Faculty Bibliography

BACKGROUND: Although adult cervical spine deformity (ACSD) is associated with pain and disability, its health impact has not been quantified in comparison to other chronic diseases. OBJECTIVE: To perform a comparative analysis of the health impact of symptomatic ACSD to US normative and chronic disease values using EQ-5D (EuroQuol-5 Dimensions questionnaire) scores. METHODS: ACSD patients presenting for surgical treatment were identified from a prospectively collected multicenter database. Baseline demographics and EQ-5D scores were collected and compared with US normative and disease state values. RESULTS: Of 121 ACSD patients, 115 (95%) completed the EQ-5D (60% women, mean age 61 years, previous spine surgery in 44%). Diagnoses included kyphosis with mid-cervical (63.4%), cervico-thoracic (23.5%), or thoracic (8.7%) apex and primary coronal deformity (4.3%). The mean ACSD EQ-5D index was 0.511 (standard definition = 0.224), which is 34% below the bottom 25th percentile (0.780) for similar age- and gender-matched US normative populations. Mean ACSD EQ-5D index values were worse than the bottom 25th percentile for several other disease states, including chronic ischemic heart disease (0.708), malignant breast cancer (0.708), and malignant prostate cancer (0.708). ACSD mean index values were comparable to the bottom 25th percentile values for blindness/low vision (0.543), emphysema (0.508), renal failure (0.506), and stroke (0.463). EQ-5D scores did not significantly differ based on cervical deformity type ( P = .66). CONCLUSION: The health impact of symptomatic ACSD is substantial, with negative impact across all EQ-5D domains. The mean ACSD EQ-5D index was comparable to the bottom 25th percentile values for blindness/low vision, emphysema, renal failure, and stroke.

Cervical spondylotic myelopathy (CSM) is the most common cause of spinal cord dysfunction in patients older than age 55, with operative management being a widely adopted approach. Previous work has shown that private insurance status, gender and patient race are predictive of the operative approach patients receive (anterior-only, posterior-only, combined anterior-posterior). The Nationwide Inpatient Sample from 2001 to 2010 was used to assess the potential role of multilevel CSM as a contributing factor in determining which operative approach CSM patients receive, as it is rare for an anterior-only approach to be sufficient for CSM patients requiring fusion of four or more involved levels. Multivariate analyses revealed that female sex (OR=3.78; 95% CI=2.08-6.89; p<0.0001), private insurance (OR=5.02; 95% CI=2.26-11.12; p<0.0001), and elective admission type (OR=4.12; 95% CI=1.65-10.32; p=0.0025) were predictive of increased receipt of a 3+ level fusion in CSM. No other variables, including patient age, race, income, or admission source were predictive of either increased or decreased likelihood of receiving fusion of at least three levels for CSM. In conclusion, female sex, private insurance status, and elective admission type are each independent predictors in CSM for receipt of a 3+ level fusion, while patient age, race and income are not. Given the propensity of fusions greater than three levels to require posterior approaches and the association between posterior CSM approaches and increased morbidity/mortality, these findings may prove useful as to which patient demographics are predictive of increased morbidity and mortality in operative treatment of CSM.

Introduction: Despite the potential for profound impact of adult cervical deformity (ACD) on function and healthrelated quality of life, there remains a paucity of highquality studies that assess outcomes of surgical treatment for these patients. Our objective was to assess outcomes following surgical treatment for ACD based on a prospective multicenter consecutive case series. Materials and Methods: Surgically treated ACD patients eligible for 1-year followup were identified from a prospectively collected multicenter database. Baseline deformity characteristics, surgical parameters, and 1-year outcomes were assessed. Standardized outcome measures included: Neck Disability Index (NDI, range 0-100), neck pain numeric rating scale (NRS) score (range 0-10), and EQ-5D index (range 0 -1) and subscores (range 1-3). Paired sample t-tests were used to compare 1-year and baseline measures. Results: Of 77 ACD patients, 55 (71%) had 1-year follow-up (64% women, mean age 61 years, mean Charlson Comorbidity Index [CCI] of 0.6, previous cervical surgery in 44%). Diagnoses included: cervical sagittal imbalance (62%), cervical kyphosis (60%), proximal junctional kyphosis (8%), and coronal deformity (10%). Posterior fusion was performed in 85% (mean number of vertebral levels=10), and anterior fusion was performed in 29% (mean number of vertebral levels = 5). Three-column osteotomy was performed in 24% of patients. Mean operative time was 6.5 hours and mean estimated blood loss was 0.9L. At 1-year following surgery, ACD patients had significant improvement in NDI (50.5 to 38.0, P < .001), neck pain NRS (6.9 to 4.3, P < .001), EQ-5D index (0.51 to 0.66, P < .001), and EQ-5D subscores: mobility (1.9 to 1.7, P = .019), usual activities (2.2 to 1.9, P = .007), pain/discomfort (2.4 to 2.1, P < .001), anxiety/depression (1.8 to 1.5, P = .014). A nonsignificant trend favoring improvement was observed for EQ-5D self-care (1.5 to 1.3, P = .070). Compared with patients that achieved 1-year follow-up, those lost to followup did not differ significantly with regard to age, gender, CCI, number of fused anterior or posterior vertebral levels, or baseline NDI, neck pain NRS, or EQ-5D scores. Conclusions: Based on a prospective multicenter series of adults with cervical deformity, surgical treatment provided significant improvement in multiple measures of pain and function, including the NDI, neck pain NRS score, and EQ-5D. Further follow-up will be necessary to assess the durability of these surgical procedures and the resulting improved outcomes

Introduction: Although adult cervical deformity (ACD) has been empirically associated with significant pain and disability, the magnitude of this negative impact has not been objectively quantified. Our objective was to assess whether symptomatic ACD patients have substantial negative health impact based on the EQ-5D compared with United States (U.S.) normative and chronic disease state values. Materials and Methods: ACD patients presenting for surgical evaluation and treatment were identified from a prospectively collected multicenter database. Baseline demographics, deformity characteristics, and EQ-5D scores were collected. EQ-5D scores were compared with ageand gender-matched U.S. normative and chronic disease state values. Results: Of 121 ACD patients, 115 (95%) completed the EQ-5D (61% women, mean age 61 years, previous cervical surgery in 46%). Diagnoses included: cervical sagittal malalignment (63%), cervical kyphosis (60%), proximal junctional kyphosis (9%) and coronal deformity (8%). The mean EQ-5D index was 0.511, which is 35% below the bottom 25th percentile score (0.790) for a similar age- and gender-weighted normative population and worse than the bottom 25th percentile for several other chronic disease states (diabetes [0.708], ischemic heart disease [0.708], and myocardial infarction [0.575]). The EQ-5D index of 0.511 seen in this ACD cohort is comparable to the bottom 25th percentile for blindness (0.543), emphysema (0.508) and heart failure (0.437). Based on EQ-5D subscores, patients reported impact on mobility (87%), daily self-care (47%), daily activities (91%), pain/discomfort (98%), and anxiety/depression (67%). Conclusions: The health impact of symptomatic ACD is substantial, with an EQ-5D index that is 35% below the bottom 25th percentile for an age- and gender-matched normative U.S. population. The markedly negative health impact of ACD was demonstrated across all domains of the EQ-5D. The overall mean EQ-5D index for ACD patients was worse than the bottom 25th percentile for several other chronic disease states, including chronic ischemic heart disease, malignant breast cancer, and malignant prostate cancer, and was comparable to the bottom 25th percentile values for blindness/low vision, emphysema, renal failure, and stroke

Introduction: Although three-column osteotomy (3CO; pedicle subtraction osteotomy [PSO] or vertebral column resection [VCR]) can provide powerful alignment correction and disability improvement in adult cervical deformity (ACD), these procedures are complex and associated with high complication rates. Previous reports on complications associated with 3CO for ACD have been primarily based on retrospective complication collection, which may substantially underestimate the true rates. Our objective was to provide a prospective assessment of cervical alignment improvement and complications in ACD patients treated with 3CO. Materials and Methods: Although three-column osteotomy (3CO; pedicle subtraction osteotomy [PSO] or vertebral column resection [VCR]) can provide powerful alignment correction and disability improvement in adult cervical deformity (ACD), these procedures are complex and associated with high complication rates. Previous reports on complications associated with 3CO for ACD have been primarily based on retrospective complication collection, which may substantially underestimate the true rates. Our objective was to provide a prospective assessment of cervical alignment improvement and complications in ACD patients treated with 3CO. Results: All 24 ACD patients treated with 3CO (15 PSO/ 9 VCR) achieved minimum 90-day follow-up (71% women, mean age 62 years, previous surgery in 54%). Diagnoses included: cervical sagittal imbalance (92%), cervical kyphosis (38%), proximal junctional kyphosis (17%), coronal deformity (8%) and distal junctional kyphosis (4%). The mean number of posterior fusion levels was 13, and 4% also had an anterior fusion. The most common 3CO levels were T1 (38%), T2 (29%) and T3 (21%). A total of 25 (19 major/6 minor) complications were reported, with 14 (58%) and 6 (25%) patients affected, respectively. Overall, 17 (71%) patients had at least one complication. The most common complications were excessive blood loss (>1.7L, 25%), neurologic deficit (17%), distal junctional kyphosis (DJK, 8%), wound infection (13%), and cardiorespiratory failure (8%). Four (17%) patients required re-operation within 90-days (2 for nerve root motor deficit, 1 deep wound infection, 1 implant pain/prominence). Cervical sagittal alignment improved significantly following 3CO: cervical lordosis (CL, 3degree to 13degree, P = .031), C2-7 sagittal vertical axis (66mm to 44mm, P < .001), and T1 slope minus CL (46degree to 27degree, P < .001). Conclusions: Among 24 ACD patients treated with 3CO, cervical sagittal alignment improved significantly following surgery. Overall, 17 (71%) patients had at least one complication (19 major/6 minor). The most common complications were excessive blood loss (>1.7L), neurologic deficit, DJK, wound infection, and cardiorespiratory failure. Future research focused on reducing these complications may present the greatest opportunities for safety and cost improvements for these procedures

PURPOSE: To describe reciprocal changes in cervical alignment after adult spinal deformity (ASD) correction and subsequent development of proximal junctional kyphosis (PJK). This study also investigated these changes using two novel global sagittal angular parameters, cervical-thoracic pelvic angle (CTPA) and the T1 pelvic angle (TPA). METHODS: Multicenter, retrospective consecutive case series of ASD patients undergoing thoracolumbar three-column osteotomy (3CO) with fusion to the pelvis. Radiographs were analyzed at baseline and 1 year post-operatively. Patients were substratified into upper thoracic (UT; UIV T6 and above) and lower thoracic (LT; UIV below T6). PJK was defined by >10 degrees angle between UIV and UIV + 2 and >10 degrees change in the angle from baseline to post-op. RESULTS: PJK developed in 29 % (78 of 267) of patients. CTPA was linearly correlated with cervical plumbline (CPL) as a measure of cervical sagittal alignment (R = 0.826, p < 0.001). PJK patients had significantly greater post-operative CTPA and SVA than patients without PJK (NPJK) (p = 0.042; p = 0.021). For UT (n = 141) but not LT (n = 136), PJK patients at 1 year had larger CTPA (4.9 degrees vs. 3.7 degrees , p = 0.015) and CPL (5.1 vs. 3.8 cm, p = 0.022) than NPJK patients, despite similar corrections in PT and PI-LL. CONCLUSIONS: The prevalence of PJK was 29 % at 1 year follow-up. CTPA, which correlates with CPL as a global analog of cervical sagittal balance, and TPA describe relative proportions of cervical and thoracolumbar deformities. Patients who develop PJK in the upper thoracic spine after thoracolumbar 3CO also develop concomitant cervical sagittal deformity, with increases in CPL and CTPA.

STUDY DESIGN: Prognostic Study - Case Controlled. OBJECTIVE: Describe the rate of neurologic complications in adult spinal deformity surgery and describe the impact of these complications on clinical outcomes. SUMMARY OF BACKGROUND DATA: The incidence of neurologic complications and the risk factors for neurologic complications has not been reported in a large series of patients with Adult Spinal Deformity (ASD). Existing series include a mixed patient cohort undergoing different types of spine surgery. METHODS: Patients with ASD undergoing surgery between 2008-2014 were analyzed. Patients with neurologic complications were identified; demographics, operative details, radiographic, clinical outcomes were compared. A sub-analysis of those with surgical and non-surgical (e.g. stroke) neurologic complications was performed. Statistical analysis included t-tests or X tests as appropriate and a multivariate analysis. A p-value of less than 0.025 was considered significant. RESULTS: 564 patients met the inclusion criteria. The average age was 57. There were a total of 116 neurologic complications in 99 patients (17.6%). There were 88 surgical procedure related neurologic complications in 77 patients (13.7%) and 28 non-surgical neurologic complications in 28 patients (5.0%). The most common complications were: radiculopathy (30%), motor deficits (22%), mental status changes (12%) and sensory deficits (12%). Revisions (OR 1.7, 95% CI 1.2 - 2.4) and interbody fusions (OR 2.1, 95% CI 1.4-3.2) were associated with an increased risk of neurologic complications. Decompression and osteotomies (including three column osteotomies) did not increase the risk of neurologic complications. Patients with neurologic complications were not more likely to sustain other complications; however, they were more likely to undergo another operation during the follow-up period (OR 1.9, 95% CI 1.3-2.8). CONCLUSIONS: The overall incidence of neurologic complications in ASD surgery was 17.6%. The incidence of surgical neurologic complications was 13.7%. There was a higher risk of neurologic complications in revision cases and in cases where interbody fusion was required. LEVEL OF EVIDENCE: 3.

STUDY DESIGN: This is a review of a prospective multicenter database. OBJECTIVE: To investigate the relationship between preoperative disability and sagittal deformity in patients with high Oswestry Disability Index (ODI) and no sagittal malalignment, or low ODI and high sagittal malalignment. SUMMARY OF BACKGROUND DATA: The relationship between ODI and sagittal malalignment varies between each adult spinal deformity (ASD) patient. METHODS: A prospective multicenter database of 365 patients with ASD undergoing surgical reconstruction was analyzed. Inclusion criteria entailed: age 18 years or above and the presence of spinal deformity as defined by a coronal Cobb angle>/=20 degrees, sagittal vertical axis (SVA)>/=5 cm, pelvic tilt (PT) angle>/=25 degrees, or thoracic kyphosis>/=60 degrees. Radiographic and health-related quality of life (HRQOL) variables were examined and compared, preoperatively and at 2-year postoperative follow-up. Group 1 (low disability high sagittal-LDHS) consisted of ODI<40 and SVA>/=5 cm or PT>/=25 degrees or pelvic incidence-lumbar lordosis>/=11 degrees and group 2 (high disability low sagittal-HDLS) consisted of ODI>40 and SVA<5 cm and PT<25 degrees and pelvic incidence-lumbar lordosis<11 degrees. RESULTS: Of 264 patients with follow-up, 58 (22.0%) patients were included in LDHS and 30 (11.4%) were included in HDLS. Both groups had similar demographics and preoperative coronal angles. HDLS had worse baseline HRQOL for all measures (P<0.05) except leg and back pain. HDLS had a higher rate of self-reported leg weakness, arthritis, depression and neurological disorder. Both groups had similar 2-year improvements in HRQOL (P>0.05), except only HDLS had a significant Scoliosis Research Society Mental improvement and a significantly higher rate of reaching minimal clinically important differences in Scoliosis Research Society Mental scores (P<0.05). CONCLUSIONS: There is an association of worse baseline HRQOL measures, weakness, arthritis, and mental disease in HDLS. Furthermore, HDLS patients demonstrated similar improvements to LDHS. However, HDLS had greater improvements in the mental domains, perhaps indicating the responsiveness of the mental disability to surgical treatment. LEVEL OF EVIDENCE: Level III.

Adult spinal deformity is a complex pathologic process that has many etiologies and several mechanisms of compensation. A complete understanding of spinopelvic alignment is required to differentiate the origin of spinal deformity from its compensation and, ultimately, optimize surgical correction. Surgeons should understand the spinopelvic parameters involved in the evaluation of a patient who has an adult spinal deformity and their implications for treatment.