fusion (PLDF) or transforaminal lumbar interbody fusion (TLIF).

METHODS

Electronic medical records were reviewed for patients ≥18 years old who underwent PLDF or TLIF between 2012 and 2020. Lumbar lordosis and segmental lordosis were compared between pre-, intra-, and post-operative radiographs using paired t-tests. Significance was set at p<0.05.

RESULTS

A total of 200 patients met inclusion criteria. No significant differences in preoperative, intraoperative, or postoperative measurements were found between groups. Patients who underwent PLDF experienced less disc height loss over one year postoperatively (PLDF: 0.45 + 0.9 mm vs TLIF: 1.2 + 1.4 mm, p<0.001). Lumbar lordosis significantly decreased between intraoperative to postoperative radiographs at 2-6 weeks for PLDF (Δ: -4.0°, p<0.001) and TLIF (Δ: -5.6°, p<0.001), but no change was identified between the intraoperative and >6 month postoperative radiographs for PLDF (Δ: -0.3°, p=0.634) or TLIF (Δ: -1.6°, p=0.087). Segmental lordosis significantly increased from the preoperative to post-instrumentation intraoperative radiographs for PLDF (Δ: 2.7°, p<0.001) and TLIF (Δ: 1.8°, p<0.001), but it subsequently decreased at the final follow up for PLDF (Δ: -1.9°, p<0.001) and TLIF (Δ: -2.3°, p<0.001).

CONCLUSION

Subtle decreases in lumbar lordosis may be noticed in the early postoperative radiographs compared to intraoperative images on Jackson operative tables. However, these changes are not present at one-year follow-up as lumbar lordosis increases to a similar level as intraoperative fixation.

Evaluating Nonoperative Treatment for Low Back Pain in the Presence of Modic Changes: A Systematic Review

OBJECTIVE

The objective of this study was to summarize and assess the current literature evaluating nonoperative treatments for patients with Modic changes (MCs) and low back pain (LBP).

METHODS

A systematic review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The PubMed database was searched from its inception until May 1, 2022 for studies evaluating MC and clinical outcomes. Key findings, treatment details, and patient information were extracted from included studies. Study quality was assessed using the Newcastle-Ottawa Scale.

RESULTS

Eighteen studies were included in this review, encompassing a total of 2452 patients, 1713 of whom displayed baseline MC. Seventy-eight percent of studies were high quality. Of included studies, 2 evaluated antibiotics, 5 evaluated steroid injections, 6 evaluated conservative therapies, and 5 evaluated other treatment modalities. Antibiotics and bisphosphonates improved treatment in patients with MC. Patients with MC without disc herniation benefited from conservative therapy, while those with Type I Modic changes and disc herniation experienced poorer improvement. Significant variability exists in reported outcomes following steroid injections.

CONCLUSIONS

Nonoperative therapy may provide patients with MC with significant benefits. Patients may benefit from therapies not traditionally utilized for LBP such as antibiotics or bisphosphonates, but conservative therapy is not recommended for patients with concomitant MC and disc herniation. The large variation in follow-up times and outcome measures contributes to significant heterogeneity in studies and inability to predict long-term patient outcomes. More long-term studies are needed to assess nonoperative treatments for LBP in patients with MC.

Management of C0 Sacral Fractures Based on the AO Spine Sacral Injury Classification: A Narrative Review

The Arbeitsgemeinschaft fur Osteosynthese fragen Spine Sacral Injury Classification hierarchically separates fractures based on their injury severity with A-type fractures representing less severe injuries and C-type fractures representing the most severe fracture types. C0 fractures represent moderately severe injuries and have historically been referred to as nondisplaced "U-type" fractures. Injury management of these fractures can be controversial. Therefore, the purpose of this narrative review is to first discuss the Arbeitsgemeinschaft fur Osteosynthese fragen Spine Sacral Injury Classification System and describe the different fracture types and classification modifiers, with particular emphasis on C0 fracture types. The narrative review will then focus on the epidemiology and etiology of C0 fractures with subsequent discussion focused on the clinical presentation for patients with these injuries. Next, we will describe the imaging findings associated with these injuries and discuss the injury management of these injuries with particular emphasis on operative management. Finally, we will outline the outcomes and complications that can be expected during the treatment of these injuries.

Does a High Postoperative Opioid Dose Predict Chronic Use After ACDF?

OBJECTIVE

The purpose of this study is to determine if increased postoperative prescription opioid dosing is an isolated predictor of chronic opioid use after anterior cervical diskectomy and fusion (ACDF).

METHODS

A retrospective cohort analysis of patients undergoing ACDF for degenerative diseases from 2016-2019 at a single institution was performed. Preoperative and postoperative opioid and benzodiazepine prescriptions, including morphine milligram equivalents (MMEs) and duration of use, were obtained from the Pennsylvania Prescription Drug Monitoring Program. Univariate analysis compared patient demographics and surgical factors across groups on the basis of postoperative opioid dose (high: MME ≥90, low: MME <90) and chronicity of use (chronic: ≥120 days or >10 prescriptions). Logistic regressions identified predictors of high opioid dose and chronic use.

RESULTS

A total of 385 patients were included. Preoperative opioid tolerance and tobacco use were associated with high postoperative opioid dose and chronic usage. Younger age correlated with high-dose prescriptions. Increased body mass index and preoperative benzodiazepine use were associated with chronic opioid use. Chronic postoperative opioid use correlated with high-dose prescriptions, change in opioid prescribed, private pay scripts, and more than 1 prescriber and pharmacy. Logistic regression identified high postoperative opioid dose, opioid tolerance, increased body mass index, and no prior cervical surgery as predictors of chronic opioid use. Regression analysis determined younger age, increased medical comorbidities, and opioid tolerance to be predictors for high MME prescriptions.

CONCLUSIONS

High postoperative opioid dose independently predicted chronic opioid use after ACDF regardless of preoperative opioid tolerance.

Do Patient Outcomes Predict Loss to Long-Term Follow-Up After Spine Surgery?

OBJECTIVE

To determine if spine surgery patients with greater improvement in patient-reported outcomes measures (PROMs) at early postoperative follow-up are more likely to be lost to follow-up at the 1-year and 2-year postoperative visits.

METHODS

All patients older than 18 years who underwent primary or revision decompression or fusion surgery for degenerative spinal conditions at an academic institution were retrospectively identified. Univariate analysis compared patient demographics, surgical factors, and changes in short-term and long-term postoperative PROMs (Neck Disability Index, Oswestry Disability Index, visual analog scale [VAS] neck, VAS arm, VAS back, VAS leg, and Short-Form 12 Physical and Mental Component Scores) across groups with and without 1 year and 2 years follow-up. Logistic regression isolated predictors of loss to follow-up.

RESULTS

A total of 1412 patients were included. Younger patient age, primary surgery, and single surgical approach independently predicted loss at 1 year follow-up. Female sex predicted loss at 2 years follow-up, whereas multilevel fusion surgery predicted attendance at 2 years clinical follow-up. In patients lost at 1 year follow-up compared with those who attended, preoperative to 3-month Mental Component Score and VAS neck pain improvement was significantly greater. When comparing patients based on 2 years follow-up status, VAS back pain improvement at 1 year postoperatively was significantly greater in patients lost to 2 years follow-up. All other changes in PROMs did not differ significantly by 1 or 2 years follow-up attendance.

CONCLUSIONS

Overall patient outcomes were not found to affect loss to long-term follow-up after spine surgery. The general lack of association between postoperative follow-up status and clinical outcome may limit bias introduced in retrospective PROM studies.

Patients with radiculopathy have worse baseline disability and greater improvements following anterior cervical discectomy and fusion compared to patients with myelopathy

BACKGROUND CONTEXT

Anterior cervical discectomy and fusion (ACDF) is commonly performed in patients with radiculopathy and myelopathy. Although the goal of surgery in patients with radiculopathy is to improve function and reduce pain, patients with myelopathy undergo surgery to halt disease progression. Although the expectations between these preoperative diagnoses are generally understood to be disparate by spine surgeons, there is limited literature demonstrating their discordant outcomes.

PURPOSE

To compare improvements in patient reported outcome measures (PROMs) for patients undergoing ACDF for myelopathy or radiculopathy. Secondarily, we analyzed the proportion of patients who attain the minimum clinically important difference (MCID) postoperatively using thresholds derived from radiculopathy, myelopathy, and mixed cohort studies.

STUDY DESIGN/SETTING

Single institution retrospective cohort study PATIENT SAMPLE: Patients undergoing primary, elective ACDF with a preoperative diagnosis of radiculopathy or myelopathy and a complete set of preoperative and one-year postoperative PROMs.

OUTCOME MEASURES

Outcome measures included the following PROMs: Short-Form 12 Physical Component (PCS-12) and Mental Component (MCS-12) scores, the Visual Analog Scale (VAS) Arm score, and the Neck Disability Index (NDI). Hospital readmissions and revision surgery were also collected and evaluated.

METHODS

Patients undergoing an ACDF from 2014 to 2020 were identified and grouped based on preoperative diagnosis (radiculopathy or myelopathy). We utilized "general MCID" thresholds from a cohort of patients with degenerative spine conditions, and "specific MCID" thresholds generated from cohorts of patients with myelopathy or radiculopathy, respectively. Multivariate linear regressions were performed for delta (∆) PROMs and multivariate logistic regressions were performed for both general and specific MCID improvements.

RESULTS

A total of 798 patients met inclusion criteria. Patients with myelopathy had better baseline function and arm pain (MCS-12: 49.6 vs 47.6, p=.018; VAS Arm: 3.94 vs 6.02, p<.001; and NDI: 34.1 vs 41.9, p<.001), were older (p<.001), had more comorbidities (p=.014), more levels fused (p<.001), and had decreased improvement in PROMs following surgery compared to patients with radiculopathy (∆PCS-12: 4.76 vs 7.21, p=.006; ∆VAS Arm: -1.69 vs -3.70, p<.001; and ∆NDI: -11.94 vs -18.61, p<.001). On multivariate analysis, radiculopathy was an independent predictor of increased improvement in PCS-12 (β=2.10, p=.019), ∆NDI (β=-5.36, p<.001), and ∆VAS Arm (β=-1.93, p<.001). Radiculopathy patients were more likely to achieve general MCID improvements following surgery (NDI: Odds ratio (OR): 1.42, p=.035 and VAS Arm: OR: 2.98, p<.001), but there was no difference between patients with radiculopathy or myelopathy when using radiculopathy and myelopathy specific MCID thresholds (MCS-12: p=.113, PCS-12: p=.675, NDI: p=.108, and VAS Arm: p=.314).

CONCLUSIONS

Patients undergoing ACDF with myelopathy or radiculopathy represent two distinct patient populations with differing treatment indications and clinical outcomes. Compared to radiculopathy, patients with myelopathy have better baseline function, decreased improvement in PROMs, and are less likely to reach MCID using general threshold values, but there is no difference in the proportion reaching MCID when using specific threshold values.

LEVEL OF EVIDENCE

IRB.

Modified Frailty Index Does Not Provide Additional Value in Predicting Outcomes in Patients Undergoing Elective Transforaminal Lumbar Interbody Fusion

OBJECTIVE

To determine the predictive value of the modified Frailty Index (mFI) in evaluating sarcopenia and clinical outcomes in patients undergoing 1-level or 2-level transforaminal lumbar interbody fusion (TLIF).

METHODS

Patients who underwent a 1-level or 2-level TLIF between 2012 and 2020 were retrospectively identified. Frailty was compared among groups using mFI, and sarcopenia was classified by the psoas muscle cross-sectional area. Bivariate statistics compared demographics, comorbidities, and clinical outcomes. A linear regression model was developed using the Charlson Comorbidity Index (CCI) or mFI as independent variables to determine potential predictors for improvement in 1-year patient-reported outcomes.

RESULTS

Of 488 included patients, 60 were severely frail and 60 patients had sarcopenia, but sarcopenia was not associated with patient frailty (P = 0.469). Severely frail patients had worse baseline Oswestry Disability Index (ODI) (P < 0.001), Mental Component Score-12 (P = 0.001), and Physical Component Score-12 (P < 0.001), and worse improvement in ODI (P = 0.037), Physical Component Score-12 (P < 0.001), and visual analog scale (VAS) back (P = 0.007). mFI was an independent predictor of poorer improvement in VAS back and ODI, whereas age + CCI in addition predicted poorer improvement in VAS leg. Patients with higher mFI experienced longer length of stay, less frequent home discharge, and higher rates of complications, but similar readmission and reoperation rates.

CONCLUSIONS

Frailer patients experience poorer improvement in back pain, physical functioning, and disability after TLIF. mFI and the combination of age and CCI comparably predict patient-reported outcomes but do not correlate to baseline sarcopenia. Frailty increased the risk of complications, length of hospital stay, and risk of nonhome discharge.

Impact of surface roughness and bulk porosity on spinal interbody implants

Spinal fusion surgeries are performed to treat a multitude of cervical and lumbar diseases that lead to pain and disability. Spinal interbody fusion involves inserting a cage between the spinal vertebrae, and is often utilized for indirect neurologic decompression, correction of spinal alignment, anterior column stability, and increased fusion rate. The long-term success of interbody fusion relies on complete osseointegration between the implant surface and vertebral end plates. Titanium (Ti)-based alloys and polyetheretherketone (PEEK) interbody cages represent the most commonly utilized materials and provide sufficient mechanics and biocompatibility to assist in fusion. However, modification to the surface and bulk characteristics of these materials has been shown to maximize osseointegration and long-term stability. Specifically, the introduction of intrinsic porosity and surface roughness has been shown to affect spinal interbody mechanics, vascularization, osteoblast attachment, and ingrowth potential. This narrative review synthesizes the mechanical, in vitro, in vivo, and clinical effects on fusion efficacy associated with introduction of porosity in Ti (neat and alloy) and PEEK intervertebral implants.

Technical Aspects of Intra-Operative Ultrasound for Spinal Cord Injury and Myelopathy: A Practical Review

OBJECTIVES

To compile intra-operative techniques, established imaging parameters, available equipment and software, and clinical applications of intraoperative ultrasound imaging (IOUSI) for spinal cord injury (SCI) and myelopathy.

METHODS

PubMed and Google Scholar were searched for relevant articles. The articles were reviewed and selected by 2 independent researchers. After article selection, data were extracted and summarized into research domains. PRISMA systematic review process was followed.

RESULTS

Of the 2477 articles screened, 16 articles met the inclusion criteria. In patients with SCI and myelopathy, common quantitative measurements obtained using IOUSI were noted: 1) ultrasound elastography, 2) midsagittal anteroposterior diameter, 3) transverse, 4) transverse diameter, 5) maximum spinal cord compression, and 6) compression ratioTo ensure adequate decompression and to look for residual compression, the lateral and the craniocaudal margins of the laminectomy site were inspected in both axial and sagittal planes. In instances where quantitative assessment was not possible, cord decompression and degree of residual compression were gauged by inspecting the interface between the ventral border of the spinal cord and any potentially compressive elements, and by searching for symmetric and rhythmic cerebrospinal fluid pulsations. Use of contrast-enhanced ultrasoundand molecular imaging are additional advances in objective assessments for SCI and myelopathy.

CONCLUSIONS

This review outlines the potential of IOUSI in patients presenting with SCI and myelopathy. Moreover, by identifying potential for inter-operator variability in certain subjective measurements, we illustrate the need for further research to quantify and standardize those assessments.

Impact of Prolonged Operative Duration on Postoperative Symptomatic Venous Thromboembolic Events After Thoracolumbar Spine Surgery

OBJECTIVE

To determine the effect of operative duration on the rate of postoperative symptomatic venous thromboembolic (VTE) events in patients undergoing thoracolumbar spine fusion.

METHODS

We identified all thoracolumbar spine fusion patients between 2012 and 2021. Operative duration was defined as time from skin incision to skin closure. A 1:1 propensity match was conducted incorporating patient and surgical characteristics. Logistic regression was performed to assess predictors of postoperative symptomatic VTE events. A receiver operating characteristic curve was created to determine a cutoff time for increased likelihood of VTE.

RESULTS

We identified 101 patients with VTE and 1108 patients without VTE. Seventy-five patients with VTE were matched to 75 patients without VTE. Operative duration (339 vs. 262 minutes, P = 0.010) and length of stay (5.00 vs. 3.54 days, P = 0.008) were significantly longer in patients with a VTE event. Operative duration was an independent predictor of VTE on multivariate regression (odds ratio: 1.003, 95% confidence interval: 1.001-1.01, P = 0.021). For each additional hour of operative duration, the risk of VTE increased by 18%. A cutoff time of 218 minutes was identified (area under the curve [95% confidence interval] = 0.622 [0.533-0.712]) as an optimal predictor of increased risk for a VTE event.

CONCLUSIONS

Operative duration significantly predicted symptomatic VTE, especially after surgical time cutoff of 218 minutes. Each additional hour of operative duration was found to increase VTE risk by 18%. We also identify the impact of VTE on 90-day readmission rates, suggesting significantly higher costs and opportunity for hospital acquired conditions, in line with prior literature.

The impact of cage positioning on lumbar lordosis and disc space restoration following minimally invasive lateral lumbar interbody fusion

OBJECTIVE

The objective of this study was to evaluate patient and surgical factors that predict increased overall lumbar lordosis (LL) and segmental lordosis correction following a minimally invasive lateral lumbar interbody fusion (LLIF) procedure.

METHODS

A retrospective review was conducted of all patients who underwent one- or two-level LLIF. Preoperative, initial postoperative, and 6-month postoperative measurements of LL, segmental lordosis, anterior disc height, and posterior disc height were collected from standing lateral radiographs for each patient. Cage placement was measured utilizing the center point ratio (CPR) on immediate postoperative radiographs. Spearman correlations were used to assess associations between cage lordosis and radiographic parameters. Multivariate linear regression was performed to assess independent predictors of outcomes.

RESULTS

A total of 106 levels in 78 unique patients were included. Most procedures involved fusion of one level (n = 50, 64.1%), most commonly L3-4 (46.2%). Despite no differences in baseline segmental lordosis, patients with anteriorly or centrally placed cages experienced the greatest segmental lordosis correction immediately (mean anterior 4.81° and central 4.46° vs posterior 2.47°, p = 0.0315) and at 6 months postoperatively, and patients with anteriorly placed cages had greater overall lordosis correction postoperatively (mean 6.30°, p = 0.0338). At the 6-month follow-up, patients with anteriorly placed cages experienced the greatest increase in anterior disc height (mean anterior 6.24 mm vs posterior 3.69 mm, p = 0.0122). Cages placed more posteriorly increased the change in posterior disc height postoperatively (mean posterior 4.91 mm vs anterior 1.80 mm, p = 0.0001) and at 6 months (mean posterior 4.18 mm vs anterior 2.06 mm, p = 0.0255). There were no correlations between cage lordotic angle and outcomes. On multivariate regression, anterior cage placement predicted greater 6-month improvement in segmental lordosis, while posterior placement predicted greater 6-month improvement in posterior disc height. Percutaneous screw placement, cage lordotic angle, and cage height did not independently predict any radiographic outcomes.

CONCLUSIONS

LLIF procedures reliably improve LL and increase intervertebral disc space. Anterior cage placement improves the lordosis angle greater than posterior placement, which better corrects sagittal alignment, but there is still a significant improvement in lordosis even with a posteriorly placed cage. Posterior cage placement provides greater restoration in posterior disc space height, maximizing indirect decompression, but even the anteriorly placed cages provided indirect decompression. Cage parameters including cage height, lordosis angle, and material do not impact radiographic improvement.

An international validation of the AO spine subaxial injury classification system

PURPOSE

To validate the AO Spine Subaxial Injury Classification System with participants of various experience levels, subspecialties, and geographic regions.

METHODS

A live webinar was organized in 2020 for validation of the AO Spine Subaxial Injury Classification System. The validation consisted of 41 unique subaxial cervical spine injuries with associated computed tomography scans and key images. Intraobserver reproducibility and interobserver reliability of the AO Spine Subaxial Injury Classification System were calculated for injury morphology, injury subtype, and facet injury. The reliability and reproducibility of the classification system were categorized as slight (ƙ = 0-0.20), fair (ƙ = 0.21-0.40), moderate (ƙ = 0.41-0.60), substantial (ƙ = 0.61-0.80), or excellent (ƙ = > 0.80) as determined by the Landis and Koch classification.

RESULTS

A total of 203 AO Spine members participated in the AO Spine Subaxial Injury Classification System validation. The percent of participants accurately classifying each injury was over 90% for fracture morphology and fracture subtype on both assessments. The interobserver reliability for fracture morphology was excellent (ƙ = 0.87), while fracture subtype (ƙ = 0.80) and facet injury were substantial (ƙ = 0.74). The intraobserver reproducibility for fracture morphology and subtype were excellent (ƙ = 0.85, 0.88, respectively), while reproducibility for facet injuries was substantial (ƙ = 0.76).

CONCLUSION

The AO Spine Subaxial Injury Classification System demonstrated excellent interobserver reliability and intraobserver reproducibility for fracture morphology, substantial reliability and reproducibility for facet injuries, and excellent reproducibility with substantial reliability for injury subtype.

Effect of surgical experience and spine subspecialty on the reliability of the AO Spine Upper Cervical Injury Classification System

OBJECTIVE

The objective of this paper was to determine the interobserver reliability and intraobserver reproducibility of the AO Spine Upper Cervical Injury Classification System based on surgeon experience (< 5 years, 5-10 years, 10-20 years, and > 20 years) and surgical subspecialty (orthopedic spine surgery, neurosurgery, and "other" surgery).

METHODS

A total of 11,601 assessments of upper cervical spine injuries were evaluated based on the AO Spine Upper Cervical Injury Classification System. Reliability and reproducibility scores were obtained twice, with a 3-week time interval. Descriptive statistics were utilized to examine the percentage of accurately classified injuries, and Pearson's chi-square or Fisher's exact test was used to screen for potentially relevant differences between study participants. Kappa coefficients (κ) determined the interobserver reliability and intraobserver reproducibility.

RESULTS

The intraobserver reproducibility was substantial for surgeon experience level (< 5 years: 0.74 vs 5-10 years: 0.69 vs 10-20 years: 0.69 vs > 20 years: 0.70) and surgical subspecialty (orthopedic spine: 0.71 vs neurosurgery: 0.69 vs other: 0.68). Furthermore, the interobserver reliability was substantial for all surgical experience groups on assessment 1 (< 5 years: 0.67 vs 5-10 years: 0.62 vs 10-20 years: 0.61 vs > 20 years: 0.62), and only surgeons with > 20 years of experience did not have substantial reliability on assessment 2 (< 5 years: 0.62 vs 5-10 years: 0.61 vs 10-20 years: 0.61 vs > 20 years: 0.59). Orthopedic spine surgeons and neurosurgeons had substantial intraobserver reproducibility on both assessment 1 (0.64 vs 0.63) and assessment 2 (0.62 vs 0.63), while other surgeons had moderate reliability on assessment 1 (0.43) and fair reliability on assessment 2 (0.36).

CONCLUSIONS

The international reliability and reproducibility scores for the AO Spine Upper Cervical Injury Classification System demonstrated substantial intraobserver reproducibility and interobserver reliability regardless of surgical experience and spine subspecialty. These results support the global application of this classification system.

Anterior cervical discectomy and fusion is more effective than cervical arthroplasty in relieving atypical symptoms in patients with cervical spondylosis

BACKGROUND AND PURPOSE

Patients with cervical spondylosis often present with concurrent 'atypical symptoms' of unknown etiology that have been associated with cervical spondylotic disease, including dizziness, headache, nausea, tinnitus, blurred vision, palpitations, and memory and gastrointestinal disturbances. Few studies have addressed whether surgical intervention to treat classic symptoms of cervical spondylosis can also effectively alleviate atypical symptoms. Accordingly, the purpose of this study is to compare the ability of cervical arthroplasty (CA) and anterior cervical discectomy and fusion (ACDF) to alleviate atypical symptoms associated with cervical spondylosis.

MATERIALS AND METHODS

A retrospective analysis of 140 patients with cervical spondylosis and associated atypical symptoms was performed. Atypical symptoms were defined vertigo, headache, nausea and vomiting, tinnitus, blur vision, palpitation, hypomnesia, and gastroenteric disturbances not otherwise explained by medical comorbidities. Seventy-eight patients (55.7%) underwent ACDF and 62 (44.3%) patients underwent CA. Demographics, surgical characteristics, patient reported outcome measures (PROMs), radiographs, complication rates, and resolution in atypical symptoms were recorded and compared between groups. Atypical symptoms were assessed using a 20-point system. All the patients had a minimum of five years follow-up.

RESULTS

VAS, SF-36, JOA, and NDI scores improved significantly in all the patients (p < 0.001). At the last follow-up, the fusion rate was 97% in the ACDF group. Atypical symptoms improved in both groups (p < 0.001), although the ACDF group demonstrated greater improvement in headache and vertigo resolution compared to the CA group (p < 0.0001).

CONCLUSIONS

While both ACDF and CA are effective in alleviating atypical symptoms associated with cervical spondylosis, ACDF demonstrated greater improvements in atypical symptoms.

AO Spine upper cervical injury classification system: a description and reliability study

BACKGROUND CONTEXT

Prior upper cervical spine injury classification systems have focused on injuries to the craniocervical junction (CCJ), atlas, and dens independently. However, no previous system has classified upper cervical spine injuries using a comprehensive system incorporating all injuries from the occiput to the C2-3 joint.

PURPOSE

To (1) determine the accuracy of experts at correctly classifying upper cervical spine injuries based on the recently proposed AO Spine Upper Cervical Injury Classification System (2) to determine their interobserver reliability and (3) identify the intraobserver reproducibility of the experts.

STUDY DESIGN/SETTING

International Multi-Center Survey.

PATIENT SAMPLE

A survey of international spine surgeons on 29 unique upper cervical spine injuries.

OUTCOME MEASURES

Classification accuracy, interobserver reliability, intraobserver reproducibility.

METHODS

Thirteen international AO Spine Knowledge Forum Trauma members participated in two live webinar-based classifications of 29 upper cervical spine injuries presented in random order, four weeks apart. Percent agreement with the gold-standard and kappa coefficients (ƙ) were calculated to determine the interobserver reliability and intraobserver reproducibility.

RESULTS

Raters demonstrated 80.8% and 82.7% accuracy with identification of the injury classification (combined location and type) on the first and second assessment, respectively. Injury classification intraobserver reproducibility was excellent (mean, [range] ƙ=0.82 [0.58-1.00]). Excellent interobserver reliability was found for injury location (ƙ = 0.922 and ƙ=0.912) on both assessments, while injury type was substantial (ƙ=0.689 and 0.699) on both assessments. This correlated to a substantial overall interobserver reliability (ƙ=0.729 and 0.732).

CONCLUSIONS

Early phase validation demonstrated classification of upper cervical spine injuries using the AO Spine Upper Cervical Injury Classification System to be accurate, reliable, and reproducible. Greater than 80% accuracy was detected for injury classification. The intraobserver reproducibility was excellent, while the interobserver reliability was substantial.

Evolution of the AO Spine Sacral and Pelvic Classification System: a systematic review

OBJECTIVE

The purpose of this study was to describe the genesis of the AO Spine Sacral and Pelvic Classification System in the context of historical sacral and pelvic grading systems.

METHODS

A systematic search of MEDLINE, EMBASE, Google Scholar, and Cochrane databases was performed consistent with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to identify all existing sacral and pelvic fracture classification systems.

RESULTS

A total of 49 articles were included in this review, comprising 23 pelvic classification systems and 17 sacral grading schemes. The AO Spine Sacral and Pelvic Classification System represents both the evolutionary product of these historical systems and a reinvention of classic concepts in 5 ways. First, the classification introduces fracture types in a graduated order of biomechanical stability while also taking into consideration the neurological status of patients. Second, the traditional belief that Denis central zone III fractures have the highest rate of neurological deficit is not supported because this subgroup often includes a broad spectrum of injuries ranging from a benign sagittally oriented undisplaced fracture to an unstable "U-type" fracture. Third, the 1990 Isler lumbosacral system is adopted in its original format to divide injuries based on their likelihood of affecting posterior pelvic or spinopelvic stability. Fourth, new discrete fracture subtypes are introduced and the importance of bilateral injuries is acknowledged. Last, this is the first integrated sacral and pelvic classification to date.

CONCLUSIONS

The AO Spine Sacral and Pelvic Classification is a universally applicable system that redefines and reorders historical fracture morphologies into a rational hierarchy. This is the first classification to simultaneously address the biomechanical stability of the posterior pelvic complex and spinopelvic stability, while also taking into consideration neurological status. Further high-quality controlled trials are required prior to the inclusion of this novel classification within a validated scoring system to guide the management of sacral and pelvic injuries.

Preoperative epidural steroid injections do not increase the risk of postoperative infection in patients undergoing lumbar decompression or fusion: a systematic review and meta-analysis

PURPOSE

Epidural corticosteroid injections (ESI) are a mainstay of nonoperative treatment for patients with lumbar spine pathology. Recent literature evaluating infection risk following ESI after elective orthopedic surgery has produced conflicting evidence. Our primary objective was to review the literature and provide a larger meta-analysis analyzing the temporal effects of steroid injections on the risk of infection following lumbar spine surgery.

METHODS

We conducted a query of the PubMed, Embase, and Scopus databases from inception until April 1, 2022 for studies evaluating the risk of infection in the setting of prior spinal steroid injections in patients undergoing lumbar spine decompression or fusion. Three meta-analyses were conducted, (1) comparing ESI within 30-days of surgery to control, (2) comparing ESI within 30-days to ESI between 1 and 3 months preoperatively, and (3) comparing any history of ESI prior to surgery to control. Tests of proportions were utilized for all comparisons between groups. Study heterogeneity was assessed via forest plots, and publication bias was assessed quantiatively via funnel plots and qualitatively with the Newcastle-Ottawa Scale.

RESULTS

Nine total studies were included, five of which demonstrated an association between ESI and postoperative infection, while four found no association. Comparison of weighted means demonstrated no significant difference in infection rates between the 30-days ESI group and control group (2.67% vs. 1.69%, p = 0.144), 30-days ESI group and the > 30-days ESI group (2.34% vs. 1.66%, p = 0.1655), or total ESI group and the control group (1.99% vs. 1.70%, p = 0.544). Heterogeneity was low for all comparisons following sensitivity analyses.

CONCLUSION

Current evidence does not implicate preoperative ESI in postoperative infection rates following lumbar fusion or decompression. Operative treatment should not be delayed due to preoperative steroid injections based on current evidence. There remains a paucity of high-quality data in the literature evaluating the impact of preoperative ESI on postoperative infection rates.

LEVEL OF EVIDENCE

II.

A Novel Method to Classify Cervical Incomplete Spinal Cord Injury Based on Potential for Recovery: A Group-Based Trajectory Analysis

The outcomes of cervical incomplete spinal cord injury (SCI) are heterogeneous. This study sought to dissociate subgroups of cervical incomplete SCI patients with distinct longitudinal temporal profiles of recovery in upper limb motor function. Patients with cervical incomplete SCI (American Spinal Injury Association Impairment Scale [AIS] B-D; C1-C8) were identified from four prospective, multi-center SCI datasets. A group-based trajectory model was fit to longitudinal upper extremity motor scores out to 1 year. Multi-variable multinomial logistic regression was performed to identify features that characterize each trajectory group. A classification system for predicting trajectory group at baseline was developed by recursive partitioning. In total, 801 patients were eligible. Four distinct trajectory groups were identified: 1) "Poor outcome": Severe injury, very minimal recovery; 2) "Moderate recovery": Moderate-to-severe injury, moderate recovery; most recovery occurs by 6 months, with mild, gradual recovery continuing thereafter; 3) "Good recovery": Moderate injury, good recovery; most recovery occurs by 3 months, with mild, gradual recovery continuing thereafter; and 4) "Excellent outcome": Mild injury, recovery to normal/near-normal by 3 months. On adjusted analyses, older age was associated with lower likelihood of "excellent outcome" (p = 0.020). AIS C and D injuries were associated with "moderate recovery," "good recovery," and "excellent outcome" (p < 0.001). Mid-cervical injuries occurred more frequently in "moderate recovery," "good recovery," and "excellent outcome" (p < 0.001) groups. Early surgical decompression (< 24 h) was associated with increased propensity for "good recovery" (p = 0.039) and "excellent outcome" (p = 0.048). A classification model based on recursive partitioning could predict trajectory group using age, AIS grade, and neurological level with an area under the curve of 0.81. Patients with cervical incomplete SCI demonstrate distinct temporal profiles of recovery in upper limb motor function. The trajectory a patient is likely to follow may be predicted at baseline with fair accuracy.

Does displacement of cervical and thoracolumbar dislocation-translation injuries predict spinal cord injury or recovery?

OBJECTIVE

For patients with cervical and thoracolumbar AO Spine type C injuries, the authors sought to 1) identify whether preoperative vertebral column translation is predictive of a complete spinal cord injury (SCI) and 2) identify whether preoperative or postoperative vertebral column translation is predictive of neurological improvement after surgical decompression.

METHODS

All patients who underwent operative treatment for cervical and thoracolumbar AO Spine type C injuries at the authors' institution between 2006 and 2021 were identified. CT and MRI were utilized to measure vertebral column translation in millimeters prior to and after surgery. A receiver operating characteristic (ROC) curve was generated to predict the probability of sustaining a complete SCI on the basis of the amount of preoperative vertebral column translation. ROC curves were then used to predict the probability of neurological recovery on the basis of preoperative and postoperative vertebral column translation.

RESULTS

ROC analysis of 67 patients identified 6.10 mm (area under the curve [AUC] 0.77, 95% CI 0.650-0.892) of preoperative vertebral column translation as predictive of complete SCI. Additionally, ROC curve analysis found that 10.4 mm (AUC 0.654, 95% CI 0.421-0.887) of preoperative vertebral column translation was strongly predictive of no postoperative neurological improvement. Residual postoperative vertebral column translation after fracture reduction and instrumentation had no predictive value on neurological recovery (AUC 0.408, 95% CI 0.195-0.622).

CONCLUSIONS

For patients with cervical and thoracolumbar AO Spine type C injuries, the amount of preoperative vertebral column translation is highly predictive of complete SCI and the likelihood of postoperative neurological recovery.

A Short-Term Assessment of Lumbar Sagittal Alignment Parameters in Patients Undergoing Anterior Lumbar Interbody Fusion

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

To determine if intraoperative on-table lumbar lordosis (LL) and segmental lordosis (SL) coincide with perioperative change in lordosis.

SUMMARY OF BACKGROUND DATA

Improvements in sagittal alignment are believed to correlate with improvements in clinical outcomes. Thus, it is important to establish whether intraoperative radiographs predict postoperative improvements in LL or SL.

MATERIALS AND METHODS

Electronic medical records were reviewed for patients ≥18 years old who underwent single-level and two-level anterior lumbar interbody fusion with posterior instrumentation between 2016 and 2020. LL, SL, and the lordosis distribution index were compared between preoperative, intraoperative, and postoperative radiographs using paired t tests. A linear regression determined the effect of subsidence on SL and LL.

RESULTS

A total of 118 patients met inclusion criteria. Of those, 75 patients had one-level fusions and 43 had a two-level fusion. LL significantly increased following on-table positioning [delta (Δ): 5.7°, P <0.001]. However, LL significantly decreased between the intraoperative to postoperative radiographs at two to six weeks (Δ: -3.4°, P =0.001), while no change was identified between the intraoperative and more than three-month postoperative radiographs (Δ: -1.6°, P =0.143). SL was found to significantly increase from the preoperative to intraoperative radiographs (Δ: 10.9°, P <0.001), but it subsequently decreased at the two to six weeks follow up (Δ: -2.7, P <0.001) and at the final follow up (Δ: -4.1, P <0.001). On linear regression, cage subsidence/allograft resorption was predictive of the Δ SL (β=0.55; 95% confidence interval: 0.16-0.94; P =0.006), but not LL (β=0.10; 95% confidence interval: -0.44 to 0.65; P =0.708).

CONCLUSION

Early postoperative radiographs may not accurately reflect the improvement in LL seen on intraoperative radiographic imaging, but they are predictive of long-term lumbar sagittal alignment. Each millimeter of cage subsidence or allograft resorption reduces SL by 0.55°, but subsidence does not significantly affect LL.

LEVELS OF EVIDENCE

4.

Reporting demographics in randomized control trials in spine surgery - we must do better

BACKGROUND CONTEXT

Demographic factors contribute significantly to spine surgery outcomes. Although race and ethnicity are not proxies for disease states, the intersection between these patient characteristics and socioeconomic status significantly impact patient outcomes.

PURPOSE

The purpose of this study is to investigate the frequency of demographic reporting and analysis in randomized controlled clinical trials (RCTs) published in the three highest impact spine journals.

STUDY DESIGN

Systematic review.

PATIENT SAMPLE

We analyzed 278 randomized control trials published in The Spine Journal, Spine, and Journal of Neurosurgery: Spine between January 2012 - January 2022.

OUTCOME MEASURES

Extracted manuscript characteristics included the frequency of demographic reporting, sample size, and demographic composition of studies.

METHODS

We conducted a systematic review of RCTs published between January 2012 - January 2022 in the three highest impact factor spine journals in 2021: The Spine Journal, Spine, and Journal of Neurosurgery: Spine. We determined if age, gender, BMI, race, and ethnicity were reported and analyzed for each study. The overall frequency of demographic reporting was assessed, and the reporting trends were analyzed for each individual year and journal. Among studies that did report demographics, the populations were analyzed in comparison to the national population per United States (US) census reports. Studies were evaluated for bias using Cochrane risk-of-bias.

RESULTS

Our search identified 278 RCTs for inclusion. 166 were published in Spine, 65 in The Spine Journal, and 47 in Journal of Neurosurgery: Spine. Only 9.35% (N=26) and 3.9% (N=11) of studies reported race and ethnicity, respectively. Demographic reporting frequency did not vary based on the publishing journal. Reporting of age and BMI increased over time, but reporting of race and ethnicity did not. Among RCTs that reported race, 88% were conducted in the US, and 85.71% of the patients in these US studies were White. White subjects were overly represented compared to the US population (85.71% vs. 61.63%, p<.001), and non-White or Black patients were most underrepresented (2.89 vs. 25.96%, p<.001).

CONCLUSIONS

RCTs published in the three highest impact factor spine journals failed to frequently report patient race or ethnicity. Among studies published in the US, study populations are increasingly represented by non-Hispanic White patients. As we strive to care for an increasingly diverse population and reduce disparities to care, spine surgeons must do a better job reporting these variables to increase the external validity and generalizability of RCTs.

Marijuana Use and its Effect on Clinical Outcomes and Revision Rates in Patients Undergoing Anterior Cervical Discectomy and Fusion

STUDY DESIGN

A retrospective cohort study.

OBJECTIVE

To determine if (1) preoperative marijuana use increased complications, readmission, or reoperation rates following anterior cervical discectomy and fusion (ACDF), (2) identify if preoperative marijuana use resulted in worse patient-reported outcome measures (PROMs), and (3) investigate if preoperative marijuana use affects the quantity of opioid prescriptions in the perioperative period.

SUMMARY OF BACKGROUND DATA

A growing number of states have legalized recreational and/or medical marijuana, thus increasing the number of patients who report preoperative marijuana use. The effects of marijuana on clinical outcomes and PROMs in the postoperative period are unknown.

METHODS

All patients 18 years of age and older who underwent primary one- to four-level ACDF with preoperative marijuana use at our academic institution were retrospectively identified. A 3:1 propensity match was conducted to compare patients who used marijuana versus those who did not. Patient demographics, surgical characteristics, clinical outcomes, and PROMs were compared between groups. Multivariate regression models measured the effect of marijuana use on the likelihood of requiring a reoperation and whether marijuana use predicted inferior PROM improvements at the one-year postoperative period.

RESULTS

Of the 240 patients included, 60 (25.0%) used marijuana preoperatively. Multivariate logistic regression analysis identified marijuana use (odds ratio=5.62, P <0.001) as a predictor of a cervical spine reoperation after ACDF. Patients who used marijuana preoperatively had worse one-year postoperative Physical Component Scores of the Short-Form 12 (PCS-12) ( P =0.001), Neck Disability Index ( P =0.003), Visual Analogue Scale (VAS) Arm ( P =0.044) and VAS Neck ( P =0.012). Multivariate linear regression found preoperative marijuana use did not independently predict improvement in PCS-12 (β=-4.62, P =0.096), Neck Disability Index (β=9.51, P =0.062), Mental Component Scores of the Short-Form 12 (MCS-12) (β=-1.16, P =0.694), VAS Arm (β=0.06, P =0.944), or VAS Neck (β=-0.44, P =0.617).

CONCLUSION

Preoperative marijuana use increased the risk of a cervical spine reoperation after ACDF, but it did not significantly change the amount of postoperative opioids used or the magnitude of improvement in PROMs.

LEVEL OF EVIDENCE

Levwl III.

Global Validation of the AO Spine Upper Cervical Injury Classification

STUDY DESIGN

Global cross-sectional survey.

OBJECTIVE

To determine the classification accuracy, interobserver reliability, and intraobserver reproducibility of the AO Spine Upper Cervical Injury Classification System based on an international group of AO Spine members.

SUMMARY OF BACKGROUND DATA

Previous upper cervical spine injury classifications have primarily been descriptive without incorporating a hierarchical injury progression within the classification system. Further, upper cervical spine injury classifications have focused on distinct anatomical segments within the upper cervical spine. The AO Spine Upper Cervical Injury Classification System incorporates all injuries of the upper cervical spine into a single classification system focused on a hierarchical progression from isolated bony injuries (type A) to fracture dislocations (type C).

METHODS

A total of 275 AO Spine members participated in a validation aimed at classifying 25 upper cervical spine injuries through computed tomography scans according to the AO Spine Upper Cervical Classification System. The validation occurred on two separate occasions, three weeks apart. Descriptive statistics for percent agreement with the gold-standard were calculated and the Pearson χ 2 test evaluated significance between validation groups. Kappa coefficients (κ) determined the interobserver reliability and intraobserver reproducibility.

RESULTS

The accuracy of AO Spine members to appropriately classify upper cervical spine injuries was 79.7% on assessment 1 (AS1) and 78.7% on assessment 2 (AS2). The overall intraobserver reproducibility was substantial (κ=0.70), while the overall interobserver reliability for AS1 and AS2 was substantial (κ=0.63 and κ=0.61, respectively). Injury location had higher interobserver reliability (AS1: κ = 0.85 and AS2: κ=0.83) than the injury type (AS1: κ=0.59 and AS2: 0.57) on both assessments.

CONCLUSION

The global validation of the AO Spine Upper Cervical Injury Classification System demonstrated substantial interobserver agreement and intraobserver reproducibility. These results support the universal applicability of the AO Spine Upper Cervical Injury Classification System.

LEVEL OF EVIDENCE

4.

Symptomatic Postoperative Epidural Hematoma in the Lumbar Spine

A symptomatic postoperative epidural hematoma (SPEH) in the lumbar spine is a complication with variable presentation and the potential to rapidly cause an irrecoverable neurological injury. Significant heterogeneity exists among current case series reporting SPEH in the literature. This review attempts to clarify the known incidence, risk factors, and management pearls. Currently, literature does not support the efficacy of subfascial drains in reducing the incidence of SPEHs and possibly suggests that medication for thromboembolism prophylaxis may increase risk. Acute back pain and progressing lower extremity motor weakness are the most common presenting symptoms of SPEH. Magnetic resonance imaging is the mainstay of diagnostic imaging necessary to confirm the diagnosis, but if not acutely available, an immediate return to the operative theater for exploration without advanced imaging is justified. Treatment of a SPEH consists of emergent hematoma evacuation as a delay in repeat surgery has a deleterious effect on neurological recovery. Outcomes are poorly defined, though a significant portion of patients will have lasting neurological impairments even when appropriately recognized and managed.

Early vs Late Surgical Decompression for Central Cord Syndrome

Importance

The optimal clinical management of central cord syndrome (CCS) remains unclear; yet this is becoming an increasingly relevant public health problem in the face of an aging population.

Objective

To provide a head-to-head comparison of the neurologic and functional outcomes of early (<24 hours) vs late (≥24 hours) surgical decompression for CCS.

Design, Setting, and Participants

Patients who underwent surgery for CCS (lower extremity motor score [LEMS] - upper extremity motor score [UEMS] ≥ 5) were included in this propensity score-matched cohort study. Data were collected from December 1991 to March 2017, and the analysis was performed from March 2020 to January 2021. This study identified patients with CCS from 3 international multicenter studies with data on the timing of surgical decompression in spinal cord injury. Participants were included if they had a documented baseline neurologic examination performed within 14 days of injury. Participants were eligible if they underwent surgical decompression for CCS.

Exposures

Early surgery was compared with late surgery.

Main Outcomes and Measures

Propensity scores were calculated as the probability of undergoing early compared with late surgery using the logit method and adjusting for relevant confounders. Propensity score matching was performed in a 1:1 ratio by an optimal-matching technique. The primary end point was motor recovery (UEMS, LEMS, American Spinal Injury Association [ASIA] motor score [AMS]) at 1 year. Secondary end points were Functional Independence Measure (FIM) motor score and complete independence in each FIM motor domain at 1 year.

Results

The final study cohort consisted of 186 patients with CCS. The early-surgery group included 93 patients (mean [SD] age, 47.8 [16.8] years; 66 male [71.0%]), and the late-surgery group included 93 patients (mean [SD] age, 48.0 [15.5] years; 75 male [80.6%]). Early surgical decompression resulted in significantly improved recovery in upper limb (mean difference [MD], 2.3; 95% CI, 0-4.5; P = .047), but not lower limb (MD, 1.1; 95% CI, -0.8 to 3.0; P = .30), motor function. In an a priori-planned subgroup analysis, outcomes were comparable with early or late decompressive surgery in patients with ASIA Impairment Scale (AIS) grade D injury. However, in patients with AIS grade C injury, early surgery resulted in significantly greater recovery in overall motor score (MD, 9.5; 95% CI, 0.5-18.4; P = .04), owing to gains in both upper and lower limb motor function.

Conclusions and Relevance

This cohort study found early surgical decompression to be associated with improved recovery in upper limb motor function at 1 year in patients with CCS. Treatment paradigms for CCS should be redefined to encompass early surgical decompression as a neuroprotective therapy.

Demographics and Medical Comorbidities as Risk Factors for Increased Episode of Care Costs Following Lumbar Fusion in Medicare Patients

The objective was to evaluate medical comorbidities and surgical variables as independent risk factors for increased health care costs in Medicare patients undergoing lumbar fusion. Care episodes limited to lumbar fusions were retrospectively reviewed on the Centers of Medicare and Medicaid Innovation (CMMI) Bundled Payment for Care Improvement (BPCI) reimbursement database at a single academic institution. Total episode of care cost was also collected. A multivariable linear regression model was developed to identify independent risk factors for increased total episode of care cost, and logistic models for surgical complications and readmission. A total of 500 Medicare patients were included. Risk factors associated with increased total episode of care cost included transforaminal interbody fusion (TLIF) and anterior lumbar interbody fusion (ALIF) (β = $5,399, P < 0.001) and ALIF+PLF (AP) fusions (β = $24,488, P < 0.001), levels fused (β = $3,989, P < 0.001), congestive heart failure (β = $6,161, P = 0.022), hypertension with end-organ damage (β = $10,138, P < 0.001), liver disease (β = $16,682, P < 0.001), inpatient complications (β = $4,548, P = 0.001), 90-day complications (β = $10,012, P = 0.001), and 90-day readmissions (β = $15,677, P < 0.001). The most common surgical complication was postoperative anemia, which was associated with significantly increased costs (β = $18,478, P < 0.001). Female sex (OR = 2.27, P = 0.001), AP fusion (OR = 2.59, P = 0.002), levels fused (OR = 1.45, P = 0.005), cerebrovascular disease (OR = 4.19, P = 0.003), cardiac arrhythmias (OR = 2.32, P = 0.002), and fluid electrolyte disorders (OR = 4.24, P = 0.002) were independent predictors of surgical complications. Body mass index (OR = 1.07, P = 0.029) and AP fusions (OR = 2.87, P = 0.049) were independent predictors of surgical readmission. Among medical comorbidities, congestive heart failure, hypertension with end-organ damage, and liver disease were independently associated with a significant increase in total episode of care cost. Interbody devices were associated with increased admission cost.

New Evaluation and Management Code Level Selection Trends in Hip and Knee Osteoarthritis Patients

BACKGROUND

On January 1, 2021, the American Medical Association implemented changes regarding the outpatient Evaluation and Management (E/M) criteria dictating Current Procedural Terminology code level selection to help diminish administrative burden and emphasize medical decision-making as the primary determinant in E/M level of service (EML). The goal of this study was to describe EML coding trends in outpatient visits for hip and knee osteoarthritis after the 2021 Centers for Medicare and Medicaid Services changes to the E/M system.

METHODS

All outpatient visits for primary hip and knee osteoarthritis within the divisions of Joint Replacement, Operative Sports Medicine, and Nonoperative Sports Medicine at a single orthopaedic practice were retrospectively analyzed during 2 separate 10-month timeframes in 2019 and 2021. The primary endpoint was the visit EML (1 through 5) based on Current Procedural Terminology E/M codes.

RESULTS

In 2019, 7.8% of all visits were billed as level 2, 85.8% of all visits were billed as level 3, and 6.3% of all visits were billed as level 4. In 2021, 2.8% of visits were billed as level 2, 54% of visits were billed as level 3, and 41.3% of visits were billed as level 4. Level 1 and Level 5 visits did not exceed 2% in either year. Across all 3 divisions, level 2 and 3 visits decreased significantly (P < .05), while level 4 visits increased significantly (P < .05).

CONCLUSION

Since the E/M coding criteria overhaul in 2021, there has been a significant trend towards higher level of service code selection across multiple divisions in our orthopaedic practice.

Does Age Younger Than 65 Affect Clinical Outcomes in Medicare Patients Undergoing Lumbar Fusion?

STUDY DESIGN

This was a retrospective cohort study.

OBJECTIVE

To determine if age (younger than 65) and Medicare status affect patient outcomes following lumbar fusion.

SUMMARY OF BACKGROUND DATA

Medicare is a common spine surgery insurance provider, but most qualifying patients are older than age 65. There is a paucity of literature investigating clinical outcomes for Medicare patients under the age of 65.

MATERIALS AND METHODS

Patients 40 years and older who underwent lumbar fusion surgery between 2014 and 2019 were queried from electronic medical records. Patients with >2 levels fused, >3 levels decompressed, incomplete patient-reported outcome measures (PROMs), revision procedures, and tumor/infection diagnosis were excluded. Patients were placed into 4 groups based on Medicare status and age: no Medicare under 65 years (NM<65), no Medicare 65 years or older (NM≥65), yes Medicare under 65 (YM<65), and yes Medicare 65 years or older (YM≥65). T tests and χ 2 tests analyzed univariate comparisons depending on continuous or categorical type. Multivariate regression for ∆PROMs controlled for confounders. Alpha was set at 0.05.

RESULTS

Of the 1097 patients, 567 were NM<65 (51.7%), 133 were NM≥65 (12.1%), 42 were YM<65 (3.8%), and 355 were YM≥65 (32.4%). The YM<65 group had significantly worse preoperative Visual Analog Scale back ( P =0.01) and preoperative and postoperative Oswestry Disability Index (ODI), Short-Form 12 Mental Component Score (MCS-12), and Physical Component Score (PCS-12). However, on regression analysis, there were no significant differences in ∆PROMs for YM <65 compared with YM≥65, and NM<65. NM<65 (compared with YM<65) was an independent predictor of decreased improvement in ∆ODI following surgery (β=12.61, P =0.007); however, overall the ODI was still lower in the NM<65 compared with the YM<65.

CONCLUSION

Medicare patients younger than 65 years undergoing lumbar fusion had significantly worse preoperative and postoperative PROMs. The perioperative improvement in outcomes was similar between groups with the exception of ∆ODI, which demonstrated greater improvement in Medicare patients younger than 65 compared with non-Medicare patients younger than 65.

LEVEL OF EVIDENCE

Level III (treatment).

Trends in Single-Level Lumbar Fusions Over the Past Decade Using a National Database

OBJECTIVE

To compare rates of different fusion techniques using a nationwide database over the last decade and identify differences in complications and readmissions based on fusion technique.

METHODS

All elective, single-level lumbar fusions performed by orthopaedic surgeons from 2011 to 2020 were identified from the American College of Surgeons National Surgical Quality Improvement Program. Rates of lumbar fusion technique posterolateral decompression and fusion [PLDF], combined transforaminal lumbar interbody fusion and PLDF, anterior lumbar or lateral lumbar interbody fusion [ALIF/LLIF], and combined ALIF/LLIF and PLDF were recorded, and 30-day complications and readmissions were compared. Secondary analysis included multiple logistic regression to determine independent predictors of each outcome.

RESULTS

Inclusion criteria were met by 28,413 fusions: 8749 (30.8%) PLDFs, 11,973 (42.1%) transforaminal lumbar interbody fusions, 4769 (16.8%) ALIF/LLIFs, and 2922 (10.3%) combined ALIF/LLIF and PLDFs. The number of fusions increased over time with 1227 fusions performed in 2011 and 3958 fusions performed in 2019. Interbody fusions also increased over time with a subsequent decrease in PLDFs (39.0% in 2011, 25.2% in 2020). Patients were more likely to be discharged home over the course of the decade (85.4% in 2011, 95.0% in 2020). No difference was observed between the techniques regarding complications or readmissions. The modified 5-item frailty index was predictive of complications (odds ratio, 2.05; P = 0.001) and readmissions (odds ratio, 2.61; P < 0.001).

CONCLUSIONS

Lumbar fusions have continued to increase over the last decade with an increasing proportion of interbody fusions. Complications and readmissions appear to be driven by patient comorbidity and not fusion technique.

Benzodiazepines and Related Drugs in Orthopaedics

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Benzodiazepines are among the most commonly prescribed drugs worldwide and are often used as anxiolytics, hypnotics, anticonvulsants, and muscle relaxants.

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The risk of dependence on and abuse of these medications has recently gained more attention in light of the current opioid epidemic.

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Benzodiazepines can increase the risk of prolonged opioid use and abuse.

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Given the prevalence of the use of benzodiazepines and related drugs, orthopaedic patients are often prescribed these medications.

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Orthopaedic surgeons need to be aware of the prevalence of benzodiazepine and related drug prescriptions in the general population, their current uses in orthopaedic surgery, and the risks and adverse effects of their use.

Lumbo-sacral Junction Instability by Traumatic Sacral Fractures: Isler's Classification Revisited - A Narrative Review

STUDY DESIGN

Narrative review.

OBJECTIVES

Multiple classifications have been proposed for sacral fractures since the last century. While initial classifications focussed on vertical and transverse fractures, the recent fracture classifications encompass all injury patterns. In 1990, Isler classified unilateral vertical sacral fractures based on its potential influence on lumbo-sacral joint (LSJ) stability.

METHODS

We re-visited the original description of Isler's classification of sacral fractures and subsequent studies that have cited it. We will further describe basic LSJ anatomy, evolution of sacral classification systems and the use of Isler's classification system as it relates to LSJ instability and chronic low back pain.

RESULTS

Isler described a subset of unilateral vertical sacral fractures where the fracture line exited medial or through the L5-S1 facet joint, based on radiographic review of 193 sacral fractures (incidence -3.5%). He stated that such a fracture should be recognised as it can impede hemi-pelvis reduction and can result in late LSJ instability. The article has been cited in 106 studies and only a few studies have described the incidence of this variant. Nevertheless, the injury is considered as an indication for surgical fixation.

CONCLUSION

A review of various classifications indicates that sacral fractures have three important bio-mechanical implications, namely, pelvic ring continuity (vertical fractures), spino-pelvic alignment (high transverse fractures) and lumbo-sacral joint integrity (Isler's fractures). Though there is a universal recognition of Isler's fractures and its impact on LSJ integrity, there is a lack of clinical and bio-mechanical evidence regarding the concept of instability caused by a unilateral Isler fracture.

Does Age and Medicare Status Affect Clinical Outcomes in Patients Undergoing Anterior Cervical Discectomy and Fusion?

OBJECTIVE

The objective of this study was to determine if Medicare status and age affect clinical outcomes following anterior cervical discectomy and fusion.

METHODS

Patients who underwent cervical discectomy and fusion between 2014 and 2020 with complete preoperative and 1-year postoperative patient-reported outcome measures (PROMs) were grouped based on Medicare status and age: no Medicare under 65 years (NM < 65), Medicare under 65 years (M < 65), no Medicare 65 years or older (NM ≥ 65), and Medicare 65 years or older (M ≥ 65). Multivariate regression for ΔPROMs (Δ: postoperative minus preoperative) controlled for confounding differences between groups. Significant was set at P < 0.05.

RESULTS

A total of 1288 patients were included, with each group improving in the visual analog score (VAS) Neck (all, P < 0.001), VAS Arm (M < 65: P = 0.003; remaining groups: P < 0.001), and Neck Disability Index (M < 65: P = 0.009; remaining groups: P < 0.001) following surgery. Only M < 65 did not significantly improve in the Physical Component Score (PCS-12) and modified Japanese Orthopaedic Association (mJOA) score (P = 0.256 and P = 0.092, respectively). When comparing patients under 65 years, non-Medicare patients had better preoperative PCS-12 (P < 0.001), Neck Disability Index (P < 0.001), and modified Japanese Orthopaedic Association (P < 0.001), as well as better postoperative values for all PROMs (P < 0.001), but there were no differences in ΔPROMs. Multivariate analysis identified M < 65 to be an independent predictor of decreased improvement in ΔPCS-12 (β = -4.07, P = 0.015), ΔVAS Neck (β = 1.17, P = 0.010), and ΔVAS Arm (β = 1.15, P = 0.025) compared to NM < 65.

CONCLUSIONS

Regardless of age and Medicare status, all patients undergoing cervical discectomy and fusion had significant clinical improvement postoperatively. However, Medicare patients under age 65 have a smaller magnitude of improvement in PROMs.

Instrumentation Across the Cervicothoracic Junction Does Not Improve Patient-reported Outcomes in Multilevel Posterior Cervical Decompression and Fusion

STUDY DESIGN

This was a retrospective cohort.

OBJECTIVE

The objective of this study was to determine if instrumentation across the cervicothoracic junction (CTJ) in elective multilevel posterior cervical decompression and fusion (PCF) is associated with improved patient-reported outcome measures (PROMs).

SUMMARY OF BACKGROUND DATA

Fusion across the CTJ may result in lower revision rates at the expense of prolonged operative duration. However, it is unclear whether constructs crossing the CTJ affect PROMs.

MATERIALS AND METHODS

Standard Query Language (SQL) identified patients with PROMs who underwent elective multilevel PCF (≥3 levels) at our institution. Patients were grouped based on anatomic construct: crossing the CTJ (crossed) versus not crossing the CTJ (noncrossed). Subgroup analysis compared constructs stopping at C7 or T1. Independent t tests and χ 2 tests were utilized for continuous and categorical data, respectively. Regression analysis controlled for baseline demographics. The α was set at 0.05.

RESULTS

Of the 160 patients included, the crossed group (92, 57.5%) had significantly more levels fused (5.27 vs. 3.71, P <0.001), longer operative duration (196 vs. 161 min, P =0.003), greater estimated blood loss (242 vs. 160 mL, P =0.021), and a decreased revision rate (1.09% vs. 10.3%, P =0.011). Neither crossing the CTJ (vs. noncrossed) nor constructs spanning C3-T1 (vs. C3-C7) were independent predictors of ∆PROMs (change in preoperative minus postoperative patient-reported outcomes) on regression analysis. However, C3-C7 constructs had a greater revision rate than C3-T1 constructs (15.6% vs. 1.96%, P =0.030).

CONCLUSION

Crossing the CTJ in patients undergoing elective multilevel PCF was not an independent predictor of improvement in PROMs at 1 year, but they experienced lower revision rates.

LEVEL OF EVIDENCE

Level III.