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

Adult versus adolescent idiopathic scoliosis surgery: a meta-analysis of clinical and radiographic outcomes

INTRODUCTION

While the natural history of adolescent idiopathic scoliosis (AIS) and adult idiopathic scoliosis (AdIS) is well documented in the literature, the impact of age on postoperative outcomes remains an active area of research. We performed a systematic review and meta-analysis to compare patients undergoing surgery for AIS and AdIS with respect to: (1) postoperative Cobb correction, (2) perioperative variables, and (3) postoperative complications.

METHODS

A systematic literature search was performed in accordance with preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines.

INCLUSION CRITERIA

studies published between 2002 and 2022, retrospective, and comparing AIS vs. AdIS patients undergoing deformity surgery. The primary outcome was postoperative Cobb correction. Secondary outcomes included estimated blood loss (EBL), operative time, total instrumented levels, length of stay (LOS), and postoperative complications. Random-effects models were performed according to the method of DerSimonian and Laird.

RESULTS

Of 190 identified articles, 14 fit the inclusion criteria. A total of 1788 patients were included, 1275(71.3%) with AIS, and 513(28.7%) with AdIS. There was a significant age difference between AIS and AdIS (15.3 vs. 36.7 years, mean difference (MD) = 21.3 years, 95%CI = 14.3-28.4,p < 0.001). Mean postoperative Cobb percentage correction was reported in 5 articles and was significantly higher in AIS (68.4%) vs. AdIS (61.4%) (MD = -7.2, 95%CI = -11.6,-2.7,p = 0.001). EBL was not significantly different between AIS and AdIS (695.6 mL vs 817.7 mL,p = 0.204). Furthermore, no difference was found in operative time (MD = 37.9 min,95%CI = -10.7;86.6,p = 0.127), total instrumented level (MD = 0.88,95%CI = -0.7,2.4,p = 0.273), and LOS (MD = 0.5, 95%CI = -0.2;1.2, p = 0.188). Four articles reported postoperative complications in AIS vs AdIS, with no difference in neurological deficit, instrumentation-related complications, and medical complications.

CONCLUSION

AIS patients had better radiographic correction compared to AdIS. Though no difference was found in perioperative outcomes and complications, these findings emphasize the importance of counseling patients regarding the optimal timing of surgical correction.

Ensemble learning-assisted prediction of prolonged hospital length of stay after spine correction surgery: a multi-center cohort study

PURPOSE

This research aimed to develop a machine learning model to predict the potential risk of prolonged length of stay in hospital before operation, which can be used to strengthen patient management.

METHODS

Patients who underwent posterior spinal deformity surgery (PSDS) from eleven medical institutions in China between 2015 and 2022 were included. Detailed preoperative patient data, including demographics, medical history, comorbidities, preoperative laboratory results, and surgery details, were collected from their electronic medical records. The cohort was randomly divided into a training dataset and a validation dataset with a ratio of 70:30. Based on Boruta algorithm, nine different machine learning algorithms and a stack ensemble model were trained after hyperparameters tuning visualization and evaluated on the area under the receiver operating characteristic curve (AUROC), precision-recall curve, calibration, and decision curve analysis. Visualization of Shapley Additive exPlanations method finally contributed to explaining model prediction.

RESULTS

Of the 162 included patients, the K Nearest Neighbors algorithm performed the best in the validation group compared with other machine learning models (yielding an AUROC of 0.8191 and PRAUC of 0.6175). The top five contributing variables were the preoperative hemoglobin, height, body mass index, age, and preoperative white blood cells. A web-based calculator was further developed to improve the predictive model's clinical operability.

CONCLUSIONS

Our study established and validated a clinical predictive model for prolonged postoperative hospitalization duration in patients who underwent PSDS, which offered valuable prognostic information for preoperative planning and postoperative care for clinicians. Trial registration ClinicalTrials.gov identifier NCT05867732, retrospectively registered May 22, 2023, https://classic.

CLINICALTRIALS

gov/ct2/show/NCT05867732 .

Predicting major complications and discharge disposition after adult spinal deformity surgery

BACKGROUND CONTEXT

Several spine-specific comorbidity indices are available to help risk-stratify patients before they undergo invasive spine procedures. Studies of patients with adult spinal deformity (ASD) typically use the Charlson Comorbidity Index (CCI), which is not specific to spine patients.

PURPOSE

To compare the CCI with the Seattle Spine Score (SSS), the Adult Spinal Deformity-Comorbidity Score (ASD-CS), and the Modified 5-Item Frailty Index (mFI-5) and identify which tool more accurately predicted major perioperative complications and discharge disposition after ASD surgery.

STUDY DESIGN/SETTING

Retrospective review.

PATIENT SAMPLE

Patients with ASD who underwent spinal arthrodesis of at least four levels at a single institution.

OUTCOME MEASURES

Self-reported measures include SSS, ASD-CS, and mFI-5. Functional measures include the CCI.

METHODS

We retrospectively reviewed records of 164 patients with ASD who underwent spinal arthrodesis of ≥ four levels from January 2008 to February 2018 at our U.S. academic tertiary care center and who had available Oswestry Disability Index values. To assess the predictive ability of the comorbidity indices, we created five multivariable logistic regression models, with the presence of major complications and discharge disposition (home or inpatient rehabilitation) as the primary outcome variables. The base model used validated demographic and surgical factors that were predictors of complications and outcomes in those with ASD and within the broader spinal literature. The other four models used the base model along with one of the four indices. The predictive ability of each model was compared using goodness-of-fit testing, with higher pseudo-R2 values and lower Akaike information criteria (AIC) values indicating better model fit.

RESULTS

Thirty-one patients (19%) experienced major perioperative complications, and 68 (42%) were discharged to inpatient rehabilitation facilities (vs home). The model using the SSS had the highest pseudo-R2 value and lowest AIC value for both major complications and discharge disposition. The mFI-5 had a similar predictive ability. The models using the CCI and ASD-CS were weaker predictors.

CONCLUSIONS

Compared with the CCI and the ASD-CS, the SSS and the mFI-5 were strong predictors of major complications and discharge disposition after ASD surgery. These results suggest that the SSS and the mFI-5 are preferable to the CCI for clinical risk stratification and outcomes research in patients undergoing ASD surgery.

Measuring Outcomes in Spinal Deformity Surgery

Outcome assessment in adult spinal deformity has evolved from radiographic analysis of curve correction to patient-centered perception of health-related quality-of-life. Oswestry Disability Index and the Scoliosis Research Society-22 Patient Questionnaire are the predominantly used patient-reported outcome (PRO) measurements for deformity surgery. Correction of sagittal alignment correlates with improved PRO. Functional outcomes and accelerometer measurements represent newer methods of measuring outcomes but have not yet been widely adopted or validated. Further adoption of a minimum set of core outcome domains will help facilitate international comparisons and benchmarking, and ultimately enhance value-based healthcare.

Personalized Medicine in Orthopaedic Surgery: The Case of Spine Surgery

Personalized medicine has made a tremendous impact on patient care. Although initially, it revolutionized pharmaceutical development and targeted therapies in oncology, it has also made an important impact in orthopaedic surgery. The field of spine surgery highlights the effect of personalized medicine because the improved understanding of spinal pathologies and technological innovations has made personalized medicine a key component of patient care. There is evidence for several of these advancements to support their usage in improving patient care. Proper understanding of normative spinal alignment and surgical planning software has enabled surgeons to predict postoperative alignment accurately. Furthermore, 3D printing technologies have demonstrated the ability to improve pedicle screw placement accuracy compared with free-hand techniques. Patient-specific, precontoured rods have shown improved biomechanical properties, which reduces the risk of postoperative rod fractures. Moreover, approaches such as multidisciplinary evaluations tailored to specific patient needs have demonstrated the ability to decrease complications. Personalized medicine has shown the ability to improve care in all phases of surgical management, and several of these approaches are now readily available to orthopaedic surgeons.

Should Global Realignment Be Tailored to Frailty Status for Patients Undergoing Surgical Intervention for Adult Spinal Deformity?

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

Assess whether modifying spinal alignment goals to accommodate frailty considerations will decrease mechanical complications and maximize clinical outcomes.

SUMMARY OF BACKGROUND DATA

The Global Alignment and Proportion (GAP) score was developed to assist in reducing mechanical complications, but has had less success predicting such events in external validation. Higher frailty and many of its components have been linked to the development of implant failure. Therefore, modifying the GAP score with frailty may strengthen its ability to predict mechanical complications.

MATERIALS AND METHODS

We included 412 surgical ASD patients with two-year follow-up. Frailty was quantified using the modified Adult Spinal Deformity Frailty Index (mASD-FI). Outcomes: proximal junctional kyphosis and proximal junctional failure (PJF), major mechanical complications, and "Best Clinical Outcome" (BCO), defined as Oswestry Disability Index<15 and Scoliosis Research Society 22-item Questionnaire Total>4.5. Logistic regression analysis established a six-week score based on GAP score, frailty, and Oswestry Disability Index US Norms. Logistic regression followed by conditional inference tree analysis generated categorical thresholds. Multivariable logistic regression analysis controlling for confounders was used to assess the performance of the frailty-modified GAP score.

RESULTS

Baseline frailty categories: 57% not frail, 30% frail, 14% severely frail. Overall, 39 of patients developed proximal junctional kyphosis, 8% PJF, 21% mechanical complications, 22% underwent reoperation, and 15% met BCO. The mASD-FI demonstrated a correlation with developing PJF, mechanical complications, undergoing reoperation, and meeting BCO at two years (all P <0.05). Regression analysis generated the following equation: Frailty-Adjusted Realignment Score (FAR Score)=0.49×mASD-FI+0.38×GAP Score. Thresholds for the FAR score (0-13): proportioned: <3.5, moderately disproportioned: 3.5-7.5, severely disproportioned: >7.5. Multivariable logistic regression assessing FAR score demonstrated associations with mechanical complications, reoperation, and meeting BCO by two years (all P <0.05), whereas the original GAP score was only significant for reoperation.

CONCLUSION

This study demonstrated adjusting alignment goals in adult spinal deformity surgery for a patient's baseline frailty status and disability may be useful in minimizing the risk of complications and adverse events, outperforming the original GAP score in terms of prognostic capacity.

LEVEL OF EVIDENCE

III.

Association of telomere length with risk of complications in adult spinal deformity surgery: a pilot study of 43 patients

OBJECTIVE

Risk stratification is a critical element of surgical planning. Early tools were fairly crude, while newer instruments incorporate disease-specific elements and markers of frailty. It is unknown if discrepancies between chronological and cellular age can guide surgical planning or treatment. Telomeres are DNA-protein complexes that serve an important role in protecting genomic DNA. Their shortening is a consequence of aging and environmental exposures, with well-established associations with diseases of aging and mortality. There are compelling data to suggest that telomere length can provide insight toward overall health. The authors sought to determine potential associations between telomere length and postoperative complications.

METHODS

Adults undergoing elective surgery for spinal deformity were prospectively enrolled. Telomere length was measured from preoperative whole blood using quantitative polymerase chain reaction and expressed as the ratio of telomere (T) to single-copy gene (S) abundance (T/S ratio), with higher T/S ratios indicating longer telomere length. Demographic and patient data included age, BMI, and results for the following rating scales: the Adult Spinal Deformity Frailty Index (ASD-FI), Oswestry Disability Index (ODI), Scoliosis Research Society-22r (SRS-22r), American Society of Anesthesiology (ASA) classification, and Charlson Comorbidity Index (CCI). Operative and postoperative complication data (medical or surgical within 90 days) were also collected.

RESULTS

Forty-three patients were enrolled, including 31 women (53%), with a mean age of 66 years and a mean BMI of 28.5. The mean number of levels fused was 11, with 21 (48.8%) combined anterior-posterior approaches. Twenty-two patients (51.2%) had a medical or surgical complication. Patients with a postoperative complication had a significantly lower T/S ratio (0.712 vs 0.813, p = 0.008), indicating shorter telomere length, despite a mild difference in age compared with patients without a postoperative complication (68 vs 63 years, p = 0.069). Patients with complications also had higher CCI scores than patients without complications (2.3 vs 3.8, p = 0.004). There were no significant differences in sex, BMI, ASD-FI score, ASA class, preoperative ODI and SRS-22r scores, number of levels fused, or use of three-column osteotomies. In a multivariate model including age, frailty, ASA class, use of an anterior-posterior approach, CCI score, and telomere length, the authors found that short telomere length was significantly associated with postoperative complications. Patients whose telomere length fell in the shortest quartile had the highest risk (OR 18.184, p = 0.030).

CONCLUSIONS

Short telomere length was associated with an increased risk of postoperative complications despite only a mild difference in chronological age. Increasing comorbidity scores also trended toward significance. Larger prospective studies are needed; however, these data provide a compelling impetus to investigate the role of biological aging as a component of surgical risk stratification.

Risk factors of early complications after thoracic and lumbar spinal deformity surgery: a systematic review and meta-analysis

PURPOSE

To determine risk factors increasing susceptibility to early complications (intraoperative and postoperative within 6 weeks) associated with surgery to correct thoracic and lumbar spinal deformity.

METHODS

We systematically searched the PubMed and EMBASE databases for studies published between January 1990 and September 2021. Observational studies evaluating predictors of early complications of thoracic and lumbar spinal deformity surgery were included. Pooled odds ratio (OR) or standardized mean difference (SMD) with 95% confidence intervals (CI) was calculated via the random effects model.

RESULTS

Fifty-two studies representing 102,432 patients met the inclusion criteria. Statistically significant patient-related risk factors for early complications included neurological comorbidity (OR = 3.45, 95% CI 1.83-6.50), non-ambulatory status (OR = 3.37, 95% CI 1.96-5.77), kidney disease (OR = 2.80, 95% CI 1.80-4.36), American Society of Anesthesiologists score > 2 (OR = 2.23, 95% CI 1.76-2.84), previous spine surgery (OR = 1.98, 95% CI 1.41-2.77), pulmonary comorbidity (OR = 1.94, 95% CI 1.21-3.09), osteoporosis (OR = 1.60, 95% CI 1.17-2.20), cardiovascular diseases (OR = 1.46, 95% CI 1.20-1.78), hypertension (OR = 1.37, 95% CI 1.23-1.52), diabetes mellitus (OR = 1.84, 95% CI 1.30-2.60), preoperative Cobb angle (SMD = 0.43, 95% CI 0.29, 0.57), number of comorbidities (SMD = 0.41, 95% CI 0.12, 0.70), and preoperative lumbar lordotic angle (SMD = - 0.20, 95% CI - 0.35, - 0.06). Statistically significant procedure-related factors were fusion extending to the sacrum or pelvis (OR = 2.53, 95% CI 1.53-4.16), use of osteotomy (OR = 1.60, 95% CI 1.12-2.29), longer operation duration (SMD = 0.72, 95% CI 0.05, 1.40), estimated blood loss (SMD = 0.46, 95% CI 0.07, 0.85), and number of levels fused (SMD = 0.37, 95% CI 0.03, 0.70).

CONCLUSION

These data may contribute to development of a systematic approach aimed at improving quality-of-life and reducing complications in high-risk patients.

Comorbidity data collection across different spine registries: an evidence map

INTRODUCTION

Comorbidities are significant patient factors that contribute to outcomes after surgery. There is highly variable collection of this information across the literature. To help guide the systematic collection of best practice data, the Australian Spine Registry conducted an evidence map to investigate (i) what comorbidities are collected by spine registries, (ii) how they are collected and (iii) the compliance and completeness in collecting comorbidity data.

METHOD

A literature search was performed to identify published studies of adult spine registry data reporting comorbidities. In addition, targeted questionnaires were sent to existing global spine registries to identify the maximum number of relevant results to build the evidence map.

RESULTS

Thirty-six full-text studies met the inclusion criteria. There was substantial variation in the reporting of comorbidity data; 55% of studies reported comorbidity collection, but only 25% reported the data collection method and 20% reported use of a comorbidity index. The variation in the literature was confirmed with responses from 50% of the invited registries (7/14). Of seven, three use a recognised comorbidity index and the extent and methods of comorbidity collection varied by registry.

CONCLUSION

This evidence map identified variations in the methodology, data points and reporting of comorbidity collection in studies using spine registry data, with no consistent approach. A standardised set of comorbidities and data collection methods would encourage collaboration and data comparisons between patient cohorts and could facilitate improved patient outcomes following spine surgery by allowing data comparisons and predictive modelling of risk factors.

Patient and Spine Surgeon Perceptions on Shared Decision-Making in the Treatment of Older Adults Undergoing Corrective Surgery for Adult Spinal Deformity

STUDY DESIGN

Retrospective.

OBJECTIVE

To understand patients' and spine surgeons' perspectives about decision-making around surgery for adult spinal deformity.

SUMMARY OF BACKGROUND DATA

Surgery for correction of adult spinal deformity is often beneficial; however, in over 20% of older adults (≥ 65 yrs of age), outcomes from surgery are less desirable.

MATERIALS AND METHODS

We conducted semistructured, in-depth interviews with six patients and five spine surgeons. Two investigators independently coded the transcripts using constant comparative method, as well as an integrative, team-based approach to identify themes.

RESULTS

Patients themes: 1) patients felt surgery was their only choice because they were running out of time to undergo invasive procedures; 2) patients mentally committed to surgery prior to the initial encounter with their surgeon and contextualized the desired benefits while minimizing the potential risks; 3) patients felt that the current decision support tools were ineffective in preparing them for surgery; and 4) patients felt that pain management was the most difficult part of recovery from surgery. Surgeons themes: 1) surgeons varied substantially in their interpretations of shared decision-making; 2) surgeons did not consider patients' chronological age as a major contraindication to undergoing surgery; 3) there is a goal mismatch between patients and surgeons in the desired outcomes from surgery, where patients prioritize complete pain relief whereas surgeons prioritize concrete functional improvement; and 4) surgeons felt that patient expectations from surgery were often established prior to their initial surgery visit, and frequently required recalibration.

CONCLUSION

Older adult patients viewed the decision to have surgery as time-sensitive, whereas spine surgeons expressed the need for recalibrating patient expectations and balancing the risks and benefits when considering surgery. These findings highlight the need for improved understanding of both sides of shared decision-making which should involve the needs and priorities of older adults to help convey patient-specific risks and choice awareness.

LEVEL OF EVIDENCE

3.

COVID-19 Significantly Impacted Hospital Length of Stay and Discharge Patterns for Adult Spinal Deformity Patients

STUDY DESIGN

Retrospective review.

OBJECTIVE

The primary aim was to compare length of stay (LOS) and discharge disposition of adult spinal deformity (ASD) patients undergoing surgery before and during the pandemic. Secondary aims were to compare the rates of 30-day complications, reoperations, readmissions, and unplanned emergency department (ED) visits.

SUMMARY OF BACKGROUND DATA

ASD patients often require extended LOS and non-routine discharge. Given resource limitations during the Coronavirus Disease 2019 (COVID-19) pandemic and caution regarding hospital stays, surgeons modified standard postoperative protocols to minimize patient exposure.

METHODS

We identified all patients who underwent elective thoracolumbar ASD surgery with more than or equal to five levels fusion at a tertiary care center during two distinct time intervals: July to December 2019 (Pre-COVID, N = 60) and July to December 2020 (During-COVID, N = 57). Outcome measures included LOS and discharge disposition (home vs. non-home), as well as 30-day major complications, reoperations, readmissions, and ED visits. Regression analyses controlled for demographic and surgical factors.

RESULTS

Patients who underwent ASD surgery during the pandemic were younger (61 vs. 67 yrs) and had longer fusion constructs (nine vs. eight levels) compared with before the pandemic (P < 0.05 for both). On bivariate analysis, patients undergoing surgery during the pandemic had shorter LOS (6 vs. 9 days) and were more likely to be discharged home (70% vs. 28%) (P < 0.05 for both). After controlling for age and levels fused on multivariable regression, patients who had surgery during the pandemic had shorter LOS (IRR = 0.83, P = 0.015) and greater odds of home discharge (odds ratios [OR] = 7.2, P < 0.001). Notably, there were no differences in major complications, reoperations, readmissions, or ED visits between the two groups.

CONCLUSION

During the COVID-19 pandemic, LOS for patients undergoing thoracolumbar ASD surgery decreased, and more patients were discharged home without adversely affecting complication or readmission rates. Lessons learned during the pandemic may help improve resource utilization without negatively influencing short-term outcomes.Level of Evidence: 3.