Faculty Bibliography

STUDY DESIGN/METHODS:Systematic literature review. OBJECTIVES/OBJECTIVE:In this study we assessed evidence for the use of osteobiologics in single vs multi-level anterior cervical discectomy and fusion (ACDF) in patients with cervical spine degeneration. The primary objective was to compare fusion rates after single and multi-level surgery with different osteobiologics. Secondary objectives were to compare differences in patient reported outcome measures (PROMs) and complications. METHODS:After a global team of reviewers was selected, a systematic review using different repositories was performed, confirming to PRISMA and GRADE guidelines. In total 1206 articles were identified and after applying inclusion and exclusion criteria, 11 articles were eligible for analysis. Extracted data included fusion rates, definition of fusion, patient reported outcome measures, types of osteobiologics used, complications, adverse events and revisions. RESULTS:Fusion rates ranged from 87.7% to 100% for bone morphogenetic protein 2 (BMP-2) and 88.6% to 94.7% for demineralized bone matrix, while fusion rates reported for other osteobiologics were lower. All included studies showed PROMs improved significantly for each osteobiologic. However, no differences were reported when comparing osteobiologics, or when comparing single vs multi-level surgery specifically. CONCLUSION/CONCLUSIONS:The highest fusion rates after 2-level ACDF for cervical spine degeneration were reported when BMP-2 was used. However, PROMs did not differ between the different osteobiologics. Further blinded randomized trials should be performed to compare the use of BMP-2 in single vs multi-level ACDF specifically.

PURPOSE/OBJECTIVE:To evaluate the relationship between nerve root retraction time, post-operative radiculitis and patient reported outcomes. METHODS:Patients who underwent single- or multi-level lumbar discectomy between 2020 and 2022 for lumbar disk herniations were prospectively followed with pre-operative, interoperative and post-operative variables including radiculitis and patient reported outcomes including VAS, ODI and CAT domains Pain interference, Pain intensity and Physical function. Intraoperative nerve root retraction time was recorded. Paired sample two-tailed t-test and multivariate regression were utilized with p < 0.05 being significant. RESULTS:A total of 157 patients who underwent single- or multi-level endoscopic lumbar discectomy. Average patient age was 44 years, and 64% were male patients. Nerve retraction time ranged from 4 to 15 min. Eighteen percent reported new radiculitis at 2-weeks post-operatively. In patients with new-onset radiculitis 79.2% reported significantly worse VAS leg at 2 weeks post-operative (4.2 vs. 8.3, p < 0.001) compared to 12.5% who had improved VAS leg (9.3 vs. 7, p = 0.1181). Patients with radiculitis and worse VAS scores had substantially longer nerve retraction time (13.8 ± 7.5 min) than patients with improved VAS leg (6.7 ± 1.2 min). At 6 months, patients with longer nerve retraction time had no significant improvement in the ODI or CAT compared to the baseline. CONCLUSIONS:This is the first study in discectomy literature to show that new onset radiculitis and poorer outcomes in VAS leg correlate with longer nerve retraction time at early and later time points.

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.

BACKGROUND CONTEXT/BACKGROUND:Several studies have shown that factors such as insurance type and patient income are associated with different readmission rates following certain orthopaedic procedures. The literature, however, remains sparse with regard to these demographic characteristics and their associations to perioperative lumbar spine fusion outcomes. PURPOSE/OBJECTIVE:The purpose of this study was to assess the associations between hospital type, insurance type, and patient median income to both 30-day complication and readmission rates following lumbar spine fusion. PATIENT SAMPLE/METHODS:Patients who underwent primary lumbar spine fusion (n = 596,568) from 2010-2016 were queried from the National Readmissions Database (NRD). OUTCOME MEASURES/METHODS:Incidence of 30-day complication and readmission rates. METHODS:All relevant diagnoses and procedures were identified using International Classification of Disease, 9th and 10th Edition (ICD-9, 10) codes. Hospital types were categorized as metropolitan non-teaching (n = 212,131), metropolitan teaching (n = 364,752), and rural (n = 19,685). Insurance types included: Medicare (n = 213,534), Medicaid (n = 78,520), private insurance (n = 196,648), and out-of-pocket (n = 45,025). Patient income was divided into the following quartiles: Q1 (n = 112,083), Q2 (n = 145,755), Q3 (n = 156,276), and Q4 (n = 147,289), wherein quartile 1 corresponded to lower income ranges and quartile 4 to higher ranges. Statistical analysis was conducted in R. Kruskal-Wallis tests with Dunn's pairwise comparisons were performed to analyze differences in 30-day readmission and complication rates in patients who underwent lumbar spine fusion. Complications analyzed included infection, wound injury, hematoma, neurological injury, thromboembolic event, and hardware failure. RESULTS:< .001). Patients in Quartile 4 experienced significantly greater rates of hematoma formation compared to those in Quartiles 1 and 2 and were more likely to experience a thromboembolic event compared to all other groups. CONCLUSION/CONCLUSIONS:Patients undergoing lumbar spine fusion at metropolitan non-teaching hospitals and paying with private insurance had significantly lower 30-day readmission rates than their counterparts. Complications within 30 days following lumbar spine fusion were significantly higher in patients treated at metropolitan teaching hospitals and in Medicare and Medicaid beneficiaries. Aside from a few exceptions, however, patient income was generally not associated with differential complication rates.

STUDY DESIGN/METHODS:Retrospective cohort study. OBJECTIVE:To analyze the effect of hyperlipidemia (HLD) on postoperative complications in patients who underwent anterior cervical discectomy and fusion (ACDF). SUMMARY OF BACKGROUND DATA/BACKGROUND:ACDF represents the standard procedure performed for focal anterior nerve root or spinal cord compression with low complication rates. HLD is well known as a risk factor for major complications after vascular and transplant surgery, and orthopedic surgery. To date, there have been no studies on HLD as a risk factor for cervical spine surgery. PATIENTS AND METHODS/METHODS:Patients who underwent ACDF from 2010 through quarter 3 of 2020 were enrolled using the MSpine subset of the PearlDiver Patient Record Database. The patients were divided into single-level ACDF and multilevel ACDF groups. In addition, each group was divided into subgroups according to the presence or absence of HLD. The incidence of surgical and medical complications was queried using relevant International Classification of Disease and Current Procedural Terminology codes. Charlson Comorbidity Index was used as a broad measure of comorbidity. χ 2 analysis, with populations matched for age, sex, and Charlson Comorbidity Index, was performed. RESULTS:A total of 24,936 patients who underwent single-level ACDF and 26,921 patients who underwent multilevel ACDF were included. In the multilevel ACDF group, wound complications were significantly higher in the patients with HLD. Among medical complications, myocardial infarction, renal failure, and urinary tract infection/urinary incontinence were significantly higher in the patients with HLD in both groups. Revision surgery and readmission were significantly higher in the patients with HLD who underwent multilevel ACDF. CONCLUSIONS:In patients who underwent ACDF, several surgical and medical complications were found to be higher in patients with HLD than in patients without HLD. Preoperative serum lipid concentration levels and management of HLD should be considered during preoperative planning to prevent postoperative complications in patients undergoing ACDF.

STUDY DESIGN/METHODS:A retrospective database study. OBJECTIVES/OBJECTIVE:The purpose of the current study was to investigate the impact of hyperlipidemia (HLD) on the incidence of perioperative complications associated with posterior cervical spine fusion (PCF). BACKGROUND:HLD is a very common disease that leads to atherosclerosis. Therefore, it can cause fatal diseases as well as lifestyle-related diseases. The possible impact of HLD on outcomes after PCF has not yet been investigated. METHODS:Patients with cervical degeneration underwent initial PCF from 2010 through the third quarter of 2020 using the MSpine subset of the PearlDiver Patient Record Database. The incidence of perioperative complications was queried using relevant ICD-9, 10, and CPT codes. χ 2 analysis was performed in age-, sex-, and Charlson Comorbidity Index (CCI)-matched populations to compare between non-HLD and HLD patients in each single-level and multilevel PCF. RESULTS:Through propensity score matching, 1600 patients each in the HLD and non-HLD groups were analyzed in the single-level PCF, 6855 patients were analyzed in the multilevel PCF were analyzed. The comorbidity of HLD significantly decreased the incidence of respiratory failure in single-level PCF (OR=0.58, P <0.01). In the multilevel PCF, the presence of HLD increased the incidence of cervicalgia (OR=1.26, P =0.030). On the contrary, the incident of spinal cord injury (OR=0.72, P <0.01), dysphagia (OR=0.81, P =0.023), respiratory failure (OR=0.85, P =0.030), pneumonia (OR=0.70, P =0.045), neurological bladder (OR=0.84, P =0.041), and urinary tract infection (OR=0.85, P =0.021) in the HLD group were significantly lower than those in non-HLD group. CONCLUSIONS:In the current study, the presence of HLD significantly increased the incidence of postoperative cervicalgia in multilevel PCF. On the other hand, the incidence of some complications was significantly decreased with HLD. Further studies are needed taking into account other factors such as the treatment of HLD, its efficacy, and intraoperative events. LEVEL OF EVIDENCE/METHODS:Level III.

STUDY DESIGN/METHODS:Cross-sectional survey. OBJECTIVE:Although literature does not recommend routine wound drain utilization, there is a disconnect between the evidence and clinical practice. This study aims to explore into this controversy and analyze the surgeon preferences related to drain utilization, and the factors influencing drain use and criterion for removal. METHODS:A survey was distributed to AO Spine members worldwide. Surgeon demographics and factors related to peri-operative drain use in 1 or 2-level open fusion surgery for lumbar degenerative pathologies were collected. Multivariate analyses by drain utilization, and criterion of removal were conducted. RESULTS:= .010) were more likely to remove drains based on outputs. CONCLUSIONS:Most spine surgeons worldwide prefer to place a subfascial wound drain for degenerative open lumbar surgery. The choice for drain placement is associated with the surgeon's age and use of coaptive films for wound closure, while the criterion for drain removal is associated with the surgeons' region of practice and experience.

PURPOSE/OBJECTIVE:Current decision-making in multilevel cervical fusion weighs the potential to protect adjacent levels and reduce reoperation risk by crossing the cervicothoracic junction (C7/T1) against increased operative time and risk of complication. Careful planning is required, and the planned distal and adjacent levels should be assessed for degenerative disc disease (DDD). This study assessed whether DDD at the cervicothoracic junction was associated with DDD, disc height, translational motion, or angular variation in the adjacent superior (C6/C7) or inferior (T1/T2) levels. METHODS:This study retrospectively analyzed 93 cases with kinematic MRI. Cases were randomly selected from a database with inclusion criteria being no prior spine surgery and images having sufficient quality for analysis. DDD was assessed using Pfirrmann classification. Vertebral body bone marrow lesions were assessed using Modic changes. Disc height was measured at the mid-disc in neutral and extension. Translational motion and angular variation were calculated by assessing translational or angular motion segment integrity respectively in flexion and extension. Statistical associations were assessed with scatterplots and Kendall's tau. RESULTS:DDD at C7/T1 was positively associated with DDD at C6/C7 (tau = 0.53, p < 0.01) and T1/T2 (tau = 0.58, p < 0.01), with greater disc height in neutral position at T1/T2 (tau = 0.22, p < 0.01), and with greater disc height in extended position at C7/T1 (tau = 0.17, p = 0.04) and at T1/T2 (tau = 0.21, p < 0.01). DDD at C7/T1 was negatively associated with angular variation at C6/C7 (tau = - 0.23, p < 0.01). No association was appreciated between DDD at C7/T1 and translational motion. CONCLUSION/CONCLUSIONS:The association of DDD at the cervicothoracic junction with DDD at the adjacent levels emphasizes the necessity for careful selection of the distal level in multilevel fusion in the distal cervical spine.