Faculty Bibliography

PURPOSE/OBJECTIVE:To evaluate the effectiveness of the use of topical tranexamic acid (tTXA) in spinal deformity correction in AIS patients METHODS: Sixty consecutive operative AIS patients were reviewed from a single institution and divided into two groups with similar demographics. Standardized peri-operative blood salvage techniques were utilized in all 60 patients. In the latter 30 patients, tTXA soaked sponges (1 g mixed in 500 ml Normal Saline) was utilised for wound packing during the entire surgical procedure compared to dry sponges as used in the former 30 patients. Both the groups were compared for the magnitude of deformity corrected, EBL per level fused, total EBL, blood transfused, drain output and peri-operative events. RESULTS:Sixty AIS patients (mean age 14.4 yrs, 43 females, mean BMI 21.5, mean levels 10.7) were included. Both groups achieved similar change in Coronal Cobb correction. The EBVL (Estimated blood volume loss) % lost in the topical TXA group was 38% less than the control group (11.2 vs. 18.3%, p = 0.006). Similarly, the EBL/level was significantly lower in the topical TXA group (41 ± 30 ml vs. 57 ± 26 ml, p = 0.03). Three of 30 patients in the control group required at least 1 unit of blood transfusion, whereas only 1 patient in the topical TXA group required transfusion (10 vs. 3.3%, p = 0.001). No differences were noted in post-operative drain output, change in hemoglobin levels, and peri-operative complication rates. CONCLUSION/CONCLUSIONS:When used as an adjunct to the conventional blood salvage techniques in spinal deformity correction procedures, the use of tTXA resulted in reduced operative blood loss, and blood transfusion requirements.

STUDY DESIGN/UNASSIGNED:Retrospective study. OBJECTIVES/UNASSIGNED:Our goal was to evaluate the rate of rod fracture and persistent pseudarthrosis in cohorts of patients treated with a dual rod or multiple-rod construct in revision surgery for pseudarthrosis. METHODS/UNASSIGNED:A dual rod construct was used in 23 patients, and a multiple rod construct in 24 patients, spanning the pseudarthrosis level. Two-year fusion grading, and rates of pseudarthrosis and implant failure, were assessed. RESULTS/UNASSIGNED:There were no differences in patient or surgical characteristics between the groups: (2- rod construct: Age 60 ± 14, Levels 10 ± 5, 3-column osteotomy:17%; multiple-rod construct: Age: 62 ± 11, Levels 9 ± 4, 3-column osteotomy:30%). Patients in the multiple rod construct were transfused a greater volume of packed red blood cells (pRBCs) intraoperatively (2.6 ± 2.9 vs. 1.1 ± 1.5 U, p < 0.0001). At 2 year follow up there was no difference in fusion grades at the previous level of pseudarthrosis, the rate of rod fracture or pseudarthrosis between the 2 groups, or rate of reoperation for pseudarthrosis, rod fracture, wound infection, hardware prominence, or PJK/PJF. CONCLUSIONS/UNASSIGNED:Our data demonstrate no difference in fusion grade, or rates of rod fracture and revision at 2 years, after utilizing a dual rod versus multiple rod construct in revision surgery for pseudarthrosis. The low complication rates seen with either configuration warrant further investigation of the optimal instrumentation configuration.

BACKGROUND:Cerebral palsy (CP) is a static encephalopathy with progressive musculoskeletal pathology. Non-ambulant children (GMFCS IV and V) with CP have high rates of spastic hip disease and neuromuscular scoliosis. The effect of spinal fusion and spinal deformity on hip dislocation following total hip arthroplasty has been well studied, however in CP this remains largely unknown. This study aimed to identify factors associated with worsening postoperative hip status (WHS) following corrective spinal fusion in children with GMFCS IV and V CP. METHODS:Retrospective review of GMFSC IV and V CP patients in a prospective multicenter database undergoing spinal fusion, with 5 years follow-up. WHS was determined by permutations of baseline (BL), 1 year, 2 years, and 5 years hip status and defined by a change from an enlocated hip at BL that became subluxated, dislocated or resected post-op, or a subluxated hip that became dislocated or resected. Hip status was analyzed against patient demographics, hip position, surgical variables, and coronal and sagittal spinal alignment parameters. Cutoff values for parameters at which the relationship with hip status was significant was determined using receiver operating characteristic curves. Logistic regression determined odds ratios for predictors of WHS. RESULTS:Eighty four patients were included. 37 (44%) had WHS postoperatively. ROC analysis and logistic regression demonstrated that the only spinopelvic alignment parameter that significantly correlated with WHS was lumbar hyperlordosis (T12-L5) > 60° (p = 0.028), OR = 2.77 (CI 1.10-6.94). All patients showed an increase in pre-to-postop LL. Change in LL pre-to-postop was no different between groups (p = 0.318), however the WHS group was more lordotic at BL and postop (pre44°/post58° vs pre32°/post51° in the no change group). Age, sex, Risser, hip position, levels fused, coronal parameters, global sagittal alignment (SVA), thoracic kyphosis, and reoperation were not associated with WHS. CONCLUSION/CONCLUSIONS:Postoperative hyperlordosis(> 60°) is a risk factor for WHS at 5 years after spinal fusion in non-ambulant CP patients. WHS likely relates to anterior pelvic tilt and functional acetabular retroversion due to hyperlordosis, as well as loss of protective lumbopelvic motion causing anterior femoracetabular impingement. LEVEL OF EVIDENCE/METHODS:III.

STUDY DESIGN/UNASSIGNED:Retrospective cohort study. OBJECTIVES/UNASSIGNED:The purpose of the study is to evaluate the role of supine radiographs in determining flexibility of thoracic and thoracolumbar curves. METHODS/UNASSIGNED:Ninety operative AIS patients with 2-year follow-up from a single institution were queried and classified into MT structural and TL structural groups. Equations were derived using linear regression to compute cut-off values for MT and TL curves. Thresholds were externally validated in a separate database of 60 AIS patients, and positive and negative predictive values were determined for each curve. RESULTS/UNASSIGNED:< 0.001). CONCLUSIONS/UNASSIGNED:A single preoperative supine radiograph is highly predictive of side-bending radiographs to assess curve flexibility in AIS. A cut-off of ≥ 30° for MT and ≥ 35° for TL curves in supine radiographs can determine curve structurality.

STUDY DESIGN/METHODS:Bibliometric literature review. OBJECTIVE:The aim of this study was to recognize and analyze the most frequently cited manuscripts published in the journal Spine. SUMMARY OF BACKGROUND DATA/BACKGROUND:Although the journal Spine is considered a premiere location for distributing influential spine research, no previous study has evaluated which of their publications have had the most impact. Knowledge and appreciation of the most influential Spine publications can guide and inspire future research endeavors. METHODS:Using the Scopus database, the 100 most cited articles published in Spine were accessed. The frequency of citations, year of publication, country of origin, level-of-evidence (LOE), article type, and contributing authors/institutions were recorded. The 10 most cited articles (per year) from the past decade were also determined. RESULTS:"Guidelines For The Process Of Cross-Cultural Adaptation Of Self-Report Measures" by Beaton DE was the most cited article with 2960 citations. 2000 to 2009 (n = 46) was the most productive period. A LOE of III (n = 35) followed by II (n = 34) were the most common. Deyo RA (n = 8), Bombardier C (n = 6), and Waddell G (n = 6) produced the most articles. University of Washington (n = 8) and University of Toronto (n = 8) ranked first for institutional output. Clinical Outcome (n = 28) was the most recurring article topic. The United States (n = 51) ranked first for country of origin. CONCLUSION/CONCLUSIONS:Using citation analysis as an objective proxy for influence, certain publications can be distinguished from others due to their lasting impact and recognition from peers. Of the top cited Spine publications, many pertained to clinical outcomes (28%) and had a LOE of I, II, or III (60%). Although older publications have had longer time to accrue citations, those in the most recent decade comprise this list almost 2:1. Knowledge of these "classic" publications allows for a better overall understanding of the diagnosis, management, and future direction of spine health care.Level of Evidence: 3.

Advanced age and other comorbid factors correlate with age-increased morbidity associated with spine surgery. It is crucial that spine surgeons critically assess perioperative risks versus postoperative benefits of spine surgery in the growing elderly population. Close coordination between the surgeon, anesthesia team and the patient can minimize complications, improve function and contribute to decreased costs of these complex procedures.

STUDY DESIGN/UNASSIGNED:This was a single-center retrospective review. OBJECTIVES/UNASSIGNED:To explore how age and gender affect PROMIS scores compared with traditional health-related quality of life (HRQL) in spine patients. METHODS/UNASSIGNED:Patients presenting with a primary complaint of back pain (BP) or neck pain (NP) were included. Legacy HRQLs were Oswestry Disability Index (ODI), Neck Disability Index (NDI), and Visual Analogue Scale (VAS). PROMIS Physical Function (PF), Pain Intensity (Int), and Pain Interference (Inf) were also administered to patients in a clinical setting. Patients were grouped by chief complaint, age (18-44, 45-64, 65+ years) and gender. Two parallel analyses were conducted to identify the effects of age and gender on patient-reported outcomes. Age groups were compared after propensity-score matching by VAS-pain and gender. Separately, genders were compared after propensity-score matching by age and VAS-pain. RESULTS/UNASSIGNED:= .022) but not PROMIS-Int or PROMIS-Inf. CONCLUSIONS/UNASSIGNED:Age and gender confound traditional HRQLs as well as PROMIS domains. However, PROMIS offers age and gender-specific scores, which traditional HRQLs lack.

INTRODUCTION/BACKGROUND:Students seek gap years to enhance knowledge and improve chances of professional success. Although many institutions offer research opportunities, no studies have examined outcomes after these experiences. This study evaluates a dedicated year of orthopaedic research on a cohort's ultimate orthopaedic surgery match rate. METHODS:From 2001 to 2018, 129 learners spent a year with our Department of Orthopedic Surgery at a major academic medical center. The students were either completing a gap year after college, during or after medical school, or after an unsuccessful match. Participants were asked to respond to a survey, which included demographics, educational information, and metrics related to the program. For the subcohort of students who ranked orthopaedic surgery, the match rate was compared with the mean for the US orthopaedic surgery match rates from 2006 to 2018 using a chi-square analysis. In addition, a Mann-Whitney U test was used to compare the number of publications before and after the year. RESULTS:One hundred three students (80%) returned completed questionnaires. Of all learners who applied to and ranked orthopaedic surgery, 91% matched into an orthopaedic surgery residency program. These results compared favorably with the US orthopaedic match from 2006 to 2018 (67.9%; P < 0.001), despite a 4-point lower United States Medical Licensing Examination (USMLE) Step 1 score for the research cohort. Finally, the research cohort had a greater percentage of women (23%) and minorities (40%) than the proportion of woman and minority practicing orthopaedic surgeons. CONCLUSION/CONCLUSIONS:Students who completed a gap year in research matched into orthopaedics at a higher rate than the national average, despite a lower Step score. Mentors may also target traditionally underrepresented groups to help increase the pool of diverse applicants.

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.

OBJECTIVE:To quantify muscle characteristics (volumes and fat infiltration) and identify their relationship to sagittal malalignment and compensatory mechanism recruitment. METHODS:Female adult spinal deformity patients underwent T1-weighted MRI with a 2-point Dixon protocol from the proximal tibia up to the T12 vertebra. 3D reconstructions of 17 muscles, including extensors and flexors of spine, hip and knee, were obtained. Muscle volume standardized by bone volume and percentage of fat infiltration (Pfat) were calculated. Correlations and regressions were performed. RESULTS: = 0.45, p = 0.001). Sagittally malaligned patients with larger PT (26.8° vs. 17.2°) had significantly smaller volume and larger Pfat of gluteus medius, gluteus minimus and biceps femoris, but similar values for gluteus maximus, the hip extensor. CONCLUSION/CONCLUSIONS:This study is the first to quantify the relationship between degeneration of spino-femoral muscles and sagittal malalignment. This pathoanatomical study identifies the close relationship between gluteal, hamstring muscles and PT, SVA, which deepens our understanding of the underlying etiology that contributes to adult spinal deformity.