Faculty Bibliography

OBJECTIVES/OBJECTIVE:To evaluate the effect of pre-existing mental health (MH) conditions on 90-day complication, 90-day readmission, and all-time revision surgical intervention rates following femoral, tibial, and pilon fractures. DESIGN/METHODS:Data were collected using a commercially available database software for which Current Procedural Terminology codes were used to identify patients who underwent surgical treatment of tibial, femoral, or pilon fractures. These patients were then subdivided into those with and without pre-existing MH condition using International Classification of Disease, Ninth Edition codes. Ninety-day postoperative complications, revision surgery, and 90-day readmission rates were then compared between those with and without MH conditions. SETTING/METHODS:National databases of 70 million combined patients from 2007 to 2015. PATIENTS/PARTICIPANTS/METHODS:Humana and Medicare insured patients. INTERVENTION/METHODS:Surgical treatment of tibial, femoral, and pilon fractures. MAIN OUTCOME MEASUREMENTS/METHODS:Ninety-day readmission, 90-day complications, and all-time revision surgical intervention. RESULTS:The total number of patients for femoral, tibial, and pilon treatment, respectively, included 6207, 6253, and 5940 without MH conditions and 4879, 5247, and 2911 with MH conditions. Femoral, tibial, and pilon readmission rates, revision rates, and complication rates were significantly higher among patients with MH disorders in matched cohorts after controlling for medical comorbidities (P ≤ 0.05 for all). CONCLUSIONS:Comorbid MH conditions are associated with higher postoperative complication, readmission, and revision surgery rates for treated femoral, tibial, and pilon fractures. LEVEL OF EVIDENCE/METHODS:Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Study Design/UNASSIGNED:Retrospective, database study. Objectives/UNASSIGNED:The aim of this study was to investigate incidence and risk factors associated with venous thromboembolic events (VTEs) after lumbar spine surgery. Methods/UNASSIGNED:Patients who underwent lumbar surgery between 2007 and 2014 were identified using the Humana within PearlDiver database. ICD-9 (International Classification of Diseases Ninth Revision) diagnosis codes were used to search for the incidence of VTEs among surgery types, patient demographics and comorbidities. Complications including DVT and PE were queried each day from the day of surgery to postoperative day 7 and for periods 0 to 1 week, 0 to 1 month, 0 to 2 months, and 0 to 3 months postoperatively. Results/UNASSIGNED:< .001). Risk factors associated with the highest VTE incidence and odds ratios (ORs) were primary coagulation disorder (10.01%, OR 4.33), extremity paralysis (7.49%, OR 2.96), central venous line (6.70%, OR 2.87), and varicose veins (6.51%, OR 2.58). Conclusions/UNASSIGNED:This study identified several patient comorbidities that were independent predictors of postoperative VTE occurrence after lumbar surgery. Clinical VTE risk assessment may improve with increased focus toward patient comorbidities rather than surgery type or patient demographics.

Study Design/UNASSIGNED:Retrospective cohort study. Objective/UNASSIGNED:To determine the rates of perioperative complications in patients undergoing anterior cervical discectomy and fusion (ACDF) with allograft versus synthetic cage. Methods/UNASSIGNED:test. Complications within 90 days were identified via ICD-9 codes and compared between the 2 cohorts. Revision rates within 2 years were noted. Results/UNASSIGNED:= .03). Conclusions/UNASSIGNED:This data suggests that synthetic cages are associated with a marginally higher overall rate of complications with similar revision rates.

Study Design/UNASSIGNED:Systematic review. Objective/UNASSIGNED:To review, critically appraise, and synthesize evidence on use of cell therapy for intervertebral disc repair. Methods/UNASSIGNED:A systematic search of PubMed/MEDLINE was conducted for literature published through October 31, 2018 and EMBASE and ClinicalTrials.gov databases through April 13, 2018 comparing allogenic or autologous cell therapy for intervertebral disc (IVD) repair in the lumbar or cervical spine. In the absence of comparative studies, case series of ≥10 patients were considered. Results/UNASSIGNED:From 1039 potentially relevant citations, 8 studies across 10 publications on IVD cell therapies in the lumbar spine met the inclusion criteria. All studies were small and primarily case series. For allogenic cell sources, no difference in function or pain between mesenchymal cell treatment and sham were reported in 1 small randomized controlled trial; 1 small case series reported improved function and pain relative to baseline but it was unclear if the change was clinically significant. Similarly for autologous cell sources, limited data across case series suggest pain and function may be improved relative to baseline; whether the changes were clinically significant was not clear. Safety data was sparse and poorly reported. The need for subsequent surgery was reported in 3 case-series studies ranging from 6% to 80%. Conclusions/UNASSIGNED:The overall strength of evidence for efficacy and safety of cell therapy for lumbar IVD repair was very low primarily due to substantial risk of bias, small sample sizes and lack of a comparator intervention. Methodologically sound studies comparing cell therapies to other treatments are needed.

Study Design/UNASSIGNED:Systematic review. Objectives/UNASSIGNED:To review, critically appraise, and synthesize evidence on the use of allogenic stem cell products for spine fusion compared with other bone graft materials. Methods/UNASSIGNED:Systematic searches of PubMed/MEDLINE, through October 31, 2018 and of EMBASE and ClinicalTrials.gov through April 13, 2018 were conducted for literature comparing allogenic stem cell sources for fusion in the lumbar or cervical spine with other fusion methods. In the absence of comparative studies, case series of ≥10 patients were considered. Results/UNASSIGNED:From 382 potentially relevant citations identified, 6 publications on lumbar fusion and 5 on cervical fusion met the inclusion criteria. For lumbar arthrodesis, mean Oswestry Disability Index (ODI), visual analogue scale (VAS) pain score, and fusion rates were similar for anterior lumbar interbody fusion (ALIF) using allogenic multipotent adult progenitor cells (Map3) versus recombinant human bone morphogenetic protein-2 (rhBMP-2) in the one comparative lumbar study (90% vs 92%). Across case series of allogenic stem cell products, function and pain were improved relative to baseline and fusion occurred in ≥90% of patients at ≥12 months. For cervical arthrodesis across case series, stem cell products improved function and pain compared with baseline at various time frames. In a retrospective cohort study fusion rates were not statistically different for Osteocel compared with Vertigraft allograft (88% vs 95%). Fusion rates varied across time frames and intervention products in case series. Conclusions/UNASSIGNED:The overall quality (strength) of evidence of effectiveness and safety of allogenic stem cells products for lumbar and cervical arthrodesis was very low, meaning that we have very little confidence that the effects seen are reflective of the true effects.

OBJECTIVE:To compare the rates of deep venous thrombosis (DVT), rates of pulmonary embolus (PE), and complication profiles of warfarin and low-molecular-weight heparin (LMWH) in patients undergoing operative fixation of hip fractures. DESIGN/METHODS:Retrospective cohort study. SETTING/METHODS:Insurance-based database of more than 22 million patient records. PATIENTS/METHODS:Adult hip fracture patients who were treated operatively and received chemoprophylaxis from 2007 to 2016. A total of 7594 patients met inclusion criteria and were available for final analysis. INTERVENTION/METHODS:Pharmacological anticoagulation with warfarin or LMWH to prevent postoperative venous thromboembolism after hip fracture surgery. MAIN OUTCOME MEASURES/METHODS:Development of DVT or PE within 30 and 90 days of surgery. RESULTS:Patients prescribed warfarin had higher rates of DVT and PE compared with those prescribed LMWH. Patients on warfarin were more likely to develop a postoperative hematoma and to be readmitted within 30 and 90 days compared with those on LMWH. Patients in both groups had similar rates of total complications. CONCLUSIONS:Patients prescribed warfarin after hip fractures had higher rates of DVT and PE compared with those prescribed LMWH, although both agents had similar complication profiles. LEVEL OF EVIDENCE/METHODS:Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

STUDY DESIGN:This is a retrospective analysis of kinematic magnetic resonance images (kMRI). OBJECTIVE:To assess the association of cervical paraspinal muscle with cervical sagittal balance and degenerative spinal disorders. SUMMARY OF BACKGROUND DATA:Although the effects of spinal disorders and cervical imbalance on patient's symptoms have been well described, the relationship of the cervical muscle quality and volume to cervical imbalance or spinal disorders is not well established. MATERIALS AND METHODS:In total, 100 kMRI taken in a neutral weight-bearing position were analyzed. The adjusted cross-sectional area ratio (aCSA ratio: the value of muscle CSA divided by the vertebral CSA) and fat infiltration ratio of the transversospinalis muscles at C4 and C7 vertebral levels were measured using axial slice of kMRI. The correlation with cervical balance parameters [Oc-C2 angle, C2-C7 angle, C7-T1 angle, C7 slope, T1 slope, cranial tilt, cervical tilt, thoracic inlet angle (TIA), and neck tilt] and cervical degenerative disorders (disk degeneration, Modic change, and spondylolisthesis) were evaluated. RESULTS:The aCSA ratio at C4 correlated with C2-C7 angle (r=0.267), C7 slope (r=0.207), T1 slope (r=0.221), disk degeneration at C3-4, C4-5, C5-6 (r=-0.234, -0.313, -0.262) and spondylolisthesis at C3 (anterior: r=-0.206, posterior: r=-0.249). The aCSA ratio at C7 correlated with disk degeneration at C3-4, C4-5, C5-6, C6-7 (r=-0.209, -0.294, -0.239, -0.209). The fat infiltration ratio at C4 correlated with TIA (r=0.306) and neck tilt (r=0.353), likewise the ratio at C7 correlated with TIA (r=0.270) and neck tilt (r=0.405). All correlations above were statistically significant with P<0.05. CONCLUSIONS:The paraspinal muscle volume showed significant relationship with the cervical balance parameters and disk degeneration. While, paraspinal muscle quality related to the thoracic inlet parameters. Our findings can be an important step to develop the knowledge of the association between cervical muscle and cervical degenerative disorders, as well as the sagittal balance of the cervical spine. LEVEL OF EVIDENCE:Level III.

STUDY DESIGN/METHODS:It is a retrospective analysis of 1806 consecutive cervical magnetic resonance images taken in weight-bearing flexion, neutral, and extension positions. OBJECTIVE:The aim was to identify the kinematic characteristics of patients with cervical imbalance. Additionally, factors were analysed in the neutral position that could predict the characteristics. Little is known about the kinematic characteristics during cervical flexion and extension positions of the patient with cervical imbalance (cervical sagittal vertical axis (cSVA) in neutral position ≥ 40 mm). METHODS:After evaluating the whole images, cervical imbalance group (cSVA ≥ 40 mm, n = 43) and matched control group (< 40 mm, n = 43) were created using propensity score adjusting for age, gender, and cervical alignment. They were compared for cervical motion, changes in disc bulge, and ligamentum flavum (LF) bulge from flexion to extension. Multinomial logistic regression analysis and receiver operating characteristic curve analysis were calculated to verify the predictive factors and cut-off value of the identified characteristics. RESULTS:There were no significant differences in range of motion and the change in bulged discs. There was significant difference in the presence of LF bulge from flexion to extension (p = 0.023); the incidence of LF bulge increased sharply from neutral to extension in imbalance group, while there was linear increase in control group. The canal diameter (odds ratio = 0.61, p = 0.002) and disc height (odds ratio = 1.60, p = 0.041) showed significant relationship with the segments with LF bulge observed in extension but not in neutral position in the imbalance group; the cut-off values were 10.7 mm for canal diameter (sensitivity 82.5%, specificity 66.7%) and 7.1 mm for disc height (70.8%, 58.5%). CONCLUSION/CONCLUSIONS:Patients with cervical imbalance had a stark increase in LF bulge from the neutral to extension position. Canal diameter < 10.7 mm and disc height > 7.1 mm on neutral images may predict the segments with LF bulge observed in extension, but not in the neutral position. LEVEL OF EVIDENCE/METHODS:II (Diagnostic: individual cross-sectional studies with consistently applied reference standard and blinding). These slides can be retrieved from Electronic Supplementary Material.

BACKGROUND CONTEXT:Previous studies have found an association between mental illness and poor outcomes in spine surgery, but little is known about the effects of depression and/or anxiety on the adult spinal deformity population. In addition, most relevant studies exclusively focused on the lumbar spine and had relatively small patient sizes. PURPOSE:The aim of this study was to investigate whether adult spinal deformity patients with depression and/or anxiety have an increased risk of postoperative complications and reoperation following posterior thoracolumbar spinal surgery. STUDY DESIGN/SETTING:Retrospective database study. METHODS:Adult patients (over 18 years of age) with a diagnosis of spinal deformity undergoing any reconstructive thoracic or thoracolumbar spinal procedure with a posterior approach between 2007 and 2015 Q2 were identified using Current Procedural Terminology codes to query the Pearl Diver patient record database (Pearl Diver Technologies, West Conshohocken, PA, USA). The database includes records of approximately 18 million patients across the United States having Humana insurance. Further selection of patients with depression and/or anxiety and their associated postoperative complications were identified using ICD-9 and ICD-10 diagnosis codes (International Classification of Diseases 9th-10th edition). The mental illness cohort was matched to a control group according to age, sex, and Charlson Comorbidity Index. Patient data was analyzed for reoperation rates and incidence of common postoperative complications. RESULTS:Multilevel posterolateral fusion was the most common included posterior thoracic reconstructive surgery. The mental illness cohort (n = 327) had significantly increased rates of infection (odds ratio [OR] = 1.743, p = .022) and respiratory complications (OR = 1.492, p = .02) at the 90-day postoperative period. The rates of incision and drainage (OR = 1.379, p = .475) and pneumonia (OR = 1.22, p = .573) were increased in the mental illness cohort at the 90-day postoperative period, but not significantly. There were no significant differences in complication and reoperation rates at 1-year postoperatively. CONCLUSIONS:Patients with spinal deformity and pre-existing depression and/or anxiety treated with a posterior thoracolumbar reconstructive spinal surgery had significantly elevated risk of postoperative infections and respiratory complications when compared with the control group.

Study Design/UNASSIGNED:Systematic review. Objectives/UNASSIGNED:The AOSpine thoracolumbar injury classification system (ATLICS) is a relatively simple yet comprehensive classification of spine injuries introduced in 2013. This systematic review summarizes the evidence on measurement properties of this new classification, particularly the reliability and validity of the main morphologic injury types with and without inclusion of the subtypes. Methods/UNASSIGNED:A literature search was performed using PubMed and Embase in September 2016. A revised version of the COSMIN checklist was used for evaluation of the quality of studies. Two independent reviewers performed all steps of the review. Results/UNASSIGNED:Nine articles were included in the final review, all of which evaluated the reliability of the ATLICS and had a fair methodological quality. The reliability of the modifiers was unknown. Overall, the quality of evidence for reliability of the morphologic and neurologic classification sections was low. However, there was moderate evidence for poor interobserver reliability of the morphologic classification when all subtypes were included, and moderate evidence for good intraobserver reliability with exclusion of subtypes. The reliability of the morphologic classification was independent of the observer's experience and cultural background. Conclusions/UNASSIGNED:ATLICS represents the most current system for evaluation of thoracolumbar injuries. Based on this review, further studies with robust methodological quality are needed to evaluate the measurement properties of ATLICS. Shortcomings of the reliability studies are discussed.