Prior reports have focused on grading fusion status after adult spinal deformity (ASD) surgery; however, few focused on fusion status after 4-years postop.
To identify risk factors for nonunion in a ...prospective cohort of ASD patients with long-term follow-up (=4 years).
Prospective multicenter observational series.
Database enrollment required age =18 years, scoliosis =20°, sagittal vertical axis (SVA) =5cm, pelvic tilt =25°, or thoracic kyphosis =60°.
Fusions were rated as bilaterally fused (A), unilaterally fused (B), partially fused (C), or not fused (D). Primary outcome was fusion (grade A or B) vs nonunion (grade C or D) at minimum 4-year follow-up. Secondary outcome measures included health-related quality of life (HRQL) (Oswestry Disability Index ODI, Short Form-36 SF-36 scores, Scoliosis Research Society-22 SRS-22r scores).
Surgically treated ASD patients prospectively enrolled into a multicenter study (2008-2020) were assessed for fusion (grade A or B) vs nonunion (grade C or D). Inclusion required postop fusion grading at minimum 4-year follow-up. Demographics, frailty, comorbidities, alignment (baseline and initial correction), index surgery (total levels fused, iliac fixation, interbody fusion IBF, use of bone morphogenetic protein BMP and/or demineralized bone matrix DBM, 3-column osteotomy 3CO) were assessed to identify potential predictors of nonunion (grade C or D), which were then analyzed using Kaplan-Meier survival curves and log-rank comparisons.
A total of 227 patients achieved minimum 4-year follow-up and were included (age 58±14y, 82% women, BMI 27±5kg/m2, 40% prior spine surgery, ASD-FI 0.31 frail, 15% osteoporosis). Index operations had 12±4 posterior levels, 70% iliac fixation, 62% IBF, 76% had BMP, 33% had DBM (of which 52% also had BMP), and 15% had 3CO. At final follow-up, 61 patients (27%) demonstrated nonunion (grade C or D). Older age (61±14 vs 57±14, p=0.015), no BMP usage (p 60 years) had significantly higher probability of nonunion (log-rank test p=0.024), and BMP had protective effect (log-rank test p 0.05).
This study demonstrated that older age (>60 years) was associated with significantly higher rates of nonunion at long-term follow-up (4 years) after ASD surgery, and that use of BMP had significant protective effect against this complication.
This abstract does not discuss or include any applicable devices or drugs.
Adult spinal deformity (ASD) is a highly heterogeneous condition with a broad range of surgical options. Unsupervised machine-based pattern clustering of patient types based on radiographic ...parameters and quality of life measures alongside combinations of surgical options may simplify ASD patient types, procedures and outcomes. Artificial intelligence (AI) based pattern recognition may provide augmented preoperative decision analysis to surgeons in real time.
Subtle similarity patterns may exist across patient and surgery types that may not be specified but may significantly influence surgical outcomes and major complication (MC) rates. Our objective was to explore whether AI may potentially augment our decision-making capability by identifying similarity patterns in patient types when combined with procedure groups.
Retrospective analysis of prospectively collected data.
Adult spinal deformity patients from two prospective observational cohorts.
Major complication rates, SF36v2, Scoliosis Research Society-22R (SRS-22R).
Two prospective observational cohorts were queried for surgical ASD patients with SRS-22/ODI/SF-36v2 data at baseline, 1 year and 2 years. Two dendrograms on the same observations were fitted, one with surgical features and the other with patient characteristics. Both were built with Ward distances and optimized with the Gap method. For each of the possible n patient clusters by m surgeries, normalized average improvement at 2 years and adjusted MC rates were computed.
A total of 570 patients were included in the analysis. Three optimal patient types were identified: young with coronal plane deformity (YC)(n=195), older with prior spine surgeries (ORev) (n=194) and Older without prior spine surgeries (OPrim)(n=218). Osteotomy type, instrumentation and interbody fusion were identified and combined to define four optimal average surgical options. Two-year normalized average improvement ranged from −0.074% for SF36v2 MCS score in cluster (1,3) to 100.21% for SRS self-image score in cluster (2,1). MC rates at 2 years ranged from 0% to 51.8%.
Unsupervised AI hierarchical clustering can identify subtle data patterns and classification clusters that may augment preoperative decision-making through construction of a 2-year risk/benefit grid. In addition to enhancing outcome and complication prediction, pattern identification may facilitate treatment optimization by educating surgeons on which treatment patterns yield optimal improvement with lowest risk.
This abstract does not discuss or include any applicable devices or drugs.
Few predictive models allow for proper patient selection, adjustment of invasiveness and patient frailty optimization to predict and reduce postoperative major complications (MC), hospital ...readmissions (READMIT), and unplanned surgery (UNPLAN).
The objective of this project is to create accurate predictive models for the occurrence and timing of MC, READMIT, and UNPLAN following ASD surgery.
Retrospective analysis of two independent prospective, multicenter ASD databases with identical fixed data fields.
Data from 1,018 ASD surgically treated patients (57 surgeons, 24 sites, and 5 countries) were used to build MC, READM and UNPLAN risk calculating models with proved successful model fit.
Postoperative major complications (MC), hospital readmissions (READMIT), unplanned surgery (UNPLAN).
Surgical ASD patients with >2yFU were identified. Patient demographic, radiographic, operative, baseline PROMs, and complications data were analyzed to build event free survival curves for MC, READMIT and UNPLAN, and to create predictive models by means of a random survival forest with 80/20 train or test sets. 101 variables were used. Missing value imputation was performed with the missForest package.
A total of 1,018 ASD patients treated surgically before September-2014 (77.7% women, 55.5 mean age, 10.7 levels fused segments, 55.5% pelvic fixation, 21.2% 3CO) by 57 surgeons at 24 sites in 5 countries (2 continents), with 2,047.9 observation-years, were included in the analysis. Missing value imputation was 14.59%. C-statistic value (70.6%) proved successful model fit. Models demonstrate that 87.9% of patients are MC-free at 10days postop, 78.5% at 90days and 63% at 2years. Surgical invasiveness (LIV-pelvic fixation, length of fusion, prior surgery), age, magnitude of sagittal deformity, patient frailty (walking and lifting capacity) and blood loss most strongly predict MC. Surgeon and site most strongly predict READMIT and UNPLAN. Curves show a continued survivorship decrease for event free MC, READMIT and UNPLAN beyond >2yFU.
Risk calculating models for event-free MC, READMIT and UNPLAN following ASD surgery demonstrate that patient-related factors, >1/3 of which are modifiable, account for 55% of the MC predictive model weight. Surgeon and site represent 4% for MC, but are most relevant for READMIT and UNPLAN.
Although short-term adult symptomatic lumbar scoliosis (ASLS) outcomes studies favor operative over nonoperative treatment, long-term outcomes are critical for assessment of treatment durability.
To ...assess whether operative treatment for ASLS provides greater improvement of patient-reported outcomes measures than nonoperative treatment at 5-6-year follow-up.
Secondary analysis of prospective multicenter cohort.
Adults with symptomatic lumbar scoliosis enrolled into an NIH-sponsored study to assess outcomes of operative and nonoperative treatments.
Scoliosis Research Society-22 subscore (SRS-22 subscore), Oswestry Disability Index (ODI), occurrence of related serious adverse events (SAEs)
The ASLS study is an NIH-sponsored multicenter prospective study to assess operative vs nonoperative treatment for ASLS, with randomized and observational treatment arms. Patients were 40-80 years of age with ASLS (Cobb >30° and ODI >20 or SRS-22 subscore (SRS-22) <4.0 in pain, function and/or self-image domains). Patient-reported outcomes measures at 5-6-year follow-up were compared between operative and nonoperative patients using as-treated analysis. Rates and impact of treatment related SAEs were assessed for op patients.
The 286 ASLS patients (108 nonoperative, 178 operative) had follow-up rates at 2 and 5-6 years of 90% (256) and 74% (212), respectively. At 5 years, compared with nonoperative, operative patients had greater improvement in SRS-22 subscore (adjusted mean difference, 0.6 95% CI, 0.5 to 0.6) and ODI (adjusted mean difference, -14 95% CI, -18 to -9) (p<0.001 for both), with treatment effects (TEs) exceeding minimal detectable measurement difference (MDMD) for SRS-22 subscore (0.4) and ODI (7). TEs at 5 years remained as favorable as TEs at 2 years (SRS-22 subscore=0.7; ODI=-16). The SAE incidence rates for operative patients during the first 2 years and 2-6 years following surgery were 35 and 23 SAEs per 100 person-years, respectively. During the first 2 years and first 6 years postsurgery, there were 34 and 73 revisions in 24 and 55 operative patients, respectively. At 5 years, operative patients with one SAE still had significant improvement, with TEs that exceeded MDMD (SRS-22 subscore=0.55, ODI=-12.9, p<0.001 for both). The 12 operative patients with 2+ SAEs had improvement based on SRS-22 subscore (TE=0.3, p=0.027) that did not exceed MDMD, and lacked significant improvement based on ODI (TE=-7.7, p=0.06).
The significantly greater clinical improvement of operative vs nonoperative treatment for ASLS at 2 years is maintained at 5-6-year follow-up. Overall, operative patients with a related SAE still had greater improvement than nonoperative patients, but for operative patients with 2+ SAEs, the TEs were markedly reduced. These findings have important implications for patient counseling and cost-effectiveness assessments.
This abstract does not discuss or include any applicable devices or drugs.
