Morbidity and mortality in adult spinal deformity surgery: Norwich Spinal Unit experience. Eur Spine J. 2013;22 Suppl 1:S42-S46. [PMID: 23288452 DOI: 10.1007/s00586-012-2627-y]

AM-PAC Mobility Score <13 Predicts Development of Ileus Following Adult Spinal Deformity Surgery

STUDY DESIGN

Retrospective review.

OBJECTIVE

To determine whether the Activity Measure for Post-Acute Care (AM-PAC) "6-Clicks" score is associated with the development of postoperative ileus.

SUMMARY OF BACKGROUND DATA

Adult spinal deformity (ASD) surgery has a high complication rate. One common complication is postoperative ileus, and poor postoperative mobility has been implicated as a modifiable risk factor for this condition.

METHODS

Eighty-five ASD surgeries in which ≥5 levels were fused were identified in a single institution database. A physical therapist/physiatrist collected patients' daily postoperative AM-PAC scores, for which we assessed first, last, and daily changes. We used multivariable linear regression to determine the marginal effect of ileus on continuous AM-PAC scores; threshold linear regression with Bayesian information criterion to identify a threshold AM-PAC score associated with ileus; and multivariable logistic regression to determine the utility of the score thresholds when controlling for confounding variables.

RESULTS

Ten of 85 patients (12%) developed ileus. The mean day of developing ileus was postoperative day 3.3±2.35. The mean first and last AM-PAC scores were 16 and 18, respectively. On bivariate analysis, the mean first AM-PAC score was lower in patients with ileus than in those without (13 vs. 16; P< 0.01). Ileus was associated with a first AM-PAC score of 3 points lower (Coef. -2.96; P< 0.01) than that of patients without ileus. Patients with an AM-PAC score<13 had 8 times greater odds of developing ileus ( P= 0.023). Neither the last AM-PAC score nor the daily change in AM-PAC score was associated with ileus.

CONCLUSIONS

In our institutional cohort, a first AM-PAC score of <13, corresponding to an inability to walk or stand for more than 1 minute, was associated with the development of ileus. Early identification of patients who cannot walk or stand after surgery can help determine which patients would benefit from prophylactic management.

LEVEL OF EVIDENCE

Level-III.

Impact of Controlled Versus Uncontrolled mFI-5 Frailty on Perioperative Complications After Adult Spinal Deformity Surgery

STUDY DESIGN

Retrospective review.

OBJECTIVES

We substratified the mFI-5 frailty index to reflect controlled and uncontrolled conditions and assess their relationship to perioperative complications.

SUMMARY OF BACKGROUND DATA

Risk assessment before adult spinal deformity (ASD) surgery is critical because the surgery is highly invasive with a high complication rate. Although frailty is associated with risk of surgical complications, current frailty measures do not differentiate between controlled and uncontrolled conditions.

METHODS

Frailty was calculated using the mFI-5 index for 170 ASD patients with fusion of ≥5 levels. Uncontrolled frailty was defined as blood pressure >140/90 mm Hg, HbA1C >7% or postprandial glucose >180 mg/dL, or recent chronic obstructive pulmonary disease (COPD) exacerbation, while on medication. Patients were divided into nonfrailty, controlled frailty, and uncontrolled frailty cohorts. The primary outcome measure was perioperative major and wound complications. Bivariate analysis was performed. Multivariable analysis assessed the relationship between frailty and perioperative complications.

RESULTS

The cohorts included 97 nonfrail, 54 controlled frail, and 19 uncontrolled frail patients. Compared with nonfrail patients, patients with uncontrolled frailty were more likely to have age older than 60 years (84% vs. 24%), hyperlipidemia (42% vs. 20%), and Oswestry Disability Index (ODI) score >42 (84% vs. 52%) ( P <0.05 for all). Controlled frailty was associated with those older than 60 years (41% vs. 24%) and hyperlipidemia (52% vs. 20%) ( P <0.05 for all). On multivariable regression analysis controlling for hyperlipidemia, functional independence, motor weakness, ODI>42, and age older than 60 years, patients with uncontrolled frailty had greater odds of major complications (OR 4.24, P =0.03) and wound complications (OR 9.47, P =0.046) compared with nonfrail patients. Controlled frailty was not associated with increased risk of perioperative complications ( P >0.05 for all).

CONCLUSIONS

Although patients with uncontrolled frailty had higher risk of perioperative complications compared with nonfrail patients, patients with controlled frailty did not, suggesting the importance of controlling modifiable risk factors before surgery.

LEVEL OF EVIDENCE

3.

Long-term Outcomes After Adult Spinal Deformity Surgery Using Lateral Interbody Fusion: Short Versus Long Fusion

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To investigate long-term outcomes after short or long fusion for adult spinal deformity using lateral interbody fusion.

SUMMARY OF BACKGROUND DATA

Lateral interbody fusion is commonly used in adult spinal deformity surgery. Favorable short-term outcomes have been reported, but not long-term outcomes. Lateral interbody fusion with strong ability to correct deformity may allow the selection of short fusion techniques.

MATERIALS AND METHODS

We retrospectively reviewed adults who underwent this surgery with a minimum of 5 years of follow-up. Short fusion with the uppermost instrumented vertebra in the lumbar spine was performed in patients without degenerative changes at the thoracolumbar junction (S-group); others underwent long fusion with the uppermost instrumented vertebra in the thoracic spine (L-group). We assessed radiographic and clinical outcomes.

RESULTS

Short fusion was performed in 29 of 54 patients. One patient per group required revision surgery. Of the remainder, with similar preoperative characteristics and deformity correction between groups, correction loss (pelvic incidence-lumbar lordosis, P =0.003; pelvic tilt, P =0.005; sagittal vertical axis, P ˂0.001) occurred within 2 years postoperatively in the S-group, and sagittal vertical axis continued to increase until the 5-year follow-up ( P =0.021). Although there was a significant change in Oswestry disability index in the S-group ( P =0.031) and self-image of Scoliosis Research Society 22r score in both groups ( P =0.045 and 0.02) from 2- to 5-year follow-up, minimum clinically important differences were not reached. At 5-year follow-up, there was a significant difference in Oswestry Disability Index ( P =0.013) and Scoliosis Research Society 22r scores (function: P =0.028; pain: P =0.003; subtotal: P =0.006) between the groups, but satisfaction scores were comparable and Oswestry Disability Index score (29.8%) in the S-group indicated moderate disability.

CONCLUSIONS

Health-related quality of life was maintained between 2- and 5-year follow-up in both groups. Short fusion may be an option for patients without degenerative changes at the thoracolumbar junction.

LEVEL OF EVIDENCE

III.

Willingness to undergo the same surgery again among older patients who have undergone corrective fusion surgery for adult spinal deformity

Despite less invasive surgical procedures in adult spinal deformity (ASD) surgery, some older patients have complications and long recovery time. We investigated patients' willingness to undergo the same surgery again and sought to elucidate the factors related to their perception of surgical outcomes. Enrolled were 60 of our patients (≥65 years old) that underwent long corrective fusion using lateral interbody fusion and who had a minimum of 2 years of follow-up. Patients were asked whether they would theoretically undergo the same surgery again: 28 answered yes (46.7 %; Group-Y), and 32 answered no (53.3 %; Group-N). There was no difference between the groups in age, sex, body mass index, frailty, preoperative patient-reported outcomes (PROs; Oswestry disability index [ODI] and Scoliosis Research Society 22r [SRS-22r]), surgical time, estimated blood loss, or pre-operative and 2-year post-operative radiographic parameters. Major complications had occurred more frequently in Group-N (P = 0.048). Although at 2-year follow-up there was significant improvement of spinal deformity and PROs (P < 0.001) in both groups, PROs in Group-N were inferior (Visual analogue scale [VAS] for low back pain, P = 0.043; VAS for satisfaction, P = 0.001; ODI: P = 0.005; SRS-22r: pain, P = 0.032; self-image, P = 0.014; subtotal, P = 0.005; satisfaction, P < 0.001). After multivariate logistic regression analysis with the willingness to undergo the same surgery again as an objective factor, incidence of major complication was found to be an independently-associated factor in unwillingness to undergo the same surgery again for older patients with ASD if they had the same condition in the future. Avoiding major perioperative complications is important in obtaining satisfactory perception of outcomes in ASD surgery.

Explainable Machine Learning Approach to Prediction of Prolonged Intesive Care Unit Stay in Adult Spinal Deformity Patients: Machine Learning Outperforms Logistic Regression

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

Prolonged ICU stay is a driver of higher costs and inferior outcomes in Adult Spinal Deformity (ASD) patients. Machine learning (ML) models have recently been seen as a viable method of predicting pre-operative risk but are often 'black boxes' that do not fully explain the decision-making process. This study aims to demonstrate ML can achieve similar or greater predictive power as traditional statistical methods and follows traditional clinical decision-making processes.

METHODS

Five ML models (Decision Tree, Random Forest, Support Vector Classifier, GradBoost, and a CNN) were trained on data collected from a large urban academic center to predict whether prolonged ICU stay would be required post-operatively. 535 patients who underwent posterior fusion or combined fusion for treatment of ASD were included in each model with a 70-20-10 train-test-validation split. Further analysis was performed using Shapley Additive Explanation (SHAP) values to provide insight into each model's decision-making process.

RESULTS

The model's Area Under the Receiver Operating Curve (AUROC) ranged from 0.67 to 0.83. The Random Forest model achieved the highest score. The model considered length of surgery, complications, and estimated blood loss to be the greatest predictors of prolonged ICU stay based on SHAP values.

CONCLUSIONS

We developed a ML model that was able to predict whether prolonged ICU stay was required in ASD patients. Further SHAP analysis demonstrated our model aligned with traditional clinical thinking. Thus, ML models have strong potential to assist with risk stratification and more effective and cost-efficient care.

A comparative cohort study of surgical approaches for adult spinal deformity at a minimum 2-year follow-up

STUDY DESIGN

This study was a retrospective multi-center comparative cohort study.

MATERIALS AND METHODS

A retrospective institutional database of operative adult spinal deformity patients was utilized. All fusions > 5 vertebral levels and including the sacrum/pelvis were eligible for inclusion. Revisions, 3 column osteotomies, and patients with < 2-year clinical follow-up were excluded. Patients were separated into 3 groups based on surgical approach: 1) posterior spinal fusion without interbody (PSF), 2) PSF with interbody (PSF-IB), and 3) anteroposterior (AP) fusion (anterior lumbar interbody fusion or lateral lumbar interbody fusion with posterior screw fixation). Intraoperative, radiographic, and clinical outcomes, as well as complications, were compared between groups with ANOVA and χ2 tests.

RESULTS

One-hundred and thirty-eight patients were included for study (PSF, n = 37; PSF-IB, n = 44; AP, n = 57). Intraoperatively, estimated blood loss was similar between groups (p = 0.171). However, the AP group had longer operative times (547.5 min) compared to PSF (385.1) and PSF-IB (370.7) (p < 0.001). Additionally, fusion length was shorter in PSF-IB (11.4) compared to AP (13.6) and PSF (12.9) (p = 0.004). There were no differences between the groups in terms of change in alignment from preoperative to 2 years postoperative. There were no differences in clinical outcomes. While postoperative complications were largely similar between groups, operative complications were higher in the AP group (31.6%) compared to the PSF (5.4%) and PSF-IB (9.1) groups (p < 0.001).

CONCLUSION

While there were differences in intraoperative outcomes (operative time and fusion length), there were no differences in postoperative clinical or radiographic outcomes. AP fusion was associated with a higher rate of operative complications.

Revision Strategy for Proximal Junctional Failure: Combined Effect of Proximal Extension and Focal Correction

STUDY DESIGN

Retrospective review of a prospectively-collected multicenter database.

OBJECTIVES

The objective of this study was to determine optimal strategies in terms of focal angular correction and length of proximal extension during revision for PJF.

METHODS

134 patients requiring proximal extension for PJF were analyzed in this study. The correlation between amount of proximal junctional angle (PJA) reduction and recurrence of proximal junctional kyphosis (PJK) and/or PJF was investigated. Following stratification by the degree of PJK correction and the numbers of levels extended proximally, rates of radiographic PJK (PJA >28° & ΔPJA >22°), and recurrent surgery for PJF were reported.

RESULTS

Before revision, mean PJA was 27.6° ± 14.6°. Mean number of levels extended was 6.0 ± 3.3. Average PJA reduction was 18.8° ± 18.9°. A correlation between the degree of PJA reduction and rate of recurrent PJK was observed (r = -.222). Recurrent radiographic PJK (0%) and clinical PJF (4.5%) were rare in patients undergoing extension ≥8 levels, regardless of angular correction. Patients with small reductions (<5°) and small extensions (<4 levels) experienced moderate rates of recurrent PJK (19.1%) and PJF (9.5%). Patients with large reductions (>30°) and extensions <8 levels had the highest rate of recurrent PJK (31.8%) and PJF (16.0%).

CONCLUSION

While the degree of focal PJK correction must be determined by the treating surgeon based upon clinical goals, recurrent PJK may be minimized by limiting reduction to <30°. If larger PJA correction is required, more extensive proximal fusion constructs may mitigate recurrent PJK/PJF rates.

Can Dynamic Spinal Stabilization Be an Alternative to Fusion Surgery in Adult Spinal Deformity Cases?

BACKGROUND

Rigid stabilization and fusion surgery are widely used for the correction of spinal sagittal and coronal imbalance (SCI). However, instrument failure, pseudoarthrosis, and adjacent segment disease are frequent complications of rigid stabilization and fusion surgery in elderly patients. In this study, we present the results of dynamic stabilization and 2-stage dynamic stabilization surgery for the treatment of spinal SCI. The advantages and disadvantages are discussed, especially as an alternative to fusion surgery.

METHODS

In our study, spinal, sagittal, and coronal deformities were corrected with dynamic stabilization performed in a single session in patients with good bone quality (without osteopenia and osteoporosis), while 2-stage surgery was performed in patients with poor bone quality (first stage: percutaneous placement of screws; second stage: placement of dynamic rods and correction of spinal SCI 4-6 months after the first stage). One-stage dynamic spinal instrumentation was applied to 20 of 25 patients with spinal SCI, and 2-stage dynamic spinal instrumentation was applied to the remaining 5 patients.

RESULTS

Spinal SCI was corrected with these stabilization systems. At 2-year follow-up, no significant loss was observed in the instrumentation system, while no significant loss of correction was observed in sagittal and coronal deformities.

CONCLUSION

In adult patients with spinal SCI, single or 2-stage dynamic stabilization is a viable alternative to fusion surgery due to the very low rate of instrument failure.

CLINICAL RELEVANCE

This study questions the use of dynamic stabilization systems for the treatment of adult degenerative deformities.

LEVEL OF EVIDENCE: 4

Development of a modified frailty index for adult spinal deformities independent of functional changes following surgical correction: a true baseline risk assessment tool

PURPOSE

To develop a simplified, modified frailty index for adult spinal deformity (ASD) patients dependent on objective clinical factors.

METHODS

ASD patients with baseline (BL) and 2-year (2Y) follow-up were included. Factors with the largest R2 value derived from multivariate forward stepwise regression were including in the modified ASD-FI (clin-ASD-FI). Factors included in the clin-ASD-FI were regressed against mortality, extended length of hospital stay (LOS, > 8 days), revisions, major complications and weights for the clin-ASD-FI were calculated via Beta/Sullivan. Total clin-ASD-FI score was created with a score from 0 to 1. Linear regression correlated clin-ASD-FI with ASD-FI scores and published cutoffs for the ASD-FI were used to create the new frailty cutoffs: not frail (NF: < 0.11), frail (F: 0.11-0.21) and severely frail (SF: > 0.21). Binary logistic regression assessed odds of complication or reop for frail patients.

RESULTS

Five hundred thirty-one ASD patients (59.5 yrs, 79.5% F) were included. The final model had a R2 of 0.681, and significant factors were: < 18.5 or > 30 BMI (weight: 0.0625 out of 1), cardiac disease (0.125), disability employment status (0.3125), diabetes mellitus (0.0625), hypertension (0.0625), osteoporosis (0.125), blood clot (0.1875), and bowel incontinence (0.0625). These factors calculated the score from 0 to 1, with a mean cohort score of 0.13 ± 0.14. Breakdown by clin-ASD-FI score: 51.8% NF, 28.1% F, 20.2% SF. Increasing frailty severity was associated with longer LOS (NF: 7.0, F: 8.3, SF: 9.2 days; P < 0.001). Frailty independently predicted occurrence of any complication (OR: 9.357 [2.20-39.76], P = 0.002) and reop (OR: 2.79 [0.662-11.72], P = 0.162).

CONCLUSIONS

Utilizing an existing ASD frailty index, we proposed a modified version eliminating the patient-reported components. This index is a true assessment of physiologic status, and represents a superior risk factor assessment compared to other tools for both primary and revision spinal deformity surgery as a result of its immutability with surgery, lack of subjectivity, and ease of use.

PreOperative Planning for Adult Spinal Deformity Goals: Level Selection and Alignment Goals

Adult Spinal Deformity (ASD) is a complex pathologic condition with significant impact on quality of life, including pain, loss of function, and fatigue. Achieving realignment goals is crucial for long-term results. Reliable preoperative planning strategies, including nomograms, measurement tools, and level selection, are key to maximizing the likelihood of achieving a good outcome following ASD corrective surgery. This review covers recent literature on such strategies, including review of the different targets for realignment and their association with outcomes (both patients-reported outcomes and complications), selection of upper and lower instrumented vertebrae, and the latest innovation in preoperative planning for deformity surgery.

What Are the Benefits of Lateral Lumbar Interbody Fusion on the Treatment of Adult Spinal Deformity: A Systematic Review and Meta-Analysis Deformity

STUDY DESIGN

A systematic review and meta-analysis.

OBJECTIVE

The purpose of this systematic review and meta-analysis was to compare the efficacy of lateral lumbar interbody fusion (LLIF) combined with posterior spinal fusion (PSF) with that of conventional PSF in the treatment of adult spinal deformity (ASD).

METHODS

A comprehensive literature search was performed for relevant studies in PubMed, EMBASE, Web of Science, and the Cochrane Library. Spinopelvic parameters, surgical data, complications, and clinical outcomes at the last follow-up were compared between patients with ASD who underwent LLIF combined with PSF (LLIF+PSF group) and those who underwent conventional PSF (only-PSF group).

RESULTS

Ten studies, comprising 621 patients with ASD (313 in the LLIF+PSF group and 308 in the only-PSF group), were included. The level of evidence was III for 7 studies and IV for 3 studies. There was no significant difference in the improvement in the visual analog scale score, systemic complication rate, and revision rate between groups. In the LLIF+PSF group, we noted a superior restoration of lumbar lordosis (weighted mean difference [WMD], 9.77; 95% confidence interval [CI] 7.10 to 12.44, P < .001), pelvic tilt (WMD, -2.50; 95% CI -4.25 to -.75, P = .005), sagittal vertical axis (WMD, -21.92; 95% CI -30.73 to -13.11, P < .001), and C7 plumb line-center sacral vertical line (WMD, -4.03; 95% CI -7.52 to -.54, P = .024); a lower estimated blood loss (WMD, -719.99; 95% CI -1105.02 to -334.96, P < .001) while a prolonged operating time (WMD, 104.89; 95% CI 49.36 to 160.43, P < .001); lower incidence of pseudarthrosis (risk ratio [RR], .26; 95% CI .08 to .79, P = .017) while higher incidence of neurologic deficits (RR, 2.04; 95% CI 1.27 to 3.25, P = .003); and a better improvement in Oswestry Disability Index score (WMD, -7.04; 95% CI -10.155 to -3.93, P < .001) and Scoliosis Research Society-22 total score (WMD, .27; 95% CI .11 to .42, P = .001). The level of evidence in this systematic review and meta-analysis was II.

CONCLUSION

Compared with conventional PSF, LLIF combined with PSF was associated with superior restoration of sagittal and coronal alignment, lower incidence of pseudarthrosis, better improvement in quality of life, and less surgical invasiveness in the treatment of ASD, albeit at the cost of prolonged surgical times and substantially high incidence of lower extremity symptoms. Surgeons should weigh the advantages and disadvantages of this procedure, and inform patients about its side effects.

Why are frailty indices not used systematically during preoperative spine consultations?

INTRODUCTION

Frailty indices are highly predictive of major medical and mechanical complications, lengths of hospital stay, and mortality rates after spine procedures. However, several barriers limit the extent to which spine surgeons employ these indices. The main purposes of the current study were to assess the use of frailty indices by Latin-American spine surgeons and identify the main barriers perceived to restrict their clinical application.

METHODS

For this cross-sectional survey, a questionnaire evaluating the demographic characteristics of participating surgeons and their utilization of frailty indices were created in Google form and sent by e-mail to every registered member of AO Spine Latin America between October and November 2020.

RESULTS

Of the 1047 surgeons sent the survey, 293 responded (response rate=28%). Half of the surgeons (51.7%) said they were unfamiliar with the terms ¨frailty´ and ¨frailty index", while 70.3% claimed not to use any frailty scale during their pre-operative assessments. The most frequently utilized index was the modified Frailty Index (mFI) (18%). The most important perceived barrier was the excessive amount of time required to calculate each patient's frailty score. Ninety-two percent of the spine surgeons felt sure that these scores could influence their therapeutic decisions, while 91% desired an easier-to-use risk-prevention scale.

CONCLUSION

The main perceived barriers restricting the use of frailty indices were the time required to complete them, lack of index validation, and need for specific instruments to calculate the index score.

Are Minimally Invasive Spine Surgeons or Classical Open Spine Surgeons More Consistent with Their Treatment of Adult Spinal Deformity?

OBJECTIVE

Spine surgeons have a heuristic sense of how to surgically restore alignment and address adult spinal deformity (ASD) symptoms, but consensus on the extent of treatment remains unclear. We sought to determine the variability of surgical approaches in treating ASD.

METHODS

Sixteen spine surgeons were surveyed on treatment approaches in 10 select ASD cases. We repeated the survey with the same surgeons 4 weeks later, with cases ordered differently. We examined the variability in length of construct, use of interbody spacers, osteotomies, and pelvic fixation frequency.

RESULTS

Treatment approaches for each case varied by surgeon, with some surgeons opting for long fusion constructs in cases for which others offered no surgery. There was no consensus among surgeons on the number of levels fused, interbody spacer use, or anterior/posterior osteotomies. Intersurgeon and intrasurgeon variability was 48% (kappa = 0.31) and 59% (kappa = 0.44) for surgeons performing minimally invasive surgery (MIS) versus 37% (kappa = 0.21) and 47% (kappa = 0.30) for those performing open surgery. In the second-round survey, 8 of 15 (53%) surgeons substantially changed the construct length, number of interbody spacers, and osteotomies in at least half the cases they previously reviewed. Surgeons performing MIS versus open surgery were less likely to extend constructs to the pelvis (42.5% vs. 67.5%; P = 0.02), but construct length was not correlated with whether a surgeon performed MIS or open surgery.

CONCLUSIONS

Spinal deformity surgeons lack consensus on the optimal surgical approach for treating ASD. Classifying surgeons as performing MIS or open surgery does not mitigate this variability.

The 5-factor modified frailty index (mFI-5) is predictive of 30-day postoperative complications and readmission in patients with adult spinal deformity (ASD)

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

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.

The Modified 11-Item Frailty Index and Postoperative Outcomes in Patients Undergoing Lateral Lumbar Interbody Fusion

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The aim of this study was to analyze postoperative complications and recovery patterns in different modified 11-item frailty index (mFI-11) groups after lateral lumbar interbody fusion (LLIF) surgery.

SUMMARY OF BACKGROUND DATA

The relationship between the mFI-11 score and LLIF surgery has not been previously reported.

METHODS

A single-center, consecutive series of patients who underwent LLIF with at least two years of follow-up were retrospectively reviewed. Complications after LLIF surgery were recorded. Clinical outcomes, including the visual analog scale (VAS) for back/leg pain and the Oswestry Disability Index (ODI), were evaluated preoperatively and at 1 and 2 years postoperatively. The proportions of patients who achieved substantial clinical benefit (SCB) for the VAS-B, VAS-L, and ODI were also analyzed.

RESULTS

One hundred fifty-two patients included in the present study were grouped according to their mFI-11 score: 0 (n = 39), 0.09 (n = 69), 0.18 (n = 31), and ≥0.27 (n = 13). An mFI-11 score ≥0.27 was a significant predictor of urinary complications (adjusted odds ratio: 3.829, P = 0.013). At 2 years postoperatively, patients in all frailty categories experienced improvements in the VAS for back pain, VAS for leg pain, and ODI, without significant differences between the four groups (p = 0.182, 0.121, and 0.804, respectively). There were also no significant differences in the proportions of patients achieving SCB for back/leg pain and the ODI between the four groups (P = 0.843, 0.957, and 0.915, respectively).

CONCLUSION

An mFI-11 score was found to be independently associated with urologic complications in patients who underwent LLIF. Patients in all frailty categories experienced significant improvements in back pain, leg pain, and the ODI at 1 year and 2 years postoperatively. LLIF surgery may be useful for patients with high frailty index.Level of Evidence: 4.

Complications of adult spinal deformity surgery: A literature review

Purpose:

Adult spinal deformity incidence increases accordingly as the population ages. Even though surgery is the best option for the treatment, the complications due to surgery are pretty challenging. This study aims to review the complication rates of adult spinal deformity surgery.

Methods:

A literature review of the last decade was performed searching for the query “Adult spine deformity and complication.” This search yielded 2781 results, where 79 articles were chosen to investigate the complications of adult spinal deformity surgery. In addition, the demographic data, surgical interventions, and complications were extracted from the publications.

Results:

A total of 26,207 patients were analyzed, and 9138 complications were found (34.5%). Implant failure, including screw loosening, breakage, distal and proximal junctional kyphosis, were the most common complications. The neurologic complications were about 10.8%, and the infection rate was 3.6%. Cardiac and pulmonary complications were about 4.8%.

Discussion:

Age, body mass index, smoking, osteoporosis, and other comorbidities are the significant risk factors affecting adult spinal deformity surgery. Presurgical planning and preoperative risk factor assessment must be done to avoid complications. Furthermore, intra and postoperative complications affect the patients’ quality of life and length of stay, and hospital readmissions. Revision surgery also increases the risk of complications.

Conclusion:

Good patient evaluation before surgery and careful planning of the surgery are essential in avoiding complications of adult spinal deformity.

Comparison of surgical invasiveness and morbidity of adult spinal deformity surgery to other major operations

BACKGROUND CONTEXT

Adult spinal deformity (ASD) surgeries are complex, involving long operative times and surgical morbidity. It is currently unclear how the invasiveness of ASD surgery compares to other major operations.

PURPOSE

To: (1) develop a quantitative score of surgical morbidity and invasiveness, and (2) compare this score between ASD surgery and other major operations.

STUDY DESIGN

Retrospective review of prospectively collected data.

PATIENT SAMPLE

A prospective surgical registry was used to identify all patients undergoing ASD surgery involving ≥ 7 segments. Seventeen additional procedures were included: coronary artery bypass grafting (CABG), pancreatectomy, and esophagectomy, among others.

OUTCOME MEASURES

Perioperative factors (operative time, transfusions, ventilation) and complications were collected and combined with a previously validated Postoperative Morbidity Survey to create a Surgical Invasiveness and Morbidity Score (SIMS).

METHODS

Computed scores were compared across surgeries using Welch's t-test. Multiple linear regression modeling was used to compare the SIMS of major surgeries relative to ASD while controlling for patient demographics and comorbidities.

RESULTS

A total of 1,245,282 surgical patients were included, 4,656 of which underwent ASD surgery. After multiple regression modeling controlling for patient demographics and comorbidities, ASD surgery ranked fourth in SIMS. ASD surgery had a significantly greater SIMS than 13 other major procedures including 6th esophagectomy (adjusted mean difference=-0.05, 95%CI -0.01-0.09, p<.001), 8th pancreatectomy (-0.40, 0.37-0.44, p<.001), 11th craniotomy for tumor (-1.01, 0.98-1.04, p<.001), and 12th sacral chordoma resection (-1.31, 1.26-1.37, p<.001).

CONCLUSIONS

ASD surgery was associated with significantly greater SIMS than many other major operations, even when controlling for important perioperative factors. These data have implications for patient counseling, resource allocation, and informed consent.

Single- versus Dual-Attending Surgeon Approach for Spine Deformity: A Systematic Review and Meta-Analysis

BACKGROUND

Surgical management of spine deformity is associated with significant morbidity. Recent literature has inconsistently demonstrated better outcomes after utilizing 2 attending surgeons for spine deformity.

OBJECTIVE

To conduct a systematic review and meta-analysis on studies reporting outcomes following single- vs dual-attending surgeons for spine deformity.

METHODS

MEDLINE, Embase, Web of science, and Cochrane databases were last searched on July 16, 2020. A total of 1013 records were identified excluding duplicates. After screening, 10 studies (4 cohort, 6 case series) were included in the meta-analysis. Random-effect models were used to pool the effect estimates by study design. When feasible, further subgroup analysis by deformity type was conducted.

RESULTS

A total of 953 patients were analyzed. Pooled results from propensity score-matched cohort studies revealed that the single-surgeon approach was unfavorably associated with a nonstatistically significant higher blood loss (mean difference = 421.0 mL; 95% CI: -28.2, 870.2), a statistically significant higher operative time (mean difference = 94.3 min; 95% CI: 54.9, 133), length of stay (mean difference = 0.84 d; 95% CI: 0.46, 1.22), and an increased risk of complications (Mantel-Haenszel risk ratio = 2.93; 95% CI: 1.12, 7.66). Data from pooled case series demonstrated similar results for all outcomes. Moreover, these results did not differ significantly between deformity types (adolescent idiopathic scoliosis and adult spinal deformity).

CONCLUSION

Dual-attending surgeon approach appeared to be associated with reduced operative time, shorter hospital stays, and reduced risk of complications. These findings may potentially improve outcomes in surgical treatment of spine deformity.

Postoperative Complication Burden, Revision Risk, and Health Care Use in Obese Patients Undergoing Primary Adult Thoracolumbar Deformity Surgery

STUDY DESIGN

This is a retrospective cohort study using a nationally representative administrative database.

OBJECTIVE

To identify the impact of obesity on postoperative outcomes in patients undergoing thoracolumbar adult spinal deformity (ASD) surgery.

BACKGROUND

The obesity rate in the United States remains staggering, with approximately one-third of all Americans being overweight or obese. However, the impact of elevated body mass index on spine surgery outcomes remains unclear.

METHODS

We queried the MarketScan database to identify patients who were diagnosed with a spinal deformity and underwent ASD surgery from 2007 to 2016. Patients were then stratified by whether or not they were diagnosed as obese at index surgical admission. Propensity score matching (PSM) was then utilized to mitigate intergroup differences between obese and nonobese patients. Patients <18 years and those with any prior history of trauma or tumor were excluded from this study. Baseline demographics and comorbidities, postoperative complication rates, and short- and long-term reoperation rates were determined.

RESULTS

A total of 7423 patients met the inclusion criteria of this study, of whom 597 (8.0%) were obese. Initially, patients with obesity had a higher 90-day postoperative complication rate than nonobese patients (46.1% vs 40.8%, P < .05); however, this difference did not remain after PSM. Revision surgery rates after 2 years were similar across the 2 groups following primary surgery (obese, 21.4%, vs nonobese, 22.0%; P = .7588). Health care use occurred at a higher rate among obese patients through 2 years of long-term follow-up (obese, $152 930, vs nonobese, $140 550; P < .05).

CONCLUSION

Patients diagnosed with obesity who underwent ASD surgery did not demonstrate increased rates of complications, reoperations, or readmissions. However, overall health care use through 2 years of follow-up after index surgery was higher in the obesity cohort.

Osteoporosis is under recognized and undertreated in adult spinal deformity patients

Background

Adult spinal deformity (ASD) patients may have osteoporosis, predisposing them to an increased risk for surgical complications. Prior studies have demonstrated that treating osteoporosis improves surgical outcomes. In this study we determine the prevalence of osteoporosis in ASD patients undergoing long spinal fusions and the rate at which osteoporosis is treated.

Methods

ASD patients who frequented either of two major academic medical centers from 2010 through 2019 were studied. All study participants were at least 40 years of age and endured a spinal fusion of at least seven vertebral levels. Medical records were explored for a diagnosis of osteoporosis via ICD-10 code and, if present, whether pharmacological treatment was prescribed. T-tests and chi-squared analyses were used to determine statistical significance.

Results

Three hundred ninety-nine patients matched the study's inclusion criteria. Among this group, 131 patients (32.8%) had been diagnosed with osteoporosis prior to surgery. With a mean age of 66.4 years, osteoporotic patients were on average three years older than non-osteoporotic (P=0.002) and more likely to be female (74.8% vs. 61.9%; P=0.01). At the time of surgery, 34.4% of osteoporotic patients were receiving pharmacological treatment. Although not statistically significant, women were more likely to receive medical treatment than men (P=0.07).

Conclusions

The prevalence of osteoporosis in ASD patients undergoing a long spinal fusion is substantially higher than that of the general population. Surgeons should have a low threshold for bone density testing in ASD patients. With only about one-third of osteoporotic patients treated, there is a classic "missed opportunity" in this population.

Development of a Preoperative Adult Spinal Deformity Comorbidity Score That Correlates With Common Quality and Value Metrics: Length of Stay, Major Complications, and Patient-Reported Outcomes

STUDY DESIGN

Retrospective review of a multicenter prospective registry.

OBJECTIVES

Our goal was to develop a method to risk-stratify adult spinal deformity (ASD) patients on the basis of their accumulated health deficits. We developed a novel comorbidity score (CS) specific to patients with ASD based on their preoperative health state and investigated whether it was associated with major complications, length of hospital stay (LOS), and self-reported outcomes after ASD surgery.

METHODS

We identified 273 operatively treated ASD patients with 2-year follow-up. We assessed associations between major complications and age, comorbidities, Charlson Comorbidity Index score, and Oswestry Disability Index score. Significant factors were used to construct the ASD-CS. Associations of ASD-CS with major complications, LOS, and patient-reported outcomes were analyzed.

RESULTS

Major complications increased significantly with ASD-CS (P < .01). Compared with patients with ASD-CS of 0, the odds of major complications were 2.8-fold higher (P = .068) in patients with ASD-CS of 1 through 3; 4.5-fold higher (P < .01) in patients with ASD-CS of 4 through 6; and 7.5-fold higher (P < .01) in patients with ASD-CS of 7 or 8. Patients with ASD-CS of 7 or 8 had the longest mean LOS (10.7 days) and worst mean Scoliosis Research Society-22r total score at baseline; however, they experienced the greatest mean improvement (0.98 points) over 2 years.

CONCLUSIONS

The ASD-CS is significantly associated with major complications, LOS, and patient-reported outcomes in operatively treated ASD patients.

Are Higher Global Alignment and Proportion Scores Associated With Increased Risks of Mechanical Complications After Adult Spinal Deformity Surgery? An External Validation

BACKGROUND

The Global Alignment and Proportion (GAP) score, based on pelvic incidence-based proportional parameters, was recently developed to predict mechanical complications after surgery for spinal deformities in adults. However, this score has not been validated in an independent external dataset.

QUESTIONS/PURPOSES

After adult spinal deformity surgery, is a higher GAP score associated with (1) an increased risk of mechanical complications, defined as rod fractures, implant-related complications, proximal or distal junctional kyphosis or failure; (2) a higher likelihood of undergoing revision surgery to treat a mechanical complication; and (3) is a lower (more proportioned) GAP score category associated with better validated outcomes scores using the Oswestry Disability Index (ODI), Scoliosis Research Society-22 (SRS-22) and the Short Form-36 questionnaires?

METHODS

A total of 272 patients who had undergone corrective surgeries for complex spinal deformities were enrolled in the Scoli-RISK-1 prospective trial. Patients were included in this secondary analysis if they fulfilled the original inclusion criteria by Yilgor et al. From the original 272 patients, 14% (39) did not satisfy the radiographic inclusion criteria, the GAP score could not be calculated in 14% (37), and 24% (64) did not have radiographic assessment at postoperative 2 years, leaving 59% (159) for analysis in this review of data from the original trial. A total of 159 patients were included in this study,with a mean age of 58 ± 14 years at the time of surgery. Most patients were female (72%, 115 of 159), the mean number of levels involved in surgery was 12 ± 4, and three-column osteotomy was performed in 76% (120 of 159) of patients. The GAP score was calculated using parameters from early postoperative radiographs (between 3 and 12 weeks) including pelvic incidence, sacral slope, lumbar lordosis, lower arc lordosis and global tilt, which were independently obtained from a computer software based on centralized patient radiographs. The GAP score was categorized as proportional (scores of 0 to 2), moderately disproportional (scores of 3 to 6), or severely disproportional (scores higher than 7 to 13). Receiver operating characteristic area under curve (AUC) was used to assess associations between GAP score and risk of mechanical complications and risk of revision surgery. An AUC of 0.5 to 0.7 was classified as "no or low associative power", 0.7 to 0.9 as "moderate" and greater than 0.9 as "high". We analyzed differences in validated outcome scores between the GAP categories using Wilcoxon rank sum test.

RESULTS

At a minimum of 2 years' follow-up, a higher GAP score was not associated with increased risks of mechanical complications (AUC = 0.60 [95% CI 0.50 to 0.70]). A higher GAP score was not associated with a higher likelihood of undergoing a revision surgery to treat a mechanical complication (AUC = 0.66 [95% 0.53 to 0.78]). However, a moderately disproportioned GAP score category was associated with better SF-36 physical component summary score (36 ± 10 versus 40 ± 11; p = 0.047), better SF-36 mental component summary score (46 ± 13 versus 51 ± 12; p = 0.01), better SRS-22 total score (3.4 ± 0.8 versus 3.7 ± 0.7, p = 0.02) and better ODI score (35 ± 21 versus 25 ± 20; p = 0.003) than severely disproportioned GAP score category.

CONCLUSION

Based on the findings of this external validation study, we found that alignment targets based on the GAP score alone were not associated with increased risks of mechanical complications and mechanical revisions in patients with complex adult spinal disorders. Parameters not included in the original GAP score needed to be considered to reduce the likelihood of mechanical complications.

LEVEL OF EVIDENCE

Level III, diagnostic study.

Multidisciplinary approaches to complication reduction in complex spine surgery: a systematic review

BACKGROUND CONTEXT

Complex spine surgery carries a high complication rate that can produce suboptimal outcomes for patients undergoing these extensive operations. However, multidisciplinary pathways introduced at multiple institutions have demonstrated a promising potential toward reducing the burden of complications in patients being treated for spinal deformities. To date, there has been no effort to systematically collate the multidisciplinary approaches in use at various institutions.

PURPOSE

The present study aims to determine effective multidisciplinary strategies for reducing the complication rate in complex spine surgery by analyzing existing institutional multidisciplinary approaches and delineating common themes across multiple practice settings.

STUDY DESIGN

Systematic review.

METHODS

We followed guidelines established under the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The studies reported on data from PubMed, Embase, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Web of Science and Cochrane. We included articles that described either approaches to, or results from, the implementation of multidisciplinary paradigms during the preoperative, perioperative, and postoperative phases of care for patients undergoing complex spine surgery. We excluded studies that only targeted one complication unless such an approach was in coordination with more extensive multidisciplinary planning at the same institution.

RESULTS

A total of 406 unique articles were identified. Following an initial determination based on title and abstract, 22 articles met criteria for full-text review, and 10 met the inclusion criteria to be included in the review. Key aspects of multidisciplinary approaches to complex spine surgery included extensive preoperative workup and interdisciplinary conferencing, intraoperative communication and monitoring, and postoperative floor management and discharge planning. These strategies produced decreases in surgical duration and complication rates.

CONCLUSIONS

This study represents the first to systematically analyze multidisciplinary approaches to reduce complications in complex spine surgery. This review provides a roadmap toward reducing the elevated complication rate for patients undergoing complex spine surgery.

Frailty and Post-Operative Outcomes in the Older Patients Undergoing Elective Posterior Thoracolumbar Fusion Surgery

Background and Aim

Frailty is an independent predictor of mortality and adverse events (AEs) in patients undergoing surgery. This study aimed to quantify the ability of Modified Frailty Index (mFI) to predict AEs in older patients undergoing elective posterior thoracolumbar fusion surgery.

Methods

We retrospectively reviewed the results of 426 patients with the following diagnoses and follow-up evaluations of at least 12 months duration: lumbar disc herniation, 125; degenerative spondylolisthesis, 81; lumbar spinal canal stenosis, 187; and adult spinal deformities, 33. The cases were divided into two groups. The long spinal fusion (LSF) group was defined as ≥3 spinal levels with segmental pedicle-screw fixation. Short spinal fusion (SSF) were defined with at most two levels. The mFI used in the present study is an 11-variable assessment. The association of frailty with AEs was determined after adjusting for known and suspected confounders.

Results

Frailty was presented in 66 patients (15.5%) within the total population (LSF, 21.9% and SSF, 11.8%). Rates of AEs assessed in the study increased stepwise with an increase in the mFI for the two groups. The severity of frailty was an independent predictor of any, major, and minor complications in the LSF group and any, minor complication in the SSF group (P<0.05). A comparison of post-operative clinical outcomes showed that the ODI and SF-36 scores deteriorated as the mFI increased.

Conclusion

Frailty was shown to be an independent predictor of AEs in older patients undergoing elective posterior thoracolumbar fusion surgery, especially for patients undergoing LSF.

Assessment of Patient Outcomes and Proximal Junctional Failure Rate of Patients with Adult Spinal Deformity Undergoing Caudal Extension of Previous Spinal Fusion

OBJECTIVE

This case series examined patients undergoing caudal extension of prior fusion without alteration of the prior upper instrumented vertebra (UIV) to assess patient outcomes and rates of proximal junctional kyphosis (PJK)/proximal junctional failure (PJF).

METHODS

Patients eligible for 2-year minimum follow-up undergoing caudal extension of prior fusion with unchanged UIVs were identified. These patients were evaluated for PJK/PJF, and patient reported outcomes were recorded.

RESULTS

In total, 40 patients were included. Mean follow-up duration was 2.2 ± 0.3 years. Patients in this cohort had poor preoperative sagittal alignment (pelvic incidence minus lumbar lordosis [PI-LL] 26.7°, T1 pelvic angle [TPA] 29.0°, sagittal vertical axis [SVA] 93.4 mm) and achieved substantial sagittal correction (ΔSVA -62.2 mm, ΔPI-LL -19.8°, ΔTPA -11.1°) after caudal extension surgery. At final follow-up, there was a 0% rate of PJF among patients undergoing caudal extension of previous fusion without creation of a new UIV, but 27.5% of patients experienced PJK. Patients experienced significant improvement in both the Oswestry Disability Index and Scoliosis Research Society-22r total score at 2 years postoperatively (P < 0.05). In total, 7.5% (n = 3) of patients underwent further revision, at an average of 1.1 ± 0.54 years after the surgery with unaltered UIV. All 3 of these patients underwent revision for rod fracture with no revisions for PJK/PJF.

CONCLUSIONS

Patients undergoing caudal extension of previous fusions for sagittal alignment correction have high rates of clinical success, low revision surgery rates, and very low rates of PJF. Minimizing repetitive tissue trauma at the UIV may result in decreased PJF risk because the PJF rate in this cohort of patients with unaltered UIV is below historical PJF rates of patients undergoing sagittal balance correction.

Upper-thoracic versus lower-thoracic upper instrumented vertebra in adult spinal deformity patients undergoing fusion to the pelvis: surgical decision-making and patient outcomes

OBJECTIVE

Optimal patient selection for upper-thoracic (UT) versus lower-thoracic (LT) fusion during adult spinal deformity (ASD) correction is challenging. Radiographic and clinical outcomes following UT versus LT fusion remain incompletely understood. The purposes of this study were: 1) to evaluate demographic, radiographic, and surgical characteristics associated with choice of UT versus LT fusion endpoint; and 2) to evaluate differences in radiographic, clinical, and health-related quality of life (HRQOL) outcomes following UT versus LT fusion for ASD.

METHODS

Retrospective review of a prospectively collected multicenter ASD database was performed. Patients with ASD who underwent fusion from the sacrum/ilium to the LT (T9-L1) or UT (T1-6) spine were compared for demographic, radiographic, and surgical characteristics. Outcomes including proximal junctional kyphosis (PJK), reoperation, rod fracture, pseudarthrosis, overall complications, 2-year change in alignment parameters, and 2-year HRQOL metrics (Lumbar Stiffness Disability Index, Scoliosis Research Society-22r questionnaire, Oswestry Disability Index) were compared after controlling for confounding factors via multivariate analysis.

RESULTS

Three hundred three patients (169 LT, 134 UT) were evaluated. Independent predictors of UT fusion included greater thoracic kyphosis (odds ratio [OR] 0.97 per degree, p = 0.0098), greater coronal Cobb angle (OR 1.06 per degree, p < 0.0001), and performance of a 3-column osteotomy (3-CO; OR 2.39, p = 0.0351). While associated with longer operative times (ratio 1.13, p < 0.0001) and greater estimated blood loss (ratio 1.31, p = 0.0018), UT fusions resulted in greater sagittal vertical axis improvement (-59.5 vs -41.0 mm, p = 0.0035) and lower PJK rates (OR 0.49, p = 0.0457). No significant differences in postoperative HRQOL measures, reoperation, or overall complication rates were detected between groups (all p > 0.1).

CONCLUSIONS

Greater deformity and need for 3-CO increased the likelihood of UT fusion. Despite longer operative times and greater blood loss, UT fusions resulted in better sagittal correction and lower 2-year PJK rates following surgery for ASD. While continued surveillance is necessary, this information may inform patient counseling and surgical decision-making.

Evaluation of a new sagittal classification system in adolescent idiopathic scoliosis

PURPOSE

The purpose of the present study was to validate a new spinal sagittal classification.

METHODS

We retrospectively included 105 consecutive AIS patients who underwent posterior spinal fusion. Preoperative long-standing EOS radiographs were available on all patients. Patients were classified according to the four suggested sagittal patterns: type 1, 2a, 2b or 3. Several predetermined sagittal parameters were compared between the groups.

RESULTS

The mean preoperative Cobb angle was 64° ± 12°, and 73% of the patients were female. Of 105 patients, 51 were type 1, 14 were type 2a, one was type 2b and 39 were type 3. The distribution of the four sagittal patterns was significantly different compared with the original publication (p < 0.05). However, the two study populations were comparable in terms of Lenke and Roussouly types (p = 0.49 and 0.47, respectively). In our study population, the sagittal groups differed significantly in terms of thoracic kyphosis, length of thoracic and lumbar curves, lumbar lordosis, thoracic slope, C7 slope, pelvic incidence and sacral slope (p < 0.05).

CONCLUSION

The distribution of the four sagittal patterns varies between AIS cohorts. Type 2b was rare, which limits the clinical applicability. Contrary to the original publication, we found that the spinopelvic parameters lumbar lordosis, pelvic incidence and sacral slope were significantly different between the Abelin-Genevois types. Hence, the corrective surgical strategy may need to incorporate these spinopelvic parameters to achieve a balanced spine requiring a minimum of energy expenditure. These slides can be retrieved under Electronic Supplementary Material.

Factors influencing patient satisfaction after adult scoliosis and spinal deformity surgery

OBJECTIVE

Achieving high patient satisfaction with management is often one of the goals after adult spinal deformity (ASD) surgery. However, literature on associated factors and their correlations with patient satisfaction is limited. The aim of this study was to determine the clinical and radiographic factors independently correlated with patient satisfaction in terms of management at 2 years after surgery.

METHODS

A multicenter prospective database of ASD surgery was retrospectively reviewed. The demographics, complications, health-related quality of life (HRQOL) subdomains, and radiographic parameters were examined to determine their correlation coefficients with the Scoliosis Research Society-22 questionnaire (SRS-22R) satisfaction scores at 2 years (Sat-2y score). Subsequently, factors determined to be independently associated with low satisfaction (Sat-2y score ≤ 4.0) were used to construct 2 types of multivariate models: one with 2-year data and the other with improvement (score at 2 years - score at baseline) data.

RESULTS

A total of 422 patients who underwent ASD surgery (mean age 53.1 years) were enrolled. All HRQOL subdomains and several coronal and sagittal radiographic parameters had significantly improved 2 years after surgery. The Sat-2y score was strongly correlated with the SRS-22R self-image (SI)/appearance subdomain (r = 0.64), followed by moderate correlation with subdomains related to standing (r = 0.53), body pain (r = 0.49-0.55), and function (r = 0.41-0.55) at 2 years. Conversely, the correlation between radiographic or demographic parameters with Sat-2y score was weak (r < 0.4). Multivariate analysis to eliminate confounding factors revealed that a worse Oswestry Disability Index (ODI) score for standing (≥ 2 points; OR 4.48) and pain intensity (≥ 2 points; OR 2.07), SRS-22R SI/appearance subdomain (< 3 points; OR 2.70) at 2 years, and a greater sagittal vertical axis (SVA) (> 5 cm; OR 2.68) at 2 years were independent related factors for low satisfaction. According to the other model, a lower improvement in ODI for standing (< 30%; OR 2.68), SRS-22R pain (< 50%; OR 3.25) and SI/appearance (< 50%; OR 2.18) subdomains, and an inadequate restoration of the SVA from baseline (< 2 cm; OR 3.16) were associated with low satisfaction.

CONCLUSIONS

Self-image, pain, standing difficulty, and sagittal alignment restoration may be useful goals in improving patient satisfaction with management at 2 years after ASD surgery. Surgeons and other medical providers have to take care of these factors to prevent low satisfaction.

Adult spinal deformity

Adult spinal deformity affects the thoracic or thoracolumbar spine throughout the ageing process. Although adolescent spinal deformities taken into adulthood are not uncommon, the most usual causes of spinal deformity in adults are iatrogenic flatback and degenerative scoliosis. Given its prevalence in the expanding portion of the global population aged older than 65 years, the disorder is of growing interest in health care. Physical examination, with a focus on gait and posture, along with radiographical assessment are primarily used and integrated with risk stratification indices to establish optimal treatment planning. Although non-operative treatment is regarded as the first-line response, surgical outcomes are considerably favourable. Global disparities exist in both the assessment and treatment of adults with spinal deformity across countries of varying incomes, which represents an area requiring further investigation. This Seminar presents evidence and knowledge that represent the evolution of data related to spinal deformity in adults over the past several decades.

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

STUDY DESIGN

Retrospective review of prospective multicenter database.

OBJECTIVE

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.

SUMMARY OF BACKGROUND DATA

Surgical correction of adult spinal deformity (ASD) can be complex and therefore, may come with high revision rates due to PJF.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

LEVEL OF EVIDENCE

4.

Pedicle screw insertion with patient-specific 3D-printed guides based on low-dose CT scan is more accurate than free-hand technique in spine deformity patients: a prospective, randomized clinical trial

BACKGROUND

Screw misplacement incidence can be as high as 15-30% in spine deformity surgery, with possible devastating consequences. Some technical solutions to prevent misplacement require expensive devices. MySpine^TM comprises a low-dose CT scan of the patient's spine to build a virtual model of the spine to plan the screw trajectories and a 3D-printed patient-specific guide system to prepare the screw trajectories and to implant the screws in the vertebrae in order to increase reproducibility and safety of the implants. The aim of this open-label, single-center, prospective randomized clinical trial with independent evaluation of outcomes was to compare the accuracy of free-hand insertion of pedicle screws to MySpine^TM 3D-printed patient-specific guides.

METHODS

Twenty-nine patients undergoing surgical correction for spinal deformity were randomized to Group A (pedicle screws implantation with MySpine^TM) or Group B (free-hand implantation). Group A received 297 pedicle screws, and Group B 243 screws. Forty-three screws in Group A crossed over to free-hand implantation. Screw position was graded according to Gertzbein in grades 0, A, B or C, with grades 0 or A considered as "safe area." Total fluoroscopy dose and time were compared in six patients of each group.

RESULTS

Comparing the two study groups, we observed a statistically significant difference between the two groups (p < 0.05), with 96.1% of screws in the "safe area" in Group A versus a 82.9% in Group B. Group-A patients had a mean effective dose of 0.23 mSv compared to 0.82 mSv in Group B. Patient-specific, 3D-printed pedicle screw guides increase safety in a wide spectrum of deformity conditions. In addition, the total radiation dose is reduced, even considering the need of a low-dose preoperative CT for surgical planning.

LEVEL OF EVIDENCE

I. These slides can be retrieved under Electronic Supplementary Material.

ISSLS PRIZE IN CLINICAL SCIENCE 2019: clinical importance of trunk muscle mass for low back pain, spinal balance, and quality of life-a multicenter cross-sectional study

STUDY DESIGN

A multicenter cross-sectional study.

OBJECTIVES

To clarify the relationship of trunk muscle mass with low back pain, spinal sagittal balance, and quality of life. Few reports have investigated the relationship of trunk muscle mass with lumbar spine function and spinal balance, and the clinical significance of trunk muscle mass remains unclear.

METHODS

Patients attending spinal outpatient clinics at 10 different medical institutions were enrolled in this study. Patient demographics, trunk muscle mass and appendicular skeletal muscle mass (ASM) measured by bioelectrical impedance analysis (BIA), body mass index (BMI), Charlson Comorbidity Index (CCI), the Oswestry Disability Index (ODI), visual analog scale (VAS) for low back pain, sagittal vertical axis (SVA), and EuroQol 5 Dimension (EQ5D) score were investigated. Multivariate nonlinear regression analysis was used to investigate the association of trunk muscle mass with the ODI, VAS score, SVA, and EQ5D score.

RESULTS

Of 2551 eligible patients, 1738 (mean age 70.2 ± 11.0 years; 781 men and 957 women) were enrolled. Trunk muscle mass was significantly correlated with the ODI, VAS score, SVA, and EQ5D score (P < 0.001) when adjusted for age, sex, BMI, ASM, CCI, and history of lumbar surgery. Patient deterioration was associated with a decrease in trunk muscle mass, and the deterioration accelerated from approximately 23 kg.

CONCLUSIONS

Trunk muscle mass was significantly associated with the ODI, VAS score, SVA, and EQ5D score. Trunk muscle mass may assume an important role to elucidate and treat lumbar spinal dysfunction and spinal imbalance. These slides can be retrieved under Electronic Supplementary Material.

Neurologic Comorbidities Predict Proximal Junctional Failure in Adult Spinal Deformity

STUDY DESIGN

Retrospective case-control matched cohort from a single institution.

OBJECTIVE

To examine the contribution of nonmechanical factors to the incidence of proximal junctional failure (PJF) after adult spinal deformity (ASD) surgery.

SUMMARY OF BACKGROUND DATA

Multiple studies have reported on the prevalence of PJF following surgery for ASD. However, little is known about the contribution of nonmechanical factors to the incidence of PJF.

METHODS

We identified a consecutive series of ASD patients who required revision surgery for PJF between 2013 and 2015. A matched cohort of ASD patients who did not develop PJF after surgical correction was identified based on age, gender, preoperative deformity type, number of fusion levels, and the lower instrumented vertebra level. We compared medical and surgical histories in the matched cohorts, with particular attention to the prevalence of preoperative neurologic comorbidities that might affect standing balance. Preoperative, immediate postoperative, and follow-up radiographs were reviewed to document specific characteristics of mechanical failure that resulted in PJF and required revision surgery.

RESULTS

Twenty-eight cases of PJF requiring revision surgery were identified. The prevalence rates of preoperative neurologic comorbidities in PJF cohort were significantly higher than in non-PJF cohort (75% vs. 32%, p < .001). Neurologic comorbidities included prior stroke (4), metabolic encephalopathy (2), Parkinson disease (1), seizure disorder (1), cervical and thoracic myelopathy (7), diabetic neuropathy (4), and other neuropathy (4). The mean preoperative sagittal vertical axis in PJF cohort was more positive compared with the non-PJF cohort (144 mm vs. 65 mm, p = .009) There were no significant differences in immediate postoperative or follow-up radiographic parameters between cohorts.

CONCLUSIONS

In this study, risk factors identified for the development of PJF included nonmechanical neurologic comorbidities, emphasizing the need to look beyond radiographic alignment in order to reduce the incidence of PJF.

LEVEL OF EVIDENCE

Level 3.

Baseline mental status predicts happy patients after operative or non-operative treatment of adult spinal deformity

Background

The study is a retrospective review of a multi-institutional database, aiming to determine predictors of non-depressed, satisfied adult spinal deformity (ASD) patients with good self-image at 2-year follow-up (2Y). ASD significantly impacts a patients' psychological status. Following treatment, little is known about predictors of satisfied patients with high self-image and mental status.

Methods

Inclusion: primary ASD pts >18 y/o with complete 2Y follow-up. Non-depressed [Short Form 36-mental component score (SF36-MCS) >42], satisfied patients (SRS22-satisfaction >3) with good self-image (SR22-self-image >3) at 2Y were isolated (happy). Happy and control patients were propensity-matched by baseline and 2Y leg pain, Charlson, frailty, and radiographic measures for the operative (OP) and non-operative cohorts (NOP). Health related quality of life (HRQL), surgical and radiographic metrics were compared. Regression models identified predictors of happy patients. Thresholds were calculated using area under the curve (AUC) and 95%CI.

Results

Of 480 patients, 94 OP (happy: 47 vs. control: 47) and 92 NOP (46 each) reached inclusion. At baseline, groups had similar age, gender, Oswestry disability index (ODI) (OP: 39.13 vs. 37.49, NOP: 17.70 vs. 19.74) and SF36-physical component score (PCS) (OP: 33.51 vs. 35.04, NOP: 47.93 vs. 44.72). Despite similar (P>0.05) surgeries, length of stay (LOS), and radiographic outcomes between OP happy and control groups, happy had less peri-operative complications (31.9% vs. 57.4%, P=0.13), better 2Y ODI (17.77 vs. 29.98), SRS22 component, total, and SF36 scores (P<0.05). NOP happy patients also exhibited better 2Y ODI (13.24 vs. 22.09), SRS22 component, total, and SF36 scores (P<0.05). Baseline SRS-mental (OR: 2.199, AUC: 0.617, cutoff: 2.5) and ODI improvement (OR: 1.055, AUC: 0.717, cutoff: >12) predicted happy OP patients, while baseline SRS-self-image (OR: 5.195, AUC: 0.740, cutoff: 3.5) and ODI improvement (OR: 1.087, AUC: 0.683, cutoff: >9) predicted happy NOP patients.

Conclusions

Baseline mental-status, self-image and ODI improvement significantly impact long-term happiness in ASD patients. Despite equivalent management and alignment outcomes, operative and non-operative happy patients had better 2Y disability scores. Management strategies aimed at improving baseline mental-status, perception-of-deformity, and maximizing ODI may optimize treatment outcomes.

Incidence and risk factors for multiple medical complications in adult degenerative scoliosis long-level fusion

Adult degenerative scoliosis (ADS) surgery is known for its high incidence of complications. The propose of this study was to determine current complication rates and the predictors of medical complications in surgical ASD patients. A retrospective study of 153 ADS patients who underwent long level spinal fusion with 2-year follow-up between 2012 and 2017. The patient- and surgical-related risk factors for each individual medical complication were identified by using univariate testing. All patients were divided into groups with and without medical complication, infection, neurological complications, and cardiopulmonary complications, respectively. Potential risk factors were identified using univariate testing. Multivariate Logistic regression was used to evaluate independent predictors of medical complications. The total medical complication incidence was 26.1%. Patient-related independent risk factors for the development of medical complications included diabetes, smoking; for infection were diabetes and smoking; for neurological complications were BMI and diabetes; for cardiopulmonary complications were hypertension, smoking and cardiac comorbidity. Surgical-related independent risk factors for the development of medical complications were fusion level, operative time, osteotomy, blood transfusion and LOS; for infection were fusion level, blood transfusion, and LOS; for neurological complication were fusion level, osteotomy and blood transfusion; for cardiopulmonary complication were fusion level. Diabetes and smoking were the most common patient-related independent risk factors increase the development of each individual medical complication. On the other hand, fusion levels and blood transfusion were the most common surgical-related independent risk factors increase the development of each individual medical complication. Prevention of these risk factors can reduce the incidence of complications in Chinese patients with ADS surgery.

Pseudarthrosis in adult and pediatric spinal deformity surgery: a systematic review of the literature and meta-analysis of incidence, characteristics, and risk factors

We conducted a systematic review with meta-analysis and qualitative synthesis. This study aims to characterize pseudarthrosis after long-segment fusion in spinal deformity by identifying incidence rates by etiology, risk factors for its development, and common features. Pseudarthrosis can be a painful and debilitating complication of spinal fusion that may require reoperation. It is poorly characterized in the setting of spinal deformity. The MEDLINE, EMBASE, and Cochrane databases were searched for clinical research including spinal deformity patients treated with long-segment fusions reporting pseudarthrosis as a complication. Meta-analysis was performed on etiologic subsets of the studies to calculate incidence rates for pseudarthrosis. Qualitative synthesis was performed to identify characteristics of and risk factors for pseudarthrosis. The review found 162 articles reporting outcomes for 16,938 patients which met inclusion criteria. In general, the included studies were of medium to low quality according to recommended reporting standards and study design. Meta-analysis calculated an incidence of 1.4% (95% CI 0.9-1.8%) for pseudarthrosis in adolescent idiopathic scoliosis, 2.2% (95% CI 1.3-3.2%) in neuromuscular scoliosis, and 6.3% (95% CI 4.3-8.2%) in adult spinal deformity. Risk factors for pseudarthrosis include age over 55, construct length greater than 12 segments, smoking, thoracolumbar kyphosis greater than 20°, and fusion to the sacrum. Choice of graft material, pre-operative coronal alignment, post-operative analgesics, and sex have no significant impact on fusion rates. Older patients with greater deformity requiring more extensive instrumentation are at higher risk for pseudarthrosis. Overall incidence of pseudarthrosis requiring reoperation is low in adult populations and very low in adolescent populations.

Comparative analysis of 3 surgical strategies for adult spinal deformity with mild to moderate sagittal imbalance

OBJECTIVE Surgical treatment of adult spinal deformity (ASD) is an effective endeavor that can be accomplished using a variety of surgical strategies. Here, the authors assess and compare radiographic data, complications, and health-related quality-of-life (HRQoL) outcome scores among patients with ASD who underwent a posterior spinal fixation (PSF)-only approach, a posterior approach combined with lateral lumbar interbody fusion (LLIF+PSF), or a posterior approach combined with anterior lumbar interbody fusion (ALIF+PSF). METHODS The medical records of consecutive adults who underwent thoracolumbar fusion for ASD between 2003 and 2013 at a single institution were reviewed. Included were patients who underwent instrumentation from the pelvis to L-1 or above, had a sagittal vertical axis (SVA) of < 10 cm, and underwent a minimum of 2 years' follow-up. Those who underwent a 3-column osteotomy were excluded. Three groups of patients were compared on the basis of the procedure performed, LLIF+PSF, ALIF+PSF, and PSF only. Perioperative spinal deformity parameters, complications, and HRQoL outcome scores (Oswestry Disability Index [ODI], Scoliosis Research Society 22-question Questionnaire [SRS-22], 36-Item Short Form Health Survey [SF-36], visual analog scale [VAS] for back/leg pain) from each group were assessed and compared with each other using ANOVA. The minimal clinically important differences used were -1.2 (VAS back pain), -1.6 (VAS leg pain), -15 (ODI), 0.587/0.375/0.8/0.42 (SRS-22 pain/function/self-image/mental health), and 5.2 (SF-36, physical component summary). RESULTS A total of 221 patients (58 LLIF, 91 ALIF, 72 PSF only) met the inclusion criteria. Average deformities consisted of a SVA of < 10 cm, a pelvic incidence-lumbar lordosis (LL) mismatch of > 10°, a pelvic tilt of > 20°, a lumbar Cobb angle of > 20°, and a thoracic Cobb angle of > 15°. Preoperative SVA, LL, pelvic incidence-LL mismatch, and lumbar and thoracic Cobb angles were similar among the groups. Patients in the PSF-only group had more comorbidities, those in the ALIF+PSF group were, on average, younger and had a lower body mass index than those in the LLIF+PSF group, and patients in the LLIF+PSF group had a significantly higher mean number of interbody fusion levels than those in the ALIF+PSF and PSF-only groups. At final follow-up, all radiographic parameters and the mean numbers of complications were similar among the groups. Patients in the LLIF+PSF group had proximal junctional kyphosis that required revision surgery significantly less often and fewer proximal junctional fractures and vertebral slips. All preoperative HRQoL scores were similar among the groups. After surgery, the LLIF+PSF group had a significantly lower ODI score, higher SRS-22 self-image/total scores, and greater achievement of the minimal clinically important difference for the SRS-22 pain score. CONCLUSIONS Satisfactory radiographic outcomes can be achieved similarly and adequately with these 3 surgical approaches for patients with ASD with mild to moderate sagittal deformity. Compared with patients treated with an ALIF+PSF or PSF-only surgical strategy, patients who underwent LLIF+PSF had lower rates of proximal junctional kyphosis and mechanical failure at the upper instrumented vertebra and less back pain, less disability, and better SRS-22 scores.

Usage of Chewing Gum in Posterior Spinal Fusion Surgery for Adolescent Idiopathic Scoliosis: A Randomized Controlled Trial

STUDY DESIGN

Randomized controlled trial.

OBJECTIVE

The present study investigated the effectiveness of chewing gum on promoting faster bowel function and its ability to hasten recovery for patients with adolescent idiopathic scoliosis (AIS) after posterior spinal fusion (PSF) surgery.

SUMMARY OF BACKGROUND DATA

Sham feeding with chewing gum had been reported to reduce the incidence of postoperative ileus by accelerating recovery of bowel function.

METHODS

We prospectively recruited and randomized 60 patients with AIS scheduled for PSF surgery into treatment (chewing gum) and control group. The patient-controlled anesthesia usage, wound pain score, abdominal pain score, nausea score, and abdominal girth were assessed and recorded at 12, 24, 36, 48, and 60 hours postoperatively. The timing for the first fluid intake, first oral intake, sitting up, walking, first flatus after surgery, first bowel opening after surgery, and duration of hospital stay were also assessed and recorded.

RESULTS

We found that there were no significant differences (P > 0.05) in patient-controlled anesthesia usage, wound pain score, abdominal pain score, nausea score, and abdominal girth between treatment (chewing gum) and control groups. We also found that there were no significant difference (P > 0.05) in postoperative recovery parameters, which were the first fluid intake, first oral intake, sitting up after surgery, walking after surgery, first flatus after surgery, first bowel opening after surgery, and duration of hospital stay between both groups. The wound pain was the worst at 12 hours postoperatively, which progressively improved in both groups. The abdominal pain progressively worsened to the highest score at 48 hours in the treatment group and 36 hours in the control group before improving after that. The pattern of severity and recovery of wound pain and abdominal pain was different.

CONCLUSION

We found that chewing gum did not significantly reduce the abdominal pain, promote faster bowel function, or hasten patient recovery.

LEVEL OF EVIDENCE

1.

Adult Spinal Deformity: National Trends in the Presentation, Treatment, and Perioperative Outcomes From 2003 to 2010

STUDY DESIGN

Retrospective review of a prospective database.

OBJECTIVES

To investigate adult spinal deformity (ASD) surgery outcome trends on a nationwide scale using the Nationwide Inpatient Sample (NIS) from 2003 to 2010.

METHODS

ASD patients ≥25 years from 2003 to 2010 in the NIS undergoing anterior, posterior, or combined surgical approaches were included. Fractures, 9+ levels fused, or any cancer were excluded. Patient demographics, hospital data, and procedure-related complications were evaluated. Yearly trends were analyzed using univariate analysis and linear regression modeling.

RESULTS

Of 10,966 discharges, 1,952 were anterior, 6,524 were posterior, and 1,106 were combined. The total surgical ASD volume increased by 112.5% (p = .029), and both the average patient age (p < .001) and number of patients >65 years old significantly increased from 2003 to 2010 (p = .009). Anterior approach case volume decreased by 13.7% (p = .019), whereas that of combined increased by 22.7% (p = .047). Posterior case volume increased by 38.9% from 2003 to 2010, though insignificantly (p = .084). Total hospital charges for all approaches increased over the interval (p < .001). Total length of stay for all approaches decreased over the time interval (p < .005). Although the overall morbidity for all approaches increased by 22.7% (p < .001), mortality did not change (p = .817). The most common morbidities in 2003 were hemorrhagic anemia, accidental cut, puncture, perforation, or laceration during a procedure, and device-related complications, which persisted in 2010 with the exception of increased acute respiratory distress syndrome and pulmonary-related complications.

CONCLUSIONS

For ASD surgery from 2003 to 2010, the volume of anterior approaches decreased, whereas posterior procedures did not change, and combined approaches increased. Total hospital charges increased for all considered procedures, length of hospital stay decreased, whereas operative patients were increasingly elderly, and more procedures were observed for patients >65 years old. For all approaches, morbidity increased whereas mortality did not change. Future study is required to develop methods to reduce morbidity and costs, thereby optimizing patient outcomes.

Frailty Is Predictive of Adverse Postoperative Events in Patients Undergoing Lumbar Fusion

STUDY DESIGN

Retrospective study of prospectively collected data.

OBJECTIVE

To analyze the modified frailty index (mFI) as a predictor of adverse postoperative events following posterior lumbar fusion.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database including all adult patients undergoing posterior lumbar interbody fusion or transforaminal lumbar interbody fusion between 2005 and 2012. Outcomes measured included mortality, postoperative complications, length of stay, reoperations, and readmissions. The previously described mFI was calculated, and univariate and multivariate logistic regression analysis were used to analyze risk factors associated with morbidity, mortality, and adverse postoperative events. This study was qualified as exempt by the Mount Sinai Hospital Institutional Review Board.

RESULTS

A total of 6094 patients met inclusion criteria. The mean mFI was 0.087(0-0.545). Increasing mFI score was associated with increased complications, reoperations, prolonged length of stay (LOS), and morbidity (P < .05). As the mFI score increased from 0.27 (3/11 variables present) to ≥0.36 (4/11), the rate of any complication increased from 26.8% to 35% (P < .0001), sepsis 2.4% to 5.2% (P < .0001), wound complications 4.4% to 6.5% (P < .0001), unplanned readmissions 4.7% to 20% (P = .02), and urinary tract infection 4.1% to 10.4% (P < .0001). An mFI of ≥0.36 was an independent predictor of any complication (odds ratio [OR]= 2.2, 95% confidence interval [CI] = 1.3-3.7), sepsis (OR = 6.3, 95%, CI = 1.8-21), wound complications (OR = 2.9, 95% CI = 1.1-8.2), prolonged LOS (OR = 2.3, 95% CI = 1.4-3.7), and readmission (OR = 4.3, 95% CI = 1.5-12.7).

CONCLUSION

Patients with higher mFI scores (≥ 4/11 variables) are at a significantly higher risk of major complications, readmissions, and prolonged LOS following lumbar fusion.

Early Complications and Outcomes in Adult Spinal Deformity Surgery: An NSQIP Study Based on 5803 Patients

STUDY DESIGN

Retrospective analysis.

OBJECTIVE

The purpose of this study is to determine the incidence, impact, and risk factors for short-term postoperative complications following elective adult spinal deformity (ASD) surgery.

METHODS

Current Procedural Terminology codes were used to query the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) for adults who underwent spinal deformity surgery from 2010 to 2014. Patients were separated into groups of those with and without complications. Univariate analysis and multivariate logistic regression were used to assess the impact of patient characteristics and operative features on postoperative outcomes.

RESULTS

In total, 5803 patients were identified as having undergone ASD surgery in the NSQIP database. The average patient age was 59.5 (±13.5) years, 59.0% were female, and 81.1% were of Caucasian race. The mean body mass index was 29.5(±6.6), with 41.9% of patients having a body mass index of 30 or higher. The most common comorbidities were hypertension requiring medication (54.5%), chronic obstructive pulmonary disease (4.9%), and bleeding disorders (1.2%). Nearly a half of the ASD patients had an operative time >4 hours. The posterior fusion approach was more common (56.9%) than an anterior one (39.6%). The mean total relative value unit was 73.4 (±28.8). Based on multivariate analyses, several patient and operative characteristics were found to be predictive of morbidity.

CONCLUSION

Surgical correction of ASD is associated with substantial risk of intraoperative and postoperative complications. Preoperative and intraoperative variables were associated with increased morbidity and mortality. This data may assist in developing future quality improvement activities and saving costs through measurable improvement in patient safety.

A Critical Analysis of Sagittal Plane Deformity Correction With Minimally Invasive Adult Spinal Deformity Surgery: A 2-Year Follow-Up Study

INTRODUCTION

Sagittal plane realignment is important to achieve desirable clinical outcomes after adult spinal deformity (ASD) surgery. This study evaluates the impact of minimally invasive (MIS) techniques on sagittal plane alignment and clinical outcomes in ASD patients.

METHODS

A retrospective, multi-center review of ASD patients (age ≥18 years, and with one of the following: coronal Cobb ≥20°, sagittal vertical axis [SVA] >5 cm, and/or pelvic tilt >25°), MIS surgery, and four or more levels instrumented. Patients were stratified by baseline SRS-Schwab global alignment modifier (GAM) into three groups: 0 (SVA <4 cm), + (SVA 4-9.5 cm), or ++ (SVA >9.5 cm). Radiographic and clinical outcomes measures were analyzed with a minimum of 2-year follow-up.

RESULTS

A total of 96 ASD patients were identified, and 63 met the study's inclusion criteria of circumferential MIS or posterior MIS only, with four or more levels instrumented (n: Group 0 = 37, Group + = 15, and Group ++ = 11). Group 0 was younger than ++ (56.8 vs. 69.6 years), with a higher proportion of females than Group + or ++ (83.8% vs. 66.7% and 54.5%, respectively). Baseline HRQoL was similar. Postoperatively, Groups 0 and + had improved Oswestry Disability Index (ODI) and numeric rating scale (NRS) back and leg scores. Group ++ only had improvement in NRS scores. At the latest follow-up, Groups 0 and ++ had similar sagittal measurements except for PT (21.6 vs. 23.6, p = .009). The + group had improvement in PI-LL (24.2 to 17; p = .015) and LL (30.9 to 38.3; p = .013). Eight of 27 (21.6%) Group 0 patients deteriorated (4 to Group +, 4 to Group ++). Three of 15 (20.0%) Group + patients deteriorated to Group ++, and 3 improved to Group 0. Six of 11 (54.5%) Group ++ patients improved (3 to Group + and 3 to Group 0).

CONCLUSIONS

MIS techniques successfully stabilized ASD patients with Group 0 and + deformities and improved HRQoL. This study suggests that severe sagittal imbalance is not adequately treated with MIS approaches.