The Cost of Malnutrition in Total Joint Arthroplasty

Prevalence of anemia and association with outcome in joint arthroplasty - is there a difference between primary and revision cases?

PURPOSE

Anemia has been shown to be a modifiable pre-operative, patient factor associated with outcome following arthroplasty. The aims of this retrospective study were to (1) ascertain the prevalence of preoperative anemia in patients undergoing primary and revision hip and knee arthroplasty at a tertiary referral center and (2) to test the association with outcome and whether it differs between primary and revision cases.

METHODS

All hip and knee primary and revision arthroplasties performed at a Canadian academic, tertiary-care, arthroplasty center between 2012 and 2017 were included in this study. The study group consisted of 5944 patients, of which 5251 were primary Total Hip and Knee Arthroplasties or Hip Resurfacings and 693 were revision arthroplasties (65% hip revisions/35% knee revisions). Anemia was classified as per WHO definition (hemoglobin < 130 g/L for men and < 120 g/L for women). All anemic patients were grouped into mild, moderate or severe anemia. Length-of-stay, perioperative transfusion-rate, 90-day readmission, overall complication rate and reoperation rates were recorded. The effect of preoperative anemia and the effect of severity of the anemia was evaluated through multivariable regression analysis controlling for relevant covariates.

RESULTS

Preoperatively, 15% (786/5251) of the primary patients and 47% (322/693) of the revision arthroplasty patients were anemic preoperatively. Anemic revision patients were 3.1 times more likely (95% CI: 1.47-6.33) to obtain blood transfusions during the hospital stay, compared to a 4.9 times higher risk in primary patients. The odds ratio to sustain any postoperative complication if anemic was 1.5 times higher (95% CI: 0.73-3.16) in revision patients and 1.7 in primary cases. In addition, the 90-day readmission rate among both groups was 1.6 times higher in anemic patients. Furthermore, anemic revision patients had a 5.3 days longer length of stay (95% CI: 2.63-7.91), compared to only 1 additional day in anemic primary patients (95% CI: 0.69-1.34).

CONCLUSION

In this study cohort, the prevalence of anemia in patients awaiting revision arthroplasty was 3 times higher (46.6%) than in primary arthroplasty patients (18.7%). Preoperative anemia was associated with similarly, inferior outcomes in both groups. To reduce postoperative complications and the "burden" associated with anemia, these findings strongly recommend optimizing the preoperative hemoglobin in all arthroplasty patients. However, revision patients are affected more frequently, and particular attention must therefore be taken to this growing group in the future.

LEVEL OF EVIDENCE

Level III.

Nutritional Laboratory Studies Prior to Total Knee Arthroplasty: Practice Versus Publication

BACKGROUND

Recent emphasis has been placed on nutritional status assessment prior to total knee arthroplasty (TKA), including multiple American Academy of Orthopaedic Surgeons publications recommending specific laboratory studies; however, the frequency with which surgeons obtain these laboratory studies remains unclear. We sought to assess the incidence of ordering nutritional laboratory studies in the 90 days prior to TKA, utilizing data from a large administrative claims database.

METHODS

With use of the PearlDiver database, we identified 557,670 patients undergoing primary TKA from 2011 to 2020 with a metabolic panel or blood cell count claim within 90 days prior to TKA. We then determined the incidence of prealbumin, transferrin, vitamin D, and zinc laboratory tests claimed 90 days prior to TKA. Associations between claims and the year of surgery, patient demographics, and clinical characteristics were assessed by comparing proportions and chi-square testing.

RESULTS

Nutritional laboratory studies were infrequently claimed within 90 days prior to TKA, with studies for prealbumin being performed in 2.2% of patients; transferrin, 1.9%; vitamin D, 10.2%; and zinc, 0.2%. From 2011 to 2020, there was a moderate but steady increase in the proportion of patients with claims for prealbumin (change from 0.8% in 2011 to 3.4% in 2020; p < 0.001), transferrin (0.8% to 2.7%; p < 0.001), and vitamin D (7.6% to 9.4%; p < 0.001) laboratory tests but there was less of a change for zinc (0.1% to 0.2%; p < 0.001). There were weak-to-absent associations of age, gender, obesity, diabetes, and anemia with laboratory claims.

CONCLUSIONS

Despite multiple publications and recommendations, nutritional laboratory studies are infrequently ordered prior to TKA. Although there has been a slight increase in the use of nutritional laboratory studies over the past decade, patient factors such as gender and obesity were not associated with this increase. Understanding current practice patterns may help target future areas for improvement.

LEVEL OF EVIDENCE

Diagnostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Effects of malnutrition on outcomes of patients with femoral head osteonecrosis undergoing total hip arthroplasty: A population-based study

BACKGROUND

This study aimed to evaluate the impact of malnutrition on in-hospital outcomes in patients undergoing total hip arthroplasty (THA) for osteonecrosis of the femoral head (ONFH).

METHODS

This population-based retrospective study extracted data of patients undergoing THA for ONFH in the US National Inpatient Sample between 2005 and 2018. Factors associated with in-hospital mortality, medical and surgical complications, unfavorable discharge, and prolonged hospital stay were determined by logistic regression analysis.

RESULTS

A total of 72,304 adults ≥18 years old with nontraumatic ONFH admitted for primary THA were included. Malnutrition was detected in 7152 (9.9%) patients using validated discharge codes. In-hospital mortality was 0.8% vs 0.1% for patients who were malnourished vs nonmalnourished. After adjusting for confounders, malnutrition was significantly associated with an increased risk of in-hospital death (adjusted odds ratio [aOR], 4.67; 95% CI, 2.43-8.97), medical complications (aOR, 1.49; 95% CI, 1.32-1.68), surgical complications (aOR, 1.78; 95% CI, 1.61-1.96), unfavorable discharge (aOR, 1.24; 95% CI, 1.11-1.39), and prolonged hospital stay (aOR, 1.90; 95% CI, 1.67-2.16) compared with adequate nutrition. Malnutrition was also associated with higher total hospital costs (adjusted β = $9620; 95% CI, 7.87-11.36). Furthermore, the association between malnutrition, any medical or surgical complications, and unfavorable discharge was stronger in patients younger than 50 years than those ≥50 years old.

CONCLUSIONS

In US patients undergoing primary THA for ONFH, malnutrition increases the risk of unfavorable in-hospital outcomes. This patient subgroup may require special attention and better strategies to improve perioperative care.

Hypoalbuminemia increases the risk of failure following one-stage septic revision for periprosthetic joint infection

PURPOSE

Malnutrition is a potentially modifiable risk factor of periprosthetic joint infection (PJI). The purpose of this study was to analyze the role of nutritional status as a risk factor for failure after one- stage revision hip or knee arthroplasty for PJI.

METHODS

Retrospective, single-center, case-control study. Patients with PJI according to the 2018 International Consensus Meeting criteria were evaluated. Minimum follow-up was 4 years. Total lymphocyte count (TLC), albumin values, hemoglobin, C-reactive protein, white blood cell (WBC) count and glucose levels were analyzed. An analysis was also made of the index of malnutrition. Malnutrition was defined as serum albumin < 3.5 g/dL and TLC < 1500/mm3. Septic failure was defined as the presence of local or systemic symptoms of infection and the need of further surgery as a result of persistent PJI.

RESULTS

No significant differences were found between increased failure rates after a one-stage revision hip or knee arthroplasty for PJI and TLC, hemoglobin level, WBC count, glucose levels, or malnutrition. Albumin and C-reactive protein values were found to have a positive and significant relationship with failure (p < 0.05). Multivariate logistic regression identified only hypoalbuminemia (serum albumin < 3.5 g/dL) (OR 5.64, 95% CI 1.26-25.18, p = 0.023) as a significant independent risk factor for failure. The receiver operating characteristic (ROC) curve for the model yielded an area under the curve of 0.67.

CONCLUSION

TLC, hemoglobin; WBC count; glucose levels; and malnutrition, understood as the combination of albumin and TLC, were not found to be statically significant risk factors for failure after single-stage revision for PJI. However, albumin < 3.5 g/dL, alone was a statically significant risk factor for failure after single-stage revision for PJI. As hypoalbuminemia seems to influence the failure rate, it is advisable to measure albumin levels in preoperative workups.

Screening and Management of Malnutrition in Total Joint Arthroplasty

Malnutrition is an increasingly prevalent problem in patients undergoing total joint arthroplasty (TJA). Increased risks associated with TJA in the setting of malnourishment have been well documented. Standardized scoring systems in addition to laboratory parameters such as albumin, prealbumin, transferrin, and total lymphocyte count have been developed to identify and evaluate malnourished patients. Despite an abundance of recent literature, there is no consensus on the best approach for screening TJA patients from a nutritional standpoint. Although there are a variety of treatment options, including nutritional supplements, nonsurgical weight loss therapies, bariatric surgery, and the involvement of dieticians and nutritionists, the effect of these interventions on TJA outcomes has not been well characterized. This overview of the most current literature aims to provide a clinical framework for approaching nutrition status in arthroplasty patients. A comprehensive understanding of the tools available for managing malnourishment will facilitate improved arthroplasty care.

Relationship Between Preoperative Nutritional Status and Predicting Short-Term Complications Following Revision Total Hip Arthroplasty

BACKGROUND

The association between malnutrition and complications following primary total joint arthroplasty is well-delineated, however, nutritional status has yet to be explored specifically in revision total hip arthroplasty (THA). Therefore, our objective was to examine if a patient's nutritional status based on body mass index, diabetic status, and serum albumin predicted complications following a revision THA.

METHODS

A retrospective national database review identified 12,249 patients who underwent revision THA from 2006 to 2019. Patients were stratified based on body mass index (<18.5=underweight, 18.5 to 29.9=healthy/overweight, >30=obese), diagnosis of diabetes (no diabetes, insulin-dependent diabetes mellitus (IDDM), non-insulin-dependent diabetes mellitus (NIDDM)), and preoperative serum albumin (<3.5=malnourished, >3.5=non-malnourished). Multivariate analyses was performed using Chi-squared tests and multiple logistic regressions.

RESULTS

In all groups including underweight (1.8%), healthy/overweight (53.7%), and obese (44.5%), those without diabetes were less likely to be malnourished (p<0.001), while those with IDDM had a higher rate of malnutrition (p<0.001). Underweight patients were significantly more malnourished compared to healthy/overweight or obese patients (p<0.05). Malnourished patients had an increased risk of wound dehiscence/surgical site infections (p<0.001), urinary tract infection (p<0.001), requiring a blood transfusion (p<0.001), sepsis (p<0.001), and septic shock (p<0.001). Malnourished patients also have worse postoperative pulmonary and renal function.

CONCLUSIONS

Patients who are underweight or have IDDM are more likely to be malnourished. The risk of complications within 30 days of surgery following revision THA significantly increases with malnutrition. This study shows the utility of screening underweight and IDDM patients for malnutrition prior to revision THA to minimize complications.

Universal Screening for Malnutrition Prior to Total Knee Arthroplasty Is Cost-Effective: A Markov Analysis

BACKGROUND

Patients undergoing total knee arthroplasty (TKA) who have malnutrition possess an increased risk of periprosthetic joint infection (PJI). Although malnutrition screening and intervention may decrease the risk of PJI, it utilizes healthcare resources. To date, no cost-effectiveness analyses have been performed on the screening and treatment of malnutrition prior to TKA.

METHODS

A Markov model projecting lifetime costs and quality-adjusted life years (QALYs) was built to determine the cost-effectiveness of malnutrition screening and intervention for TKA patients from a societal perspective. Costs, health state utilities, and state transition probabilities were obtained from previously published literature, hospital costs at our institution, and expert opinions. Two important assumptions included that 30% of patients would be malnourished and that a malnutrition intervention would be 50% effective. The primary outcome of this study was the incremental cost-effectiveness ratio, with a willingness-to-pay threshold of $100,000 per QALY. One-way and two-way sensitivity analyses were performed to evaluate model parameter assumptions.

RESULTS

When using the base case values, universal malnutrition screening and intervention was cost-effective compared to no malnutrition screening or intervention, with an incremental cost-effectiveness ratio of $6,454 per QALY. Universal screening and intervention remained cost-effective, provided the cost of screening remained less than $3,373, the cost of nutritional intervention remained less than $12,042, the prevalence of malnutrition among surgical candidates was higher than 2%, and the risk of PJI among patients with malnutrition was greater than 1%.

CONCLUSION

Universal preoperative malnutrition screening and intervention among TKA candidates is cost-effective at parameters encountered in clinical practice. Nutritional optimization programs should be considered to facilitate malnutrition screening and intervention and future studies should evaluate their efficacy at lowering PJI risk.

Immunonutrition in Orthopedic and Traumatic Patients

The role of nutrition intervention in surgical settings is constantly developing and evolving. Immunonutrition represents a viable option to reduce perioperative and postoperative complications in surgical oncology. However, as far as we know, little research has been conducted in the orthopedic field. With this review, we aim to summarize the state of the art in the application of immune-enhanced compounds to surgical, orthopedic, and traumatic patients. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were adopted. A comprehensive search was carried out using the PubMed (MEDLINE), EMBASE, and Cochrane Library databases. All the studies dealing with immunonutrition fed to traumatic and orthopedic patients were pooled, the data were extracted, and the studies were discussed. A total of eight studies were included: six focused on trauma surgery and two on elective orthopedic surgery. The epidemiological characteristics of participants and the assessment of results were reported. Data were analyzed using R software (2020; R Core Team). Based on the current available literature, a positive impact of immunonutrition in orthopedic and trauma surgical settings was registered. All studies analyzed showed the favorable impact of the immunonutrition diet on clinical outcomes. The full effect of this type of nutrition and its different applications in the orthopedic and traumatic fields should be critically investigated through more extensive randomized controlled trials.

Are the preoperative albumin levels and the albumin to fibrinogen ratio the risk factors for acute infection after primary total joint arthroplasty?

Background

Acute infection, such as periprosthetic joint infection and superficial surgical site infection, after primary total joint arthroplasty (TJA) is a serious complication, and its risk factors remain controversial. This study aimed to identify the risk factors for acute infection after primary TJA, especially the serological indicators that reflect preoperative nutritional statuses, such as albumin level and albumin to fibrinogen ratio (AFR).

Methods

We retrospectively reviewed patients who underwent elective primary hip or knee arthroplasty at our institution from 2009 to 2021. Potential risk factors of acute infection and demographic information were extracted from an electronic health record. Patients who suffered acute infection, such as PJI or SSI, after TJA were considered the study group. Non-infected patients were matched 1:2 with the study group according to sex, age, the involved joint (hip or knee), and year of surgery (control group). The variables of potential risk factors for acute postoperative infection (demographic characteristics, preoperative comorbidities and drug use, operative variables, and laboratory values) were collected and evaluated by regression analysis. Restrictive cubic spline regression analysis was also used to examine the relationship between preoperative serum albumin levels and acute postoperative infection.

Results

We matched 162 non-infected patients with 81 patients who suffered from acute postoperative infection. Among the patients who suffered from acute infection within 90 days after TJA, 18 were diagnosed with periprosthetic joint infection and 63 with surgical site infection. Low albumin levels were strongly associated with acute postoperative infection (95% confidence interval, 0.822-0.980; P = 0.015). This risk increased as preoperative albumin levels decreased, with a negative dose-response relationship (P _overall = 0.002; P _nonlinear = 0.089). However, there was no significant association between the AFR and acute infection after primary TJA (P = 0.100).

Conclusion

There is currently insufficient evidence to confirm the relationship between preoperative AFR and acute infection after elective primary TJA, while a lower preoperative albumin level is an independent risk factor for acute infection with a negative dose-response relationship. This suggests that optimal nutritional management may be benefited before elective primary TJA.

Opportunities for Patient Participation in Perioperative Malnutrition Care: A Qualitative Study

Introduction

In the perioperative period of hospitalization, barriers to food intake are common due to special nutritional needs, compromised nutritional status, and metabolic stress. Good nutritional care call for an interdisciplinary approach. And patients themselves may also play an essential role in managing nutritional care.

Objective

This study aimed to explore how patients with malnutrition experience nutritional care, their perspectives on patient participation, and their own role in malnutrition care in the perioperative period of hospitalization.

Methods

A qualitative study was conducted using an interpretive phenomenological approach. To follow patients' experiences, in-depth longitudinal interviews were undertaken before, during, and after hospitalization. Interview transcripts were analyzed thematically using open, axial, and selective coding and interpreted in an iterative process.

Results

Fifty-six interviews were undertaken with 26 patients with malnutrition scheduled for surgery and during the perioperative period of hospitalization. Four themes were identified: (1) unawareness and stigmata about being malnourished, (2) feasibility of optimal nutritional care, (3) needs and expectations for self-management, and (4) barriers and facilitators of taking own responsibilities in nutritional care.

Conclusion

Awareness and responsiveness to patients' perspectives, motivation, and compliance are prerequisites for patient participation in malnutrition care. This requires good communication between healthcare professionals and patients in all phases of hospitalization.

Nutritional Risk Screening 2002 predicts surgical outcomes in 1532 patients undergoing total joint arthroplasty: A retrospective cohort study

BACKGROUND

Limited information exists about the predictive effect of Nutritional Risk Screening (NRS) 2002 on orthopedic surgery. The aim of the present study is to explore the role of NRS 2002 in postoperative complications and resource utilization in patients with total joint arthroplasty (TJA).

METHODS

We retrospectively collected the demographics and surgical results of nearly 2000 TJA patients admitted from 2016 to 2020 and assessed the differences in short- and long-term complications and resource utilization parameters. Multivariate linear, logistic regression, and subgroup analysis were subsequently used to control for potential confounders. Survival analysis was performed to further verify the cumulative incidence of postoperative complications.

RESULTS

We identified 1532 patients receiving TJA, 8.7% of which were at nutrition risk (NRS 2002 score ≥3 out of 7). Preoperative nutrition risk was associated with an increased risk of systemic complications, incisional complications, surgical site infection (SSI), incisional SSI, periprosthetic joint infection, dislocation, and periprosthetic fracture after TJA (odds ratio [OR], 3.62-31.99; all P < 0.05). Preoperative nutrition risk was further associated with an increased risk of cardiac complications, respiratory complications, urinary complications, and arthroplasty-related reoperation (OR, 3.16-12.29; all P < 0.01). Moreover, preoperative nutrition risk was associated with increased costs and length of stay, and increased risk of unplanned intensive care unit admission, arthroplasty-related readmission, infection-related readmission, and SSI-related readmission.

CONCLUSIONS

NRS 2002 is associated with an elevated risk of postoperative complications and increased resource utilization, following TJA. Thus, routine screening is recommended to identify nutrition risk statuses of patients undergoing elective TJA.

Optimización preoperatoria del paciente antes de una artroplastia de cadera o rodilla: parte 1

Las artroplastias de cadera y rodilla son estrategias que han demostrado ser efectivas en el tratamiento de la patología degenerativa articular. El reemplazo articular mejora la calidad de vida de la mayoría de los pacientes cuando el tratamiento conservador falla. Sin embargo, estas son cirugías mayores que conllevan un riesgo significativo de complicaciones, incluyendo la necesidad de una revisión. El propósito de este artículo es analizar los factores de riesgo modificables del paciente antes de la cirugía, a finde disminuir el riesgo de complicaciones posoperatorias. Estudios recientes han descripto ciertos factores de riesgo modificables, inherentes al paciente y que incrementan la posibilidad de complicaciones posoperatorias luego de un reemplazo articular de cadera o rodilla. Estos incluyen obesidad, malnutrición, tabaquismo, diabetes, anemia, deficiencia de vitamina D, consumo de opioides, artropatías inflamatorias, insuficiencia renal crónica y colonización por estafilococco meticilino-resistente. Si conseguimos optimizar estas condiciones durante el preoperatorio, reduciremos el riesgo de complicaciones posoperatorias.

Preoperative Hypoalbuminemia Is Associated With Early Morbidity and Mortality After Revision Total Hip Arthroplasty

Hypoalbuminemia is associated with early morbidity and mortality in revision total knee arthroplasty. We evaluated the effect of preoperative hypoalbuminemia on 30-day morbidity and mortality in revision total hip arthroplasty (THA). The National Surgical Quality Improvement Program (NSQIP) database was queried from 2015 to 2018 to identify patients who underwent revision THA. Patients were stratified based on the presence or absence of preoperative hypoalbuminemia and their odds of a major complication or death within 30 days of revision THA with multivariate logistic regression. After Bonferroni correction for these 2 primary outcomes, statistical significance was defined as P<.025. A total of 2492 revision THAs with complete data were identified, of which 486 (20%) had preoperative hypoalbuminemia. Preoperative hypoalbuminemia increased the absolute risk of a major complication by 15.3% compared with patients with revision THA without hypoalbuminemia (30% vs 14.7%, P<.001). Patients with preoperative hypoalbuminemia also had nearly a 7-fold higher incidence of death (3.3%) compared with those with revision THA without preoperative hypoalbuminemia (0.5%, P<.001). After logistic regression, the odds of having a major complication after revision THA with preoperative hypoalbuminemia within 30 days were increased by 80% (odds ratio, 1.8; 95% CI, 1.4-2.3; P<.001), and the odds of death within 30 days were increased by 210% (odds ratio, 3.1; 95% CI, 1.2-7.8; P=.020). Hypoalbuminemia is associated with early morbidity and mortality after revision THA. [Orthopedics. 2022;45(5):281-286.].

Preoperative Patient Optimization in Total Joint Arthroplasty-The Paradigm Shift from Preoperative Clearance: A Narrative Review

Background: Total joint arthroplasty (TJA) is one of the most common procedures performed in the United States. Outcomes of this elective procedure may be improved via preoperative optimization of modifiable risk factors. Purposes: We sought to summarize the literature on the clinical implications of preoperative risk factors in TJA and to develop recommendations regarding preoperative optimization of these risk factors. Methods: We searched PubMed in August 2019 with an update in September 2020 for English-language, peer-reviewed publications assessing the influence on outcomes in total hip and knee replacement of 7 preoperative risk factors-obesity, malnutrition, hypoalbuminemia, diabetes, anemia, smoking, and opioid use-and recommendations to mitigate them. Results: Sixty-nine studies were identified, including 3 randomized controlled trials, 8 prospective cohort studies, 42 retrospective studies, 6 systematic reviews, 3 narrative reviews, and 7 consensus guidelines. These studies described worse outcomes associated with these 7 risk factors, including increased rates of in-hospital complications, transfusions, periprosthetic joint infections, revisions, and deaths. Recommendations for strategies to screen and address these risk factors are provided. Conclusions: Risk factors can be optimized, with evidence suggesting the following thresholds prior to surgery: a body mass index <40 kg/m², serum albumin ≥3.5 g/dL, hemoglobin A1C ≤7.5%, hemoglobin >12.0 g/dL in women and >13.0 g/dL in men, and smoking cessation and ≥50% decrease in opioid use by 4 weeks prior to surgery. Surgery should be delayed until these risk factors are adequately optimized.

The Geriatric Nutritional Risk Index Is an Independent Predictor of Adverse Outcomes for Total Joint Arthroplasty Patients

BACKGROUND

Malnutrition affects patient outcomes after total joint arthroplasty (TJA). Although hypoalbuminemia has been used as a surrogate, there is no unanimous method for screening and assessing malnutrition. This study aimed to determine if malnutrition, as defined by the Geriatric Nutritional Risk Index (GNRI), is independently correlated with short-term (<30 days) postoperative complications and prognosis in patients undergoing TJA.

METHODS

The 2016-2019 American College of Surgeons National Surgical Quality Improvement Program was queried for all patients aged >65 years who underwent TJA. Based on GNRI value, patients were divided into 3 groups: normal nutrition (GNRI >98), moderate malnutrition (GNRI 92-98), and severe malnutrition (GNRI <92). After adjusting for potential confounders, multivariable regression models were used to analyze the association between GNRI and patient outcomes.

RESULTS

A total of 191,087 patients were included in the study. Prevalence of malnutrition based on body mass index (<18.5 kg/m²), albumin (<3.5 mg/dL), and GNRI (≤98) was 0.41% (784), 4.17% (7975), and 15.83% (30,258). Adjusted analysis showed that compared with normal nutrition, moderate and severe malnutrition status were associated with a higher rate of transfusion, readmission, and postoperative length of stay over 8 days (P < .05). Severe malnutrition was also associated with pneumonia, surgical site infection, urinary tract infection, sepsis, and revision surgery (P < .05).

CONCLUSION

Malnutrition, as defined by GNRI, is an independent predictor of adverse outcomes after TJA, including 30-day readmission, revision surgery, and increased length of stay. GNRI can be used to routinely screen and assess patient nutritional status before TJA and counsel patients and families appropriately.

LEVEL OF EVIDENCE

Level 3: Retrospective Cohort Study.

Social Determinants of Health in Total Hip Arthroplasty: Are They Associated With Costs, Lengths of Stay, and Patient Reported Outcomes?

BACKGROUND

Social determinants of health (SDOH) may play a larger role in predicting patient outcomes as outpatient total hip arthroplasty (THA) expands. We specifically examined the association between SDOH and patient metrics (demographics and comorbidities) for: (1) 30-day post-discharge costs of care; (2) lengths of stay (LOS); and (3) patient-reported outcomes (Hip Disability and Osteoarthritis Outcomes Score for Joints Replacement (HOOS JR)).

METHODS

Medicare patients who underwent primary THA between 2018 and 2019 were identified. Those who had complete social determinant data were included (n = 136). Data elements were drawn from institutional, regional, and government databases, as well as the Social Vulnerability Index (SVI). Multiple regression analyses were performed to determine SDOH and baseline comorbidities associations with costs, LOS, and HOOS JR scores.

RESULTS

Various SDOH factors were associated with higher 30-day costs, including residing in a food desert ($53,695 ± 15,485; P < .001) and the following SVI themes: 'Minority Status and Language' ($24,075 ± 9845; P = .01) and 'Housing and Transportation' ($16,190 ± 8501; P = .06), although the latter did not meet statistical significance. Baseline depression was associated with longer LOS (P = .02), while none of the other SDOH or patient metrics affected LOS. No relationships were observed between SDOH and HOOS JR changes from baseline.

CONCLUSION

Patients who live in food deserts and have minority status had higher costs of care after primary THA. Poor housing and transportation may also increase costs, albeit insignificantly. These results highlight the utility of assessing SDOH-related risk factors to optimize post-operative outcomes, with potential implications for bundled care.

Risk Factors for Delayed Discharge and Adverse Outcomes Following Outpatient Billed Total Knee Arthroplasty

BACKGROUND

The volume of outpatient total knee arthroplasty (TKA) has increased with advances in perioperative protocols, patient selection, and recent policy changes regarding insurance authorization. This study analyzed 30-day outcomes from a national database to better understand risk factors for delayed discharge (length of stay [LOS] ≥1), readmission, and reoperation after outpatient TKA.

METHODS

The National Surgical Quality Improvement Program (NSQIP) database was utilized to collect TKA (CPT 27447) billed as outpatient surgery performed from 2013 to 2018. Patient demographics, comorbidities, and short-term outcomes were collected and compared in LOS 0 versus LOS ≥1 cohorts. Subgroup analysis was completed for TKA performed in 2018, after the Center for Medicare Services removal of TKA from the inpatient-only list.

RESULTS

A total of 13,669 patients had outpatient TKA performed from 2013 to 2018. Most patients had LOS ≥1 day (77.1%). The LOS 0 cohort demonstrated a lower 30-day readmission rate (1.8%) compared to LOS ≥1 (2.8%), P > .01. Both groups demonstrated a low 30-day reoperation rate, LOS 0 (0.7%) and LOS ≥1 (1.1%), P = .05. Regression analysis demonstrated risk factors for LOS ≥1 day included COPD, ASA ≥3, age >75, and BMI >35 kg/m². Regression analysis demonstrated male gender, age >75, ASA ≥3, and albumin <3.5 g/dL were risk factors for readmission. Hypertension was a risk factor for 30-day reoperation.

CONCLUSION

Risk factors for LOS ≥1 day include age >75, ASA ≥3, BMI >35 kg/m². In addition, BMI >35 kg/m² was a risk factor for readmission and reoperation. These findings reinforce appropriate patient selection when considering outpatient TKA.

Patterns and Predictors of Weight Change Before and After Total Hip Arthroplasty in Class 2 and 3 Obese Patients

BACKGROUND

This study aimed to better understand body mass index (BMI) change patterns and factors associated with BMI change before and after total hip arthroplasty (THA) in Class 2 and 3 obese patients, and assess if preoperative or postoperative BMI change affects postoperative clinical outcomes.

METHODS

We retrospectively reviewed World Health Organization Class 2 and 3 obese patients (BMI > 35.0 at surgery) who underwent THA at a tertiary medical center from 2010 to 2020. BMI was recorded at 1 year preoperatively (mean 11.6 months), and at most recent postoperative visit (mean 29.0 months). Baseline demographics and postoperative clinical outcomes were recorded.

RESULTS

We reviewed 436 THAs with a mean age of 59.9 (11.5) years. Leading up to surgery 55.5% had unchanged BMI, and postoperatively 48.2% had unchanged BMI. Multivariate logistic regression revealed that those who lost BMI preoperatively were more likely to gain BMI postoperatively (odds ratio [OR] 3.28, confidence interval [CI] 1.83-5.97, P = .005), but those who gained >5% BMI preoperatively had no association with BMI change postoperatively. Those in a higher BMI class preoperatively were less likely to gain BMI preoperatively (Class 3 obese patients: OR 0.001, CI 0.0002-0.004, P < .001). African American patients were more likely to gain BMI preoperatively (OR 2.32, CI 1.16-4.66, P = .017). We did not detect an association between BMI change and postoperative clinical outcomes.

CONCLUSION

In World Health Organization Class 2 or 3 obese patients, most maintained BMI between their first preoperative and final postoperative visit. Preoperatively, Class 3 obese patients were less likely to gain weight than Class 2 obese patients. The primary predictor of postoperative weight gain was preoperative weight loss. Weight change preoperatively and postoperatively were not associated with worse clinical outcomes.

Association Between Nonsurgical Weight Loss From Body Mass Index >40 to Body Mass Index <40 and Complications and Readmissions Following Total Hip Arthroplasty

BACKGROUND

Elevated body mass index (BMI) is a risk factor for adverse outcomes following total hip arthroplasty (THA). It is unknown if preoperative weight loss to a BMI <40 kg/m² is associated with reduced risk of adverse outcomes.

METHODS

We retrospectively reviewed elective, primary THA performed at an academic center from 2015 to 2019. Patients were split into groups based on their BMI trajectory prior to THA: BMI consistently <40 ("BMI <40"); BMI >40 at the time of surgery ("BMI >40"); and BMI >40 within 2 years preoperatively, but <40 at the time of surgery ("Weight Loss"). Length of stay (LOS), 30-day readmissions, and complications as defined by Centers for Medicare and Medicaid Services were compared between groups using parsimonious regression models and Fisher's exact testing. Adjusted analyses controlled for sex, age, and American Society of Anesthesiologists class.

RESULTS

In total, 1589 patients were included (BMI <40: 1387, BMI >40: 96, Weight Loss: 106). The rate of complications in each group was 3.5%, 6.3%, and 8.5% and the rate of 30-day readmissions was 3.0%, 4.2%, and 7.5%, respectively. Compared to the BMI <40 group, the weight loss group had a significantly higher risk of 30-day readmission (odds ratio [OR] 2.70, 95% confidence interval [CI] 1.19-6.17, P = .02), higher risk of any complication (OR 2.47, 95% CI 1.09-5.59, P = .03), higher risk of mechanical complications (OR 3.07, 95% CI 1.14-8.25, P = .03), and longer median LOS (16% increase, P = .002). The BMI >40 group had increased median LOS (10% increase, P = .03), but no difference in readmission or complications (P > .05) compared to BMI <40.

CONCLUSION

Weight loss from BMI >40 to BMI <40 prior to THA was associated with increased risk of readmission and complications compared to BMI <40, whereas BMI >40 was not.

LEVEL OF EVIDENCE

Level III - Retrospective Cohort Study.

Modifiable risk factors increase length of stay and 90-day cost of care after shoulder arthroplasty

BACKGROUND

Baseline health conditions can negatively impact cost of care and risk of complications after joint replacement, necessitating additional care and incurring higher costs. Bundled payments have been used for hip and knee replacement and the Centers for Medicare & Medicaid Services (CMS) is testing bundled payments for upper extremity arthroplasty. The purpose of this study was to determine the impact of predefined modifiable risk factors (MRFs) on total encounter charges, hospital length of stay (LOS), related emergency department (ED) visits and charges, and related hospital readmissions within 90 days after shoulder arthroplasty.

METHODS

We queried the electronic medical record (EPIC) for all shoulder arthroplasty cases under DRG 483 within a regional 7-hospital system between October 2015 and December 2019. Data was used to calculate mean LOS, total 90-day charges, related emergency department (ED) visits and charges, and related hospital readmissions after shoulder arthroplasty. Data for patients who had 1 or more MRFs, defined as anemia (hemoglobin < 10 g/dL), malnutrition (albumin < 3.4 g/dL), obesity (BMI > 40), uncontrolled diabetes (random glucose > 180 mg/dL or glycated hemoglobin > 8.0%), tobacco use (International Classification of Diseases, Tenth Revision, code indicating patient is a smoker), and opioid use (opioid prescription within 90 days of surgery), were evaluated as potential covariates to assess the relationship between MRFs and total encounter charges, LOS, ED visits, ED charges, and hospital readmissions.

RESULTS

A total of 1317 shoulder arthroplasty patients were identified. Multivariable analysis demonstrated that anemia (+$19,847, confidence interval [CI] $15,743, $23,951; P < .001), malnutrition (+$5850, CI $3712, $7988; P < .001), and obesity (+$2762, CI $766, $4758, P = .007) independently contributed to higher charges after shoulder arthroplasty. Mean LOS was higher in patients with anemia (5.0 ± 4.0 days vs. 2.2 ± 1.6 days, P < .001), malnutrition (3.7 ± 2.8 days vs. 2.2 ± 1.5 days, P < .001), and uncontrolled diabetes (2.8 ± 2.8 days vs. 2.3 ± 1.7 days, P = .019). Univariate risk factors associated with a significant increase in total 90-day encounter charges included anemia (+$19,345, n = 37, P < .001), malnutrition (+$6971, n = 116, P < .001), obesity (+$2615, n = 184, P = .011), and uncontrolled diabetes (+$4377, n = 66, P = .011). Univariate risk for readmission within 90 days was higher in patients with malnutrition (odds ratio 3.0, CI 1.8, 4.9; P < .001).

CONCLUSION

Malnutrition, obesity, and anemia contribute to significantly higher costs after shoulder arthroplasty. Medical strategies to optimize patients before shoulder arthroplasty are warranted to reduce total 90-day encounter charges, length of stay, and risk of readmission within 90 days of surgery. Optimizing patient health before shoulder surgery will positively impact outcomes and cost containment for patients, institutions, and payors after shoulder arthroplasty.

Reporting of Comorbidities in Total Hip and Knee Arthroplasty Clinical Literature: A Systematic Review

BACKGROUND

The effects of comorbid disease remain an area of interest. Concurrent diagnoses not only affect clinical outcomes but also affect health-care reimbursement. As the rate of arthroplasty increases, consistent risk stratification is imperative. Therefore, our aim was to ascertain how comorbidities have been reported in the recent total hip arthroplasty (THA) and total knee arthroplasty (TKA)-related literature; we also wanted to quantify the use of comorbidity scores for the assessment of comorbid disease in arthroplasty research.

METHODS

A systematic review of the recent THA and TKA literature that was published between January 1, 2019, and September 21, 2020, was performed using the PubMed and MEDLINE databases. Clinical studies that provided data on comorbidities were evaluated for method of comorbidity reporting. The prevalence of comorbidity reporting was assessed, and the manner of reporting was analyzed.

RESULTS

Among 659 articles, a total of 207 studies (31.4%) reported comorbidities and met our inclusion criteria. Of the 207 studies that reported comorbidities, only 57% used a comorbidity index to report comorbid disease. Of all of the indices, the American Society of Anesthesiologists (ASA) Physical Status Classification System was the score that was most commonly used (TKA, 86.2%; THA, 83.3%). Additional scores were used at varying frequencies. For TKA, the scores included the Charlson Comorbidity Index (CCI) (15.5%); the New York Heart Association (NYHA) Functional Classification (3.4%); and the CCI-Deyo (adapted by Deyo et al.), the age-adjusted CCI, the Cumulative Illness Rating Scale (CIRS), and the Readmission Risk Assessment Tool (RRAT) (1.7% each). For THA, the scores included the CCI (16.7%), the Elixhauser Comorbidity Measure (ECM) (6.7%), and the CCI-Deyo (1.7%).

CONCLUSIONS

Considering the impact of comorbid disease on outcomes, complications, and, ultimately, reimbursement, standardized risk stratification in arthroplasty is necessary. Current studies demonstrate inconsistent comorbidity reporting, making it challenging to further characterize the impact of comorbidities on outcomes. Future research should target the development of a standardized data-driven model for comorbidity assessment in the orthopaedic patient population.

A Novel Biomarker to Screen for Malnutrition: Albumin/Fibrinogen Ratio Predicts Septic Failure and Acute Infection in Patients Who Underwent Revision Total Joint Arthroplasty

BACKGROUND

This study aimed to investigate the efficacy of the albumin/fibrinogen ratio (AFR) in the assessment of malnutrition and to compare its ability to predict early postoperative periprosthetic joint infection (PJI) in patients with aseptic revisions.

METHODS

Four hundred sixty-six patients undergoing revision total hip or knee arthroplasty between February 2017 and December 2019 were recruited in this retrospective study. We compared the differences in nutritional parameters between patients undergoing revision for septic and aseptic reasons. We used multivariate logistic regression and assessed the association between nutritional parameters and risk of PJI. 207 patients with aseptic revision were then evaluated for the incidence of acute postoperative infection within 90 days. The predictive ability of nutritional markers was assessed by receiver operating characteristic curves.

RESULTS

In the multivariate logistic regression analysis, low albumin level (adjusted OR 1.56, 95% CI 1.16-2.08, P = .003), low prognostic nutritional index (PNI) (adjusted OR 1.57, 95% CI 1.01-2.43, P < .043), and low AFR (adjusted OR 2.54, 95% CI 1.92-3.36, P < .001) were independently associated with revision surgery for septic reasons. In accordance with the receiver operating characteristic analysis, the AFR exhibited a greater area under the curve value (0.721) than did the prognostic nutritional index and albumin. An elevated AFR (≥11.7) was significantly associated with old age, joint type, high Charlson comorbidity index, high American Society of Anesthesiologist, and diabetes (P < .05).

CONCLUSION

Our findings demonstrated AFR may be an effective biomarker to assess nutrition status and predict acute PJIs after revision TJA.

Failure to Medically Optimize Before Total Hip Arthroplasty: Which Modifiable Risk Factor Is the Most Dangerous?

Background

There is mounting evidence that smoking, abnormal body mass index (BMI), uncontrolled diabetes, and poor nutritional status are associated with complications after total hip arthroplasty (THA). The goal of the present study was to evaluate the consequences of failure to medically optimize Medicare-eligible patients with respect to these key modifiable health targets by assessing complications in the early postoperative period after THA.

Methods

The National Surgical Quality Improvement Program database was queried for all primary THAs performed in 2018. Data were collected on preoperative serum albumin, BMI, diabetes, and tobacco use as well as postoperative infections, readmissions, complications, and mortality. We identified 47,924 THA patients with a median BMI of 29 kg/m² and age of 72 years, and 60% of whom were female.

Results

We found that preoperative albumin <3.5 g/dL, BMI ≥40 kg/m², tobacco use, and diabetes were all individually associated with increased risk of postoperative complications. Serum albumin <3.5 g/dL was the greatest overall risk factor for infection (odds ratio [OR]: 3.1, 95% confidence interval [CI]: 2.3-4.4, P < .0001), readmission (OR: 2.2, 95% CI: 1.9-2.5, P < .0001), any complication (OR: 4.2, 95% CI: 3.8-4.6, P < .0001), and mortality (OR: 7.5, 95% CI: 5.3-10.6, P < .0001).

Conclusions

Low albumin, elevated BMI, tobacco use, and diabetes are associated with increased risk of postoperative infection, readmission, any complication, and mortality after primary THA. Low albumin poses the greatest risk of these. Preoperative optimization should be obtained in all patients before elective surgery, and the final decision for surgery should be individually made between a surgeon and patient.

Level of Evidence

IV.

Impact of malnutrition and vitamin deficiency in geriatric patients undergoing orthopedic surgery

Background and purpose - There is growing evidence that hypoproteinemia is an important risk factor for adverse events after surgery. Less is known about the impact of vitamin deficiency on postoperative outcome. Therefore we evaluated the prevalence and impact of malnutrition and vitamin deficiency in geriatric patients undergoing elective orthopedic surgery.Patients and methods - In a retrospective analysis of 599 geriatric patients who had undergone elective orthopedic surgery in 2018 and 2019, hypoproteinemia, and deficiency of vitamin D, vitamin B12, and folate were assessed. Reoperation rates, readmission rates, complication rates, and transfusion rates were compared between malnourished patients and patients with normal parameters. Multivariable logistic regression models were used to assess the relationship between malnutrition and postoperative adverse events, controlling for confounding factors such as age, sex, diabetes mellitus, and frailty.Results - Patients with malnutrition showed a higher rate of reoperation (13% vs. 5.5%; p = 0.01) and exhibited more wound-healing disorders (7.4% vs. 1.3%, p = 0.001) as well as Clavien-Dindo IV° complications (7.4% vs. 2.4%; p = 0.03). Deficiency of vitamin D led to a higher rate of falls (8.4% vs. 2.9%, p = 0.006). Deficiency of vitamin B12 and folate did not affect postoperative adverse events. Although correlated to frailty (p = 0.004), multivariable regression analysis identified malnutrition as independent risk factor for reoperation (OR 2.6, 95% CI 1.1-6.2) and wound healing disorders (OR 7.1, CI 1.9-26).Interpretation - Malnutrition is common among geriatric patients undergoing elective orthopedic surgery and represents an independent risk factor for postoperative adverse events.