Faculty Bibliography

STUDY DESIGN/METHODS:Prospective, multi-center analysis. OBJECTIVE:Evaluate the impact that self-image has upon operative vs. nonoperative treatment choice for adult spine deformity (ASD) patients, and evaluate the association of post-treatment self-image with treatment satisfaction. SUMMARY OF BACKGROUND DATA/BACKGROUND:ASD outcomes traditionally focus upon pain and physical function. Self-image is an important outcome measure for pediatric spine deformity. Little data exists regarding the impact self-image has upon ASD treatment choice and outcomes. METHODS:Factor analysis and decision tree modeling was performed upon ASD patients prospectively enrolled into a multi-center study from 2009-2020. Data elements from physical examination, demographics, spinal alignment, and individual questions from administered PROMs including SRS-22r, ODI, SF-36, and NRS back and leg pain were evaluated for variables that correlated most with (1) patients electing for operative vs. nonoperative treatment and (2) treatment satisfaction at minimum 2-year follow-up. RESULTS:Evaluation of 735 ASD patients demonstrated operatively treated patients (OP; n=548) were older (58.0±15.3 vs. 52.4±16.0 years; P<0.0001), had similar scoliosis (44.9±20.1° vs. 45.5±16.1°; P=0.5555) but worse sagittal malalignment than nonoperatively treated patients (NON; n=187; P<0.0001, respectively). Baseline PROMs were worse for OP vs. NON (P<0.0001). Gradient-boosted decision trees, factor analysis, and logistic regression of demographic, physical examination, radiographic, and PROM variables associated with treatment choice demonstrated self-image (odds ratio=4.5; 95% CI=3.4-6.0; P<0.0001) had the greatest correlation for patients choosing operative treatment. At minimum 2-year follow-up self-image demonstrated the greatest health domain improvement for OP and self-image improvement correlated most with post-treatment satisfaction, while NON demonstrated deterioration of self-image and reported poor treatment satisfaction. CONCLUSION/CONCLUSIONS:Multi-variable evaluation of 735 operative and nonoperative treated ASD patients demonstrated baseline self-image strongly correlated with ASD patients pursuing surgical treatment and postoperative treatment satisfaction. Patient self-image is a critical measure that must be assessed in ASD.

OBJECTIVE:The aim of this study was to determine if there are any specific procedural, demographic, and/or radiographic factors that are associated with an improved postoperative lower extremity (LE) motor score (LEMS) among patients with adult spinal deformity (ASD) and abnormal baseline LEMS undergoing surgical correction. METHODS:Patients with ASD enrolled in an observational prospective study from 2018 to 2023 at 13 spinal deformity centers in North America were queried. Eligible participants met at least one of the following radiographic and/or procedural inclusion criteria: pelvic incidence minus lumbar lordosis mismatch ≥ 25°, T1 pelvic angle ≥ 30°, SVA ≥ 15 cm, thoracic scoliosis ≥ 70°, thoracolumbar scoliosis ≥ 50°, global coronal malalignment ≥ 7 cm, underwent 3-column osteotomy (3CO), spinal fusion ≥ 12 levels, and/or age ≥ 65 years with ≥ 7 levels of instrumentation. Patients with a baseline abnormal LEMS were dichotomized based on whether the LEMS improved or deteriorated from baseline by the 6-week postoperative visit. Patients with a maintained LEMS by 6 weeks compared with baseline were excluded. Patient and operative characteristics were compared through bivariate analyses to assess differences in treatment. A multivariable logistic regression model was built to discern independent factors associated with improved LEMS while controlling for potential confounders. RESULTS:Of 121 patients (77 female, mean age 62.9 years) included in the study, 109 (90.1%) improved and 12 (9.9%) experienced further deterioration from baseline to 6 weeks. Both groups had similar baseline LEMS by laterality and per nerve root. The groups were similar in age, sex, comorbidities, baseline LEMS, BMI, surgical indication, number of instrumented levels, estimated blood loss, operating room time, and hospital length of stay (p > 0.05). No differences in radiographic parameters at baseline and 6 weeks were observed aside from patients whose score had deteriorated experiencing greater change in the L1 pelvic angle (∆L1PA) (-8.0° ± 8.3° vs -1.6° ± 7.6°, p = 0.0413). Despite having similar frequencies of lumbar decompressions performed across a similar number of levels, patients whose conditions had deteriorated at 6 weeks had fewer lumbar posterior column osteotomies (PCOs) performed (50% vs 82.6%, p = 0.0169). No differences in in the frequency and number of 3COs performed were observed. Patients whose score had deteriorated experienced greater intraoperative neurophysiological monitoring (IONM) changes (41.7% vs 8.3%, p = 0.0050), all of which were motor deficits. Controlling for ∆L1PA and IONM changes revealed lumbar PCOs to be an independent driver of improved LEMS (OR 4.99 [95% CI 1.05-23.70]), with excellent model performance (p = 0.0031, area under the receiver operating characteristic curve of 0.77, Hosmer-Lemeshow goodness-of-fit test p = 0.3017). CONCLUSIONS:Performing lumbar decompressions alone might not be enough to improve LE weakness in patients with ASD and preoperative motor impairment, while the use of PCO was beneficial for improvement. Thus, more aggressive and thorough decompressions afforded by a combined approach of lumbar PCOs and decompression should be considered in this patient population to optimize postoperative motor strength.

STUDY DESIGN/METHODS:Single-center retrospective study. OBJECTIVE:To evaluate the risks associated with postoperative kyphosis and loss of range of motion after cervical disc replacement (CDR). SUMMARY OF BACKGROUND DATA/BACKGROUND:One of the main benefits of CDR is that it maintains physiological range of motion (ROM) and lordosis while achieving decompression. However, some patients experience loss in segmental ROM or postoperative segmental kyphosis. This study analyzes the radiographic outcomes of these patients. METHODS:Adult patients who underwent CDR were included. The cohort was divided into patients with poor x-ray outcomes (PXR) and successful x-ray outcomes (SXR). The PXR group was defined as patients who had a loss in segmental ROM (≥11 degress decrease in Δ segmental ROM) after CDR and/or postoperative segmental kyphosis at the operative level at 2-year follow-up. Sagittal alignment and other measures were compared. RESULTS:A total of 151 (PXR=47; SXR=104) patients met the inclusion criteria. Pre- and postoperative segmental lateral Cobb angles were more kyphotic in the PXR group (3.5 vs. -1.4 degress, P<0.001; 2.6 vs. -5.6 degress, P<0.001). There was a larger Δ in segmental lateral Cobb angle in the SXR group (-4.2 vs. -0.9 degress, P<0.001). The PXR group had more flexion and less extension (11.3 degress vs. 6.5 degress, P<0.001; -2.2 vs. -6.1 degress, P=0.049). Segmental ROM loss was significant in the PXR group (-5.7 degress vs. 1.5 degress, P<0.001). Pre- and postoperative C2-C7 lateral Cobb angles were more kyphotic in the PXR group (-1.2 vs. -9.4 degress, P<0.001; -2.9 vs. -13.9 degress, P<0.001). Pre- and postoperative cSVA were larger in the PXR group (29.6 vs. 25.3 mm, P=0.047; 30.1 vs. 22.8 mm, P=0.004). Multiple variable regressions showed higher preoperative segmental lateral Cobb angle increased odds of SXR (OR=1.217, 95% CI: 1.083-1.369, P<0.001), while larger preoperative C2-C7 ROM decreased them (OR=0.970, 95% CI: 0.994-0.996, P=0.024). No significant differences in postoperative complications were observed. CONCLUSIONS:Patients with postoperative kyphosis or loss of ROM were more likely to have less segmental and regional C2-7 lordosis and a larger cSVA. Surgeons should consider these preoperative parameters when indicating CDR and counseling patients.

STUDY DESIGN/METHODS:A national prospective cervical spine surgery registry was developed to archive radiographic studies, patient-reported outcome measures (PROMs), and surgical implant data to assess long-term safety. OBJECTIVE:To describe the design, development, funding, and implementation of a cervical spine data registry for 1000 patients with myelopathy and radiculopathy. SUMMARY OF BACKGROUND DATA/BACKGROUND:While surgery for cervical radiculopathy and myelopathy is safe and effective, there is significant practice variation among spine surgeons. While randomized clinical trials (RCTs) can provide high-quality comparative effectiveness data, RCTs lack the ability to evaluate the safety and effectiveness of various surgical procedures and implants among heterogenous real-world patient populations. The CSRS Registry was designed to collect patient demographics, outcomes, radiographic imaging, surgical approach, and implant data for the purpose of conducting high-quality research. METHODS:Patients with cervical myelopathy or radiculopathy were enrolled in the CSRS National Registry. De-identified patient data, validated PROMs, radiographic data, and implant data were collected from multiple clinical sites across the United States. RESULTS:One thousand patients [mean age, 58 y; 456 (46%) women] were enrolled, with 31% follow-up at 1 year. Five hundred ninety-two patients were diagnosed with radiculopathy, 252 with myelopathy, and 156 with radiculopathy and myelopathy. Patients had significant improvements in their PROMs after surgery. At 1 year, the mean NDI score improved from 37.2 to 20.9 (P<0.001). The mean self-reported P-mJOA score at baseline was 14.2 and improved to 15.2 by 1 year (P<0.001). Baseline CSDI score was 23.6 and improved with a 1-year decrease to an average score of 13.6 (P<0.001). There was significant improvement in PROMIS-10 Physical Health score from 41.0 to 45.9 (n=311; P<0.001) at 1-year follow-up. CONCLUSIONS:The CSRS Registry has successfully collected clinical outcomes data that is being leveraged for comparative effectiveness research and evaluations of the long-term safety and effectiveness of spinal implants.

STUDY DESIGN/METHODS:Retrospective cohort study. OBJECTIVE:To develop parameter thresholds obtainable from cervical radiographs that correlate with concomitant thoracolumbar malalignment. SUMMARY OF BACKGROUND DATA/BACKGROUND:T1 slope (T1S) is typically discussed in the context of cervical deformity and correlated with health-related quality of life outcomes. Prior research suggests that T1S is related to global alignment; however, a definition for "high" T1S has not been established. Most patients undergoing cervical surgery do not undergo full-spine imaging; therefore, obtaining a parameter associated with thoracolumbar malalignment from cervical radiographs would be beneficial. METHODS:A database of preoperative adult spinal deformity (ASD) patients was analyzed. Measures obtained from standing lateral radiographs included T1S, thoracic kyphosis (TK), sagittal vertical axis (SVA), T1-pelvic angle (TPA), pelvic tilt (PT), and pelvic incidence minus lumbar lordosis (PI-LL). Decision tree analysis was then used to determine the T1S corresponding to published thresholds for high TK (40 degrees), SVA (40 mm), TPA (25 degrees), and PT (25 degrees). Alignment between high and normal T1S patients was compared. RESULTS:Two hundred twenty-six preoperative patients were included (mean: 58±16 y 62%F). Larger T1S was correlated with greater SVA (r=0.365), TPA (r=0.302), TK (r=0.606), and PT (r=0.230) (all P<0.001). Decision tree analysis yielded a threshold of 30 degrees for high T1S, which 50% of patients had. Compared with patients with T1S <30 degrees, those with T1S >30 degrees had higher TK (41.5 vs. 25.8 degrees), SVA (78.7 vs. 33.7 mm), TPA (27.6 vs. 18.3 degrees), and PT (26.3 vs. 20.8 degrees), and PI-LL (18.2 vs. 11.7 degrees) (all P<0.05). Seventy-nine percent of patients with high T1S had high TK (T1S <30=13%), 69% had high SVA (T1S <30=38%), 66% had high TPA (T1S <30=37%), 60% had PT >25 degrees (T1S <30=42%), and 47% had PI-LL >20 degrees (T1S <30=34%) (all P<0.05). CONCLUSION/CONCLUSIONS:Higher T1S was associated with worse global alignment. T1S was most strongly associated with TK. A T1S=30 degrees corresponded to high TK, SVA, TPA, and PT thresholds. Therefore, surgeons should consider obtaining full-spine radiographs if a T1S >30 degrees is present on cervical imaging.

PURPOSE/OBJECTIVE:Robotic-assisted spine surgery (RASS) has increased in prevalence over recent years, and while much work has been done to analyze differences in outcomes when compared to the freehand technique, little has been done to characterize the potential pitfalls associated with using robotics. This study's goal was to leverage expert opinion to develop a classification system of potential sources of error that may be encountered when using robotics in spine surgery. This not only provides practitioners, particularly those in the early stages of robotic adoption, with insight into possible sources of error but also provides the community at large with a more standardized language through which to communicate. METHODS:The Delphi method, which is a validated system of developing consensus, was utilized. The method employed an iterative presentation of classification categories that were then edited, removed, or elaborated upon during several rounds of discussion. Voting took place to accept or reject the individual classification categories with consensus defined as ≥ 80% agreement. RESULTS:After a three-round iterative survey and video conference Delphi process, followed by an in-person meeting at the Safety in Spine Surgery Summit, consensus was achieved on a classification system that includes four key types of potential sources of error in RASS as well as a list of the most commonly identified sources within each category. Initial sources of error that were considered included: cannula skidding/skive, penetration, screw misplacement, registration failure, and frame shift. After completion of the Delphi process, the final classification included four major types of pitfalls including: Reference/Navigation, Patient Factors, Technique, and Equipment Factors (available at https://safetyinspinesurgery.com/ ). CONCLUSION/CONCLUSIONS:This work provides expert insight into potential sources of error in the setting of robotic spine surgery. The working group established four discrete categories while providing a standardized language to unify communication.

INTRODUCTION/BACKGROUND:With the rapid increase in the use of robotic-assisted spine surgery (RASS), reports describing complications have inevitably emerged. This study builds on previous work done to identify, characterize, and classify potential sources of error in spine surgery performed with enabling technology in the operating room. The goal of this study is to leverage expert opinion to develop a set of best practice guidelines that can be employed to minimize complications and optimize patient safety, specifically as it relates to RASS. METHODS:After assembling a group of attending spine surgeons experienced in the use of RASS across the country, formal consensus regarding the best practices was developed using the Delphi method and nominal group technique. After a review of the relevant literature and evidence, an initial survey of study group members (n=12) helped frame potential areas for investigation. Statements were subsequently edited, removed, or elaborated upon during four iterative rounds of live discussion with the opportunity for panelists to propose new guidelines at any point in the process. Respondents were able to suggest modifications and refine the statements until consensus, defined as ≥ 80% agreement, was achieved. RESULTS:After a three-round iterative survey and video conference Delphi process, followed by an in-person meeting at the Summit for Safety in Spine Surgery, consensus was achieved on 27 best practice guideline statements. This BPG had the key focus areas of 1) general protocols, 2) screw planning/execution, 3) optimization of surgical technique, and 4) areas for robotic improvement. (available at https://safetyinspinesurgery.com/ ). CONCLUSION/CONCLUSIONS:This work provides expert insight into the best practices for minimizing errors in RASS with the presentation of 27 recommendations that can serve to reduce practice variability, optimize safety, and guide future research.

BACKGROUND CONTEXT/BACKGROUND:Correcting sagittal malalignment in adult spinal deformity (ASD) is a challenging task, often requiring complex surgical interventions like pedicle subtraction osteotomies (PSOs). Different types of three-column osteotomies (3COs), including Schwab 3, Schwab 4, Schwab 4 with interbody cages, and the "sandwich" technique, aim to optimize alignment and fusion outcomes. The role of interbody cages in enhancing fusion and segmental correction remains unclear. PURPOSE/OBJECTIVE:This study aimed to compare outcomes among these 4 3CO techniques, evaluating the impact of cage use at the osteotomy site on postoperative radiographic imaging and clinical outcomes. STUDY DESIGN/SETTING/METHODS:This is a multicenter retrospective study utilizing data from a prospective multicenter database of patients undergoing complex ASD surgery. PATIENT SAMPLE/METHODS:Ninety-seven patients who underwent 1 of 4 3CO techniques for thoracolumbar ASD correction with at least 2 years of follow-up were included. The sample consisted of 29 patients who underwent Schwab 3 osteotomy, 20 Schwab 4, 28 Schwab 4 with interbody cages, and 20 who underwent "sandwich" osteotomy. OUTCOME MEASURES/METHODS:The Scoliosis Research Society-22 revised (SRS22r) questionnaire evaluating pain, activity, appearance, mental health, and satisfaction was used to evaluate patient reported outcomes and radiographic measures including segmental lordosis and fusion rates determined by 3 blinded reviewers were used to evaluate physiologic outcomes. METHODS:This study analyzed demographic data, radiographic outcomes, patient-reported outcomes, complications, and fusion rates over a 2-year follow-up period. Fusion status was determined via serial radiographs and evaluated independently by 3 blinded reviewers. Univariate and multivariate statistical analyses were performed to assess differences among the groups and the impact of interbody cage use on outcomes. RESULTS:Patients undergoing "sandwich" osteotomy exhibited worse preoperative leg pain scores and lower SRS22r activity (p=.015), appearance (p=.007), and mental health domain scores (p=.0015). No differences in complications were found among groups (p>.05). Patients who underwent osteotomy with a cage were more likely to have had previous spine fusion (91.7% vs. 71.4%, p=.010). Additionally, these patients had lower preoperative SRS22r mental domain (2.9±1 vs. 3.5±1, p=.009), satisfaction (2.3±1 vs. 2.7±1.2, p=.034), and SRS22r total scores (2.3±0.6 vs. 2.6±0.6, p=.0026) but demonstrated the greatest improvement in the mental health domain (0.9±0.7 vs. 0.3±0.9, p=.002). Cage use was associated with a larger mean change in segmental lordosis at the osteotomy site (32.9±9.6 vs. 28.7±9.5, p=.038). Fusion rates were significantly higher in the cage group (79.2% vs. 55.1%, p=.0012). Regression analysis identified cage use as an independent predictor for fusion (odds ratio, 3.338; 95% confidence interval, 1.108-10.054, p=.032). CONCLUSIONS:Interbody cage use at the osteotomy site during 3COs for ASD correction was associated with improved fusion rates and greater segmental lordosis without increasing complication rates. Incorporating cages may provide enhanced alignment and fusion outcomes in complex ASD surgeries.

BACKGROUND/UNASSIGNED:open or minimally invasive (MIS) laminectomy using the American College of Surgeons' National Surgical Quality Improvement Program (ACS-NSQIP) database. METHODS/UNASSIGNED:Using the ACS-NSQIP database from 2017 to 2022, Current Procedural Terminology (CPT) code of 63030 or 62380 were used to filter the dataset between open/tubular retractor-based and endoscopic single-level lumbar decompression cases, respectively. Overall, as collected, the endoscopic group consisted of 336 patients and the non-endoscopic group had 55,111 patients. The groups were compared to evaluate the patient characteristics and adverse events within 30 days after their operation. Outcome measures compared were operative time, length of stay (days), adverse outcomes [superficial infection, deep infection, organ/space infection, wound dehiscence, pneumonia, unplanned intubation, pulmonary embolism, ventilator >48 hours, progressive renal insufficiency, acute renal failure, urinary tract infection, stroke/cerebrovascular accident (CVA) accident, cardiac arrest, myocardial infarction, blood transfusion, deep vein thrombosis (DVT), sepsis, and septic shock], 30-day readmission, return to operating room (OR). RESULTS/UNASSIGNED:4.8%, P=0.01), with significantly lower rate of blood transfusions (P<0.05) compared to the non-endoscopic group. CONCLUSIONS/UNASSIGNED:Patients who underwent endoscopic lumbar decompression demonstrated a significantly lower rate of total adverse events and significantly lower rate of blood transfusions compared to their counterparts. This data from the ACS-NSQIP supports the reported benefits of endoscopic technique in the current literature. As endoscopic surgery becomes more widely utilized throughout the United States, more data will become available for further studies.

BACKGROUND AND OBJECTIVES/OBJECTIVE:The concept of upper cervical (C0-C2) extension reserve (ER) capacity, ER relaxation, and their impact on outcomes following surgical correction of adult cervical deformity (ACD) has not been extensively studied. We aimed to evaluate the impact of upper cervical ER on postoperative disability and outcomes. METHODS:Patients with ACD, from a retrospective cohort study of a prospectively collected multicenter database, undergoing subaxial cervical fusion with 2-year (2Y) follow-up data were included. ER was defined as: ΔC0-C2 sagittal Cobb angle between neutral and extension. Relaxation of ER was defined as the ER mean in those that met all ideal thresholds in radiographic parameters for Passias et al CD modifiers. We used multivariable logistic regression to adjust for confounding, with conditional inference tree approaches used to determine thresholds that affect postoperative ER resolution on patient-reported outcomes. RESULTS:A total of 108 patients with ACD met inclusion. Preoperative C0-C2 ER was 8.7° ± 9.0°, and at last follow-up was 10.3° ± 11.1°. Preoperatively 29% of the cohort had adequate ER, whereas 60% had improved ER postoperatively, with 50% achieving adequate ER by 2Y. Lower ER correlated with greater CD (P < .05). Preoperatively, greater ER had lower Neck Disability Index (P < .001). Controlled analysis found improved ER to have a greater likelihood of achieving Neck Disability Index minimum clinically important difference (odds ratio 6.94, [1.378-34.961], P = .019). In those with inadequate ER at baseline, the preoperative C2-C7 of < -18° and T1 slope-cervical Lordosis mismatch of >59° for T1 slope-cervical Lordosis mismatch was predictive of ER resolution. In those with preoperative C2-C7 >-18°, a T1PA of >13° was predictive of postoperative return of ER (all P < .05). Surgical correction of C2-C7 by > 16° from baseline was found to be predictive of ER return. CONCLUSION/CONCLUSIONS:Increased preoperative use of the C0-C2 ER in CD was associated with worse baseline regional and global alignment and adversely affected health-related measures. Most of the patients had ER relaxation postoperatively. In those who didn't, however, there was a decreased likelihood of achieving satisfactory outcomes.