Faculty Bibliography

BACKGROUND/UNASSIGNED:The concept of spinal instability has been the subject of research since the 1940s and is commonly used in clinical practice to decide on patient treatment. This is despite the lack of an adequately validated diagnostic test for instability. Our goal is to describe automated tests to detect segmental translational and vertical instabilities that can be obtained from lumbar flexion-extension radiographs. We also assess the prevalence of these instabilities in different patient populations. METHODS/UNASSIGNED:Using fully automated methods: (I) flexion-extension studies of asymptomatic volunteers were analyzed to understand the performance of instability metrics in that population; (II) 7,621 lumbar spine flexion-extension from multiple clinical studies were analyzed to document the prevalence of sagittal plane translational and vertical instabilities, corrected for the amount of intervertebral rotation, across different patient populations. RESULTS/UNASSIGNED:Translational or vertical motion abnormalities were rare (<4% of levels) in the asymptomatic population, and the magnitude of translational motion was associated with radiographic disc degeneration (P<0.0001). Sagittal plane translational instabilities were uncommon (<4% of treatment levels) in lumbar disc arthroplasty and biologic disc treatment patients. They were more common (11% to 16% of treatment levels) in lumbar stenosis, lumbar fusion, and dynamic stabilization patients. A higher prevalence of vertical instabilities (27% to 48% of treatment levels) was seen in patients treated for lumbar stenosis and those selected for fusion or dynamic stabilization than those enrolled in disc arthroplasty studies or studies investigating biologics for disc disease treatment (6% to 11% of treatment levels). CONCLUSIONS/UNASSIGNED:New and fully automated approaches to detecting abnormal sagittal plane intervertebral motion may lead to enhanced and standardized diagnosis of lumbar spine instability. Further clinical research is imperative to verify prevalences and validate the efficacy of these metrics in diagnosis and treatment algorithms. If supported by additional research, these metrics may help determine, for example, which lumbar spinal stenosis patients require fusion in addition to decompression surgery.

PURPOSE/OBJECTIVE:To compare 0.55 T and 3 T MRI for imaging patients with titanium total hip arthroplasty (THA). Patients with orthopedic metallic implants often require diagnostic imaging to evaluate adjacent tissues. MRI performance measures, including artifact levels and SNR, vary with field strength. METHODS:Six patients with titanium THA were scanned with similar protocols at 0.55 T and 3 T, including proton density (PD) weighted turbo spin echo (TSE), PD TSE with view-angle tilting (TSE + VAT), PD slice encoding for metal artifact correction (SEMAC), and short tau inversion recovery with SEMAC (STIR-SEMAC). Images from both field strengths were scored by two readers and qualitatively and quantitatively compared. RESULTS:Diagnostic confidence was significantly higher at 0.55 T compared to 3 T. Perceived metal artifact was substantially reduced at 0.55 T compared to 3 T. At 0.55 T, diagnostic imaging was achieved both without and with multi spectral imaging (MSI) for PD weighted images. CONCLUSION/CONCLUSIONS:Compared to 3 T, 0.55 T MRI offers substantially reduced metal artifacts and higher diagnostic confidence when imaging titanium THA. Advanced multi-spectral techniques may not be required when the metallic components are entirely titanium.

Background Epidural steroid injections (ESIs) are a common conservative treatment for mitigating radicular pain and are often used to relieve pain, increase function, and improve mobility. However, their efficacy and duration of pain relief are relatively unclear because of the variability in clinical indications, injection techniques, injection mixtures, the number of allowable injections, and the lack of standard and objective outcome measures in the literature. Objectives This study aimed to characterize the effectiveness of ESIs in improving pain, measured with numerical rating scale (NRS) scores, and their relationship with subsequent lumbar spine surgery within a one-year period. Methods Patients who received a lumbar ESI from January 2018 to March 2022 in the Keck Medical Center of the University of Southern California were identified. Only patients with a one-year follow-up and no traumatic injuries were included. Exclusion criteria included a prior lumbar ESI within five years prior to January 2018. Demographics, comorbidities, injection information, and NRS scores were extracted. NRS score comparisons were analyzed with the Wilcoxon signed-rank test. Significance was defined at p ≤ 0.05. Results A total of 143 ESI patients were identified. The patient population consisted of 62 (43.36%) male, 81 (56.64%) female, and a median age of 63 years (IQR: 51,73). Patients who were one- and five-months post-ESI had the greatest median change in NRS of -3 (IQR: -7,0) (p < 0.05 for all). At one year post-ESI, there was a median decrease in NRS scores by 2 (IQR: 0,5). Of the cohort, only 28 (27.20%) patients went on to have lumbar spine surgery within a year. Conclusion The data suggests ESIs may be effective at relieving pain for at least one year. The data provides some evidence that ESIs are most reliable at relieving pain up to the five-month mark, after which their efficacy decreases.

STUDY DESIGN/METHODS:Multicenter, prospective observational cohort study. OBJECTIVES/OBJECTIVE:109 patients with lumbar spine stenosis (LSS) undergoing minimally invasive decompression in 6 different centers (Germany, Italy, USA). METHODS:The demographic, surgical and clinical data was collected. Patients were examined preoperatively, immediately postoperatively, at 6 and 12 months after surgery with regard to pain (back and legs) and functional outcomes (ODI, SF-36, EQ5D). RESULTS:= 0.011). SF36 physical scores also showed initial improvement but plateaued at follow-ups. Notably, high BMI and prior spine surgery were associated with worse outcomes. CONCLUSION/CONCLUSIONS:Although minimally invasive decompression without fusion initially led to a significant improvement in patients with LSS, the results deteriorated significantly over the course of the observation period. Future studies should focus on strategies to ensure sustained improvement in symptoms in patients with lumbar stenosis undergoing decompression procedure.

BACKGROUND CONTEXT/BACKGROUND:Lumbar disc herniation (LDH) is a leading cause of low back pain (LBP) and leg pain and may require surgical treatment in case of persistent pain and/or neurological deficits. Conventional discectomy involves removing the herniated fragment and additional material from the disc space, potentially accelerating disc degeneration and contributing to chronic LBP. Conversely, by resecting the herniated fragment only, sequestrectomy may reduce postoperative LBP while increasing the risk of LDH recurrence. PURPOSE/OBJECTIVE:To compare discectomy versus sequestrectomy in terms of risk of reherniation, reoperation rate, complications, pain, satisfaction, and perioperative outcomes (operative time, blood loss, length of stay [LOS]). STUDY DESIGN/METHODS:Systematic review and meta-analysis. METHODS:A systematic search of PubMed/MEDLINE and Scopus databases was performed through May 1, 2024 for both randomized and nonrandomized studies. The search was conducted according to PRISMA guidelines. The RoB-2 and MINORS tools were utilized to assess the risk of bias in included studies. The quality of the evidence was evaluated according to the GRADE approach. Relevant outcomes were pooled for meta-analysis. RESULTS:A total of 16 articles (1 randomized controlled trial with 2 follow-up studies, 6 prospective studies, and 7 retrospective studies) published between 1991 and 2020 involving 2009 patients were included for analysis. No significant differences were noted between discectomy versus sequestrectomy in terms of risk of reherniation (OR: 0.85, 95% CI: 0.57 to 1.26, p=.42), reoperation rate (OR: 0.95, 95% CI: 0.64 to 1.40, p=.78), and complications (OR: 1.03, 95% CI: 0.50 to 2.11, p=.94). Although LBP (MD: -0.06, 95% CI: -0.39 to 0.28, p=.74) and leg pain intensity (MD: 0.11, 95% CI: -0.21 to 0.42, p=.50) were similar postoperatively, significantly better outcomes were reported by patients treated with sequestrectomy at 1 year (leg pain: MD: 0.37, 95% CI: 0.19 to 0.54, p<.0001) and 2 years (LBP: MD: 0.19, 95% CI: 0.03 to 0.34, p=.02; leg pain: MD: 0.20, 95% CI: 0.09 to 0.31, p=.0005). Sequestrectomy also resulted in a higher patient satisfaction (OR: 0.60, 95% CI: 0.40 to 0.90, p=.01) and shorter operative time (MD: 8.71, 95% CI: 1.66 to 15.75, p=.02), while blood loss (MD: 0.18, 95% CI: -2.31 to 2.67, p=.89) and LOS (MD: 0.02 days, 95% CI: -0.07 to 0.12, p=.60) did not significantly differ compared to discectomy. CONCLUSIONS:Based on the current evidence, discectomy and sequestrectomy do not significantly differ in terms of risk of reherniation, reoperation rate, and postoperative complications. Patients treated with sequestrectomy may benefit from a marginally higher pain improvement, better satisfaction outcomes, and a shorter operative time, although the clinical relevance of these differences needs to be validated in larger, prospective, randomized studies.

STUDY DESIGN/METHODS:Cross-sectional survey. OBJECTIVE:Surgical treatment of degenerative lumbar spondylolisthesis is remarkably varied due to heterogeneity of clinical-radiological presentations. This study aimed to assess which spinopelvic radiological parameters were considered for decision-making. METHODS:Survey distributed to International AO Spine members to analyze surgeons' considerations for treatment. Data collected includes demographics, training background, years of experience, and treatment decisions based on various radiographical findings, including segmental and global spinopelvic parameters. RESULTS:= 0.043), respectively. Additionally, the surgeons' age was associated with using angular motion on flexion-extension radiographs, and volume of treated cases yearly with consideration for disc height. CONCLUSIONS:Treatment of degenerative lumbar spondylolisthesis was influenced by slippage on dynamic radiographs, disc height, global alignment, and PI-LL mismatch. Surgeons' age and Region, fellowship-trained, and volume of treated cases were significantly associated to apply these radiological parameters.

STUDY DESIGN/METHODS:Systematic review and meta-analysis. OBJECTIVES/OBJECTIVE:To assess the radiographic risk factors for adjacent segment disease (ASD) following anterior cervical discectomy and fusion (ACDF) for degenerative cervical spine pathologies. METHODS:PubMed, Embase and the Cochrane Library databases were searched up to December 2023. The primary inclusion criteria were degenerative spinal conditions treated with ACDF, comparing radiological parameters in patients with and without postoperative ASD. The radiographic parameters included intervertebral disc height, cervical sagittal alignment, sagittal segmental alignment, range of motion, segmental height, T1 slope, sagittal vertical axis (SVA), thoracic inlet angle (TIA), and plate to disc distance (PPD). Risk of bias was assessed for all studies. The Cochrane Review Manager was utilized to perform the meta-analysis. RESULTS:< .001). CONCLUSIONS:Decreased postoperative cervical lordosis, greater change in cervical sagittal alignment and developmental cervical canal stenosis were associated with an increased risk of ASD following ACDF.

BACKGROUND/UNASSIGNED:Management of lumbar degenerative spondylolisthesis with decompression-only procedure has been performed for its added benefit of a shorter duration of surgery, lower blood loss, and shorter hospital stay. However, reported failure rates for decompression-only procedures vary depending on the methods utilized for decompression. Hence, we aim to identify the failure rates of individual methods of decompression-only procedures performed for degenerative lumbar spondylolisthesis. METHODS/UNASSIGNED:An independent systematic review of 4 scientific databases (PubMed, Scopus, clinicaltrials.gov, Web of Science) was performed to identify relevant articles as per the preferred reporting in systematic reviews and meta-analysis guidelines. Studies reporting on failure rates defined by reoperation at the index level following decompression-only procedure for degenerative lumbar spondylolisthesis were included for analysis. Studies were appraised using ROBINS tool of Cochrane, and analysis was performed using the Open Meta[Analyst] software. RESULTS/UNASSIGNED:The overall failure rate of decompression-only procedure was 9.1% (95% confidence interval [CI] [6.5-11.7]). Furthermore, open decompression had failure rate of 10.9% (95% CI [6.0-15.8]), while microendoscopic decompression had failure rate of 6.7% (95% CI [2.9-10.6]). The failure rate gradually increased from 6.9% (95% CI [2.0-11.7]) at 1 year to 7% (95% CI [3.6-10.3]), 11.7% (95% CI [4.5-18.9]), and 11.7% (95% CI [6.6-16.7]) at 2, 3, and 5 years, respectively. Single level decompression had a failure rate of 9.6% (95% CI [6.3-12.9]), while multilevel decompression recorded a failure rate of 8.7% (95% CI [5.6-11.7]). CONCLUSION/UNASSIGNED:High-quality evidence on the decompression-only procedure for degenerative spondylolisthesis is limited. The decompression-only procedure had an overall failure rate of 9.1% without significant differences between the decompression techniques. LEVEL OF EVIDENCE/UNASSIGNED:Level IV. See Instructions for Authors for a complete description of levels of evidence.

STUDY DESIGN/METHODS:Systematic literature review. OBJECTIVE:To analyze the literature and describe the evidence supporting osteobiologic use in revision anterior cervical discectomy and fusion (ACDF) surgery. METHODS:A systematic search of PubMed/MEDLINE, EMBASE, Cochrane library, and ClinicalTrials.gov databases was conducted for literature reporting the use of osteobiologics in revision ACDF. We searched for studies reporting outcomes of using any osteobiologic use in revision ACDF surgeries (independently of the number of levels) in the above databases. RESULTS:There are currently no studies in the literature describing the outcome and comparative efficacy of diverse osteobiologic agents in the context of revision ACDF surgery. A majority of the current evidence is based only upon studies involving primary ACDF surgery. CONCLUSION/CONCLUSIONS:The current study highlights the paucity of literature evidence on the role of diverse osteobiologics in revision ACDF, and foregrounds the need for high-quality evidence on this subject.