Variation in Adolescent Idiopathic Scoliosis Surgery: Implications for Improving Healthcare Value

Predictive factors for critical care dependency after posterior spinal fusion for adolescent idiopathic scoliosis

Aims

Historically, patients undergoing surgery for adolescent idiopathic scoliosis (AIS) have been nursed postoperatively in a critical care (CC) setting because of the challenges posed by prone positioning, extensive exposures, prolonged operating times, significant blood loss, major intraoperative fluid shifts, cardiopulmonary complications, and difficulty in postoperative pain management. The primary aim of this paper was to determine whether a scoring system, which uses Cobb angle, forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and number of levels to be fused, is a valid method of predicting the need for postoperative critical care in AIS patients who are to undergo scoliosis correction with posterior spinal fusion (PSF).

Methods

We retrospectively reviewed all AIS patients who had undergone PSF between January 2018 and January 2020 in a specialist tertiary spinal referral centre. All patients were assessed preoperatively in an anaesthetic clinic. Postoperative care was defined as ward-based (WB) or critical care (CC), based on the preoperative FEV1, FVC, major curve Cobb angle, and the planned number of instrumented levels.

Results

Overall, 105 patients were enrolled. Their mean age was 15.5 years (11 to 25) with a mean weight of 55 kg (35 to 103). The mean Cobb angle was 68° (38° to 122°). Of these, 38 patients were preoperatively scored to receive postoperative CC. However, only 19% of the cohort (20/105) actually needed CC-level support. Based on these figures, and an average paediatric intensive care unit stay of one day before stepdown to ward-based care, the potential cost-saving on the first postoperative night for this cohort was over £20,000. There was no statistically significant difference between the Total Pathway Score (TPS), the numerical representation of the four factors being assessed, and the actual level of care received (p = 0.052) or the American Society of Anesthesiologists grade (p = 0.187). Binary logistic regression analysis of the TPS variables showed that the preoperative Cobb angle was the only variable which significantly predicted the need for critical care.

Conclusion

Most patients undergoing posterior fusion surgery for AIS do not need critical care. Of the readily available preoperative measures, the Cobb angle is the only predictor of the need for higher levels of care, and has a threshold value of 74.5°.

Impact of a quality improvement initiative and monthly multidisciplinary meetings on outcomes after posterior spinal fusion for adolescent idiopathic scoliosis

INTRODUCTION

Several studies have demonstrated the benefits of enhanced recovery after surgery (ERAS) protocols for patients with adolescent idiopathic scoliosis (AIS) undergoing posterior spinal instrumented fusion (PSIF). However, there are relatively few studies investigating the effect of regular multidisciplinary team meetings on level selection, surgical performance parameters, and patient outcomes after PSIF for AIS. The aim of this study was to assess changes in intra- and postoperative outcomes following multidisciplinary team meeting implementation for patients undergoing PSIF for AIS.

METHODS

The medical records of 96 adolescents (10 to 18 years old) diagnosed with AIS and undergoing PSIF at a major academic institution from 2017 to 2022 were retrospectively reviewed. A quality improvement (QI) initiative was implemented in February 2020, including institution of monthly multidisciplinary conferences focusing on preoperative indications, level selection, postoperative review of surgical performance parameters for previous cases, and discussion and optimization of postoperative ambulation and pain control protocols. Patients were placed into "Pre-QI" (treated pre-February 2020) and "Post-QI" (treated post-February 2020) cohorts. Patient demographics, comorbidities, deformity characteristics, intraoperative variables, ambulation status, postoperative complications, length of stay (LOS), and unplanned readmission rates were assessed.

RESULTS

Of the 96 study patients, 44 (45.8%) were in the Pre-QI cohort, and 52 (54.2%) were in the Post-QI cohort. Mean major curve was not significantly different between the two cohorts (Pre-QI: 58.0 ± 7.3° vs Post-QI: 57.9 ± 14.5°, p = 0.169). The Pre-QI cohort had a greater mean minor curve degree (Pre-QI: 42.7 ± 11.8° vs Post-QI: 36.8 ± 12.4, p = 0.008). The Pre-QI cohort had significantly greater mean spinal levels fused (Pre-QI: 11.7 ± 1.7 vs Post-QI: 10.4 ± 2.6, p = 0.009), significantly greater mean estimated blood loss (Pre-QI: 1063.6 ± 631.5 ml vs. Post-QI: 415.8 ± 189.9 ml, p < 0.001), significantly greater mean operative time normalized to levels fused (Pre-QI: 0.6 ± 0.1 h/level fused vs Post-QI: 0.4 ± 0.1 h/level fused, p < 0.001), and a significantly greater proportion of patients with intraoperative drain placement (Pre-QI: 93.2% vs Post-QI: 5.8%, p < 0.001). The Post-QI cohort had significantly shorter time to postoperative ambulation (Pre-QI: 2.1 ± 0.9 days vs Post-QI: 1.3 ± 0.5 days, p < 0.001). A significantly greater proportion of patients in the Pre-QI cohort developed any postoperative complication (Pre-QI: 72.7% vs Post-QI: 34.6%, p < 0.001), and mean LOS was significantly greater among Pre-QI patients (Pre-QI: 4.5 ± 1.1 days vs Post-QI: 3.2 ± 0.8 days, p < 0.001). Discharge disposition (p = 0.758) and 30-day unplanned readmissions (p = 0.207) were similar between the cohorts.

CONCLUSIONS

Our findings suggest that monthly multidisciplinary pediatric spine team meetings may improve patient care. Further studies exploring the incorporation of QI implementation with frequent multidisciplinary team meetings into existing ERAS protocols are merited.

Optimising operating theatre (OT) efficiency while maintaining the standardised patient care in adolescent idiopathic scoliosis (AIS) surgery with the dedicated spine team approach: a specialised spine unit experience

PURPOSE

To report the efficiency of OT utilisation and perioperative outcomes with a dedicated spine team approach in AIS patients who underwent posterior spinal fusion (PSF) surgeries in a consecutive case operation list.

METHODS

Three AIS patients operated in a day (8:00 AM-8:00 PM) by a dedicated spine team were recruited between 2021 and 2022. The dedicated team comprised of three senior spine consultants who operated using a dual attending surgeon strategy, an anaesthetic consultant, dedicated surgical scrub nurses, anaesthesiology nurses, radiographers, and neuromonitoring technicians. Patients were categorised according to the sequence of operation list of the day (Case 1, Case 2, and Case 3). OT efficiency was represented by OT time in five stages (preoperative time, operative time, postoperative time, total OT time, and turnover time). OT time and perioperative outcomes were compared.

RESULTS

102 cases were analysed. On average, Case 1 began at 8:38 AM whereas Case 3 ended by 5:54 PM. OT efficiency was consistent throughout the day of operation with comparable OT time in all five stages between groups (p > 0.05). The mean turnover time was 15.1 ± 13.5 min and the mean operative time was 123.0 ± 28.1 min. Intraoperative arterial blood gas (ABG) parameters were maintained in an optimal range. The complication rate was 2.0% (N = 2/102).

CONCLUSION

Consistent OT efficiency was demonstrated with a dedicated spine team approach. Despite performing three AIS cases in a consecutive case operation list, patients' safety was not compromised as perioperative outcomes between groups were comparable.

Pediatric Digit Replantation: A Nationwide Analysis of Failure Rate, Complications, and Potential Factors Affecting Failure

Purpose

Function and cosmesis may be improved by replantation following digital amputation in pediatric patients. However, accurate failure and complication rate estimates may be limited as most pertinent studies reflect single center/surgeon experience and therefore are limited by small sample sizes. The primary aim of this study was to assess the rate of failure (amputation) following pediatric digital replantation. Secondary aims include evaluating the rate of complications and associated resource utilization (intensive care unit stays, readmission rate, and hospital length of stay).

Methods

Digital replantation patients were identified from 47 pediatric hospitals using the 2004 to 2020 Pediatric Health Information System nationwide database. Using applicable International Classification of Disease 9/10 and Current Procedural Terminology codes, we identified complications after replantation, including revision amputation, infection, surgical complications, medical complications, admission to intensive care unit (ICU), and length of stay.

Results

Of the 348 patients who underwent replantation the mean age was 8.3 ± 5.1 years, and 27% were female. Mean hospital length of stay was 5.8 ± 4.7 (range, 1-28) days. Of the 53% of patients who required ICU admission, the mean ICU length of stay was 2.4 ± 3.3 days. Failure/amputation after replantation occurred in 71 (20.4%) patients, at a mean of 9.7 ± 27.2 days postoperatively. Surgical complications occurred in 58 (17%) patients, 30-day hospital readmissions occurred in 5.7% of patients, and 90-day readmissions occurred in 6.3% patients.

Conclusion

The estimated rate of failure following pediatric digit replantation was 20%. Our data on failure and complication rates and associated resource utilization may be useful in counseling pediatric replantation patients and their families and provide an update on prior literature.

Level of Evidence

IV, Prognosis.

Novel Enhanced Recovery After Surgery Pathway Reduces Length of Stay and Postoperative Opioid Usage in Adolescent Idiopathic Scoliosis Patients Undergoing Posterior Spinal Fusion

PURPOSE

The goal of this study was to compare our institution's recently implemented enhanced recovery after surgery (ERAS) protocol to previous post-operative management for adolescent idiopathic scoliosis patients undergoing posterior spinal fusion, specifically assessing length of stay, opioid consumption, and pain scores.

METHODS

This is a retrospective analysis that compares the length of stay, opioid consumption, and pain scores of patients undergoing posterior spinal fusion for adolescent idiopathic scoliosis. Patients were analyzed prior to the implementation of our ERAS protocol, deemed the traditional pain pathway (TPP), to those who underwent the ERAS pathway. All patients undergoing posterior spinal fusion for adolescent idiopathic scoliosis were included. Patients were excluded if they weighed less than 40kg, had significant comorbidities, or had non-idiopathic causes of scoliosis.

RESULTS

We examined 22 patients in the TPP cohort and 20 in the ERAS cohort. Length of stay in the ERAS cohort was significantly reduced compared to the TPP by 1.7 days (P<0.01). Overall opioid consumption was also significantly reduced in the ERAS with 1.4 ± 0.7 morphine equivalents (ME)/kg compared to the TPP 2.4 ± 1.1 ME/kg (P < 0.01). We found no difference in pain scores between the two groups.

CONCLUSION

Implementation of an ERAS pathway at our institution significantly reduced length of stay and opioid consumption in adolescent idiopathic scoliosis patients undergoing posterior spinal fusion. These outcomes reduce morbidity and costs associated with posterior spinal fusion and provide an overall improvement in the quality of care for our patients.

Influence of Sociodemographic and Psychosocial Factors on Length of Stay After Surgical Management of Traumatic Spine Fracture with Spinal Cord Injury

OBJECTIVE

Identifying patients at risk of increased health care resource utilization is a valuable opportunity to develop targeted preoperative and perioperative interventions. In the present investigation, we sought to examine patient sociodemographic factors that predict prolonged length of stay (LOS) after traumatic spine fracture.

METHODS

We performed a cohort analysis using the National Trauma Data Bank tabulated during 2012-2016. Eligible patients were those who were diagnosed with cervical or thoracic spine fracture with spinal cord injury and who were treated surgically. We evaluated the effects of sociodemographic as well as psychosocial variables on LOS by negative binomial regression and adjusted for injury severity, injury mechanism, and hospital characteristics.

RESULTS

We identified 3856 eligible patients with a median LOS of 9 days (interquartile range, 6-15 days). Patients in older age categories, who were male (incidence rate ratio (IRR), 1.05; 95% confidence interval [CI], 1.01-1.09), black (IRR, 1.12; CI, 1.05-1.19) or Hispanic (IRR, 1.09; CI, 1.03-1.16), insured by Medicaid (IRR, 1.24; CI, 1.17-1.31), or had a diagnosis of alcohol use disorder (IRR, 1.12; CI, 1.06-1.18) were significantly more likely to have a longer LOS. In addition, patients with severe injury on Injury Severity Score (IRR, 1.32; CI, 1.14-1.53) and lower Glasgow Coma Scale (GCS) scores (GCS score 3-8, IRR, 1.44; CI, 1.35-1.55; GCS score 9-11, IRR, 1.40; CI, 1.25-1.58) on admission had a significantly lengthier LOS. Patients admitted to a hospital in the Southern United States (IRR, 1.09; CI, 1.05-1.14) had longer LOS.

CONCLUSIONS

Socioeconomic factors such as race, insurance status, and alcohol use disorder were associated with a prolonged LOS after surgical management of traumatic spine fracture with spinal cord injury.

Severe Lenke 1 and 2 adolescent idiopathic scoliosis had poorer perioperative outcome, higher complication rate, longer fusion and higher operative cost compared to non-severe scoliosis

PURPOSE

To compare the perioperative outcome and operative cost of posterior spinal fusion (PSF) surgery between severe and non-severe Lenke 1 and 2 adolescent idiopathic scoliosis (AIS) patients.

METHODS

A total of 509 AIS patients who underwent single-staged PSF between 2013 and 2020 were reviewed. Fifty-four severe scoliosis patients (Cobb angle ≥ 90°) were categorized into Gp1, and 455 non-severe scoliosis (Cobb angle < 90°) patients into Gp2. Propensity score matching (PSM) analysis using one-to-one nearest neighbor matching and match tolerance of 0.001 were performed. Outcome measures were operative time, intraoperative blood loss (IBL), allogeneic transfusion rate, perioperative complication, length of stay, fusion level, number of screws used, postoperative Cobb angle, correction rate (CR), side bending correction index (SBCI) and operative cost.

RESULTS

From the PSM analysis, 35 patients from each group were matched. The operative time was 155.9 ± 41.4 and 130.0 ± 30.3 min for Gp1 and Gp2, respectively (p = 0.004). The IBL was 1349.2 ± 1019.0 and 781.9 ± 325.1 mLs for Gp1 and Gp2, respectively (p = 0.003). Fusion level (12.5 ± 0.8 vs. 11.2 ± 1.3, p < 0.001) and number of screws used (16.4 ± 1.6 vs. 14.6 ± 1.4, p < 0.001) were higher in Gp1. Four perioperative complications were observed in Gp1 compared to none in Gp2 (p < 0.039). Gp1 had larger postoperative Cobb angle (p < 0.001), lower CR (p = 0.005) and higher SBCI (p < 0.001). The operative cost was higher in Gp1 (p < 0.001).

CONCLUSIONS

Severe Lenke 1 and 2 AIS patients had poorer perioperative outcome, higher complication rate, longer fusion and higher operative cost than non-severe AIS.

Impact of race on outcomes and healthcare utilization following spinal fusion for adolescent idiopathic scoliosis

OBJECTIVES

Racial disparities in spine surgery have been shown to impact surgical management and postoperative complications. However, for adolescent patients with idiopathic scoliosis (AIS) treated by posterior spinal fusion (PSF), the influence of race on postoperative outcomes remains unclear. The aim of the study was to investigate the differences in baseline patient demographics, inpatient management, and postoperative complications for adolescents with AIS undergoing elective, posterior spinal surgery (≥ 4 levels).

PATIENTS AND METHODS

The Kids' Inpatient Database year 2012 was queried. Adolescent patients (age 10-17 years old) with AIS undergoing elective, PSF (≥ 4 levels) were selected using the International Classification of Diseases, Ninth Revision, Clinical Modification coding system. Patients were divided into 4 cohorts: Black, White, Hispanic, and Other. Patient demographics, comorbidities, complications, length of hospital stay (LOS), discharge disposition and total cost were recorded. The primary outcome was the rate of intraoperative and postoperative complications and resource utilization after elective PSF intervention.

RESULTS

Patient demographics significantly differed between the four cohorts. While age was similar (p = 0.288), the White cohort had a greater proportion of female patients (White: 79.0%; Black: 72.1%; Hispanic: 78.2%; Other: 75.9%, p = 0.006), and the Black cohort had the largest proportion of patients in the 0-25th income quartile (White: 16.1%; Black: 43.3%; Hispanic: 28.0%; Other: 15.3%, p < 0.001). There were significant differences in hospital region (p < 0.001) and bed size (p < 0.001) between the cohorts, with more Hispanic adolescents being treated in the West (White: 21.9%; Black: 8.9%; Hispanic: 40.3%; Other: 29.3%) at small hospitals (White: 14.0%; Black: 13.9%; Hispanic: 16.2%; Other: 7.1%). Baseline comorbidities were similar between the cohorts. The use of blood transfusions was significantly greater in the Black cohort compared to the other racial groups (White: 16.7%; Black: 25.0%; Hispanic: 24.5%; Other: 22.7%, p < 0.001). The number of vertebral levels involved differed significantly between the cohorts (p < 0.001), with the majority of patients having 9-levels or greater involved (White: 80.9%; Black: 81.7%; Hispanic: 84.3%; Other: 67.3%). The rate of complications encountered during admission was greatest in the Other cohort (White: 21.9%; Black: 23.6%; Hispanic: 22.2%; Other: 34.9%, p < 0.001). While LOS was similar between the cohorts (p = 0.702), median total cost of admission was highest for Hispanic patients (White: $49,340 [37,908-65,078]; Black: $47,787 [37,718-64,670]; Hispanic: $54,718 [40,689-69,266]; Other: $54,110 [41,292-71,540], p < 0.001).

CONCLUSIONS

Our study suggests that race may not have a significant impact on surgical outcomes after elective posterior spine surgery for adolescent idiopathic scoliosis. Further studies are necessary to corroborate our findings.

Cost-Utility Analysis of Anterior Vertebral Body Tethering versus Spinal Fusion in Idiopathic Scoliosis from a US Integrated Healthcare Delivery System Perspective

Purpose

Anterior vertebral body tethering (VBT) is a non-fusion, minimally invasive, growth-modulating procedure with some early positive clinical outcomes reported in pediatric patients with idiopathic scoliosis (IS). VBT offers potential health-related quality of life (HRQoL) benefits over spinal fusion in allowing patients to retain a greater range of motion after surgery. We conducted an early cost-utility analysis (CUA) to compare VBT with fusion as a first-choice surgical treatment for skeletally immature patients (age >10 years) with moderate to severe IS, who have failed nonoperative management, from a US integrated healthcare delivery system perspective.

Patients and Methods

The CUA uses a Markov state transition model, capturing a 15-year period following index surgery. Transition probabilities, including revision risk and subsequent fusion, were based on published surgical outcomes and an ongoing VBT observational study (NCT02897453). Patients were assigned utilities derived from published patient-reported outcomes (PROs; SRS-22r mapped to EQ-5D) following fusion and the above VBT study. Index and revision procedure costs were included. Probabilistic (PSA) and deterministic sensitivity analyses (DSA) were performed.

Results

VBT was associated with higher costs but also higher quality-adjusted life years (QALYs) than fusion (incremental costs: $45,546; QALYs gained: 0.54). The subsequent incremental cost-effectiveness ratio for VBT vs fusion was $84,391/QALY gained. Mean PSA results were similar to the base case, indicating that results were generally robust to uncertainty. The DSA indicated that results were most sensitive to variations in utility values.

Conclusion

This is the first CUA comparing VBT with fusion in pediatric patients with IS and suggests that VBT may be a cost-effective alternative to fusion in the US, given recommended willingness-to-pay thresholds ($100,000–$150,000). The results rely on HRQoL benefits for VBT compared with fusion. For improved model accuracy, further analyses with longer-term PROs for VBT, and comparative effectiveness studies, would be needed.

The risks, reasons, and costs for 30- and 90-day readmissions after fusion surgery for adolescent idiopathic scoliosis

OBJECTIVE

With the continued evolution of bundled payment plans, there has been a greater focus within orthopedic surgery on quality metrics up to 90 days of care. Although the Centers for Medicare and Medicaid Services does not currently penalize hospitals based on their pediatric readmission rates, it is important to understand the drivers for unplanned readmission to improve the quality of care and reduce costs.

METHODS

The National Readmission Database provides a nationally representative sample of all discharges from US hospitals and allows follow-up across hospitals up to 1 calendar year. Adolescents (age 10-18 years) who underwent idiopathic scoliosis surgery from 2012 to 2015 were included. Patients were separated into those with and those without readmission within 30 days or between 31 and 90 days. Demographics, operative conditions, hospital factors, and surgical outcomes were compared using the chi-square test and t-test. Independent predictors for readmissions were identified using stepwise multivariate logistic regression.

RESULTS

A total of 30,677 patients underwent adolescent idiopathic scoliosis surgery from 2012 to 2015. The rates of 30- and 90-day readmissions were 2.9% and 1.4%, respectively. The mean costs associated with the index admission and 30- and 90-day readmissions were $60,680, $23,567, and $16,916, respectively. Common risk factors for readmissions included length of stay > 5 days, obesity, neurological disorders, and chronic use of antiplatelets or anticoagulants. The index admission complications associated with readmissions were unintended durotomy, syndrome of inappropriate antidiuretic hormone, and superior mesenteric artery syndrome. Hospital factors, discharge disposition, and operative conditions appeared to be less important for readmission risk. The top reasons for 30-day and 90-day readmissions were wound infection (34.7%) and implant complications (17.3%), respectively. Readmissions requiring a reoperation were significantly higher for those that occurred between 31 and 90 days after the index readmission.

CONCLUSIONS

Readmission rates were low for both 30- and 90-day readmissions for adolescent idiopathic scoliosis surgery patients. Nevertheless, readmissions are costly and appear to be associated with potentially modifiable risk factors, although some risk factors remain potentially unavoidable.

Clinical utility of enhanced recovery after surgery pathways in pediatric spinal deformity surgery: systematic review of the literature

OBJECTIVES

More than 7500 children undergo surgery for scoliosis each year, at an estimated annual cost to the health system of $1.1 billion. There is significant interest among patients, parents, providers, and payors in identifying methods for delivering quality outcomes at lower costs. Enhanced recovery after surgery (ERAS) protocols have been suggested as one possible solution. Here the authors conducted a systematic review of the literature describing the clinical and economic benefits of ERAS protocols in pediatric spinal deformity surgery.

METHODS

The authors identified all English-language articles on ERAS protocol use in pediatric spinal deformity surgery by using the following databases: PubMed/MEDLINE, Web of Science, Cochrane Reviews, EMBASE, CINAHL, and OVID MEDLINE. Quantitative analyses of comparative articles using random effects were performed for the following clinical outcomes: 1) length of stay (LOS); 2) complication rate; 3) wound infection rate; 4) 30-day readmission rate; 5) reoperation rate; and 6) postoperative pain scores.

RESULTS

Of 950 articles reviewed, 7 were included in the qualitative analysis and 6 were included in the quantitative analysis. The most frequently cited benefits of ERAS protocols were shorter LOS, earlier urinary catheter removal, and earlier discontinuation of patient-controlled analgesia pumps. Quantitative analyses showed ERAS protocols to be associated with shorter LOS (mean difference -1.12 days; 95% CI -1.51, -0.74; p < 0.001), fewer postoperative complications (OR 0.37; 95% CI 0.20, 0.68; p = 0.001), and lower pain scores on postoperative day (POD) 0 (mean -0.92; 95% CI -1.29, -0.56; p < 0.001) and POD 2 (-0.61; 95% CI -0.75, -0.47; p < 0.001). There were no differences in reoperation rate or POD 1 pain scores. ERAS-treated patients had a trend toward higher 30-day readmission rates and earlier discontinuation of patient-controlled analgesia (both p = 0.06). Insufficient data existed to reach a conclusion about cost differences.

CONCLUSIONS

The results of this systematic review suggest that ERAS protocols may shorten hospitalizations, reduce postoperative complication rates, and reduce postoperative pain scores in children undergoing scoliosis surgery. Publication biases exist, and therefore larger, prospective, multicenter data are needed to validate these results.

Predictors of cost for posterior spinal fusion in adolescent idiopathic scoliosis

STUDY DESIGN

Single-center retrospective review of pediatric patients who underwent posterior spinal fusion for adolescent idiopathic scoliosis (AIS).

OBJECTIVE

To determine what clinical and operative factors influence inflation-adjusted hospital costs of posterior spine fusion surgery for AIS. With rising healthcare costs and the advent of bundled payments, it is essential understand the predictors of costs for surgical procedures. We sought to determine the components of hospital costs for AIS posterior spine fusion surgery using standardized, inflation-adjusted, line-item costs for services and procedures.

METHODS

The study population comprised 148 AIS patients who underwent spinal fusion surgery at a large tertiary care center between 2009 and 2016. Data on medical characteristics, curve type, curve magnitude, number of screws and the number of levels was collected through manual chart review of X-rays and medical records. Hospital costs from admission until discharge were retrieved from an institutional database that contained line-item details of all procedures and services billed during the hospital episode. Bottom-up microcosting valuation techniques were used to generate standardized inflation-adjusted estimates of costs and standard deviations in 2016 dollars.

RESULTS

Mean cost of AIS surgery was $48,058 ± 9379. Physician fees averaged 15% of the total cost ($7045 ± 1732). Implant costs and surgical/anesthesia/surgeon's fees accounted for over 70% of the hospital costs. Mean number of screws was 16 ± 4.5, mean number of levels fused was 11.2 ± 2.2, and the mean implant density (screws per level fused) was 1.45 ± 0.35. On multivariate analysis, the number of screws per level fused, number of levels fused, curve magnitude and length of stay were all significantly associated with hospital costs (p < 0.01).

CONCLUSIONS

Bundled payments for AIS surgery should include adjustments for number of levels fused and curve size. Areas for cost savings include further reduction in implant costs, shortening length of stay, and reducing intraoperative costs.

LEVEL OF EVIDENCE

III.

The effect of hospital characteristics on pediatric neuromuscular scoliosis fusion cost

OBJECTIVE

Spinal fusion is used in the treatment of pediatric neuromuscular scoliosis (NMS) to improve spine alignment and delay disease progression. However, patients with NMS are often medically complex and require a higher level of care than those with other types of scoliosis, leading to higher treatment costs. The purpose of this study was to 1) characterize the cost of pediatric NMS fusion in the US and 2) determine hospital characteristics associated with changes in overall cost.

METHODS

Patients were identified from the National Inpatient Sample (2012 to the first 3 quarters of 2015). Inclusion criteria selected for patients with NMS, spinal fusion of at least 4 vertebral levels, and elective hospitalization. Patients with no cost information were excluded. Sociodemographics, treating hospital characteristics, disease etiology/severity, comorbidities, length of stay, and hospital costs were collected. Univariable analysis and multivariable gamma log-link regression were used to determine hospital characteristics associated with changes in cost.

RESULTS

A total of 1780 weighted patients met inclusion criteria. The median cost was $68,815. Following multivariable regression, both small (+$11,580, p < 0.001) and medium (+$6329, p < 0.001) hospitals had higher costs than large hospitals. Rural hospitals had higher costs than urban teaching hospitals (+$32,438, p < 0.001). Nonprofit hospitals were more expensive than both government (-$4518, p = 0.030) and investor-owned (-$10,240, p = 0.001) hospitals. There was significant variability by US census division; compared with the South Atlantic, all other divisions except for the Middle Atlantic had significantly higher costs, most notably the West North Central (+$15,203, p < 0.001) and the Pacific (+$22,235, p < 0.001). Hospital fusion volume was not associated with total cost.

CONCLUSIONS

A number of hospital factors were associated with changes in fusion cost. Larger hospitals may be able to achieve decreased costs due to economies of scale. Regional differences could reflect uncontrolled-for variability in underlying patient populations or systems-level and policy differences. Overall, this analysis identified multiple systemic patterns that could be targets of further cost-related interventions.

Paraspinal muscle ladybird homeobox 1 (LBX1) in adolescent idiopathic scoliosis: a cross-sectional study

BACKGROUND CONTEXT

Adolescent idiopathic scoliosis (AIS) is the leading cause of spinal deformity in adolescents globally. Recent evidence from genome-wide association studies has implicated variants in or near the ladybird homeobox 1 (LBX1) gene, encoding the ladybird homeobox 1 transcription factor, in AIS development. This gene plays a critical role in guiding embryonic neurogenesis and myogenesis and is vital in muscle mass determination. Despite the confirmation of the role for LBX1 gene variants in the development of AIS, the biological basis of LBX1 contribution to AIS remains mostly unknown.

PURPOSE

To investigate the potential role of LBX1 in driving spinal curving, curve laterality, and progression through muscle-based mechanisms in AIS patients by analyzing its gene and protein expression.

STUDY DESIGN

This is a cross-sectional study using clinical data and biological samples from the Immunometabolic CONnections to Scoliosis study (ICONS study).

PATIENT SAMPLE

Twenty-five patients with AIS provided informed consent. Paraspinal muscle biopsies from the maximal points of concavity and convexity for gene expression and protein analysis were obtained at the start of corrective spinal surgery.

OUTCOME MEASURES

The outcome measures included the detection of paraspinal muscle LBX1 mRNA abundance and LBX1 protein expression and the correlation of the latter with age, sex, and curve severity.

METHODS

The measurement of mRNA abundance was done using quantitative real-time polymerase chain reaction (qRT-PCR). Additionally, protein lysates from the biopsied muscle samples were probed with a monoclonal LBX1 antibody to compare the muscle protein levels on either side of the scoliotic curve by western blot. This study received funding from the Division of Orthopedics, Department of Surgery, McMaster University, Hamilton, Ontario, Canada ($39,900 CAN for 2 years). The authors have no conflicts of interest to disclose.

RESULTS

LBX1 mRNA abundance (concave 2.98±0.87, convex 3.40±1.10, p value 0.73) and protein expression (concave 1.20±0.13, convex 1.21±0.10, p value 0.43) were detected on both sides of the scoliotic curve at equivalent levels. The expression of LBX1 protein did not correlate with age (concave: correlation coefficient 0.32, p value 0.12; convex: correlation coefficient 0.08, p value 0.69), sex (concave: correlation coefficient -0.03, p value 0.08; convex: correlation coefficient 0.07, p value 0.72), or the severity of spinal curving measured using the Cobb angle (concave: correlation coefficient -0.16, p value 0.45; convex: correlation coefficient -0.08, p value 0.69).

CONCLUSIONS

LBX1 is expressed in erector spinae muscles, and its levels are equal in muscles on both sides of the scoliotic curve in AIS. The expression of LBX1 on the convex and concave sides of the scoliotic curve did not correlate with age, sex, or the severity of spinal curving. The molecular mechanisms by which LBX1contributes to the development and propagation of AIS need to be explored further in muscle and other tissues.

Impact of patient and hospital-level risk factors on extended length of stay following spinal fusion for adolescent idiopathic scoliosis

OBJECTIVE

Health policy changes have led to increased emphasis on value-based care to improve resource utilization and reduce inpatient hospital length of stay (LOS). Recently, LOS has become a major determinant of quality of care and resource utilization. For adolescent idiopathic scoliosis (AIS), the determinants of extended LOS after elective posterior spinal fusion (PSF) remain relatively unknown. In the present study, the authors investigated the impact of patient and hospital-level risk factors on extended LOS following elective PSF surgery (≥ 4 levels) for AIS.

METHODS

The Kids' Inpatient Database (KID) was queried for the year 2012. Adolescent patients (age range 10-17 years) with AIS undergoing elective PSF (≥ 4 levels) were selected using the International Classification of Diseases, Ninth Revision, Clinical Modification coding system. Extended hospital LOS was defined as greater than the 75th percentile for the entire cohort (> 6 days), and patients were dichotomized as having normal LOS or extended LOS. Patient demographics, comorbidities, complications, LOS, discharge disposition, and total cost were recorded. A multivariate logistic regression model was used to determine the odds ratio for risk-adjusted LOS. The primary outcome was the degree to which patient comorbidities or postoperative complications correlated with extended LOS.

RESULTS

Comorbidities were overall significantly higher in the extended-LOS cohort than the normal-LOS cohort. Patients with extended LOS had a significantly greater proportion of blood transfusion (p < 0.001) and ≥ 9 vertebral levels fused (p < 0.001). The overall complication rates were greater in the extended-LOS cohort (20.3% [normal-LOS group] vs 43.5% [extended-LOS group]; p < 0.001). On average, the extended-LOS cohort incurred $18,916 more in total cost than the normal-LOS group ($54,697 ± $24,217 vs $73,613 ± $38,689, respectively; p < 0.001) and had more patients discharged to locations other than home (p < 0.001) than did patients in the normal-LOS cohort. On multivariate logistic regression, several risk factors were associated with extended LOS, including female sex, obesity, hypertension, fluid electrolyte disorder, paralysis, blood transfusion, ≥ 9 vertebrae fused, dural injury, and nerve cord injury. The odds ratio for extended LOS was 1.95 (95% CI 1.50-2.52) for patients with 1 complication and 5.43 (95% CI 3.35-8.71) for patients with > 1 complication.

CONCLUSIONS

The authors' study using the KID demonstrates that patient comorbidities and intra- and postoperative complications all contribute to extended LOS after spinal fusion for AIS. Identifying multimodality interventions focused on reducing LOS, bettering patient outcomes, and lowering healthcare costs are necessary to improve the overall value of care for patients undergoing spinal fusion for AIS.