Faculty Bibliography

BACKGROUND CONTEXT: Accurate radiographic measurement of sagittal alignment is essential for evaluating adult spinal deformity (ASD) and preoperative planning. However, the limited capabilities of traditional picture archiving and communication systems (PACS) often necessitate rudimentary techniques and estimations of anatomic landmarks and angles. PURPOSE: To assess the reliability and variation between dedicated surgical measurement software (SMS) and PACS measurements. STUDY DESIGN/SETTING: Comparison of radiograph measurement reliability between PACS and SMS. PATIENT SAMPLE: Eleven observers completed measurements of 20 ASD patient radiographs. OUTCOME MEASURES: User-generated radiographic measurements for pelvic incidence (PI), pelvic tilt (PT), lumbar lordosis (LL), PI-LL, thoracic kyphosis (TK), and sagittal vertical axis (SVA); intra-class correlation coefficient (ICC); coefficient of variation (CV). METHODS: Eleven independent observers (7 surgeons, 4 researchers) with varying levels of experience digitally measured 20 primary and revision ASD patient radiographs for PI, PT, PI-LL, LL, TK, and SVA in 2 rounds. Round 1 used the basic line and angle tools in traditional PACS; Round 2 used the sagittal alignment tool in a previously validated software dedicated to spine measurement and operative planning. The SMS automatically calculates spino-pelvic parameters from 6 user-identified anatomic landmarks, including the outline of the femoral heads and vertebral endplates. Results were analyzed for means, CV and ICC. RESULTS: There were significant differences between SMS and PACS in mean values for PI, PT, PI-LL (all P<0.0001), and TK (P=0.019). For each parameter, the PACS measurement was larger than the SMS measurement. The standard deviations were also significantly larger for the PACS measurements in all parameters (P<0.012 for all) except TK. Excluding TK, the variation in measurement was significantly greater for PACS (CV=14-34%) versus SMS (CV=11-23%). The ICC values for all parameters were greater than 0.64, and when PI was excluded, all were greater than 0.92. Inter-rater reliability was greater in SMS compared to PACS for nearly all measurements: PI, PT, PI-LL, LL and SVA. For both SMS and PACS, the lowest ICC was observed in PI, and the highest ICC was seen in SVA. The parameters with the greatest differences in inter-rater reliability between PACS and SMS were PI (PACS ICC: 0.647 vs SMS ICC: 0.810) and PI-LL (PACS ICC: 0.921 vs SMS ICC: 0.970). TK had the most similar ICC values between PACS (0.955) and SMS (0.945), and was the only parameter for which the PACS ICC was greater than the SMS ICC. When only the surgeons' measurements were considered, the differences between PACS and SMS ICC were substantially greater. Among the surgeons, SMS had higher ICC than PACS for all parameters (ex PI-LL: 0.957 vs 0.896). PI still had the lowest inter-rater reliability (PACS ICC: 0.505 vs SMS ICC: 0.752) and SVA had the highest (PACS ICC: 0.985 vs SMS ICC: 0.994). CONCLUSIONS: SMS measurements provide significantly more accurate and reliable measurements with less variation than PACS. The greater reliability of SMS is amplified in surgeon-only analyses, demonstrating the clinical utility of SMS versus traditional PACS. Consistent use of SMS in the clinical evaluation and operative planning of ASD patients would be advantageous given the significant differences in values, standard deviations, variances and reliability between PACS and SMS

BACKGROUND CONTEXT: ASD surgery is associated with high complication rates. The reported effect, on individual complications on patients is variable, and the cumulative effect of increasing number of surgical complications on HRQOL metrics at 2 years for ASD patients has not been reported. PURPOSE: To report the cumulative effect of increasing number of surgical complications on HRQOL metrics at 2 years for ASD patients. STUDY DESIGN/SETTING: Retrospective review. PATIENT SAMPLE: 345 patients who underwent surgery for ASD from 2008-2012. OUTCOME MEASURES: HRQOLs (SRS-22r, ODI, SF-36), complications data and related patient descriptive demographics with 2 years minimum follow-up. METHODS: From 2008-2012, patients enrolled into a prospective, multicenter ASD database were evaluated. Inclusion criteria: ASD surgery, > 2- year follow-up. Demographic, radiographic, operative, HRQOL (SRS-22r, ODI, SF-36) and complications (infection, implant failure, operative, neurologic, gastrointestinal, cardiopulmonary, renal, radiographic and vascular events) data were evaluated. Patients were grouped according to number of complications incurred over 2-year time period: G0=no complication; G1=1 complication; G2=2 complications; G3= >3 complications. RESULTS: At 2 years, 265/345 (76.8%) patients had minimum follow-up. There were significant differences in BMI, estimated blood loss (EBL) and hospital length of stay (LOS; p<0.04), between Groups 0, 1, 2 and 3 with all variables increasing as complications increased. There were no significant differences in baseline HRQOL metrics between groups. Significant differences at 2 years were as follows: G0 v 1 (ODI, PCS, SRS-Total); G0 v 2 (ODI, PCS, MCS, SRS-Satisfaction and SRS-Total); G0 v 3 (ODI, SRS-Total). CONCLUSIONS: Compared to patients without complications following ASD surgery, increasing number of complications had cumulative adverse impact on 2-year HRQOL metrics. Patients with increasing number of complications had higher BMI, EBL and LOS

BACKGROUND CONTEXT: The classification and treatment strategy for atlantoaxial rotatory fixation (AARF) has been previously described yet remain controversial. Most cases of AARF can be treated conservatively. However, AARF concomitant with atlantoaxial dislocation (AARFD), has different clinical features and treatment strategies compared to common AARF. Due to deficiency of the transverse ligament or odontoid, the atlantoaxial remains instable even after the torticollis is relieved or cured. Because of the rarity of this condition, treatment strategies have not been specialized or fully explored. PURPOSE: This study aims to describe clinical features and the surgical treatment of AARFD. STUDY DESIGN/SETTING: Retrospective case report series of patients with AARFD from a single study center. PATIENT SAMPLE: 32 pediatric patients with AARFD. OUTCOME MEASURES: Radiographic findings and clinical treatment outcomes, including complications and recovery. METHODS: Over 11 years (2001 to 2012), 32 children with AARFD (sustained torticollis more than six weeks and atlantodens interval (ADI) more than 5mm) were treated in our center. The mean age at the initial visit was 11.3 years. Radiographic findings and clinical courses were retrospectively reviewed. Treatment methodology and benefits were discussed. RESULTS: 32 cases sustained torticollis for an average of 5.7 months. The mean age at initial visit was 11.3 years. ADI ranged from 8-22 mm (mean: 11.3 mm). Sixteen cases had valid predisposing factors, including mild cervical trauma (8 cases), cervical surgery (4), and cervical or nasopharyngeal infection (4). Eight cases presented with signs and symptoms of spinal cord dysfunction. All cases underwent unsuccessful preoperative conservative treatments, including collar (12), cervical belt traction (9), skeletal traction (8) and bracing (2). All 32 cases underwent surgery and had no spinal cord or vertebral artery injury. The surgeries comprised posterior reduction and fusion (reducible dislocation and torticollis, 16 cases) and transoral release followed by posterior reduction and fusion (irreducible dislocation and torticollis, 16 cases). The average follow-up time was 42 months (range: 25-120 months). Solid fusion and torticollis healing were achieved in 31 patients (96.9%), as detected radiologically. Two cases (6.3%) suffered complications: one had recurring torticollis 1 month postoperative and underwent successful revision; another had CSF leakage during transoral release and was treated successfully by lumbar CSF drainage. For the 8 cases with preoperative myelopathy, average JOA scores progressed from 11.9-16.0. CONCLUSIONS: In the current case series, pediatric patients presenting with AARFD had distinct clinical features relative to common presentations of AARF. Notably, a higher prevalence of cervical myelopathy was observed. Because of deficiency of the transverse ligament or odontoid and subsequent atlantoaxial dislocation, surgical treatments were recommended for these cases. Surgery involved intraoperative traction based assessment of the irreducibility, with subsequent transoral release (when indicated) and posterior C1-2 reduction and fusion. In this report, AARFD cases were successfully managed surgically without preoperative traction, with few complications seen

BACKGROUND CONTEXT: Although dysphagia after cervical spine surgery has been described, it has focused mostly on those with cervical degenerative conditions. We aimed to delineate dysphagia in patients undergoing surgery for cervical deformity. PURPOSE: To evaluate pre- and postoperative dysphagia in patients with cervical deformities. STUDY DESIGN/SETTING: Prospective cohort study. PATIENT SAMPLE: Prospective study of dysphagia in cervical deformity patients, a preliminary study of the first 57 patients enrolled. OUTCOME MEASURES: SWAL-QOL, mJOA, EQ5D, NDI, radiographs. METHODS: Prospective database of operative cervical deformity (CD) patients from 2013-2014 were followed with dysphagia as one study outcome. Inclusion criteria: cervical kyphosis (CK) >10degree, cervical scoliosis (CS) >10degree, C2-7 SVA >4cm and/or horizontal gaze impairment (chin-brow vertical angle (CBVA) >25degree). Neoplasm, infection, acute trauma, pregnancy and prisoners were excluded. Demographic, operative and radiographic variables were analyzed with the SWAL-QOL to measure dysphagia. A paired t-test or Kruskal-Wallis test and a bivariate Pearson correlation was performed with a p-value of <0.05 significant. RESULTS: A total of 57 patients met inclusion and 52 had complete data for analysis. The average age was 62 years. There were 41% primary and 59% revision cases; 27% had a prior anterior fusion (ACF) and 17% had prior posterior fusion (PCF). BMI correlated with increased baseline swallowing dysfunction (r=0.33, p=0.02). There was a negative correlation between Charlson Comorbidity Index (CCI) and baseline SWAL-QOL (r=0.35, p=0.01). Patients with previous ACF had significantly worse SWAL-QOL (68 vs 82, p=0.02), (r=0.30, p=0.04) while there were no differences in SWAL-QOL in patients who had undergone a previous PCF (74 vs 79, p = 0.42). Surgery did not result in a decline in SWAL-QOL at 3 months. Follow-up (p = 0.25) with 50% exhibiting improved scores. The < of levels for ACF averaged 3.8 (range 2-6) and did not correlate with 3- month SWAL-QOL score (r=0.03, p 0.07) or change in score with surgery (r=0.22, p 0.29). There was no correlation between the < of levels with PCF (r=0.01, p 0.93) and no difference in postop SWAL-QOL scores based on UIV, surgical approach or osteotomy. Steroids were used in 30 patients (58%) but there was no difference in SWAL-QOL scores (74 vs 80, p=0.78). Similarly, posterior BMP use (n=24, 46%) did not affect total SWAL-QOL scores (73 vs 77, p= 0.11); Swallowing dysfunction correlated with global measures of disability such as NDI (r 50.51, p<0.01) and EQ5D (r=0.51, p<0.01). CONCLUSIONS: In this preliminary report, patients with previous anterior cervical fusion (ACF) had worse baseline SWAL-QOL scores compared to those who had prior posterior cervical fusion (PCF). Surgery did not result in a decline in SWAL-QOL scores in the 3-month postop period. There was no correlation between the < of levels fused with dysphagia and no difference in postop SWAL-QOL scores based on UIV, surgical approach or osteotomy. Swallowing dysfunction correlated with the NDI, EQ5D and mJOA

BACKGROUND CONTEXT: Complications in ASD are frequent and surgeons are constantly attempting to decrease these and improve their outcomes. Centers have developed systems using 2 attending surgeons in attempts to improve efficiency in the operating room (OR). PURPOSE: The purpose of our study is to assess operative, clinical and radiographic outcomes of ASD surgery based on performance by 1 vs 2 attending surgeons from a multicenter (ISSG) database. STUDY DESIGN/SETTING: Retrospective review of prospectively collected multicenter data. PATIENT SAMPLE: 188 patients had ASD surgery performed by 1 surgeon (1S) and 77 were performed by 2 attendings (2S). OUTCOME MEASURES: Perioperative variables included EBL, length of stay (LOS) and operative time. Complications were recorded and X-ray parameters include: sagittal vertical axis (SVA), pelvic tilt and pelvic incidence - lumbar lordosis (PI-LL). Patients were classified by SRS-Schwab modifier grades. HRQOL questionnaires (Oswestry Disability Index [ODI], SRS-22r and Short Form SF-12) were analyzed. METHODS: Patients with surgical ASD with >5 levels posterior fusion with >2-year follow up were included. Number of attending surgeons performing each procedure was obtained from each individual institution. Outcomes were compared between 1-surgeon and 2-surgeon centers. After initial analysis, a separate cohort matched for demographic and severity of deformity was also analyzed. RESULTS: Patients in the 2S group were older (61.5 vs 54.2; p<0.01). Preoperative radiographs demonstrated that the 2S group had worsened deformity. X-ray parameters PI-LL (12.1 vs 21.7), SVA C7-S1 (54.2 vs 61.5), T1-PA (20.2 vs 25.1) and SRS-Schwab classification system were significantly different (p<0.05). There was no difference in the number of levels fused (11.2 vs 11.5 p=0.57). There was no significant difference in LOS (8.7 vs 8.9 days), OR time (445.9 vs 453.2 min) or EBL (2008 vs 1898 cc); (p>0.05). Patients in 2S group were more likely to obtain a 3 column osteotomy (3CO) 21.7% vs 59.6% (p=<0.001) and used less BMP 79.9% vs 15.6% (p<0.001). The 2S group had fewer intraoperative complications (1.3% vs 11.1%; p=0.006). But postoperative (6 weeks - 2 year) complications (4.8 vs 15.6%), implant related (4.2 vs 15.6%) and those requiring reoperation (5.3 vs 18.2%) were more frequent (p<0.002).After matching for PI-LL, SVA and 3CO, there was no difference in preoperative demographics. There was no difference in LOS (9.1 vs 10.1 days), OR time (467.8 vs 508.4 min) or EBL (3,045 vs 2,247 cc) p>0.05. 2SM group used less BMP (20.6% vs 84.8%; p=<0.001) and less intra operative complications (p=0.015). Postoperative (>6wks to 2 year) complications due to instrumentation failures/pseudoarthrosis were more frequent in 2SM group (p <0.01). CONCLUSIONS: Patients with ASD surgery performed by 2 surgeons were older with worse deformity. Both groups improved X-ray parameters and HRQOL but no difference was found in LOS, OR time or EBL even when matching cohorts for amount of deformity. 2S group had more 3COs, less BMP and had fewer intraoperative complications but more postoperative (>6 weeks to 2 years) complications that could be tied to low BMP use and/or fusion techniques. Overall it appears that for high complexity surgery, teams of multiple surgeons can reduce operative risk significantly

BACKGROUND CONTEXT: Radiographic parameters correlate between adjacent spinal regions. Obtaining limited cervical (C) radiographs may miss significant thoracolumbar (TL) deformity adversely impacting clinical decisions. Currently, no thresholds exist for obtaining full-length radiographs in patients with primary C pathology. It is unknown whether measurements from C radiographs can predict TL deformity. PURPOSE: Radiographic deformity measures correlate between the cervical and thoracolumbar spine, and may provide a threshold for obtaining full-length radiographs. STUDY DESIGN/SETTING: Retrospective, multicenter. PATIENT SAMPLE: Consecutively enrolled cervical deformity surgical patients. OUTCOME MEASURES: Radiographic parameters, cervical: C2 Slope, T1 Slope (T1S), cervical lordosis (CL), T1S- CL, SVA C2-C7, C0-C2 angle, thoracolumbar: SVA C7-S1 thoracic kyphosis (TK), pelvic mismatch (PI-LL), pelvic tilt, T1 pelvic angle (TPA). METHODS: Standardized radiographic data from a prospective, multicenter cervical deformity (PCD) database was retrospectively studied. C and TL measures were correlated with Pearson's r coefficient. Linear regression analysis tested which C parameters predict TL parameters. The model was then validated using data from a separate prospective, multicenter, adult deformity database: Prospective Operative vs Nonoperative (PON). Significance was set at alpha=0.05. RESULTS: Fifty-seven subjects (23M, 34F) were included from PCD. T1S correlated with TK (r=0.749, p<0.001) and TPA (r=0.501, p<0.001). Only T1S significantly predicted TK and TPA in regression analysis. Using regression calculations, the threshold for detecting TL deformity was T1S=32degree. Using the PON dataset (N=1,053) for validation, T1S<32degreepredicts TK<50degree (92% sensitivity, 50% specificity) and TPA<20degree (69% sensitivity, 63% specificity). CONCLUSIONS: T1S correlates with TK and TPA. T1S>32degreeon cervical radiographs and provides surgeons with a threshold to perform full-length spine radiographs to identify potential concurrent TL deformity. Identifying underlying thoracolumbar deformity may have implications for surgical planning of cervical fusion procedures

BACKGROUND CONTEXT: Adult thoracolumbar deformity (TLD) requires patients to recruit various compensatory mechanisms like pelvic retroversion and knee flexion. However, thoracic hypokyphosis is a less recognized and poorly defined compensation. Following ASD correction, many patients undergo reciprocal thoracic kyphosis or proximal junctional kyphosis (PJK). PURPOSE: To compare patients with postoperative reciprocal thoracic kyphosis (RK) and those who maintain thoracic alignment (MT) and to identify thoracic compensation to determine if it predicts the reciprocal change and PJK. STUDY DESIGN/SETTING: Retrospective cohort analysis. PATIENT SAMPLE: 219 patients with ASD. OUTCOME MEASURES: ODI, SRS, SF36. METHODS: Patients undergoing TLD correction were included with fusions to the pelvis and UIVof T9-L1. Patients were divided into those with postop reciprocal thoracic kyphosis (RK: D unfused TK >15degree) and those who maintained thoracic alignment (MT). Thoracic compensation was defined as theoretical thoracic kyphosis (tTK) minus preop TK. The tTK was calculated from LL52(PI+TK) + 10 where LL was PI+10 for PI<40degree, PI5PI for PI 40degree-70degree and PI-10 for PI>70degree. RESULTS: 219 patients were included. For RK (n=117), the mean change in unfused TK was 21.7degree and the mean PJK was 17.6degree vs 6.1degree and 5.7degree (p<0.001) for MT (n=102). RK and MT were similar in age, BMI, gender and comorbidities. RK had larger preop PI-LL mismatch (30.7 vs 23.6 p=0.008) and less preop TK (22.3 vs 30.6 p<0.001), otherwise SVA, PT and TPA were similar. RK patients had more PI-LL correction (29.8 vs 17.3,p<0.001) and more preop thoracic compensation (29.9 vs 20.0, p<0.001). There were no differences in preop HRQOL except RK had worse SRS appearance (2.2 vs 2.5, p=0.005). Using a logistic regression model, the only predictor for RK was more thoracic compensation. More preoperative thoracic kyphosis was a predictor for the MT group. Postoperatively both the RK and MT groups were well aligned by all SRS Schwab modifiers, but there was more postoperative PI-LL (6.5 vs -1.0 p<0.05). The RK group had 76 patients with PJK and 39 without. There were no differences between these patients in thoracic compensation, PI-LL correction, or preop/postop alignment with the exception of PT which was larger in the PJK group (22.1 vs 17.1, p = 0.012). ANOVA showed that T1-pelvic-angle was greater for MT than the RK/no PJK group (19.7 vs 14.2, p<0.05). HRQOL were not different for any group at 6 weeks and 1 year. Both younger RK and older (>65y) had larger thoracic compensation and more correction than MT young and old. Younger MT patients had more thoracic compensation than older MT (19.3 vs 8.96, p<0.05), but there was no difference in thoracic compensation between RK young and old. The tTK was similar to the postop TK for all groups. CONCLUSIONS: Postoperative reciprocal thoracic kyphosis can be anticipated and incorporated into preop planning of thoracolumbar deformity correction by calculating tTK (TK=PI-40 for PI>70, TK=PI-20 for 40

EMBASE:72100302

ISSN: 1529-9430

CID: 1905492