Faculty Bibliography

OBJECTIVE:To assess whether surgical cervical deformity (CD) patients meet spinopelvic age-adjusted alignment targets, reciprocal, and lower limb compensation changes. STUDY DESIGN/METHODS:Retrospective review. METHODS:CD was defined as C2-C7 lordosis >10°, cervical sagittal vertical angle (cSVA) >4 cm, or T1 slope minus cervical lordosis (TS-CL) >20°. Inclusion criteria were age >18 years and undergoing surgical correction with complete baseline and postoperative imaging. Published formulas were used to create age-adjusted alignment target for pelvic tilt (PT), pelvic incidence and lumbar lordosis (PI-LL), sagittal vertical angle (SVA), and lumbar lordosis and thoracic kyphosis (LL-TK). Actual alignment was compared with age-adjusted ideal values. Patients who matched ±10-year thresholds for age-adjusted targets were compared with unmatched cases (under- or overcorrected). RESULTS:= 0.269). CONCLUSIONS:In response to worsening CD postoperatively, patients increased in TK and recruited less lower limb compensation. Almost 75% of CD patients did not meet previously established spinopelvic alignment goals, of whom a subset of patients were actually made worse off in these parameters following surgery. This finding raises the question of whether we should be looking at the entire spine when treating CD. LEVEL OF EVIDENCE: 3/METHODS/:

BACKGROUND:Metabolic syndrome (MetS) is an amalgamation of medical disorders that ultimately increase patient complications. Factors such as obesity, hypertension, dyslipidemia, and diabetes are associated with this disease complex. OBJECTIVE:To assess the incremental value of improving MetS in relation to clinical outcomes. STUDY DESIGN/METHODS:Retrospective cohort study. METHODS:tests compared differences in patient demographics. Resolution of metabolic factors was incrementally analyzed for their effect on perioperative complications through utilization of logistic regressions. RESULTS:< 0.001). CONCLUSIONS:Metabolic patients improved in perioperative complications incrementally, demonstrating the utility of efforts to mitigate burden of MetS even if not completely abolished. CLINICAL RELEVANCE/CONCLUSIONS:This review contributes to the assessment of MetS optimization in the field of adult spine surgery. LEVEL OF EVIDENCE: 3/METHODS/:

Background:There is limited literature evaluating the impact of isolated cannabis use on outcomes for patients following spinal surgery. This study sought to compare 90-day complication, 90-day readmission, as well as 2-year revision rates between baseline cannabis users and non-users following thoracolumbar spinal fusion (TLF) for adult spinal deformity (ASD). Methods:The New York Statewide Planning and Research Cooperative System (SPARCS) database was queried between January 2009 and September 2013 to identify all patients who underwent TLF for ASD. Inclusion criteria were age ≥18 years and either minimum 90-day (for complications and readmissions) or 2-year (for revisions) follow-up surveillance. Cohorts were created and propensity score-matched based on presence or absence of isolated baseline cannabis use. Baseline demographics, hospital-related parameters, 90-day complications and readmissions, and two-year revisions were retrieved. Multivariate binary stepwise logistic regression identified independent outcome predictors. Results:704 patients were identified (n=352 each), with comparable age, sex, race, primary insurance, Charlson/Deyo scores, surgical approach, and levels fused between cohorts (all, p>0.05). Cannabis users (versus non-users) incurred lower 90-day overall and medical complication rates (2.4% vs. 4.8%, p=0.013; 2.0% vs. 4.1%, p=0.018). Cohorts had otherwise comparable complication, revision, and readmission rates (p>0.05). Baseline cannabis use was associated with a lower risk of 90-day medical complications (OR=0.47, p=0.005). Isolated baseline cannabis use was not associated with 90-day surgical complications and readmissions, or two-year revisions. Conclusion:.

OBJECTIVE:Hyperextension of C0-2 is a debilitating compensatory mechanism used to maintain horizontal gaze, analogous to high pelvic tilt in the lumbopelvic complex to maintain an upright posture. This study aims to investigate the impact of cervical deformity (CD) correction on this hyperextension. The authors hypothesize that correction of cervical sagittal malalignment allows for relaxation of C0-2 hyperextension and improved clinical outcomes. METHODS:A retrospective review was conducted of a multicenter database of patients with CD undergoing spinal realignment and fusion caudal to C2 and cephalad to the pelvis. Range of motion (ROM) and reserve of extension (ROE) were calculated across C2-7 and C0-2. The association between C2-7 correction and change in C0-2 ROE was investigated while controlling for horizontal gaze, followed by stratification into ΔC2-7 percentiles. RESULTS:Sixty-five patients were included (mean age 61.8 ± 9.6 years, 68% female). At baseline, patients had cervical kyphosis (C2-7, -11.7° ± 18.2°; T1 slope-cervical lordosis mismatch, 38.6° ± 18.6°), negative global alignment (sagittal vertical axis [SVA] -12.8 ± 71.2 mm), and hyperlordosis at C0-2 (mean 33.2° ± 11.8°). The mean ROM was 25.7° ± 17.7° and 21.3° ± 9.9° at C2-7 and C0-2, respectively, with an ROE of approximately 9° for each segment. Limited C0-2 ROM and ROE correlated with the Neck Disability Index (r = -0.371 and -0.394, p < 0.01). The mean number of levels fused was 7.0 ± 3.1 (24.6% anterior, 43.1% posterior), with 87.7% undergoing at least an osteotomy. At 1 year, mean C2-7 increased to 5.5° ± 13.4°, SVA became neutral (11.5 ± 54.8 mm), C0-2 hyperlordosis decreased to 27.8° ± 11.7°, and thoracic kyphosis (TK) increased to -49.4° ± 18.1° (all p < 0.001). Concurrently, mean C0-2 ROM increased to 27.6° ± 8.1° and C2-7 ROM decreased significantly to 9.0° ± 12.3° without a change in ROE. Controlling for horizontal gaze, change in C2-7 lordosis significantly correlated with increased TK (r = -0.617, p < 0.001), decreased C0-2 (r = -0.747, p < 0.001), and increased C0-2 ROE (r = 0.550, p = 0.002). CONCLUSIONS:CD correction can significantly impact cephalad and caudal compensation in the upper cervical and thoracic spine. Restoration of cervical alignment resulted in increased C0-2 ROE and TK and was also associated with improved clinical outcome.

AIM/OBJECTIVE:We sought to systematically assess and summarize the available literature on the clinical outcomes and complications following radiofrequency ablation (RFA) for painful spinal osteoid osteoma (OO). METHODS:PubMed, Scopus, and CENTRAL databases were searched in accordance with PRISMA guidelines. Studies with available data on safety and clinical outcomes following RFA for spinal OO were included. RESULTS:In the 14 included studies (11 retrospective; 3 prospective), 354 patients underwent RFA for spinal OO. The mean ages ranged from 16.4 to 28 years (Females = 31.3%). Lesion diameters ranged between 3 and 20 mm and were frequently seen in the posterior elements in 211/331 (64%) patients. The mean distance between OO lesions and neural elements ranged between 1.7 and 7.4 mm. The estimated pain reduction on the numerical rating scale was 6.85/10 (95% confidence intervals [95%CI] 4.67-9.04) at a 12-24-month follow-up; and 7.29/10 (95% CI 6.67-7.91) at a >24-month follow-up (range 24-55 months). Protective measures (e.g., epidural air insufflation or neuroprotective sterile water infusion) were used in 43/354 (12.1%) patients. Local tumor progression was seen in 23/354 (6.5%) patients who were then successfully re-treated with RFA or open surgical resection. Grade I-II complications such as temporary limb paresthesia and wound dehiscence were reported in 4/354 (1.1%) patients. No Grade III-V complications were reported. CONCLUSION/CONCLUSIONS:RFA demonstrated safety and clinical efficacy in most patients harboring painful spinal OO lesions. However, further prospective studies evaluating these outcomes are warranted.

Background/UNASSIGNED:Adolescent idiopathic scoliosis (AIS) is the most common form of abnormal spine curvature observed in patients age 10 to 18. Typically characterized by shoulder height and waistline asymmetry, AIS may drive uneven distribution of force in the hips, leading to increased rates of concurrent hip diagnoses. The relationship between AIS and concurrent hip diagnoses is underexplored in the literature, and to date, there has been little research comparing rates of hip diagnoses between patients with AIS and those unaffected. Purpose/UNASSIGNED:Assess differences in rates and clusters of hip diagnoses between patients with AIS and those unaffected. Study design/UNASSIGNED:Retrospective review of Healthcare Cost and Utilization Project's (HCUP) Nationwide Inpatient Sample (NIS). Patient sample/UNASSIGNED:224,504 weighted inpatient discharges. Outcome measures/UNASSIGNED:Rates of hip diagnoses. Methods/UNASSIGNED:Patients in the NIS database (2005-2013) ages 10-18 years were isolated. Patients were grouped by those diagnosed with AIS (ICD-9: 737.30) and those unaffected. Patient groups were propensity score matched (PSM) for age. Means comparison tests assessed differences in demographic, comorbidity, and diagnosis profiles between patient groups for corresponding age categories. ICD-9 codes were used to identify specific hip diagnoses. Results/UNASSIGNED:Following PSM, 24,656 AIS and 24,656 unaffected patients were included. The AIS patient group was comprised of more females (66% vs 59%) and had lower rates of obesity (2.4% vs 3.5%, both p < 0.001). Overall, 1.1% of patients had at least one hip diagnosis: congenital deformity (0.31%), developmental dysplasia (0.24%), recurrent dislocation (0.18%), isolated dislocation (0.09%), osteonecrosis (0.08%), osteochondrosis (0.07%), acquired deformity (0.03%), and osteoarthritis (0.02%). AIS patients had lower rates of osteonecrosis (0.04% vs 0.12%, p = 0.003), but higher rates of all other hip diagnoses, including dysplasia (0.41% vs 0.07%, p < 0.001), recurrent dislocation (0.32% vs 0.03%, p < 0.001), isolated dislocation (0.13% vs 0.06%, p < 0.001), and osteoarthritis (0.04% vs 0.01%, p = 0.084. Co-occurrences of hip diagnoses were relatively rare, with 0.03% patients having more than one hip diagnosis. Rates of co-occurring hip diagnoses did not differ between AIS and unaffected groups (0.04% vs 0.02%, p = 0.225). Conclusions/UNASSIGNED:Compared to unaffected patients of similar ages, patients with AIS had higher overall rates of hip diagnoses, including dysplasia and recurrent dislocation. A higher trend of precocious osteoarthritis was also observed at a higher rate in AIS patients, although this difference was not statistically significant. Our results present an argument for surgical realignment in the coronal and sagittal planes to neutralize asymmetrical forces in the hips, and suggest the need for increased awareness and clinical screening for hip-related disorders in AIS patients. Level of Evidence/UNASSIGNED:III.

BACKGROUND:Primary spine paragangliomas are rare tumors. Surgical resection plays a role, but aggressive lesions are challenging. We reviewed the literature on primary spine paragangliomas. METHODS:PubMed, Scopus, Web of Science, and Cochrane were searched upon the PRISMA guidelines to include studies on primary spine paragangliomas. Clinical-radiological features, treatments, and outcomes were analyzed and compared between cauda-equina vs non-cauda-equina tumors. RESULTS:We included 143 studies comprising 334 patients. Median age was 46 years (range, 6-85). The most frequent symptoms were lower-back (64.1%) and radicular (53.9%) pain, and sympathetic in 18 patients (5.4%). Cauda-equina paragangliomas (84.1%) had frequently lumbar (49.1%) or lumbosacral (29%) locations. Non-cauda-equina tumors were mostly in the thoracic (11.4%), thoracolumbar (5.1%), and cervical (3.6%) spine. Median tumor diameter was 2.5cm (range, 0.5-13.0). Surgical resection (98.5%) was preferred over biopsy (1.5%). Decompressive laminectomy (53%) and spine fusion (6.9%) were also performed. Adjuvant radiotherapy was delivered in 39 patients (11.7%) with aggressive tumors. Post-treatment symptomatic improvement was described in 86.2% cases. Median follow-up was 19.5 months (range, 0.1-468.0), and 23 patients (3.9%) had tumor recurrences. No significant differences were found between cauda-equina vs non-cauda-equina tumors. CONCLUSION/CONCLUSIONS:Surgical resection is effective and safe in treating primary spine paragangliomas; however, adjuvant treatments may be needed for aggressive lesions.

PURPOSE/OBJECTIVE:To determine the validity and responsiveness of PROMIS metrics versus the SRS-22r questionnaire in adult spinal deformity (ASD). METHODS:Surgical ASD patients undergoing ≥ 4 levels fused with complete baseline PROMIS and SRS-22r data were included. Internal consistency (Cronbach's alpha) and test-retest reliability [intraclass correlation coefficient (ICC)] were compared. Cronbach's alpha and ICC values ≥ 0.70 were predefined as satisfactory. Convergent validity was evaluated via Spearman's correlations. Responsiveness was assessed via paired samples t tests with Cohen's d to assess measure of effect (baseline to 3 months). RESULTS:One hundred and ten pts are included. Mean baseline SRS-22r score was 2.62 ± 0.67 (domains = Function: 2.6, Pain: 2.5, Self-image: 2.2, Mental Health: 3.0). Mean PROMIS domains = Physical Function (PF): 12.4, Pain Intensity (PI): 91.7, Pain Interference (Int): 55.9. Cronbach's alpha, and ICC were not satisfactory for any SRS-22 and PROMIS domains. PROMIS-Int reliability was low for all SRS-22 domains (0.037-0.225). Convergent validity demonstrated strong correlation via Spearman's rho between PROMIS-PI and overall SRS-22r (- 0.61), SRS-22 Function (- 0.781), and SRS-22 Pain (- 0.735). PROMIS-PF had strong correlation with SRS-22 Function (0.643), while PROMIS-Int had moderate correlation with SRS-22 Pain (- 0.507). Effect size via Cohen's d showed that PROMIS had superior responsiveness across all domains except for self-image. CONCLUSIONS:PROMIS is a valid measure compared to SRS-22r in terms of convergent validity, and has greater measure of effect in terms of responsiveness, but failed in reliability and internal consistency. Surgeons should consider the lack of reliability and internal consistency (despite validity and responsiveness) of the PROMIS to SRS-22r before replacing the traditional questionnaire with the computer-adaptive testing.

OBJECTIVE:The current literature has primarily focused on the 2-year outcomes of operative adult spinal deformity (ASD) treatment. Longer term durability is important given the invasiveness, complications, and costs of these procedures. The aim of this study was to assess minimum 3-year outcomes and complications of ASD surgery. METHODS:Operatively treated ASD patients were assessed at baseline, follow-up, and through mailings. Patient-reported outcome measures (PROMs) included scores on the Oswestry Disability Index (ODI), Scoliosis Research Society-22r (SRS-22r) questionnaire, mental component summary (MCS) and physical component summary (PCS) of the SF-36, and numeric rating scale (NRS) for back and leg pain. Complications were classified as perioperative (≤ 90 days), delayed (90 days to 2 years), and long term (≥ 2 years). Analyses focused on patients with minimum 3-year follow-up. RESULTS:Of 569 patients, 427 (75%) with minimum 3-year follow-up (mean ± SD [range] 4.1 ± 1.1 [3.0-9.6] years) had a mean age of 60.8 years and 75% were women. Operative treatment included a posterior approach for 426 patients (99%), with a mean ± SD 12 ± 4 fusion levels. Anterior lumbar interbody fusion was performed in 35 (8%) patients, and 89 (21%) underwent 3-column osteotomy. All PROMs improved significantly from baseline to last follow-up, including scores on ODI (45.4 to 30.5), PCS (31.0 to 38.5), MCS (45.3 to 50.6), SRS-22r total (2.7 to 3.6), SRS-22r activity (2.8 to 3.5), SRS-22r pain (2.3 to 3.4), SRS-22r appearance (2.4 to 3.5), SRS-22r mental (3.4 to 3.7), SRS-22r satisfaction (2.7 to 4.1), NRS for back pain (7.1 to 3.8), and NRS for leg pain (4.8 to 3.0) (all p < 0.001). Degradations in some outcome measures were observed between the 2-year and last follow-up evaluations, but the magnitudes of these degradations were modest and arguably not clinically significant. Overall, 277 (65%) patients had at least 1 complication, including 185 (43%) perioperative, 118 (27%) delayed, and 56 (13%) long term. Notably, the 142 patients who did not achieve 3-year follow-up were similar to the study patients in terms of demographic characteristics, deformities, and baseline PROMs and had similar rates and types of complications. CONCLUSIONS:This prospective multicenter analysis demonstrated that operative ASD treatment provided significant improvement of health-related quality of life at minimum 3-year follow-up (mean 4.1 years), suggesting that the benefits of surgery for ASD remain durable at longer follow-up. These findings should prove useful for counseling, cost-effectiveness assessments, and efforts to improve the safety of care.