Prediction of Risk Factors after Spine Surgery in Patients Aged >75 Years Using the Modified Frailty Index

Preoperative frailty and postoperative complications after non-cardiac surgery: a systematic review

OBJECTIVE

Many tools have been used to assess frailty in the perioperative setting. However, no single scale has been shown to be the most effective in predicting postoperative complications. We evaluated the relationship between several frailty scales and the occurrence of complications following different non-cardiac surgeries.

METHODS

This systematic review was registered in PROSPERO (CRD42023473401). The search strategy included PubMed, Google Scholar, and Embase, covering manuscripts published from January 2000 to July 2023. We included prospective and retrospective studies that evaluated frailty using specific scales and tracked patients postoperatively. Studies on cardiac, neurosurgical, and thoracic surgery were excluded because of the impact of underlying diseases on patients' functional status. Narrative reviews, conference abstracts, and articles lacking a comprehensive definition of frailty were excluded.

RESULTS

Of the 2204 articles identified, 145 were included in the review: 7 on non-cardiac surgery, 36 on general and digestive surgery, 19 on urology, 22 on vascular surgery, 36 on spinal surgery, and 25 on orthopedic/trauma surgery. The reviewed manuscripts confirmed that various frailty scales had been used to predict postoperative complications, mortality, and hospital stay across these surgical disciplines.

CONCLUSION

Despite differences among surgical populations, preoperative frailty assessment consistently predicts postoperative outcomes in non-cardiac surgeries.

The Evolution of Risk Assessment in Spine Surgery: A Narrative Review

BACKGROUND

Risk assessment is critically important in elective and high-risk interventions, particularly spine surgery. This narrative review describes the evolution of risk assessment from the earliest instruments focused on general surgical risk stratification, to more accurate and spine-specific risk calculators that quantified risk, to the current era of big data.

METHODS

The PubMed and SCOPUS databases were queried on October 11, 2023 using search terms to identify risk assessment tools (RATs) in spine surgery. A total of 108 manuscripts were included after screening with full-text review using the following inclusion criteria: 1) study population of adult spine surgical patients, 2) studies describing validation and subsequent performance of preoperative RATs, and 3) studies published in English.

RESULTS

Early RATs provided stratified patients into broad categories and allowed for improved communication between physicians. Subsequent risk calculators attempted to quantify risk by estimating general outcomes such as mortality, but then evolved to estimate spine-specific surgical complications. The integration of novel concepts such as invasiveness, frailty, genetic biomarkers, and sarcopenia led to the development of more sophisticated predictive models that estimate the risk of spine-specific complications and long-term outcomes.

CONCLUSIONS

RATs have undergone a transformative shift from generalized risk stratification to quantitative predictive models. The next generation of tools will likely involve integration of radiographic and genetic biomarkers, machine learning, and artificial intelligence to improve the accuracy of these models and better inform patients, surgeons, and payers.

Determining the Optimal Dosage of Dexmedetomidine for Smooth Emergence in Older Patients Undergoing Spinal Surgery: A Study of 44 Cases

BACKGROUND Emergence agitation, or delirium, occurs during early recovery from general anesthesia and involves disorientation, excitation, and uncontrolled physical movements. Dexmedetomidine is an alpha agonist that has sedative, anxiolytic, analgesic, and sympatholytic activities and is used as a continuous infusion to prevent emergence agitation. This study aimed to evaluate patients aged 65 years and older undergoing general anesthesia to determine the 90% effective dose (ED90) of dexmedetomidine continuous intraoperative infusion to prevent emergence agitation. MATERIAL AND METHODS We enrolled 44 patients aged 65 years and older undergoing spinal surgery under general anesthesia. Dexmedetomidine administration commenced 30 minutes before surgery completion, with a predetermined infusion dose (μg/kg/h), without a loading dose. The initial dose was 0.2 μg/kg/h, and subsequent step size was ±0.05 μg/kg/h. We tried to find ED90 of dexmedetomidine using the biased-coin design. Vital signs, extubation quality scores, extubation-related complications, and postoperative outcomes were monitored. RESULTS Dexmedetomidine ED₉₀ for smooth emergence in older patients was 0.34 μg/kg/h. Peri-extubation vital signs remained within 20% of baseline values, without requiring pharmacological intervention. No hypoxia, hypoventilation, or post-extubation agitation occurred. In the recovery room, 1 patient briefly exhibited excitement but quickly calmed. Nine patients initially unresponsive in the recovery room fully awoke and were promptly discharged. CONCLUSIONS For older patients who are vulnerable to adverse effects of anesthetics and opioids, dexmedetomidine enables gentle awakening without adverse vital sign changes, respiratory depression, excessive sedation, or emergence agitation (ED₉₀=0.34 μg/kg/h). Further studies should involve a larger patient cohort, considering diverse medical conditions in older individuals.

Role of Frailty Status in Prediction of Clinical Outcomes of Traumatic Spinal Injury: A Systematic Review and Meta-Analysis

Although many frailty tools have been used to predict traumatic spinal injury (TSI) outcomes, identifying predictors of outcomes after TSI in the aged population is difficult. Frailty, age, and TSI association are interesting topics of discussion in geriatric literature. However, the association between these variables are yet to be clearly elucidated. We conducted a systematic review to investigate the association between frailty and TSI outcomes. The authors searched Medline, EMBASE, Scopus, and Web of Science for relevant studies. Studies with observational designs that assessed baseline frailty status in individuals suffering from TSI published from inception until 26th March 2023 were included. Length of hospital stay (LoS), adverse events (AEs), and mortality were the outcomes of interest. Of the 2425 citations, 16 studies involving 37,640 participants were included. The modified frailty index (mFI) was the most common tool used to assess frailty. Meta-analysis was employed only in studies that used mFI for measuring frailty. Frailty was significantly associated with increased in-hospital or 30-day mortality (pooled odds ratio [OR]: 1.93 [1.19; 3.11]), non-routine discharge (pooled OR: 2.44 [1.34; 4.44]), and AEs or complications (pooled OR: 2.00 [1.14; 3.50]). However, no significant relationship was found between frailty and LoS (pooled OR: 3.02 [0.86; 10.60]). Heterogeneity was observed across multiple factors, including age, injury level, frailty assessment tool, and spinal cord injury characteristics. In conclusion, although there is limited data concerning using frailty scales to predict short-term outcomes after TSI, the results showed that frailty status may be a predictor of in-hospital mortality, AEs, and unfavorable discharge destination.

Impact of frailty on the outcomes of patients undergoing degenerative spine surgery: a systematic review and meta-analysis

BACKGROUND

Degenerative spinal diseases are common in older adults with concurrent frailty. Preoperative frailty is a strong predictor of adverse clinical outcomes after surgery. This study aimed to investigate the association between health-related outcomes and frailty in patients undergoing spine surgery for degenerative spine diseases.

METHODS

A systematic review and meta-analysis were performed by electronically searching Ovid-MEDLINE, Ovid-Embase, Cochrane Library, and CINAHL for eligible studies until July 16, 2022. We reviewed all studies, excluding spinal tumours, non-surgical procedures, and experimental studies that examined the association between preoperative frailty and related outcomes after spine surgery. A total of 1,075 articles were identified in the initial search and were reviewed by two reviewers, independently. Data were subjected to qualitative and quantitative syntheses by meta-analytic methods.

RESULTS

Thirty-eight articles on 474,651 patients who underwent degenerative spine surgeries were included and 17 papers were quantitatively synthesized. The health-related outcomes were divided into clinical outcomes and patient-reported outcomes; clinical outcomes were further divided into postoperative complications and supportive management procedures. Compared to the non-frail group, the frail group was significantly associated with a greater risk of high mortality, major complications, acute renal failure, myocardial infarction, non-home discharge, reintubation, and longer length of hospital stay. Regarding patient-reported outcomes, changes in scores between the preoperative and postoperative Oswestry Disability Index scores were not associated with preoperative frailty.

CONCLUSIONS

In degenerative spinal diseases, frailty is a strong predictor of adverse clinical outcomes after spine surgery. The relationship between preoperative frailty and patient-reported outcomes is still inconclusive. Further research is needed to consolidate the evidence from patient-reported outcomes.

Factors contributing to a longer length of stay in adults admitted to a quaternary spinal care center

BACKGROUND

Longer hospital length of stay (LOS) has been associated with worse outcomes and increased resource utilization. However, diagnostic and patient-level factors associated with LOS have not been well studied on a large scale. The goal was to identify patient, surgical and organizational factors associated with longer patient LOS for adult patients at a high-volume quaternary spinal care center.

METHODS

We performed a retrospective analysis of 13,493 admissions from January 2006 to December 2019. Factors analyzed included age, sex, admission status (emergent vs scheduled), ASIA grade, operative vs non-operative management, mean blood loss, operative time, and adverse events. Specific adverse events included surgical site infection (SSI), other infection (systemic or UTI), neuropathic pain, delirium, dural tear, pneumonia, and dysphagia. Diagnostic categories included trauma, oncology, deformity, degenerative, and "other". A multivariable linear regression model was fit to log-transformed LOS to determine independent factors associated with patient LOS, with effects expressed as multipliers on mean LOS.

RESULTS

Mean LOS for the population (SD) was 15.8 (34.0) days. Factors significantly (p < 0.05) associated with longer LOS were advanced patient age [multiplier on mean LOS 1.011/year (95% CI: 1.007-1.015)], emergency admission [multiplier on mean LOS 1.615 (95% CI: 1.337-1.951)], ASIA grade [multiplier on mean LOS 1.125/grade (95% CI: 1.051-1.205)], operative management [multiplier on mean LOS 1.211 (95% CI: 1.006-1.459)], and the occurrence of one or more AEs [multiplier on mean LOS 2.613 (95% CI: 2.188-3.121)]. Significant AEs included postoperative SSI [multiplier on mean LOS 1.749 (95% CI: 1.250-2.449)], other infections (systemic infections and UTI combined) [multiplier on mean LOS 1.650 (95% CI: 1.359-2.004)], delirium [multiplier on mean LOS 1.404 (95% CI: 1.103-1.787)], and pneumonia [multiplier on mean LOS 1.883 (95% CI: 1.447-2.451)]. Among the diagnostic categories explored, degenerative patients experienced significantly shorter LOS [multiplier on mean LOS 0.672 (95%CI: 0.535-0.844), p < 0.001] compared to non-degenerative categories.

CONCLUSION

This large-scale study taking into account diagnostic categories identified several factors associated with patient LOS. Future interventions should target modifiable factors to minimize LOS and guide hospital resource allocation thereby improving patient outcomes and quality of care and decreasing healthcare-associated costs.

Risk Factors for Postoperative Complications After Surgical Treatment of Type B and C Injuries of the Thoracolumbar Spine

BACKGROUND

Unstable thoracolumbar spinal injuries benefit from surgical fixation. However, perioperative complications significantly affect outcomes in surgicallytreated spine patients. We evaluated associations between risk factors and postoperative complications in patients surgically treated for thoracolumbar spine fractures.

METHODS

We conducted a retrospective multicenter study collating data from 21 spine centers across 9 countries on the treatment of AOSpine types B and C injuries of the thoracolumbar spine treated via a posterior approach. Comparative analysis was performed between patients with postoperative complications and those without. Univariate and multivariable analyses were performed.

RESULTS

Among 535 patients, at least 1 complication occurred in 43%. The most common surgical complication was surgical-site infection (6.9%), while the most common medical complication was urinary tract infection (13.8%). Among 136 patients with American Spinal Injury Association (ASIA) Impairment Scalelevel A disability, 77.9% experienced at least 1 complication. The rate of complications also rose sharply among patients waiting >3 days for surgery (P<0.001), peaking at 68.4% among patients waiting ≥30 days. On multivariable analysis, significant predictors of complications were surgery at a governmental hospital (odds ratio = 3.38, 95% confidence interval = 1.73-6.60), having ≥1 comorbid illness (2.44, 1.61-3.70), surgery delayed due to health instability (2.56, 1.50-4.37), and ASIA Impairment Scalelevel A (3.36, 1.78-6.35), while absence of impairment (0.39, 0.22-0.71), ASIAlevel E (0.39, 0.22-0.67) and, unexpectedly, delay caused by operating room unavailability (0.60, 0.36-0.99) were protective.

CONCLUSIONS

Types B and C thoracolumbar spine injuries are associated with a high risk of postoperative complications, especially common at governmental hospitals, and among patients with comorbidity, health instability, longer delays to surgery, and worse preoperative neurologic status.

The measurements of frailty and their possible application to spinal conditions: a systematic review

BACKGROUND CONTEXT

Frailty is associated with an increased risk of postoperative adverse events (AEs) within the surgical spine population. Multiple frailty tools have been reported in the surgical spine literature. However, the applicability of these tools remains unclear.

PURPOSE

Primary objective is to appraise the construct, feasibility, objectivity, and clinimetric properties of frailty tools reported in the surgical spine literature. Secondary objectives included determining the applicability and the most sensitive surgical spine population for each tool.

STUDY DESIGN

Systematic Review.

PATIENT SAMPLE

Studies reporting the use of a clinical frailty tool with a defined methodology in the adult surgical population (age ≥18 years).

OUTCOME MEASURES

Postoperative adverse events (AEs) including mortality, major and minor morbidity, length of stay (LOS), unplanned readmission and reoperation, admission to the Intensive Care Unit (ICU), and adverse discharge disposition; postoperative patient-reported outcomes (health-related quality of life (HRQoL), functional, cognitive, and symptomatic); radiographic outcomes; and postoperative frailty trajectory.

METHODS

This systematic review was registered with PROSPERO: CRD42019109045. Publications from January 1950 to December 2020 were identified by a comprehensive search of PubMed, Ovid, and Embase, supplemented by manual screening. Studies reporting and validating a frailty tool in the surgical spine population with a measurable outcome were included. Each tool and its clinimetric properties were evaluated using validated criteria and definitions. The applicability of each tool and its most sensitive surgical spine population was determined by panel consensus. Bias was assessed using the Newcastle-Ottawa Scale.

RESULTS

47 studies were included in the final qualitative analysis. A total of 14 separate frailty tools were identified, in which 9 tools assessed frailty according to the cumulative deficit definition, while 4 instruments utilized phenotypic or weighted frailty models. One instrument assessed frailty according to the comprehensive geriatric assessment (CGA) model. Twelve measures were validated as risk stratification tools for predicting postoperative AEs, while 1 tool investigated the effect of spine surgery on postoperative frailty trajectory. The modified frailty index (mFI), 5-item mFI, adult spinal deformity frailty index (ASD-FI), FRAIL Scale, and CGA had the most positive ratings for clinimetric properties assessed.

CONCLUSIONS

The assessment of frailty is important in the surgical decision-making process. Cumulative deficit and weighted frailty instruments are appropriate risk stratification tools. Phenotypic tools are sensitive for capturing the relationship between spinal pathology, spine surgery, and prehabilitation on frailty trajectory. CGA instruments are appropriate screening tools for identifying health deficits susceptible to improvement and guiding optimization strategies. Studies are needed to determine whether spine surgery and prehabilitation are effective interventions to reverse frailty.

Which frailty scales for patients with adult spinal deformity are feasible and adequate? A systematic review

BACKGROUND CONTEXT

Frailty as a concept is not yet fully understood, and is not the same as comorbidity. It is associated with an increased risk of adverse events and mortality after surgery, which makes its preoperative assessment significant. Despite its relevance, it still remains unclear which scales are appropriate for use in patients with spinal pathology.

PURPOSE

To evaluate the feasibility and measurement properties of frailty scales for spine patients, specifically with adult spinal deformity (ASD), and to propose adequate scales for primary triage to prevent surgery in too frail patients and for preoperative assessment to modify patients' condition and surgical plans.

STUDY DESIGN/SETTING

Systematic review.

METHODS

Systematic search was performed between 2010 and 2021 including terms relating to spinal disorders, frailty scales, and methodological quality. Characteristics of the studies and frailty scales and data describing relation to treatment outcomes were extracted. The risk of bias was determined with the QAREL score.

RESULTS

Of the 1993 references found, 88 original studies were included and 23 scales were identified. No prospective interventional study was found where the preoperative frailty assessment was implemented. Predictive value of scales for surgical outcomes varied, dependent on spinal disorders, type of surgeries, patients' age and frailty at baseline, and outcomes. Seventeen studies reported measurement properties of eight scales but these studies were not free of bias. In 30 ASD studies, ASD-Frailty Index (ASD-FI, n=14) and 11-item modified Frailty Index (mFI-11, n=11) were most frequently used. These scales were mainly studied in registry studies including young adult population, and carry a risk of sample bias and make their validity in elderly population unclear. ASD-FI covers multidisciplinary concepts of frailty with 40 items but its feasibility in clinical practice is questionable due to its length. The Risk Analysis Index, another multidisciplinary scale with 14 items, has been implemented for preoperative assessment in other surgical domains and was proven to be feasible and effective in interventional prospective studies. The FRAIL is a simple questionnaire with five items and its predictive value was confirmed in prospective cohort studies in which only elderly patients were included.

CONCLUSIONS

No adequate scale was identified in terms of methodological quality and feasibility for daily practice. Careful attention should be paid when choosing an adequate scale, which depends on the setting of interest (eg triage or preoperative work-up). We recommend to further study a simple and predictive scale such as FRAIL for primary triage and a comprehensive and feasible scale such as Risk Analysis Index for preoperative assessment for patients undergoing spine surgery, as their adequacy has been shown in other medical domains.

Modified-frailty index does not independently predict complications, hospital length of stay or 30-day readmission rates following posterior lumbar decompression and fusion for spondylolisthesis

BACKGROUND CONTEXT

Frailty has been associated with inferior surgical outcomes in various fields of spinal surgery. With increasing healthcare costs, hospital length of stay (LOS) and unplanned readmissions have emerged as clinical proxies reflecting overall value of care. However, there is a paucity of data assessing the impact that baseline frailty has on quality of care in patients with spondylolisthesis.

PURPOSE

The aim of this study was to investigate the impact that frailty has on LOS, complication rate, and unplanned readmission after posterior lumbar spinal fusion for spondylolisthesis.

STUDY DESIGN

A retrospective cohort study was performed using the National Surgical Quality Improvement Program (NSQIP) database from 2010 through 2016.

PATIENT SAMPLE

All adult (≥18 years old) patients who underwent lumbar spinal decompression and fusion for spondylolisthesis were identified using ICD-9-CM diagnosis and procedural coding systems. We calculated the modified frailty index (mFI) for each patient using 5 dichotomous comorbidities - diabetes mellitus, congestive heart failure, hypertension requiring medication, chronic obstructive pulmonary disease, and dependent functional status. Each comorbidity is assigned 1 point and the points are summed to give a score between 0 and 5. As in previous literature, we defined a score of 0 as "not frail", 1 as "mild" frailty, and 2 or greater as "moderate to severe" frailty.

OUTCOME MEASURES

Patient demographics, comorbidities, complications, LOS, readmission, and reoperation were assessed.

METHODS

A multivariate logistic regression analysis was used to identify independent predictors of adverse events (AEs), extended LOS, complications, and unplanned readmission.

RESULTS

There were a total of 5,296 patients identified, of which 2,030 (38.3%) were mFI=0, 2,319 (43.8%) patients mFI=1, and 947 (17.9%) were mFI ≥2. The mFI≥2 cohort was older (p≤.001) and had a greater average BMI (p≤.001). The mFI≥2 cohort had a slightly longer hospital stay (3.7 ± 2.3 days vs. mFI=1: 3.5 ± 2.8 days and mFI=0: 3.2 ± 2.1 days,p≤.001). Both surgical AEs and medical AEs were significantly greater in the mFI≥2 cohort than the other cohorts, (2.6% vs. mFI=1: 1.8% and mFI=0: 1.2%,p=.022) and (6.3% vs. mFI=1: 4.8% and mFI=0: 2.6%,p≤.001), respectively. While there was no significant difference in reoperation rates, the mFI≥2 cohort had greater unplanned 30-day readmission rates (8;4% vs. mFI=5.6: 4.8% and mFI=0: 3.4%,p≤.001). However, on multivariate regression analysis, mFI≥2 was not a significant independent predictor of LOS (p=.285), complications (p=.667), or 30-day unplanned readmission (p=.378).

CONCLUSIONS

Our study indicates that frailty, as measured by the mFI, does not significantly predict LOS, 30-day adverse events, or 30-day unplanned readmission in patients undergoing lumbar spinal decompression and fusion for spondylolisthesis. Further work is needed to better define variable inputs that make up frailty to optimize surgical outcome prediction tools that impact the value of care.

Central Sarcopenia, Frailty and Comorbidity as Predictor of Surgical Outcome in Elderly Patients with Degenerative Spine Disease

Objective

People are living longer and the elderly population continues to increase. The incidence of degenerative spinal diseases (DSDs) in the elderly population is quite high. Therefore, we are facing more cases of DSD and offering more surgical solutions in geriatric patients. Understanding the significance and association of frailty and central sarcopenia as risk factors for spinal surgery in elderly patients will be helpful in improving surgical outcomes. We conducted a retrospective cohort analysis of prospectively collected data to assess the impact of preoperative central sarcopenia, frailty, and comorbidity on surgical outcome in elderly patients with DSD.

Methods

We conducted a retrospective analysis of patients who underwent elective spinal surgery performed from January 1, 2019 to September 30, 2020 at our hospital. We included patients aged 65 and over who underwent surgery on the thoracic or lumbar spine and were diagnosed as DSD. Central sarcopenia was measured by the 50th percentile of psoas : L4 vertebral index (PLVI) using the cross-sectional area of the psoas muscle. We used the Korean version of the fatigue, resistance, ambulation, illnesses, and loss of weight (K-FRAIL) scale to measure frailty. Comorbidity was confirmed and scored using the Charlson Comorbidity Index (CCI). As a tool for measuring surgical outcome, we used the Clavien-Dindo (CD) classification for postoperative complications and the length of stay (LOS).

Results

This study included 85 patients (35 males and 50 females). The mean age was 74.05±6.47 years. Using the K-FRAIL scale, four patients were scored as robust, 44 patients were pre-frail and 37 patients were frail. The mean PLVI was 0.61±0.19. According to the CD classification, 50 patients were classified as grade 1, 19 as grade 2, and four as grade 4. The mean LOS was 12.35±8.17 days. Multivariate stepwise regression analysis showed that postoperative complication was significantly associated with surgical invasiveness and K-FRAIL scale. LOS was significantly associated with surgical invasiveness and CCI. K-FRAIL scale showed a significant correlation with CCI and PLVI.

Conclusion

The present study demonstrates that frailty, comorbidity, and surgical invasiveness are important risk factors for postoperative complications and LOS in elderly patients with DSD. Preoperative recognition of these factors may be useful for perioperative optimization, risk stratification, and patient counseling.

Surgical treatment of senile spinal diseases

Advanced age is a well-known risk factor for spinal surgery-related complications. Decisions on spine surgery in the elderly are difficult due to higher morbidity and mortality than in younger age groups. In addition, spine surgery is a kind of ‘functional surgery’ which does not directly affect the survival of patients. In recent years, individualized risk stratification has gained ground over simple chronological age-based assessment. In the elderly, frailty is one of the strongest factors which affect surgical outcomes for both cervical and thoracolumbar spine surgery, regardless of the surgical technique used. Spine surgery in the elderly have worse surgical outcomes in terms of duration of hospital stay, degree of functional recovery, and complication, readmission, and mortality rates. However, the benefit of spine surgery even in the very-elderly is substantial. In conclusion, surgical decisions should be made based on both personalized risk assessment and benefits of surgery. Recent advanced surgical techniques such as minimally invasive surgical techniques and robotics assistance are likely to be helpful in minimizing surgical complications. Therefore, advanced age in itself should not be considered as a contraindication for spine surgery.