Faculty Bibliography

OBJECTIVE:While health-related quality of life (HRQOL) measures have been extensively quantified in cervical deformity (CD), this clinical dimension has not yet been fully integrated into understanding CD radiographic subtypes prior to surgery. The aim of this study was to identify distinct patterns of HRQOL deficits among patients with CD by focusing on clinical scores and to examine the association of these patterns with radiographic morphotypes of CD. METHODS:This was a retrospective analysis of a prospective multicenter database of patients with CD aged 18 years or older. Patient-reported outcome measures consisted of the Neck Disability Index (NDI), modified Japanese Orthopaedic Association (mJOA) scale, and Swallowing Quality of Life (SWAL-QOL) questionnaire. After performing a principal component analysis on the individual questions of the NDI, mJOA, and SWAL-QOL, 4 factors with eigenvalues > 1 were retained and included in a cluster analysis to assign patients into homogeneous groups of outcomes. Moreover, a subgroup of patients with severe deformity was described and analyzed. RESULTS:Overall, 134 patients (59% female, mean age ± SD 60.9 ± 10.8 years) were included in this analysis. The mean HRQOL scores were NDI, 49.1 ± 17.6; mJOA, 13.5 ± 2.7; and EQ-5D, 0.7 ± 0.1). The factor analysis involving NDI, SWAL-QOL, and mJOA revealed 4 clusters. Cluster A represented patients with a predominant sleep problem. Cluster B was patients with the lowest neck disability. Cluster C represented the most disabled patients in terms of dysphagia and neck disability. Cluster D represented patients with myelopathy. Among the 71 patients with severe deformity, the distribution of cervical morphotypes significantly differed across the 4 clusters of disability (p = 0.009). Cluster C mainly consisted of patients with cervicothoracic deformity (66.7%, p = 0.002). Cluster D had a large proportion of patients (66.7%) with focal deformity (p = 0.007). In clusters A and B, 57.9% and 46.4% of patients, respectively, presented with "flat neck" deformity (p = 0.02). CONCLUSIONS:Distinct patterns of HRQOL deficits were observed across a heterogeneous population of patients with CD, and these patterns were associated with specific radiographic morphotypes. These findings provide a framework for the next generation of CD classification, wherein HRQOL measures are combined with radiographic parameters.

STUDY DESIGN/METHODS:Retrospective cohort. OBJECTIVE:The ISSG-AO Spinal Deformity Complication Classification System (SDCCS) predicts Diagnosis Related Group (DRG) coding and cost. BACKGROUND:Inconsistent definitions of complications contribute to variation in reported surgical complication rates. Incorrect complication reporting can lead to over or under DRG reimbursement. The ISSG-AO SDCCS provides improved complication reporting reproducibility and may help predict complication costs. METHODS:ASD patients were grouped into: DRG without complication or comorbidity (CC) or Major CC (MCC) (DRGs 455 & 458), with CC (DRGs 454 & 457), and with MCC (DRGs 453 & 456). Complications were graded by intervention severity per ISSG-AO system: grade 0 (none), 1 (mild-e.g., med change), 2 (moderate-e.g., ICU), 3 (severe-e.g., reoperation). Cost were based on Medicare inpatient prospective payment system (IPSS, Medicare Allowable rate). A multinomial logistic model identified key predictors of DRG assignment by complication grades. RESULTS:Of the 675 patients, 14% were in DRGs without CC/MCC, 71% in DRGs with CC, and 15% were DRGs with MCC. Patients with complications requiring intervention mostly fell into the higher DRG categories (97%). Patients who received an intervention are approximately 6.75 (2.01-22.75, P<.0021) times more likely to be classified under DRG with CC and 15.72 (95% CI, 4.23-58.45, P<.0001) times more likely to be classified with DRG with MCC compared to those who did not receive an intervention. Each unit increase in Edmonton Frailty Score raises the odds of being in DRG with MCC by 1.24 (95% CI 1.04-1.48, P 0.017). Similar trends were seen for OR time and LOS. Reimbursement showed incremental increase from $49.5K to $56K to $70K across DRG categories. CONCLUSIONS:Patients with elevated ISSG-AO scores are more likely to be categorized into higher DRGs, experience extended lengths of stay and generate greater healthcare expenditures. The ISSG-AO SDCCS predicts DRG thereby helping standardize complication reporting.

PURPOSE/OBJECTIVE:Vertebral body tethering (VBT) offers a fusion-less alternative for adolescent idiopathic scoliosis (AIS) patients, with tether breakage being a common concern, particularly in single-row VBT. Limited data exist on double-row VBT's impact on tether breakage. This study evaluates a two-row vertebral body tethering (2RVBT) technique, comparing cases with and without broken tethers in patients with over 2 year follow-up. METHODS:A single-center, retrospective review (2019-2022) included AIS patients who underwent mini-open thoracoscopic-assisted 2RVBT. Inclusion criteria were idiopathic scoliosis < 65° flexible curves, residual post-operative curves < 30°, and ≥ 2 year follow-up. Patients were divided into broken-tether (BT) and non-broken-tether (NBT) groups. Radiographic measures included thoracic (T) and thoracolumbar (TL) Cobb angles, coronal balance, L5 tilt, and sagittal parameters. Tether breakage was defined by > 5° change in screw angulation, with or without associated loss of correction. RESULTS:Among 109 patients (NBT = 94, BT = 15), the overall tether breakage rate was 13.7%. The BT group had significantly larger pre-operative TL Cobb angles (53.4 ± 14.0° vs 43.7 ± 13.8°, p = 0.02), greater TL correction (- 36.2 ± 9.1° vs -2 3.7 ± 15.9°, p = 0.002), and higher post-operative coronal imbalance (21.2 ± 14.6 mm vs 11.9 ± 9.4 mm, p = 0.049). They also had significantly lower skeletal maturity (mean Risser stage 2.0 ± 1.1 vs 3.2 ± 1.3, p = 0.019; Sanders 4.0 ± 1.5 vs 5.4 ± 2.0, p = 0.019). Most broken tethers did not require revision, but some cases underwent re-tethering or fusion. CONCLUSION/CONCLUSIONS:Double tether constructs may reduce the rate of tether breakage following VBT. The main risk factors for tether breakage following double tether VBT are residual post-operative coronal imbalance, larger corrections in the lumbar spine, large rigid thoracic curves, and skeletal immaturity. Furthermore, most broken tethers did not require revision, which may indicate that curves maintained appropriate correction post-breakage due to the functional lifespan of double tether constructs. Although these are preliminary findings that must be supported with further multicenter studies that include single-tether constructs, these findings should be taken into consideration when indicating patients for VBT.

STUDY DESIGN/METHODS:Prospective, multi-center analysis. OBJECTIVE:Evaluate preoperative and minimum 2-year postoperative health related quality of life (HRQOL) outcomes for adult spine deformity (ASD) using legacy HRQOL measures and computer adaptive testing (CAT) version of the patient reported outcome measurement information system (PROMIS). SUMMARY OF BACKGROUND DATA/BACKGROUND:PROMIS is the NIH recommended measure for patient reported outcomes. No data exists evaluating minimum 2-year ASD surgical outcomes using PROMIS CAT compared to legacy HRQOL measures. METHODS:ASD patients > 18 years of age were enrolled into a prospective, multi-center, observational study. Patients were administered legacy HRQOLs (SRS-22r, ODI, NRS back and leg pain, VR-12) and PROMIS CAT for Pain Interference, Physical Function, Satisfaction with Participation in Social Roles, Satisfaction with Participation in Discretionary Social Activities, Depression, and Anxiety. Preoperative and minimum 2-year postoperative HRQOL scores were compared and ASD PROMIS scores were compared to general population PROMIS values. RESULTS:144 of 190 patients had complete data at minimum 2-year follow-up. Mean preoperative values included: age=62.6 years, scoliosis=34.2°, SVA=74.2mm, PI-LL=16.7. At mean 2.3 year follow-up surgical treatment improved spine alignment (scoliosis=14.7°, SVA=34.5mm, and PI-LL=4.5°; P<0.0001). All legacy HRQOL and PROMIS scores improved from preoperative to minimum 2-year postoperative (P<0.005). Referencing PROMIS scores to normative values demonstrated 50-85% of ASD patients preoperatively reported moderate-severe deficits in all domains. At minimum 2-year postoperative 52-88% of ASD patients reported normal values-mild deficits in all PROMIS domains. PROMIS social health domains demonstrated the greatest improvement. CONCLUSION/CONCLUSIONS:This is the first study evaluating minimum 2-year ASD surgical outcomes using PROMIS CAT. ASD patients demonstrated postoperative improvements in all PROMIS health domains, with the social health domains improving most. The majority of ASD patients reported normal PROMIS values at minimum 2-years postoperative.

This review analyzes enabling technology in Adult Spinal Deformity (ASD), with a focus on optimizing safety and teaching. The prevalence of ASD is rising, and recent technological advancements can empower surgeons to improve outcomes for ASD patients but also each comes with specific challenges. The paper highlights opportunities and potential obstacles in effective technology integration and assesses key enabling technologies, including surgical planning software, machine leaning, three-dimensional printing, augmented and virtual reality, patient-specific instrumentation as well as navigation and robotics.

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.

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.