Faculty Bibliography

STUDY DESIGN/METHODS:Retrospective review of a prospectively collected multicenter database. OBJECTIVE:To compare outcomes of patients with cerebral palsy (CP) who undergo surgery for scoliosis with normal lordosis (NL) versus hyperlordosis. SUMMARY OF BACKGROUND DATA/BACKGROUND:Surgical correction of scoliosis with lumbar hyperlordosis is challenging. Hyperlordosis may confer higher perioperative morbidity, but this is not well understood. MATERIALS AND METHODS/METHODS:A multicenter database was queried for CP patients who underwent surgery from 2008 to 2017. The minimum follow-up was 2 years. Two groups were identified: lumbar lordosis <75° (NL) versus ≥ 75° hyperlordosis (HL). Perioperative, radiographic, and clinical outcomes were compared. RESULTS:Two hundred seventy-five patients were studied: 236 NL and 39 HL (-75 to -125°). The mean age was 14.1 years, and 52.4% were male. Patients with hyperlordosis had less cognitive impairment (76.9% vs. 94.0%, P =0.008) and higher CPCHILD scores (59.4 vs. 51.0, P =0.003). Other demographics were similar between the groups. Patients with hyperlordosis had greater lumbar lordosis (-90.5 vs. -31.5°, P <0.001) and smaller sagittal vertical axis (-4.0 vs. 2.6 cm, P <0.001). Patients with hyperlordosis had greater estimated blood loss (2222.0 vs. 1460.7 mL, P <0.001) but a similar perioperative complication rate (20.5% vs. 22.5%, P =0.787). Significant correction of all radiographic parameters was achieved in both groups. The HL group had postoperative lumbar lordosis of -68.2° and sagittal vertical axis of -1.0 cm. At a 2-year follow-up, patients with hyperlordosis continued to have higher CPCHILD scores and gained the greatest benefit in overall quality of life measures (20.0 vs. 6.1, P =0.008). The reoperation rate was 10.2%: implant failure (3.6%), pseudarthrosis (0.7%), and wound complications (7.3%). There were no differences in the reoperation rate between the groups. CONCLUSION/CONCLUSIONS:Surgical correction of scoliosis with hyperlordosis is associated with greater estimated blood loss but similar radiographic results, perioperative morbidity, and reoperation rate as normal lordosis. Patients with hyperlordosis gained greater overall health benefits. Correction of ≥25% of hyperlordosis seems satisfactory. LEVEL OF EVIDENCE/METHODS:3.

PURPOSE/OBJECTIVE:Durability of outcomes following vertebral body tethering (VBT) is a concern and may be impacted by tether breakage (TB), which has been unstudied in a large cohort. We characterized TB rates and their impact on clinical outcomes in the largest single-surgeon series to date. METHODS:Inclusion criteria were VBT patients with AIS, major Cobb angle ≤ 75°, and minimum 2-year follow-up (FU). TBs were identified on 1- and 2-year FU X-rays. TB rates between single-cord and double-cord tethers were evaluated using two-proportion z test. Curve correction rates and SRS-22 scores between patients with and without TB at 2 years were evaluated using Mann-Whitney U test. RESULTS:69 patients were included. By 2-year FU, 18 (27%) had experienced TB. TB primarily occurred in major (70%) versus minor curves and thoracolumbar tethers (75%) versus thoracic. TB rates between thoracolumbar single (32%) and double-cord tethers (30%) were not significantly different (p = 0.88). Mean major curve correction at 2-year FU was lower (p = 0.02) in patients with major curve TB (48° to 24°, 50%) versus those without (53°-21°, 60%). 2 patients (3%) required reoperation, 1 due to foraminal encroachment from a screw tip and 1 for curve progression with TB. CONCLUSION/CONCLUSIONS:TB rate was 27% at 2 years following VBT. Broken major curve tethers are associated with minor loss of correction that may not be clinically significant. TB rates are higher for thoracolumbar curvatures and double cords may not be protective against TB. Further study of long-term TB rates is imperative. LEVEL OF EVIDENCE/METHODS:IV.

PURPOSE:Anterior vertebral body tethering (VBT) is a non-fusion surgical treatment for Adolescent Idiopathic Scoliosis requiring chest tube(s) (CT). We sought to assess the efficacy of post-op intravenous tranexamic acid (IV TXA) in reducing CT drainage and retention. METHODS:35 VBT patients received 24 h of post-op IV TXA (2 mg/kg/h) were compared to 49 who did not. Group comparisons were performed using Wilcoxon rank-sum and chi-squared tests. Multivariate linear regression analysis was used to assess the relationships between TXA and both CT drainage and retention time. RESULTS:There were no group differences at baseline (Table). CTs placed for thoracic (T) and thoracolumbar (TL) curves were assessed separately. For TH CT, there was less total CT drainage in the TXA group (TXA 569.4 ± 337.4 mL vs. Non-TXA 782.5 ± 338.9 mL; p = 0.003) and shorter CT retention time (TXA 3.0 ± 1.3 vs. Non-TXA 3.9 ± 1.4 days; p = 0.003). For TL CT, there was less total CT drainage in the TXA group (TXA 206.8 ± 152.2 mL vs. Non-TXA 395.7 ± 196.1 mL; p = 0.003) and shorter CT retention time (TXA 1.7 ± 1.3 vs. Non-TXA 2.7 ± 1.0 days; p = 0.001). Following multivariate analysis, use of TXA was the only significant predictor of both drainage in T and TL CTs (p = 0.012 and p = 0.002, respectively) as well as T and TL CT retention time (p = 0.008 and p = 0.009, respectively). There were no differences in LOS (p = 0.863) or ICU stay (p = 0.290). CONCLUSION:IV TXA results in a significant decrease in CT drainage and retention time. CT retention is decreased by 1 day for those that receive TXA. LEVEL OF EVIDENCE:III.

INTRODUCTION/BACKGROUND:Surgical treatment of Adolescent Idiopathic Scoliosis (AIS) involves healthy individuals with spinal deformity. Parents are responsible for surgical consent on behalf of their children, a burden which causes trepidation and concern. Therefore, explanation of operative risk is a critical component of informed consent and parent decision-making. We set out to quantify parental risk aversion (RA). METHODS:RA questionnaires were administered preoperatively to parents of 58 AIS patients undergoing spinal fusion (SF). RA is the likelihood of a parent to consent to their child's SF (1- least likely, 10- most) with increasing allotments of data about potential complications at each stage (S1-complication named, S2-explained, S3-incidence given, S4-all information). A statistically significant mean difference in answers for each stage was assessed using paired sample t test or Wilcoxon rank t test. Normality was assessed by performing Shapiro-Wilk test. RESULTS:AIS patients (age 14.2 years, 85% female, major curve 61°) were included. Mean scores for each of the stages were 4.4 ± 3.1, 4.9 ± 3.1, 6.5 ± 3.0, 6.6 ± 3.0, respectively. Highest and lowest RA were reported for death and infection, respectively. The greatest increase in likelihood to proceed with surgery was seen after education on malposition of implants and on death, 2.6 and 2.5, respectively (p < 0.001). The lowest increase in likelihood to proceed with surgery was seen after education on infection, 1.5 (p < 0.001). For all complications, there was an increase in parent willingness to proceed after providing descriptions and occurrence rate with a mean increase from S1 to S4 of 2.1 (95% CI 1.4-2.4), p < 0.001. CONCLUSION/CONCLUSIONS:As more detailed information was made available regarding potential complications with SF for AIS, parental RA toward surgery decreased and their willingness to proceed with surgery for their child improved.

HYPOTHESIS/OBJECTIVE:AIS patients and their parents will have distinct perspectives regarding the impact of AIS on patients' lives. INTRODUCTION/BACKGROUND:Current outcome assessment tools for AIS do not fully assess patient-specific disease impact and fail to distinguish between patient and parent perspectives. Patient Generated Index (PGI) has been used in other disease states to assess individual experiences. This study assesses PGI in operative AIS patients and their parents. DESIGN/METHODS:Level 1, prospective multi-center study. METHODS:44 AIS patient and parent pairs completed the PGI questionnaire comprised of three stages (S1, S2, S3) and decision regret (DR). S1 asks for five areas of the patient's life most affected by AIS and a 6th encompassing all other areas of their lives affected, S2 focuses on the magnitude of effect, S3 identifies desire to improve affected areas and DR if the surgery did not improve the specific area. S1 free responses were organized into 14 domains. Descriptive statistics were reported for stage scores; free-response format of PGI and DR limited ability for paired sample t test analysis. RESULTS:Mean age at surgery was 14.3 years, 84% female, and mean major curve magnitude was 61°. The three most common patient-reported concerns prior to surgery were (in descending order): sports, general function, and general fitness. However, the three most common parent-reported concerns were (in descending order): general function, sports, and appearance. Patients reported self-esteem and parents reported physical appearance as the most affected domain (S2). Patients reported pain and self-esteem and parents reported sleep and self-esteem as main operative aspirations (S3). Decision regret was the highest for uncertainty of future health in patients and sleep in parents. CONCLUSION/CONCLUSIONS:AIS patients and their parents reported different concerns and DR regarding surgical treatment. PGI provides insight into patient and parent views toward the disease as well as treatment aspirations.

STUDY DESIGN/METHODS:This study is a single-center retrospective radiographic review. OBJECTIVES/OBJECTIVE:The objective of this study is to evaluate a novel measurement parameter, mandibular slope (MS), as a measure of horizontal gaze. INTRODUCTION/BACKGROUND:Assessment of sagittal spinal alignment is essential in the evaluation of spinal deformity patients. Ability to achieve a horizontal gaze, a parameter of sagittal alignment, is needed for the performance of daily activities. Standard measures of horizontal gaze, including the gold-standard chin-brow to vertical angle (CBVA) and the surrogate measures McGregor's line (McGS) and Chamberlain's line (CS), require high-quality imaging, precise head positioning, and reliance on difficult to view visual landmarks. A novel measurement parameter, MS, utilizing the caudal margin of the mandible on standard lateral spine radiographs is proposed. METHODS:90 radiographs from spine deformity patients with or without spinal implants from a single center were evaluated. Three spine surgery fellows independently measured CBVA, McGS, CS, and MS at two timepoints at least one week apart to assess accuracy and reliability. MS was measured as the angle created by the inferior edge of the mandibular body and the horizontal. Formulas for calculating CBVA based on the above parameters were derived and compared to the actual CBVA. RESULTS:Mean age was 49.7 years, 76 females and 14 males. CBVA correlated with CS, McGS, and MS, r = 0.85, 0.81, and 0.80, respectively (p < 0.001). Standard error between real CBVA and calculated CBVA using CS (0.4 ± 4.79) and McGS (0.4 ± 3.9) was higher than that calculated using MS (- 0.2 ± 4.3). ICC demonstrated the highest inter-observer reliability with MS (0.999). MS had the highest intra-observer reliabilities 0.975, 0.981, and 0.988 (p < 0.001); CS and McGS also demonstrated high intra-observer reliability. CONCLUSIONS:MS is a promising measure of horizontal gaze that correlates highly with CBVA, has excellent intra- and inter-observer reliability with CBVA, and is easily measured using standard lateral spine radiographs.

STUDY DESIGN/METHODS:Survey. OBJECTIVES/OBJECTIVE:Bracing is the mainstay of conservative treatment in Adolescent Idiopathic Scoliosis (AIS). The purpose of this study was to establish best practice guidelines (BPG) among a multidisciplinary group of international bracing experts including surgeons, physiatrists, physical therapists, and orthotists utilizing formal consensus building techniques. Currently, there is significant variability in the practice of brace treatment for AIS and, therefore, there is a strong need to develop BPG for bracing in AIS. METHODS:We utilized the Delphi process and the nominal group technique to establish consensus among a multidisciplinary group of bracing experts. Our previous work identified areas of variability in brace treatment that we targeted for consensus. Following a review of the literature, three iterative surveys were administered. Topics included bracing goals, indications for starting and discontinuing bracing, brace types, brace prescription, radiographs, physical activities, and physiotherapeutic scoliosis-specific exercises. A face-to-face meeting was then conducted that allowed participants to vote for or against inclusion of each item. Agreement of 80% throughout the surveys and face-to-face meeting was considered consensus. Items that did not reach consensus were discussed and revised and repeat voting for consensus was performed. RESULTS:Of the 38 experts invited to participate, we received responses from 32, 35, and 34 for each survey, respectively. 11 surgeons, 4 physiatrists, 8 physical therapists, 3 orthotists, and 1 research scientist participated in the final face-to-face meeting. Experts reached consensus on 67 items across 10 domains of bracing which were consolidated into the final best practice recommendations. CONCLUSIONS:We believe that adherence to these BPG will lead to fewer sub-optimal outcomes in patients with AIS by reducing the variability in AIS bracing practices, and provide a framework future research. LEVEL OF EVIDENCE/METHODS:Level IV.

STUDY DESIGN/METHODS:Retrospective review of a prospective multicenter database. OBJECTIVE:The aim of this study was to study the effects of thoracic kyphosis (TK) restoration in adolescent idiopathic scoliosis (AIS) Type 1 and 2 curves on postoperative thoracic volume (TV) and pulmonary function. SUMMARY OF BACKGROUND DATA/BACKGROUND:Surgical correction of AIS is advocated to preserve or improve pulmonary function, prevent progressive deformity and pain, and improve self-appearance. Restoration of sagittal and 3D alignment, particularly TK, has become increasingly emphasized in efforts to improve pulmonary function, TVs, sagittal balance, and prevent adjacent-segment degeneration and deformity. METHODS:AIS patients 10 to 21years undergoing surgical correction of Lenke Type 1 and 2 curves with baseline, 1-erect-postoperative, and 5-year (5Y) postoperative visits including stereoradiographic assessment and pulmonary function tests (PFTs) were included. 3D-radiographic analysis was performed to assess spinal-alignment, chest-wall, and rib-cage dimensions at each time point. Outcome variables were analyzed between time points with one-way analysis of variance and between variables with linear regression analysis. RESULTS:Thirty-nine patients (37 females, 14.4 ± 2.2 years) were included. 3D-spinal-alignment analyses demonstrated significant reduction in preoperative to first-erect thoracic and lumbar Cobb-angles, an increase in TK:T2-12 (19.67°-39.69°) and TK:T5-12 (9.47°-28.05°), and reduction in apical vertebral rotation (AVR) (P < 0.001 for all). Spinal-alignment remained stable from 1-erect to 5Y. 3D rib-cage analysis demonstrated small reductions in baseline to first-erect depth (145-139 mm), width (235-232 mm), and increase in height (219-230 mm, P < 0.01), but no significant change in volume (5161-5222 cm,P = 0.184). From 1-erect to 5Y, significant increases in depth, width, height, and volume (all P < 0.001) occurred. PFTs showed preoperative to 5Y improvement in first second of Forced Expiratory Volume (FEV1) (2.74-2.98 L, P = 0.005) and forced vital capacity (FVC) (3.23-3.47 L, P = 0.008); however, total lung capacity (TLC) did not change (P = 0.517). Percent-predicted TLC decreased (Pre: 101.3% to 5Y: 89.3%, P < 0.001); however, percent-predicted forced expiratory volume and FVC did not (P = 0.112 and P = 0.068). CONCLUSION/CONCLUSIONS:Although TK increases, coronal-Cobb and AVR decrease postoperatively; these do not directly influence TV, which increases from 1-erect to 5Y due to growth, corresponding with increases in FEV1 and FVC at 5Y; however, surgical restoration of kyphosis does not directly improve pulmonary function. LEVEL OF EVIDENCE/METHODS:3.

BACKGROUND:Selective fusion of double curves in patients with scoliosis is considered to spare fusion levels. In 2011, we studied the lumbosacral takeoff angle, defined as the angle between the center-sacral vertical line and a line through the centra of S1, L5, and L4. The lumbosacral takeoff angle was shown to moderately correlate with the lumbar Cobb angle, and a predictive equation was developed to predict the lumbar Cobb angle after selective fusions. The purposes of the present study were to validate that equation in a separate cohort and to assess differences in outcomes following selective and nonselective fusion. METHODS:Patients with Lenke 1B, 1C, 3B, or 3C curve patterns undergoing fusion (both selective and nonselective) with pedicle screw constructs and a minimum of 2 years of follow-up were included. Selective fusion was defined as a lowest level of fixation cephalad to or at the apex of the lumbar curve. To validate the previously derived equation, we used this data set and analysis of variance to check for differences between the actual and calculated postoperative lumbar Cobb angles. Pearson correlation, multiple linear regression, and t tests were used to explore relationships and differences between the selective and nonselective fusion groups. RESULTS:The mean calculated postoperative lumbar Cobb angle (and standard deviation) (22.35° ± 3.82°) was not significantly different from the actual postoperative lumbar Cobb angle (21.08° ± 7.75°), with an average model error of -1.268° (95% confidence interval, -2.649° to 0.112°). The preoperative lumbar Cobb angle was larger in patients with deformities that were chosen for nonselective fusion (50.2° versus 38.9°; p < 0.001). Performing selective fusion resulted in a 3.5° correction of the lumbosacral takeoff angle (p < 0.001), whereas nonselective fusion resulted in a 9.3° correction (p < 0.001). CONCLUSIONS:The lumbosacral takeoff angle can be used to predict the residual lumbar Cobb angle and may be used by surgeons to aid in the decision between selective and nonselective fusion. The change in the lumbosacral takeoff angle following selective fusion is small. Improvement in the lumbosacral takeoff angle and coronal balance is greater in association with nonselective fusion. LEVEL OF EVIDENCE/METHODS:Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

STUDY DESIGN/METHODS:Retrospective review of a prospectively collected multicenter database. OBJECTIVE:The aim of this study was to investigate factors associated with low preoperative SRS pain scores. SUMMARY OF BACKGROUND DATA/BACKGROUND:The prevalence of preoperative pain in patients with adolescent idiopathic scoliosis (AIS) has become increasingly evident and is a primary concern for patients and families. Greater preoperative pain is associated with more postoperative pain; however, less is understood about what contributes to preoperative pain. METHODS:A prospectively collected, multicenter database was queried for patients with AIS. Patients were divided into 2 cohorts based on preoperative SRS pain scores: ≤ 3 (Pain cohort), 4 to 5 (No Pain cohort). Univariate analysis was performed identifying which factors were associated with a low preoperative SRS score and used for a CART analysis. RESULTS:Of 2585 patients total, 2141 (83%) patients had SRS pain scores of 4 to 5 (No Pain) and 444 (17%) had SRS pain scores ≤3 (Pain). Female sex, older age, greater % body mass index, larger lumbar curves, greater T5-12 kyphosis, and lower mental health scores were associated with greater preoperative pain. In multivariate CART analysis, lower mental health SRS scores (P = 0.04) and older age (P = 0.003) remained significant, with mental health scores having the greatest contribution. In subdividing the mental health component questions, anxiety-related questions appeared to have the greatest effect followed by mood/depression (SRS Question 13: OR 2.04; Q16: OR 1.35; Q7: OR 1.31; Q3: OR 1.20). CONCLUSION/CONCLUSIONS:Anxiety and mood are potentially modifiable risk factors that have the greatest impact on pre- and postoperative pain. These results can be used to identify higher-risk patients and develop preoperative therapeutic protocols to improve postoperative outcomes. LEVEL OF EVIDENCE/METHODS:3.