Malnutrition, Body Mass Index, and Associated Risk of Complications After Posterior Lumbar Spine Fusion: A 3:1 Matched Cohort Analysis

Definition of malnutrition from routinely-collected data for orthopedic surgery research: the global leadership initiative on malnutrition (GLIM) tool and others

The correct identification of malnourished patients in the context of hip, knee, or spine surgery research would enhance the quality of analytical studies investigating the prediction potential of preoperative nutritional disorders on postoperative recovery. However, accurate malnutrition screening and diagnostic assessment rely on parameters that were not routinely collected in routine practice until a few years ago. The authors of this article present substitute literature-based equations that can be built up using historical routinely collected data to classify patients that had been at risk of malnutrition or malnourished. For what concerns the risk screening, several methods are available to identify patients at risk of over- or undernutrition, encompassing the BWd (body weight difference from the ideal weight), GNRI (geriatric nutritional risk index), INA (instant nutritional assessment), LxA (combination of lymphocyte count and albumin), PMA (protein malnutrition with acute inflammation), PMAC (protein malnutrition with acute and chronic inflammation), IDM (iron deficit malnutrition), and VBD (vitamin B deficit malnutrition). Conversely, the GLIM (global leadership initiative on malnutrition) criteria can be used to assess malnutrition and diagnose subclasses of undernutrition. Rational use of these tools can facilitate the conduction of efficient prospective studies in the future, as well as bespoke retrospective cohort studies and database research.

Adult Spinal Deformity Correction in Patients with Parkinson Disease: Assessment of Surgical Complications, Reoperation, and Cost

BACKGROUND

Parkinson disease (PD) is a neurodegenerative disorder that manifests with postural instability and gait imbalance. Correction of spinal deformity in patients with PD presents unique challenges.

METHODS

The PearlDiver database was queried between 2010 and 2020 to identify adult patients with spinal deformity before undergoing deformity correction with posterior spinal fusion. Two cohorts were created representing patients with and without a preoperative diagnosis of PD. Outcome measures included reoperation rates, surgical technique, cost, surgical complications, and medical complications. Multivariable logistic regression adjusting for Charlson Comorbidity Index, age, gender, 3-column osteotomy, pelvic fixation, and number of levels fused was used to assess rates of reoperation and complications.

RESULTS

In total, 26,984 patients met the inclusion criteria and were retained for analysis. Of these patients, 725 had a diagnosis of PD before deformity correction. Patients with PD underwent higher rates of pelvic fixation (odds ratio [OR], 1.33; P < 0.001) and 3-column osteotomies (OR, 1.53; P < 0.001). On adjusted regression, patients with PD showed increased rates of reoperation at 1 year (OR, 1.37; P < 0.001), 5 years (OR, 1.32; P < 0.001), and overall (OR, 1.33; P < 0.001). Patients with PD also experienced an increased rate of medical complications within 30 days after deformity correction including deep venous thrombosis (OR, 1.60; P = 0.021), pneumonia (OR, 1.44; P = 0.039), and urinary tract infections (OR, 1.54; P < 0.001). Deformity correction in patients with PD was associated with higher 90-day cost (P = 0.007).

CONCLUSIONS

Patients with PD undergoing long fusion for deformity correction are at significantly increased risk of 30-day medical complications and revision procedures after 1 year, controlling for comorbidities, age, and invasiveness. Surgeons should consider the risk of complications, subsequent revision procedures, and increased cost.

Treatment of adult deformity surgery by orthopedic and neurological surgeons: trends in treatment, techniques, and costs by specialty

BACKGROUND CONTEXT

Surgery to correct adult spinal deformity (ASD) is performed by both neurological surgeons and orthopedic surgeons. Despite well-documented high costs and complication rates following ASD surgery, there is a dearth of research investigating trends in treatment according to surgeon subspeciality.

PURPOSE

The purpose of this investigation was to perform an analysis of surgical trends, costs and complications of ASD operations by physician specialty using a large, nationwide sample.

STUDY DESIGN/SETTING

Retrospective cohort study using an administrative claims database.

PATIENT SAMPLE

A total of 12,929 patients were identified with ASD that underwent deformity surgery performed by neurological or orthopedic surgeons.

OUTCOME MEASURES

The primary outcome was surgical case volume by surgeon specialty. Secondary outcomes included costs, medical complications, surgical complications, and reoperation rates (30-day, 1-year, 5-year, and total).

METHODS

The PearlDiver Mariner database was queried to identify patients who underwent ASD correction from 2010 to 2019. The cohort was stratified to identify patients who were treated by either orthopedic or neurological surgeons. Surgical volume, baseline characteristics, and surgical techniques were examined between cohorts. Multivariable logistic regression was employed to assess the cost, rate of reoperation and complication according to each subspecialty while controlling for number of levels fused, rate of pelvic fixation, age, gender, region and Charlson Comorbidity Index (CCI). Alpha was set to 0.05 and a Bonferroni correction for multiple comparisons was utilized to set the significance threshold at p ≤.000521.

RESULTS

A total of 12,929 ASD patients underwent deformity surgery performed by neurological or orthopedic surgeons. Orthopedic surgeons performed most deformity procedures accounting for 64.57% (8,866/12,929) of all ASD operations, while the proportion treated by neurological surgeons increased 44.2% over the decade (2010: 24.39% vs 2019: 35.16%; p<.0005). Neurological surgeons more frequently operated on older patients (60.52 vs 55.18 years, p<.0005) with more medical comorbidities (CCI scores: 2.01 vs 1.47, p<.0005). Neurological surgeons also performed higher rates of arthrodesis between one and six levels (OR: 1.86, p<.0005), three column osteotomies (OR: 1.35, p<.0005) and navigated or robotic procedures (OR: 3.30, p<.0005). Procedures performed by orthopedic surgeons had significantly lower average costs as compared to neurological surgeons (orthopedic surgeons: $17,971.66 vs neurological surgeons: $22,322.64, p=.253). Adjusted logistic regression controlling for number of levels fused, pelvic fixation, age, sex, region, and comorbidities revealed that patients within neurosurgical care had similar odds of complications to orthopaedic surgery.

CONCLUSIONS

This investigation of over 12,000 ASD patients demonstrates orthopedic surgeons continue to perform the majority of ASD correction surgery, although neurological surgeons are performing an increasingly larger percentage over time with a 44% increase in the proportion of surgeries performed in the decade. In this cohort, neurological surgeons more frequently operated on older and more comorbid patients, utilizing shorter-segment fixation with greater use of navigation and robotic assistance.

Body Mass Index and Risk of Complications After Posterior Lumbar Spine Fusion: A Matched Cohort Analysis Investigating Underweight and Obese Patients

OBJECTIVE

Previous studies have demonstrated that obesity is associated with increased complications after lumbar fusion. However, there are little published data on the effect of being underweight on lumbar fusion outcomes. The purpose of this study was to elucidate the effect of being underweight versus obese on outcomes after lumbar spinal fusion.

METHODS

Lumbar spinal fusion patients were identified through the PearlDiver Mariner database between 2010 and 2020. Study groups were created using International Classification of Diseases codes to identify preoperative body mass index (BMI) category as morbid obesity (BMI > 40), obesity (BMI 30 to 40), normal BMI (BMI 20 to 30), and underweight (BMI < 20) cohorts. Complications that occurred within 1 year postoperatively in this study and matched control groups were then isolated. Statistical analyses were conducted using the Pearson chi square method.

RESULTS

A total of 62,616 patients were identified in this analysis. This included 1,258 underweight patients (4.0%), 17,996 obese patients (57.5%), and 12,054 morbidly obese patients (38.5%). The number of patients to experience any postoperative complication was 766 (60.9%), 9,440 (52.4%), and 6,982 (57.9%) for the underweight, obese, and morbidly obese cohorts, respectively. Underweight patients showed an increased likelihood of complications related to instrumentation (odds ratio [OR] 1.85, P = 0.0237), revision fusion (OR 1.34, P = 0.04061), pulmonary complications (OR 1.43, P < 0.001), and sepsis (OR 1.91, P < 0.001). Obese patients with BMI 30 to 40 showed increased odds of the following complications: hemorrhages and hematomas (OR 1.20, P = 0.02634), surgical site complications (OR 1.27, P < 0.001), thromboembolism (OR 1.78, P < 0.001), and urinary complications (OR 1.08, P < 0.001). Morbidly obese patients with BMI > 40 showed increased odds of all complications analyzed in this study.

CONCLUSION

This investigation indicates that both underweight and obese patients are at elevated risk of complications after lumbar fusion. Similar to obese patients, underweight patients may benefit from preoperative optimization by nutrition counseling to avoid potential complications.

LEVEL OF EVIDENCE

III.

Association of preoperative prognostic nutritional index with risk of postoperative delirium: A systematic review and meta-analysis

Study objective

To assess the association between prognostic nutritional index (PNI) and risk of postoperative delirium (POD) in adult patients.

Methods

MEDLINE, Google scholar, EMBASE, and Cochrane library databases were searched from inception till April 2022. The primary outcome was the association between PNI and the risk of POD, while the secondary outcomes were correlations of other prognostic factors with POD risk. The correlation between PNI and the incidence of POD was assessed with three approaches: Difference in preoperative PNI between POD and non-POD groups (Model 1) as well as the association of PNI as a continuous parameter (Model 2) or as a binary variable (i.e., low vs. high using a PNI cut-off value of 50) (Model 3) with POD risk.

Results

Analysis of nine observational studies published from 2010 to 2021 recruiting 3,743 patients showed a POD incidence of 6.4-35%. Our meta-analysis demonstrated a lower PNI among patients in the POD group (MD: -3.78, 95% CI: -4.85 to -2.71, p < 0.0001, I ² = 54.2%) compared to the non-POD group (Model 1). Pooled results revealed a negative association between PNI and POD risk for both Model 2 (OR: 0.91, 95% CI: 0.86-0.97, p = 0.002, I ² = 71%) and Model 3 (OR: 1.68, 95% CI: 1.26-2.23, p < 0.0001, I ² = 0%). Besides, while our results supported an age-dependent increase in POD risk, other factors including body-mass index, surgical time, health status, hypertension, diabetes mellitus, and male gender were non-significant predictors of POD.

Conclusion

Our results demonstrated a negative association between PNI and POD, which warrant further large-scale studies for validation.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42022323809.