Faculty Bibliography

BACKGROUND CONTEXT: Surgical correction of adult spinal deformity (ASD) has been associated with superior alignment and functional outcomes. However, postoperative complication rates remain relatively high. The extent to which potentially modifiable patient-related factors can influence complication rates in adult spinal deformity patients has not been effectively evaluated. PURPOSE: Evaluate the association between modifiable patient-related factors on complications following ASD corrective surgery. STUDY DESIGN/SETTING: Retrospective. PATIENT SAMPLE: A total of 689 ASD patients. OUTCOME MEASURES: Complication and reoperation rates.
METHOD(S): ASD patients with 2-year (2Y) data were included. Complication groups were defined as follows: 1) any complication; 2) major; 3) medical (cardiac event, ileus, etc.); surgical (site infection, wound dehiscence, etc.); 5) major mechanical (implant failure, rod fracture); 6) major radiographic (PJF [proximal junctional failure], pseudarthrosis, adjacent segment disease); and 7) reoperation. Modifiable risk factors included current smoker, obesity (BMI >30kg/m²), osteoporosis, alcohol use, depression (BL SF-36 MCS <35, perMatcham), psychiatric diagnosis and hypertension. Patients were stratified by BL deformity severity in T1PA (LowDef/HighDef) and age above or below 65 (Young/Older). Means comparison tests assessed prevalence of modifiable risk factors present in those developing specified complications. Binary logistic regression analysis was used to adjust for confounders.
RESULT(S): A total of 480 ASD patients met inclusion criteria (age 59+/-15 yrs, 77%F, BMI 27+/-5 kg/m², CCI: 1.7+/-1.7). By 2Y, comp rates: 72% one complication, 28% major, 21% medical, 27% surgical, 11% major radiographic, and 8% had a major mechanical complication. A total of 106 patients (22%) required reoperation. Overall, 318 patients (66%) had at least one of the preoperative risk factors. Age-Deformity Groups: 32% Young LowDef, 19% Young HighDef, 18% Older LowDef, 31% Older HighDef. Within Young LowDef, patients with osteoporosis were more likely to suffer either a major mechanical or radiographic comp (both OR >6, p<.05), although this trend was not seen in the overall cohort. Young HighDef patients were much more likely to develop complications if obese, especially major mechanical complications (OR: 2.8, [1.04-8.6]; p=.045), while patients with depression or a psychiatric diagnosis suffered major radiographic comps and underwent reoperation more often. Older patients with HighDef developed significantly more complications when diagnosed with depression, including major radiographic comps (23% vs 8%, OR: 3.5, [1.1-10.6]; p=.03). Overall, when controlling for baseline deformity, frailty, and osteoporosis, a diagnosis of depression proved to be a significant risk factor for development of major radiographic complications (OR: 2.4, [1.3-4.5]; p=.005).
CONCLUSION(S): Certain modifiable patient-related factors, especially mental health status, are associated with increased risk for complications following spinal deformity surgery. Therefore, with consideration to clinical presentation, elaborate on the utility in medical intervention prior to undergoing spinal deformity corrective surgery. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Malalignment following adult spinal deformity (ASD) surgery can negatively impact clinical outcomes and increase risk of mechanical complications. Despite improved definition of ideal alignment for ASD surgery and increasingly sophisticated preoperative alignment planning tools, it remains unclear whether the preoperative goals for alignment are actually achieved with surgery. PURPOSE: The objective of this study was to assess whether preoperative goals for sagittal alignment following ASD surgery are consistently achieved. STUDY DESIGN/SETTING: Multicenter, prospective cohort study. PATIENT SAMPLE: Operatively treatedASD patients. OUTCOME MEASURES: Sagittal vertical axis (SVA), pelvic incidence to lumbar lordosis mismatch (PI-LL), T4-T12 thoracic kyphosis (TK).
METHOD(S): From 2018-2021, ASD patients were enrolled into a prospective ASD study based on three criteria: deformity severity (PI-LL>25degree, TPA>30degree, SVA>15cm, TCobb>70degree or TLCobb>50degree), procedure complexity (>12 levels fused, 3CO or ACR), and/or patient age (>65 and >7 levels fused). The operating surgeon documented sagittal alignment goals prior to surgery, including SVA, PI-LL mismatch and TK. Alignment goals were compared with achieved alignment at 6 weeks postop and the overall mean and SD were calculated for the offset (achieved minus goal) for each measure. Goal alignment was considered attained if the offset was within +/-1 SD of the goal. Demographic, surgical and baseline radiographic measures demonstrating significant association with achieving alignment goal on univariate analysis were used for multivariate regression analysis.
RESULT(S): The 266 enrolled patients had a mean age of 61.0 yrs (SD=14.6 yrs) and 68% were women. Mean number of instrumented levels was 13.6 (SD=3.8) and 24% had a 3-column osteotomy (3CO). Mean (SD) offsets were: SVA=-8.5 mm (45.6 mm), PI-LL=-4.6degree (14.6degree), TK=7.2degree (14.7degree), reflecting a tendency to undercorrect SVA and PI-LL relative to goal and to increase TK relative to goal. Surgeons achieved goal alignment (within 1 SD) for SVA, PI-LL, and TK in 74.4%, 71.4%, and 68.8% of cases, respectively. On regression analysis: goal SVA was more likely to be achieved with lower baseline SVA (OR=0.993, 95%CI=0.988-0.997, p=0.001) and greater baseline TK (OR=1.016, 95%CI=1.002-1.031, p=0.029); goal PI-LL was more likely to be achieved with greater patient age (OR=1.021, 95%CI=1.002-1.039, p=0.026) and history of previous TL spine surgery (OR=2.028, 95% CI=1.136-3.621, p=0.017); and goal TK was more likely to be achieved with lower baseline SVA (OR=0.995, 95%CI=0.991-0.999; p=0.014). The proportions of patients with achieved alignment within 1 SD of goal were not significantly different for patients with a UIV above T7 vs those with a UIV at or below T7 for SVA (p=0.20), PI-LL (p=0.49) or TK (p=0.06). Notably, patient-specific rods were used in 21 patients and were not associated with greater achievement of goal alignment for any parameter (p>0.8), with similar tendencies to undercorrect SVA and PI-LL and increase TK (p>0.6).
CONCLUSION(S): Surgeons failed to achieve goal alignment of each sagittal parameter in ~25% of patients operated for ASD, with a tendency to undercorrect SVA and PI-LL and increase TK. Patients at greatest risk tended to be those with more severe baseline deformity. Further advancements are needed to enable more consistent translation of preoperative alignment planning to the operating room. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Minimally invasive (MIS) spine surgery techniques were developed to mitigate complications associated with open procedures while achieving functional outcomes. More recently, preoperative rehabilitation programs have been implemented to prepare patients for surgery and to promote patient health. The purpose of this study was to identify the effect of preoperative rehabilitation on MIS spine surgery patient outcomes. PURPOSE: Identify if preoperative rehabilitation influences patient outcomes following MIS spine surgery. STUDY DESIGN/SETTING: Retrospective cohort. PATIENT SAMPLE: This study included 524 MIS patients. OUTCOME MEASURES: Preoperative rehabilitation, perioperative complications, patient outcomes.
METHOD(S): MIS spine surgery patients with baseline (BL) and two-year (2Y) follow-up were included if they had preoperative rehabilitation data. Patients were divided into two groups: those who had preoperative rehabilitation [Prehab] and those who did not [no Prehab]. Prehab consisted of physical and mental components, ie, physical therapy for 3 months, 3 days a week for core, paraspinal and leg strengthening, with a review of postop protocols to do at home, including gait and balance training. Patients were also referred for cognitive behavioral therapy for 2 weeks to prepare for the stress of surgery. Patients were excluded if they presented with any of the following at baseline: severe neurological deficit (< 3/5), minimal ambulation, or current depression/anxiety. Means comparison tests and logistic regression analysis controlling for age, CCI, ASA grade, and invasiveness assessed differences between patient groups. Conditional inference tree (CIT) analysis determined thresholds for continuous variables.
RESULT(S): A total of 216 patients met inclusion criteria (76 Prehab, 140 no Prehab). The majority were male (97, 44.9%), mean age of 55.17 years, and 2.3 levels fused and 28 (13.0%) undergoing 3-CO. There was a significant difference in LOS for patients who had (3.6 days) and didn't have (5.3 days) Prehab, p <.05. Multivariate regression showed that Prehab was an independent predictor of a shorter LOS (OR.686 [CI.484-.972], p=.034). CIT analysis determined Prehab patients were 85.0% less likely to have a LOS greater than 2.0 days (OR.015 [CI.001-.258], p=.004). By 2 years, Prehab patients had lower rates of readmissions (6.7% vs 20.0%) and reoperations (4.0% vs 15.3%) than no Prehab patients, both p <.05.
CONCLUSION(S): Preoperative rehabilitation appears to be independently associated with a shorter length of stay following minimally invasive spine surgery. Patients who had preoperative rehabilitation also had lower rates of readmissions and reoperations by two years postoperatively. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: The use of robotic or navigational guidance has seen tremendous growth in recent years in minimally invasive spine surgery (MISS) due to its ability to reduce operative time, increase patient safety, and aid in surgical accessibility, especially in high incidence pathologies. However, there remain considerable gaps in the literature in regards to the cost-effectiveness of robotic or navigational guidance in the surgical treatment of L4-L5 spondylolisthesis. PURPOSE: To assess differences in patient outcomes and relative cost effectiveness in L4-L5 spondylolisthesis patients treated using robotic or navigational guidance in MISS procedures. STUDY DESIGN/SETTING: Retrospective review of prospective MISS database. PATIENT SAMPLE: A total of 524 MISS patients. OUTCOME MEASURES: HRQLs, complications, surgical factors.
METHOD(S): MISS patients with preoperative diagnoses of L4-L5 spondylolisthesis and baseline (BL) and 2-year (2Y) postoperative radiographic/HRQL data were included. Patients were split between those operated on using robotic or navigational guidance (Robotic+) or not (Robotic-). Means comparison analysis assessed differences in radiographic and clinical outcomes at BL, 1Y and 2Y postoperatively. Costs were calculated using the PearlDiver database through estimates from Medicare payscales for services within a 30-day window, including estimates regarding costs of postoperative complications, outpatient healthcare encounters, revisions and medical related readmissions. Quality-adjusted life years (QALYs) was calculated using NDI mapped to SF6D using validated methodology and utilized a 3% discount rate to account for residual decline to life expectancy (78.7 years).
RESULT(S): Eighty-eight patients (54.40+/-12.49 years, 40% female, 30.93+/-6.52 kg/m², mean CCI: 2.23+/-1.55) with L4-5 spondylolisthesis were included. At baseline, patients were comparable in age, gender, BMI and CCI (all p>.05). Similarly, patients did not differ significantly in baseline regional nor global radiographic deformity (all p>.05). Perioperatively, Robotic+ patients were significantly less likely to undergo corpectomy (p=.006), and also demonstrated significantly lower EBL (p=.013) and operative time (p=.009). Economic analysis revealed broad cost savings for Robotic+ patients. Specifically, Robotic+ patients demonstrated increased utility gained per QALYs at 1Y (p=.028), as well as Life Expectancy QALYs (p=.002). Furthermore, Robotic+ patients were significantly more likely to demonstrate increased QALYs gained by 2Y (p=.029). Conversely, overall cost per QALY by 2Y was significantly higher for Robotic- patients, which resulted in an approximately 6.5x greater cost per QALY for such patients (76,848 vs 11,839 USD). Overall, Robotic+ patients demonstrated significantly higher cost-effectiveness by 2Y (p<.001).
CONCLUSION(S): Corrective procedures for the treatment of L4-L5 spondylolisthesis and other common spinal pathologies has seen significant growth in the uptake of novel technologies such as robotic or navigational assistance. Though robotic and navigational assistance systems have a significantly higher upfront cost compared to existing techniques, our findings demonstrate reductions in intraoperative invasiveness and OR time pay great dividends in demonstrating the 2Y cost-effectiveness of such novel technologies in minimally-invasive adult spinal deformity surgery. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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OBJECTIVE:Revision surgery is often necessary for adult spinal deformity (ASD) patients. Satisfaction with management is an important component of health-related quality of life. The authors hypothesized that patients who underwent multiple revision surgeries following ASD correction would exhibit lower self-reported satisfaction scores. METHODS:This was a retrospective cohort study of 668 patients who underwent ASD surgery and were eligible for a minimum 2-year follow-up. Visits were stratified by occurrence prior to the index surgery (period 0), after the index surgery only (period 1), after the first revision only (period 2), and after the second revision only (period 3). Patients were further stratified by prior spine surgery before their index surgery. Scoliosis Research Society-22 (SRS-22r) health-related quality-of-life satisfaction subscore and total satisfaction scores were evaluated at all periods using multiple linear regression and adjustment for age, sex, and Charlson Comorbidity Index. RESULTS:In total, 46.6% of the study patients had undergone prior spine surgery before their index surgery. The overall revision rate was 21.3%. Among patients with no spine surgery prior to the index surgery, SRS-22r satisfaction scores increased from period 0 to 1 (from 2.8 to 4.3, p < 0.0001), decreased after one revision from period 1 to 2 (4.3 to 3.9, p = 0.0004), and decreased further after a second revision from period 2 to 3 (3.9 to 3.3, p = 0.0437). Among patients with spine surgery prior to the index procedure, SRS-22r satisfaction increased from period 0 to 1 (2.8 to 4.2, p < 0.0001) and decreased from period 1 to 2 (4.2 to 3.8, p = 0.0011). No differences in follow-up time from last surgery were observed (all p > 0.3). Among patients with multiple revisions, 40% experienced rod fracture, 40% proximal junctional kyphosis, and 33% pseudarthrosis. CONCLUSIONS:Among patients undergoing ASD surgery, revision surgery is associated with decreased satisfaction, and multiple revisions are associated with additive detriment to satisfaction among patients initially undergoing primary surgery. These findings have direct implications for preoperative patient counseling and establishment of postoperative expectations.

BACKGROUND:There is limited research regarding the association between the mFI-5 and postoperative complications among adult spinal deformity (ASD) patients. METHODS:Using the National Surgical Quality Improvement Project (NSQIP) database, patients with Current Procedural Terminology (CPT) codes for > 7-level fusion or < 7-level fusion with International Classification of Diseases, Ninth Revision (ICD-9) codes for ASD were identified between 2008 and 2016. Univariate analyses with post-hoc Bonferroni correction for demographics and preoperative factors were performed. Logistic regression assessed associations between mFI-5 scores and 30-day post-operative outcomes. RESULTS:2,120 patients met criteria. Patients with an mFI-5 score of 4 or 5 were excluded, given there were<20 patients with those scores. Patients with mFI-5 scores of 1 and 2 had increased 30-day rates of pneumonia (3.5 % and 4.3 % vs 1.6 %), unplanned postoperative ventilation for > 48 h (3.1 % and 4.3 % vs 0.9 %), and UTIs (4.4 % and 7.4 % vs 2.0 %) than patients with a score of 0 (all, p < 0.05). Logistic regression revealed that compared to an mFI-5 of 0, a score of 1 was an independent predictor of 30-day reoperations (OR = 1.4; 95 % CI 1.1-18). A score of 2 was an independent predictor of overall (OR = 2.4; 95 % CI 1.4-4.1) and related (OR = 2.2; 95 % CI 1.2-4.1) 30-day readmissions. A score of 3 was not predictive of any adverse outcome. CONCLUSION/CONCLUSIONS:The mFI-5 score predicted complications and postoperative events in the ASD population. The mFI-5 may effectively predict 30-day readmissions. Further research is needed to identify the benefits and predictive value of mFI-5 as a risk assessment tool.

BACKGROUND:The International Spine Study Group (ISSG) and the European Spine Study Group (ESSG) developed an adult spinal deformity (ASD) risk calculator based on one of the most granular, prospective ASD databases. The calculator utilizes preoperative radiographic, surgical, and patient-specific variables to predict patient-reported outcomes and complication rates at 2 years. Our aim was to assess the ISSG-ESSG risk calculator's usability in a single-institution ASD population. METHODS:tests. Each F patient was inputted into the ESSG risk calculator to identify individual predictive rates for postoperative 2-year health-related quality of life questions (HRQL) outcomes and major complications. These calculated predicted outcomes were analyzed against those identified from the ASD database in order to validate the calculator's predictability via Brier scores. A score closer to 1 meant the ISSG-ESSG calculator was not predictive of that specific outcome. A score closer to 0 meant the ISSG-ESSG calculator was a predictive tool for that factor. RESULTS:, 0.95 ± 1.3 Charlson Comorbidity Index). Of those patients, 7.8% were frail. Fifty percent of frail patients received an interbody fusion, 58.3% received a decompression, and 79.2% underwent osteotomy. Surgical details were as follows: mean operative time was 342.9 ± 94.3 minutes, mean estimated blood loss was 2131.82 ± 1011 mL, and average length of stay was 7.12 ± 2.5 days. The ISSG-ESSG calculator predicted the likelihood of improvement for the following HRQL's: Oswestry Disability Index (ODI) (86%), Scoliosis Research Society (SRS)-22 mental health (71.1%), SRS-22 total (87.6%), and major complication (53.4%). The single institution had lower percentages of improvement in ODI (24.6%), SRS-22 mental health (21.3%), SRS-22 total (25.1%), and lower presence of major complication (34.8%). The calculated Brier scores identified the calculator's predictability for each factor was as follows: ODI (0.24), SRS-22 mental health (0.21), SRS-22 total (0.25), and major complication (0.28). CONCLUSIONS:All of the variables had low Brier scores, indicating that the ISSG-ESSG calculator can be used as a predictive tool for ASD frail patients. LEVEL OF EVIDENCE: 3/METHODS/:

Prediction of blood transfusion after adult spinal deformity (ASD) surgery can identify at-risk patients and potentially reduce its utilization and the complications associated with it. The use of artificial neural networks (ANNs) offers the potential for high predictive capability. A total of 1173 patients who underwent surgery for ASD were identified in the 2017-2019 NSQIP databases. The data were split into 70% training and 30% testing cohorts. Eighteen patient and operative variables were used. The outcome variable was receiving RBC transfusion intraoperatively or within 72 h after surgery. The model was assessed by its sensitivity, positive predictive value, F1-score, accuracy (ACC), and area under the curve (AUROC). Average patient age was 56 years and 63% were female. Pelvic fixation was performed in 21.3% of patients and three-column osteotomies in 19.5% of cases. The transfusion rate was 50.0% (586/1173 patients). The best model showed an overall ACC of 81% and 77% on the training and testing data, respectively. On the testing data, the sensitivity was 80%, the positive predictive value 76%, and the F1-score was 78%. The AUROC was 0.84. ANNs may allow the identification of at-risk patients, potentially decrease the risk of transfusion via strategic planning, and improve resource allocation.

OBJECTIVE:Adult cervical deformity (ACD) has high complication rates due to surgical complexity and patient frailty. Very few studies have focused on longer-term outcomes of operative ACD treatment. The objective of this study was to assess minimum 2-year outcomes and complications of ACD surgery. METHODS:A multicenter, prospective observational study was performed at 13 centers across the United States to evaluate surgical outcomes for ACD. Demographics, complications, radiographic parameters, and patient-reported outcome measures (PROMs; Neck Disability Index, modified Japanese Orthopaedic Association, EuroQol-5D [EQ-5D], and numeric rating scale [NRS] for neck and back pain) were evaluated, and analyses focused on patients with ≥ 2-year follow-up. RESULTS:Of 169 patients with ACD who were eligible for the study, 102 (60.4%) had a minimum 2-year follow-up (mean 3.4 years, range 2-8.1 years). The mean age at surgery was 62 years (SD 11 years). Surgical approaches included anterior-only (22.8%), posterior-only (39.6%), and combined (37.6%). PROMs significantly improved from baseline to last follow-up, including Neck Disability Index (from 47.3 to 33.0) and modified Japanese Orthopaedic Association score (from 12.0 to 12.8; for patients with baseline score ≤ 14), neck pain NRS (from 6.8 to 3.8), back pain NRS (from 5.5 to 4.8), EQ-5D score (from 0.74 to 0.78), and EQ-5D visual analog scale score (from 59.5 to 66.6) (all p ≤ 0.04). More than half of the patients (n = 58, 56.9%) had at least one complication, with the most common complications including dysphagia, distal junctional kyphosis, instrumentation failure, and cardiopulmonary events. The patients who did not achieve 2-year follow-up (n = 67) were similar to study patients based on baseline demographics, comorbidities, and PROMs. Over the course of follow-up, 23 of the total 169 enrolled patients were reported to have died. Notably, these represent all-cause mortalities during the course of follow-up. CONCLUSIONS:This multicenter, prospective analysis demonstrates that operative treatment for ACD provides significant improvement of health-related quality of life at a mean 3.4-year follow-up, despite high complication rates and a high rate of all-cause mortality that is reflective of the overall frailty of this patient population. To the authors' knowledge, this study represents the largest and most comprehensive prospective effort to date designed to assess the intermediate-term outcomes and complications of operative treatment for ACD.

STUDY DESIGN/METHODS:Retrospective cohort review of a prospective multicenter database. OBJECTIVE:Identify rates and variations in lumbopelvic fixation failure after adult spinal deformity (ASD) correction. SUMMARY OF BACKGROUND DATA/BACKGROUND:Traditional iliac (IS) and S2-alar-iliac (S2AI) pelvic fixation methods have unique technical characteristics for their application, and result in varied bio-mechanical and anatomic impact. These differences may lead to variance in lumbopelvic fixation failure types/rates. METHODS:ASD patients undergoing correction with more than five level fusion and pelvic fixation, separated by pelvic fixation type (IS vs. S2AI). Fixation fracture or loosening assessed radiographically (Figure 1). Multivariate logistic regression, accounting for significant confounders, was used to examine differences between the two groups for screw loosening/fracture, rod fracture, and revision surgery. Level of significance set at P< 0.05. RESULTS:Four hundred eighteen of 1422 patients were included (IS = 287, S2AI = 131). The groups had similar age, body mass index (BMI), baseline comorbidities, number of levels fused (P>0.05), baseline health related quality of life measures (HRQLs) (short form survey-36, Oswestry Disability Index [ODI], Scoliosis Research Society [SRS-22], numeric rating scale [NRS] leg and back, P>0.05) and deformity (pelvic tilt [PT], pelvic incidence-lumbar lordosis [PI-LL], and sagittal vertical axis [SVA], P> 0.05). The IS group had more unilateral fixation versus S2AI (12.9% vs. 6%; P = 0.02). The overall lumbopelvic fixation failure rate was 23.74%. Pelvic fixation (13.4%) and S1 screw (2.9%) loosening was more likely with S2AI (odds ratio [OR] 2.63, P = 0.001; OR 6.05, P = 0.022). Pelvic screw (2.3%) and rod fracture (14.1%) rates similar between groups but trended toward less occurrence with S2AI (OR 0.47, P= 0.06). Revision surgery occurred in 22.7%, and in 8.5% for iliac fixation specifically, but with no differences between fixation types (P = 0.55 and P = 0.365). Pelvic fixation failure conferred worse HRQL scores (physical component score [PCS] 36.23 vs. 39.37, P= 0.04; ODI 33.81 vs. 27.93, P = 0.036), and less 2 years improvement (PCS 7.69 vs. 10.46, P = 0.028; SRS 0.83 vs. 1.03, P = 0.019; ODI 12.91 vs. 19.77, P = 0.0016). CONCLUSION/CONCLUSIONS:Lumbopelvic fixation failure rates were high following ASD correction, and associated with lesser clinical improvements. S2AI screws were more likely to demonstrate loosening, but less commonly associated with rod fractures at the lumbopelvic region.