Underwent Adult Spinal Deformity Surgery Research Articles

286. Early adoption of enhanced recovery after surgery protocol following adult spinal deformity surgery is not associated with decreased in-hospital opioid use

BACKGROUND CONTEXT The United States is facing an opioid crisis. Opioid use is common and widespread in the adult spinal deformity (ASD) population. Enhanced Recovery After Surgery (ERAS) is a multimodal and multidisciplinary evidence-based, perioperative approach for surgery intended to reduce surgical morbidity and improve recovery. We sought to evaluate the effects of ERAS implementation on postoperative opiate consumption, length of stay (LOS), and postoperative day of ambulation (PDA) following ASD surgery. PURPOSE The purpose of this study is to test if the implementation of ERAS protocol will help reduce in-hospital opioid use, length of stay and postoperative day of ambulation following ASD surgery. STUDY DESIGN/SETTING Single site, multisurgeon, retrospective longitudinal cohort study. PATIENT SAMPLE We sampled a total of 50 patients, 6 months pre- (n=20) and post- (n=30) ERAS implementation. METHODS A single center, multisurgeon, retrospective review identified patients with adult deformity who underwent ASD surgery 6 months pre- (n=20) and post- (n=30) ERAS implementation. The 2 cohorts were statistically similar in age, sex, BMI, diagnosis, ASA grade and levels fused. Total morphine equivalent doses (MED) in-hospital as well as 90-day postoperative prescriptions were calculated. LOS and PDA were also evaluated. Preoperative opiate prescriptions were recorded to determine baseline opioid use. RESULTS We found no difference in hospital postoperative mean total MED between the 2 cohorts (preERAS=263, postERAS=211, p=0.44). The 90-day mean total MED was also not significantly different between the cohorts (preERAS= 572, postERAS=326, p=0.12). 25 (50%) patients were taking opiates prior to surgery. Opiate naive patients required significantly less in-hospital mean total MED compared to nonopiate naive patients (124 vs 629, p=0.02, respectively). However, 90-day mean total MED was not significantly different between the 2 cohorts (naive=197 vs non-opiate naive=311, p=0.18). LOS for ERAS cohort (5.20.±73) was less when compared to preERAS cohort (5.9±0.6, p=0.22), but this was not significant. PDA was significantly decreased after ERAS implementation (1.1 vs 0.43, p=0.006). CONCLUSIONS Early adoption of ERAS did not decrease in-hospital opioid consumption or total 90-day opioid prescription. In-hospital opioid consumption was correlated with preoperative opioid use. Decreasing presurgical opioid use has a significant effect on postoperative patient opioid consumption and should be implemented as part of ERAS protocol. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

212. Giving patients the info they want: practical answers to FAQs for shared decision-making in ASD surgery

BACKGROUND CONTEXT The shared decision-making (SDM) process is an opportunity to deliver answers to frequently asked questions (FAQs) in adult spinal deformity (ASD) surgery. PURPOSE Our goal was to present a concise list of answers to these FAQs to aid in SDM counseling. STUDY DESIGN/SETTING Retrospective analysis of a prospective multi-center ASD database. PATIENT SAMPLE Adult spinal deformity patients undergoing surgical correction enrolled into a prospective, multicenter surgical database from 2008-2016. OUTCOME MEASURES Health related quality of life (HRQOL) outcome measures were collected such as Oswestry Disability Index (ODI), SF-36 PCS, and SF-36 MCS. METHODS Adult patients undergoing ≥ 5 level fusion with minimum 2-year follow up were included. We purposely included all deformity types (heterogeneity) to provide general applicability. We compiled a list of FAQs by patients undergoing ASD surgery and utilized a retrospective analysis to provide answers. All responses are reported as either means or reaching minimal clinically important difference (MCID) at the 2-year follow-up interval. RESULTS Out of 689 ASD patients eligible for 2-year follow-up, 521 (76%) had complete follow-up. The majority were female (77%) with mean age of 58.5 years and BMI of 27.5. Mean levels fused were 11.3 with 52% being primary vs 48% revision surgeries. Will my pain improve? Back (7.2 to 3.6) and leg (4.7 to 2.6) pain were both reduced by ∼50%. Will my activity level improve? A total of 63.9% reached MCID for SRS-22r activity. Will I feel better about myself? A total of 71.2% reached MCID for SRS-22r appearance. Is there a chance I'm worse? A total of 4.1% of patients were worse (ODI). What is the likelihood I have a complication? A total of 52.9% of patients have at least 1 complication and 29.6% have a major complication. Will I need another surgery? A total of 29.6% of patients have a reoperation within 2 years. Will I regret having surgery? A total of 32% would not choose the same treatment. Will I get a blood transfusion? A total of 79.1% of patients receive a blood transfusion. How long will I stay in the hospital? Study showed 9.9 days. Will I have to go to the ICU? A total of 79.1% of patients require an ICU stay. Will I be able to return to work? A total of 71% returned to full-time work at 2 years. Will I be taller after surgery? Yes, 1.4cm was the average CONCLUSIONS The above list provides concise, practical answers to FAQs encountered in the SDM process while counseling patients for ASD surgery. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Evolution in Surgical Approach, Complications, and Outcomes in an Adult Spinal Deformity Surgery Multicenter Study Group Patient Population

Study DesignRetrospective review of a prospectively collected multicenter database. ObjectivesTo evaluate the evolution of surgical treatment strategies, complications, and patient-reported outcomes for adult spinal deformity (ASD) patients. Summary of Background DataASD surgery is associated with high complication rates. Evolving treatment strategies may reduce these risks. MethodsAdult patients undergoing ASD surgery from 2009 to 2016 were analyzed (n = 905). Preoperative and surgical parameters were compared across years. Subgroup analysis of 436 patients with minimum two-year follow-up was also performed. ResultsFrom 2009 to 2016, there was a significant increase in the mean preoperative age (52 to 63.1, p < .001), body mass index (26.3 to 32.2, p = .003), Charlson Comorbidity index (1.4 to 2.2, p < .001), rate of previous spine surgery (39.8% to 53.1%, p = .01), and baseline disability (visual analog scale [VAS] back and leg pain) scores (p < .01), Oswestry Disability Index, and 22-item Scoliosis Research Society Questionnaire scores (p < .001). Preoperative Schwab sagittal alignment modifiers and overall surgical invasiveness index were similar across time. Three-column osteotomy utilization decreased from 36% in 2011 to 16.7% in 2016. Lateral lumbar interbody fusion increased from 6.4% to 24.1% (p = .004), anterior lumbar interbody fusion decreased from 22.9% to 16.7% (p = .043), and transforaminal lumbar interbody fusion/posterior lumbar interbody fusion utilization remained similar (p = .448). Use of recombinant human bone morphogenetic protein-2 (rhBMP-2) in 2012 was 84.6%, declined to 58% in 2013, and rebounded to 76.3% in 2016 (p = .006). Tranexamic acid use increased rapidly from 2009 to 2016 (13.3% to 48.6%, p < .001). Two-year follow-up sagittal vertical axis, pelvic tilt, pelvic incidence–lumbar lordosis, and maximum Cobb angles were similar across years. Intraoperative complications decreased from 33% in 2010 to 9.3% in 2016 (p < .001). Perioperative (<30 days, <90 days) complications peaked in 2010 (42.7%, 46%) and decreased by 2016 (24.1%, p < .001; 29.6%, p = .007). The overall complication rate decreased from 73.2% in 2008–2014 patients to 62.6% in 2015–2016 patients (p = .03). Two-year health-related quality of life outcomes did not significantly differ across the years (p > .05). ConclusionsFrom 2009 to 2016, despite an increasingly elderly, medically compromised, and obese patient population, complication rates decreased. Evolving strategies may result in improved treatment of ASD patients. Level of EvidenceLevel IV.

Comparison of Postoperative Outcomes According to Compensatory Changes of the Thoracic Spine Among Patients With a T1 Slope More Than 40°.

Retrospective study of postoperative outcomes of adult spinal deformity (ASD) surgery. To clarify the differences in postoperative outcomes depending on the presence or absence of thoracic compensatory changes among patients with a T1 slope (TS) more than 40°. Loss correction after ASD surgery is more likely to occur when preoperative TS is more than 40°. When preoperative TS is more than 40°, some cases involve compensatory changes in the thoracic spine and decreased thoracic kyphosis (TK); others involve increased TK without compensatory changes. Seventy-nine patients with TS more than 40° who underwent ASD surgery were enrolled and separated into compensated and noncompensated groups (group C: TK <40°; group NC: TK ≥40°). Radiographic parameters obtained by whole-spine standing x-ray, the Oswestry Disability Index (ODI), and Scoliosis Research Society-22 (SRS-22) questionnaire were assessed. There were 41 patients in group C and 38 patients in group NC. Preoperative significant differences in TS did not disappear after surgery (preoperative TS: group C and group NC = 46° and 55°, P < 0.001; just after surgery: group C and group NC = 27° and 40°, P < 0.001; 2 years later: group C and group NC = 34° and 47°, P < 0.001). There were no significant differences in ODI and all domains of the SRS-22 before surgery. However, 2 years after the surgery, ODI (38%), pain (3.5), self-image (3.0), and total (3.2) values of the SRS-22 for group NC were significantly worse than those (28%, 4.0, 3.4, and 3.5, respectively) for group C (P < 0.05). Changes in the thoracic spine (TS and TK >40°) result in poor postoperative outcomes. Extending the upper instrumented vertebra (UIV) to the upper thoracic spine must be considered. Even when TS is more than 40°, TK less than 40°, and upper instrumented vertebra set to the lower thoracic level result in good postoperative outcomes. 3.

Adult spinal deformity surgery: a systematic review of venous thromboprophylaxis and incidence of venous thromboembolic events.

Venous thromboprophylaxis consisting of chemical and/or mechanical prophylaxis is administered to patients undergoing adult spinal deformity (ASD) surgery to prevent venous thromboembolic events. However, the true incidence of venous thromboembolism (VTE) after these surgeries is unknown resulting in weak recommendations and lack of consensus regarding type and timing of prophylaxis in these patients. A systematic literature review was conducted to examine VTE incidence in addition to optimal type and timing of VTE prophylaxis. A detailed search was carried out on Embase, PubMed, and Cochrane Library databases through October 18, 2017, for studies that evaluated venous thromboembolic outcomes, type, and timing of prophylaxis administration among ASD surgery patients who were on VTE prophylaxis. The randomized study was assessed for risk of bias using the Cochrane tool and the observational studies using the Newcastle-Ottawa scale (NOS). The search yielded 1180 studies, and three articles published between 1996 and 2008 met the inclusion criteria. There were 583 surgeries performed on 537 patients with a mean age ranging from 45 to 52years. Females dominated the study with percentages ranging from 60 to 94% in the different study populations. VTE prophylaxis was initiated before surgery in 87.7% patients and intraoperatively in 12.3% patients. VTE incidence ranged between 0 and 9.1% among the studies. VTE can occur after ASD surgery regardless of the type of prophylaxis, and incidence may be higher when mechanical prophylaxis alone is initiated intraoperatively. Further studies to examine VTE prophylaxis in patients undergoing ASD surgery should be considered.

What Factors Predict the Risk of Proximal Junctional Failure in the Long Term, Demographic, Surgical, or Radiographic?: Results From a Time-dependent ROC Curve.

Retrospective review of prospective multicenter database. To identify an optimal set of factors predicting the risk of proximal junctional failure (PJF) while taking the time dependency of PJF and those factors into account. Surgical correction of adult spinal deformity (ASD) can be complex and therefore, may come with high revision rates due to PJF. Seven hundred sixty-three operative ASD patients with a minimum of 1-year follow-up were included. PJF was defined as any type of proximal junctional kyphosis (PJK) requiring revision surgery. Time-dependent ROC curves were estimated with corresponding Cox proportional hazard models. The predictive abilities of demographic, surgical, radiographic parameters, and their possible combinations were assessed sequentially. The area under the curve (AUC) was used to evaluate models' performance. PJF occurred in 42 patients (6%), with a median time to revision of approximately 1 year. Larger preoperative pelvic tilt (PT) (hazard ratio [HR]=1.044, P = 0.034) significantly increased the risk of PJF. With respect to changes in the radiographic parameters at 6-week postsurgery, larger differences in pelvic incidence-lumbar lordosis (PI-LL) mismatch (HR = 0.924, P = 0.002) decreased risk of PJF. The combination of demographic, surgical, and radiographic parameters has the best predictive ability for the occurrence of PJF (AUC = 0.863), followed by demographic along with radiographic parameters (AUC = 0.859). Both models' predictive ability was preserved over time. Over correction increased the risk of PJF. Radiographic along with demographic parameters have shown the approximately equivalent predictive ability for PJF over time as with the addition of surgical parameters. Radiographic rather than surgical factors may be of particular importance in predicting the development of PJF over time. These results set the groundwork for risk stratification and corresponding prophylactic interventions for patients undergoing ASD surgery. 4.

Ability of the Global Alignment and Proportion Score to Predict Mechanical Failure Following Adult Spinal Deformity Surgery—Validation in 149 Patients With Two-Year Follow-up

Study DesignRetrospective analysis of prospectively collected data. ObjectivesTo validate the Global Alignment and Proportion (GAP) score in a single-center cohort of adult spinal deformity (ASD) patients. Summary of Background DataSurgical treatment for ASD is associated with a high risk of mechanical failure and consequent revision surgery. To improve prediction of mechanical complications, the GAP score was developed with promising results. Development was based on the assumption that not all patients would benefit from the same fixed radiographic targets as pelvic incidence is an individual, morphological parameter that greatly influences the sagittal curves of the spine. MethodsIn a validation study of the GAP score, patients undergoing ASD surgery with four or more levels of instrumentation were consecutively included at a tertiary spine unit. Patients were followed for a minimum of two years. Pre- and postoperative GAP score and categories were calculated for all patients, and the association with mechanical failure and revision surgery was analyzed. ResultsA total of 149 patients with a mean age of 57.4 years were included. Overall, the rates of mechanical failure and revision surgery were 51% and 35% respectively. The area under the curve (AUC) using receiver operating characteristic was classified as “no or low discriminatory power” for the GAP score in predicting either outcome (AUC = 0.50 and 0.49, respectively). Similarly, there were no significant associations between GAP categories and the occurrence of mechanical failure or revision surgery when using Cochran-Armitage test of trend (p = .28 for mechanical failure and p = .58 for revision surgery). ConclusionsIn a consecutive series of surgically treated ASD patients, we found no significant association between postoperative GAP score and mechanical failure or revision surgery. Despite minor limitations in similarities to the original study cohort, further validation studies or adjustments to the original scoring system are proposed. Level of EvidenceLevel II.

Effect of Vertebroplasty at the Upper Instrumented Vertebra and Upper Instrumented Vertebra +1 for Prevention of Proximal Junctional Failure in Adult Spinal Deformity Surgery: A Comparative Matched-Cohort Study

This study aimed to compare radiographic outcomes of adult spinal deformity (ASD) surgery with or without 2-level prophylactic vertebroplasty (PVP) at the uppermost instrumented vertebra (UIV) and the vertebra 1 level proximal to the UIV. This retrospective 1:2 matched-cohort comparative study enrolled 2 groups of patients undergoing ASD surgery, including 28 patients with PVP (PVP group) and 56 patients without PVP (non-PVP group), in 3 institutes between 2012 and 2015. The primary outcome measure was the incidence of proximal junctional kyphosis (PJK), proximal junctional failure (PJF), and proximal junctional fracture (PJFX). The secondary outcome measure were radiologic outcomes between PVP segments and non-PVP segments. Between the PVP group and non-PVP group, no significant differences were found in the incidence of PJK (13 [46.4%] vs. 26 [46.4%]; P= 1.000), PJF (11 [39.3%] vs. 18 [32.1%]; P= 0.516), and PJFX (11 [39.3%] vs. 18 [32.1%]; P= 0.516). The number of the PJFX segments was 16 and 33 in PVP segments and non-PVP segments, respectively. Until revision surgery or final follow-up, the PJFX had progressed in 24 non-PVP segments (82.7%), but not in PVP segments. The PJFX progression in all PVP segments stopped near the PVP mass at the final follow-up. Reoperation as a result of PJFX was performed in 1 patient (3.6%) and 8 patients (14.3%) in the PVP and non-PVP groups, respectively. PVP at UIV and vertebra 1 level proximal to the UIV cannot prevent PJK, PJF, and PJFX; however, it plays a positive role by delaying their progression. Furthermore, PVP tends to lower the reoperation rate after PJFX in ASD surgery.

Surgical risk stratification based on preoperative risk factors in adult spinal deformity

BACKGROUND CONTEXTCorrective surgery for adult spinal deformity (ASD) improves health-related quality of life but has high complication rates. Predicting a patient's risk of perioperative and late postoperative complications is difficult, although several potential risk factors have been reported. PURPOSETo establish an accurate, ASD-specific model for predicting the risk of postoperative complications, based on baseline demographic, radiographic, and surgical invasiveness data in a retrospective case series. STUDY DESIGN/SETTINGMulticentered retrospective review and the surgical risk stratification. PATIENT SAMPLEOne hundred fifty-one surgically treated ASD at our hospital for risk analysis and model building and 89 surgically treated ASD at 2 other our hospitals for model validation. OUTCOME MEASURESHRQoL measures and surgical complications. METHODSWe analyzed demographic and medical data, including complications, for 151 adults with ASD who underwent surgery at our hospital and were followed for at least 2years. Each surgical risk factor identified by univariate analyses was assigned a value based on its odds ratio, and the values of all risk factors were summed to obtain a surgical risk score (range 0–20). We stratified risk scores into grades (A–D) and analyzed their correlations with complications. We validated the model using data from 89 patients who underwent ASD surgery at two other hospitals. RESULTSComplications developed in 48% of the patients in the model-building cohort. Univariate analyses identified 10 demographic, physical, and surgical risk indicators, with odds ratios from 5.4 to 1.4, for complications. Our risk-grading system showed good calibration and discrimination in the validation cohort. The complication rate increased with and correlated well with the risk grade using receiver operating characteristic curves. CONCLUSIONSThis simple, ASD-specific model uses readily accessible indicators to predict a patient's risk of perioperative and postoperative complications and can help surgeons adjust treatment strategies for best outcomes in high-risk patients.

Incidence and Predictive Factors of Sepsis Following Adult Spinal Deformity Surgery.

Surgery for adult spinal deformity (ASD) improves quality of life, yet morbidity is high. Sepsis is a challenging postoperative complication that can result in death and drive inpatient resources. To identify the incidence and risk factors for development of sepsis within 30 days following ASD surgery. Adult patients who underwent thoracolumbar spinal deformity correction between 2008 and 2014 were identified in the National Surgical Quality Improvement Program database. Demographic and operative variables were extracted. The primary outcome was development of postoperative sepsis. Multivariable logistic regression modeling was used to identify independent risk factors for sepsis. A total of 6158 patients underwent ASD surgery. Of these, 156 (2.5%) developed sepsis postoperatively. Independent risk factors included operative time (odds ratio [OR]: 1.004, 95% confidence interval [CI]: 1.003-1.005, P< .001), male sex (OR: 1.47, 95% CI: 1.05-2.05, P= .023), diabetes (OR: 1.59, 95% CI: 1.05-2.40, P= .027), functional dependency (OR: 1.82, 95% CI: 1.12-2.95, P= .015), weight loss (OR: 2.45, 95% CI: 1.04-5.78, P= .040), bleeding disorder (OR: 2.58, 95% CI: 1.34-4.93, P= .004), and ascites (OR: 56.11, 95% CI: 5.01-628.50, P= .001). This model demonstrated strong predictive capacity, with an area under the curve of 0.80. Patients who developed sepsis were significantly more likely to have a prolonged hospital stay (P< .001), be readmitted (P< .001), and die (P< .001). The median (range) time to sepsis was 9 d (0-30). In patients undergoing ASD surgery, male sex, diabetes, ascites, bleeding disorder, functional dependency, excessive weight loss and increased operative time independently predicted sepsis. This perioperative patient profile can be used for preoperative risk assessment, patient counseling, and postoperative management for patients undergoing ASD surgery.

Effect of Resident and Fellow Involvement in Adult Spinal Deformity Surgery

Adult spinal deformity (ASD) operations are complex and often require a multisurgeon team. Simultaneously, it is the responsibility of academic spine surgeons to train future complex spine surgeons. Our objective was to assess the effect of resident and fellow involvement (RFI) on ASD surgery in 4 areas: 1) perioperative outcomes, 2) length of stay (LOS), 3) discharge status, and 4) complications. Adults undergoing thoracolumbar spinal deformity correction from 2008 to 2014 were identified in the National Surgical Quality Improvement Program database. Cases were divided into those with RFI and those with attendings only. Outcomes were operative time, transfusions, LOS, discharge status, and complications. Univariate and multivariable regression modeling was used. Covariates included preoperative comorbidities, specialty, and levels undergoing instrumentation. A total of 1471 patients underwent ASD surgery with RFI in 784 operations (53%). After multivariable regression modeling, RFI was independently associated with longer operations (β= 66.01 minutes; 95% confidence interval [CI], 35.82-96.19; P < 0.001), increased odds of transfusion (odds ratio, 2.80; 95% CI, 1.81-4.32; P < 0.001), longer hospital stay (β= 1.76 days; 95% CI, 0.18-3.34; P=0.030), and discharge to an inpatient rehabilitation or a skilled nursing facility (odds ratio, 2.02; 95% CI, 1.34-3.05; P<0.001). However, RFI was not associated with any increase in major or minor complications. RFI in ASD surgery was associated with increased operative time, the need for additional transfusions, longer LOS, and nonhome discharge. However, no increase in major, minor, or severe complications occurred. These data support the continued training of future deformity and complex spine surgeons without fear of worsening complications; however, areas of improvement exist.

Transcranial Motor Evoked Potential Monitoring for the Detection of Nerve Root Injury during Adult Spinal Deformity Surgery.

Study DesignRetrospective study.PurposeWe aimed to determine the utility of transcranial motor evoked potential (TcMEP) monitoring for the detection of intraoperative nerve root injury.Overview of LiteratureIntraoperative neuromonitoring is important for the prediction of neurological injuries or postoperative paralysis. Nerve root injury can develop as a complication of adult spinal deformity (ASD) surgery.MethodsWe analyzed 295 patients who underwent ASD surgery using multi-channel TcMEP monitoring between 2010 and 2016 (58 men, 237 women; median age, 68 years; follow-up period ≥1 year). We defined the alarm point as a TcMEP amplitude <30% of that at baseline, and nerve root injury as meeting the focal TcMEP alerts shortly following surgical procedures with the presence of postoperative motor deficits in the selected muscles. Patients were classified into two groups, as those with nerve root injury and those with true-negatives.ResultsSeven patients (2.4%) exhibited neurological events related to nerve root injury, comprising six true-positive and one false-negative cases. TcMEP monitoring from multiple myotomes was effective in detecting nerve root injury. Compared to the 248 true-negative cases, the seven cases of nerve root injury were associated with significantly different preoperative pelvic tilt (PT) values, sacral slope values, and degree of change in PT. The cutoff for the degree of change in PT for predicting nerve root injury, with the best sensitivity and specificity, was 17.5°. Multivariate logistic analyses revealed that a change of >17.5° in PT (odds ratio, 17.5; 95% confidence interval, 1.994–153.560; p =0.010) was independently associated with intraoperative nerve root injury.ConclusionsMulti-channel TcMEP monitoring may be useful for detecting nerve root injuries. A change in PT of >17.5° may be a significant risk factor for neurological events related to intraoperative nerve root injury.

Development and Validation of a Novel Adult Spinal Deformity Surgical Invasiveness Score: Analysis of 464 Patients.

A surgical invasiveness index (SII) has been validated in general spine procedures but not adult spinal deformity (ASD). To assess the ability of the SII to determine the invasiveness of ASD surgery and to create and validate a novel ASD index incorporating deformity-specific factors, which could serve as a standardized metric to compare outcomes and risk stratification of different ASD procedures for a given deformity. Four hundred sixty-four patients who underwent ASD surgery between 2009 and 2012 were identified in 2 multicenter prospective registries. Multivariable models of estimated blood loss (EBL) and operative time were created using deformity-specific factors. Beta coefficients derived from these models were used to attribute points to each component. Scoring was iteratively refined to determine the R2 value of multivariate models of EBL and operative time using adult spinal deformity-surgical (ASD-S) as an independent variable. Similarly, we determined weighting of postoperative changes in radiographical parameters, which were incorporated into another index (adult spinal deformity-surgical and radiographical [ASD-SR]). The ability of these models to predict surgical invasiveness was assessed in a validation cohort. Each index was a significant, independent predictor of EBL and operative time (P < .001). On multivariate analysis, ASD-S and ASD-SR explained more variability in EBL and operative time than did the SII (P < .001). The ASD-SR explained 21% of the variation in EBL and 10% of the variation in operative time, whereas the SII explained 17% and 3.2%, respectively. The ASD-SR, which incorporates deformity-specific components, more accurately predicts the magnitude of ASD surgery than does the SII.

Incidence and predictors of all-cause mortality within one year after adult spinal deformity surgery.

Surgery for adult spinal deformity (ASD) can significantly improve quality of life but is associated with significant risk of morbidity. Among the most devastating potential complications after these operations is death. The current study aims to report the incidence, preoperative factors, and postoperative complications associated with all-cause mortality within 1 year following ASD surgery. Adults who underwent thoracolumbar spinal deformity correction between 2008 and 2014 were identified in the National Surgical Quality Improvement Program (NSQIP) database. Demographic characteristics were extracted. The primary outcome was death within 1 year of ASD surgery. Propensity score matching was used to control for confounding factors, followed by univariate/multivariable logistic regression to predict the odds of death within 1 year of ASD surgery. A total of 6,158 patients underwent ASD surgery and 61 (0.99%) died within one year of surgery. Preoperative factors: controlling for age, gender, American Society of Anesthesiologists (ASA) score and postoperative complications, four independent risk factors were associated with all-cause mortality within 1 year of ASD surgery: increased age (OR =1.03; 95% CI, 1.01-1.06; P=0.012), ASA score (OR =4.32; 95% CI, 2.68-6.94; P<0.001), cancer history (OR =7.91; 95% CI, 4.23-14.78; P<0.001) and unintentional weight loss (OR =4.65; 95% CI, 1.68-12.89; P=0.003). Postoperative complications: using propensity score matching and multivariable logistic regression, three independent risk factors were associated with all-cause mortality within 1 year of ASD surgery: pneumonia (OR =4.00; 95% CI, 1.68-9.53), deep venous thrombosis (DVT) (OR =3.12; 95% CI, 1.20-8.10) and unplanned intubation (OR =3.13; 95% CI, 1.15-8.50). Death after elective ASD surgery is a devastating yet uncommon event with an incidence of 1%. Preoperative factors of age, ASA score, cancer history, and unexpected weight loss, along with postoperative complications of pneumonia, DVT, and unplanned intubation were independently associated with all-cause mortality within 1 year of ASD surgery. Interestingly, the potentially more severe complications of sepsis, PE, and MI did not independently predict death.

Treatment strategy for rod fractures following corrective fusion surgery in adult spinal deformity depends on symptoms and local alignment change.

OBJECTIVE Despite the significant incidence of rod fractures (RFs) following long-segment corrective fusion surgery, little is known about the optimal treatment strategy. The objectives of this study were to investigate the time course of clinical symptoms and treatments in patients with RFs following adult spinal deformity (ASD) surgery and to establish treatment recommendations. METHODS This study was a retrospective case series of patients with RFs whose data were retrieved from a prospectively collected single-center database. The authors reviewed the cases of 304 patients (mean age 62.9 years) who underwent ASD surgery. Primary symptoms, time course of symptoms, and treatments were investigated by reviewing medical records. Standing whole-spine radiographs obtained before and after RF development and at last follow-up were evaluated. Osseous union was assessed using CT scans and intraoperative findings. RESULTS There were 54 RFs in 53 patients (mean age 68.5 years [range 41-84 years]) occurring at a mean of 21 months (range 6-47 months) after surgery. In 1 patient RF occurred twice, with each case at a different time and level, and the symptoms and treatments for these 2 RFs were analyzed separately (1 case of revision surgery and 1 case of nonoperative treatment). The overall rate of RF observed on radiographs after a minimum follow-up of 1 year was 18.0% (54 of 300 cases). The clinical symptoms at the time of RF were pain in 77.8% (42 of 54 cases) and no onset of new symptoms in 20.5% (11 of 54 cases). The pain was temporary and had subsided in 19 of 42 cases (45%) within 2 weeks. In 36 of the 54 cases (66.7%) (including the first RF in the patient with 2 RFs), patients underwent revision surgery at a mean of 116 days (range 5-888 days) after diagnosis. In 18 cases patients received only nonoperative treatment as of the last follow-up, including 17 cases in which the patients experienced no pain and no remarkable progression of deformity (mean 18.5 months after RF development). CONCLUSIONS This analysis of 54 RFs in 53 patients following corrective fusion surgery for ASD demonstrates a relationship between symptoms and alignment change. Revision surgeries were performed in a total of 36 cases. Nonoperative care was offered in 18 (33.3%) of 54 cases at the last follow-up, with no additional symptoms in 17 of the 18 cases. These data offer useful information regarding informed decision making for patients in whom an RF occurs after ASD surgery.

Pelvic fixation techniques and impact on sagittal balance: A literature review

As adult spinal deformity (ASD) surgery advances, pelvic fixation techniques have evolved to confront several challenges such as pseudoarthrosis and instrumentation failure. Concurrently, ASD literature has identified sagittal balance as one of the pre-eminent factors in clinical outcomes in patients undergoing ASD surgery. However, despite advances in surgical technique and understanding of clinical outcome predictors, there is limited evaluation of the impact of pelvic instrumentation on global sagittal alignment. This review provides context on historical pelvic instrumentation options and assesses the advantages and disadvantages of modern pelvic fixation techniques in ASD surgery with respect to sagittal balance. Available data suggest that pre- and postoperative sagittal balance correction remains an important clinical outcome predictor, but such a correction can be undermined by postoperative complications such as pseudoarthrosis and instrumentation failure over the long term. Therefore, choice of instrumentation construct should not only consider intraoperative factors and immediate sagittal balance correction but also prevention of complications over patients’ full postoperative course. Future research should directly evaluate pelvic fixation techniques in the context of long-term postoperative clinical and radiologic outcomes, specifically sagittal balance.

ASA Classification as a Risk Stratification Tool in Adult Spinal Deformity Surgery: A Study of 5805 Patients.

Study Design:Retrospective analysis of prospectively collected data.Objectives:Adult spinal deformity (ASD) surgery is a highly complex procedure that has high complication rates. Risk stratification tools can improve patient management and may lower complication rates and associated costs. The goal of this study was to identify the independent association between American Society of Anesthesiologists (ASA) class and postoperative outcomes following ASD surgery.Methods:The 2010-2014 American College of Surgeons National Surgical Quality Improvement Program database was queried using Current Procedural Terminology and International Classification of Diseases, Ninth Revision, codes relevant to ASD surgery. Patients were divided based on their ASA classification. Bivariate and multivariate logistic regression analyses were employed to quantify the increased risk of 30-day postoperative complications for patients with increased ASA scores.Results:A total of 5805 patients met the inclusion criteria, 2718 (46.8%) of which were ASA class I-II and 3087 (53.2%) were ASA class III-IV. Multivariate logistic regression revealed ASA class to be a significant risk factor for mortality (odds ratio [OR] = 21.0), reoperation within 30 days (OR = 1.6), length of stay ≥5 days (OR = 1.7), overall morbidity (OR = 1.4), wound complications (OR = 1.8), pulmonary complications (OR = 2.3), cardiac complications (OR = 3.7), intra-/postoperative red blood cell transfusion (OR = 1.3), postoperative sepsis (OR = 2.7), and urinary tract infection (OR = 1.6).Conclusions:This is the first study evaluating the role of ASA class in ASD surgery with a large patient database. Use of ASA class as a metric for preoperative health was verified and the association of ASA class with postoperative morbidity and mortality in ASD surgery suggests its utility in refining the risk stratification profile and improving preoperative patient counseling for those individuals undergoing ASD surgery.

Factors associated with prolonged ventilation and reintubation in adult spinal deformity surgery

Prolonged ventilation or reintubation are severe complications after scoliosis surgery, but there is limited data regarding their incidence and risk factors. The purpose of this study is to investigate the incidence and risk factors for prolonged ventilation and reintubation in adult spinal deformity (ASD) surgery. The American College of Surgeons National Surgical Quality Improvement Program database (2007–2013) was reviewed. Inclusion criteria were adult patients over 21years of age who underwent spinal fusion for ASD. The association between patient/operative characteristics and prolonged ventilation/reintubation was investigated via multivariate analysis. Results are presented as odds ratios (OR) with 95% confidence intervals (CI). There were 1250 patients who underwent ASD surgery and met our inclusion criteria. Among these, there were 34 patients who required prolonged ventilation (2.7%) and 22 patients who underwent reintubation (1.8%). Factors associated with prolonged ventilation after multivariate analysis were history of bleeding disorder (OR 5.67; 95% CI, 1.01–31.83) and operative time over 6h (OR 3.72; 95% CI, 1.17–11.80). For reintubation, these included older age (OR 1.06; 95% CI, 1.01–1.12), history of bleeding disorder (OR 12.21; 95% CI, 2.03–73.42), and fusion of 13 or more spinal levels (OR 9.14; 95% CI, 1.53–54.63). In conclusion, prolonged ventilation and reintubation in ASD surgery are uncommon events. Older patients, patients with bleeding disorders, and those undergoing long operations and fusion of 13 more spinal segments may be at an increased risk for these occurrences.

Development of a preoperative predictive model for major complications following adult spinal deformity surgery.

OBJECTIVE The operative management of patients with adult spinal deformity (ASD) has a high complication rate and it remains unknown whether baseline patient characteristics and surgical variables can predict early complications (intraoperative and perioperative [within 6 weeks]). The development of an accurate preoperative predictive model can aid in patient counseling, shared decision making, and improved surgical planning. The purpose of this study was to develop a model based on baseline demographic, radiographic, and surgical factors that can predict if patients will sustain an intraoperative or perioperative major complication. METHODS This study was a retrospective analysis of a prospective, multicenter ASD database. The inclusion criteria were age ≥ 18 years and the presence of ASD. In total, 45 variables were used in the initial training of the model including demographic data, comorbidities, modifiable surgical variables, baseline health-related quality of life, and coronal and sagittal radiographic parameters. Patients were grouped as either having at least 1 major intraoperative or perioperative complication (COMP group) or not (NOCOMP group). An ensemble of decision trees was constructed utilizing the C5.0 algorithm with 5 different bootstrapped models. Internal validation was accomplished via a 70/30 data split for training and testing each model, respectively. Overall accuracy, the area under the receiver operating characteristic (AUROC) curve, and predictor importance were calculated. RESULTS Five hundred fifty-seven patients were included: 409 (73.4%) in the NOCOMP group, and 148 (26.6%) in the COMP group. The overall model accuracy was 87.6% correct with an AUROC curve of 0.89 indicating a very good model fit. Twenty variables were determined to be the top predictors (importance ≥ 0.90 as determined by the model) and included (in decreasing importance): age, leg pain, Oswestry Disability Index, number of decompression levels, number of interbody fusion levels, Physical Component Summary of the SF-36, Scoliosis Research Society (SRS)-Schwab coronal curve type, Charlson Comorbidity Index, SRS activity, T-1 pelvic angle, American Society of Anesthesiologists grade, presence of osteoporosis, pelvic tilt, sagittal vertical axis, primary versus revision surgery, SRS pain, SRS total, use of bone morphogenetic protein, use of iliac crest graft, and pelvic incidence-lumbar lordosis mismatch. CONCLUSIONS A successful model (87% accuracy, 0.89 AUROC curve) was built predicting major intraoperative or perioperative complications following ASD surgery. This model can provide the foundation toward improved education and point-of-care decision making for patients undergoing ASD surgery.

Preoperative functional status as a predictor of short-term outcome in adult spinal deformity surgery

Adult spinal deformity (ASD) may cause severe disability and difficulty with daily activities. The purpose of this study was to investigate the impact of preoperative functional status on 30-day major complication occurrence in ASD surgery. A review of the prospectively-collected American College of Surgeons National Surgical Quality Improvement database was performed for the years 2007–2013. Inclusion criteria were adult patients (over 21years of age) who underwent spinal fusion for ASD. Functional status was defined as “independent” or “dependent” (requiring assistance from another person) for activities of daily living such as bathing, dressing, feeding, toileting, or mobility. The association between functional status and complications (overall and major) was investigated via multivariate analysis. Results are presented as odds ratios (OR) with 95% confidence intervals (CI). A total of 1247 patients met inclusion criteria (94.4% independent and 5.6% dependent patients). The overall 30-day complication rate was 16.0% (15.6% for independent patients and 22.9% for dependent patients, p=0.10); major complications occurred in 9.2% of independent patients and 17.1% for dependent patients (p=0.02). After controlling for patient age, smoking status, preoperative hematocrit, revision status, use of osteotomy, number of levels fused, and operative time, being dependent on another person for activities of daily living was found to be a significant predictor of major complication development (OR 2.09; 95% CI, 1.04–4.20; p=0.03). Depending on others for activities of daily living before undergoing ASD surgery may predict the development of major perioperative complications, increasing the risk by 2-fold compared to independent patients.