The Effect of Diabetes Mellitus on Total Joint Arthroplasty Outcomes

Continuation of Oral Antidiabetic Medications Was Associated With Better Early Postoperative Blood Glucose Control Compared to Sliding Scale Insulin After Total Knee Arthroplasty

BACKGROUND

This study evaluated blood glucose (BG), creatinine levels, metabolic issues, length of stay (LOS), and early postoperative complications in diabetic primary total knee arthroplasty (TKA) patients. It examined those who continued home oral antidiabetic medications and those who switched to insulin postoperatively. The hypothesis was that continuing home medications would lead to lower BG levels without metabolic abnormalities.

METHODS

Patients who had diabetes who underwent primary TKA from 2013 to 2022 were evaluated retrospectively. Diabetic patients who were not on home oral antidiabetic medications or who were not managed as an inpatient postoperatively were excluded. Patient demographics and laboratory tests collected preoperatively and postoperatively as well as 90-day emergency department visits and 90-day readmissions, were pulled from electronic records. Patients were grouped based on inpatient diabetes management: continuation of home medications versus new insulin coverage. Acute postoperative BG control, creatinine levels, metabolic abnormalities, LOS, and early postoperative complications were compared between groups. Multivariable regression analyses were performed to measure associations.

RESULTS

A total of 867 primary TKAs were assessed; 703 (81.1%) patients continued their home oral antidiabetic medications. Continuing home antidiabetic medications demonstrated lower median maximum inpatient BG (180.0 mg/dL versus 250.0 mg/dL; P < .001) and median average inpatient BG (136.7 mg/dL versus 173.7 mg/dL; P < .001). Logistic regression analyses supported the presence of an association (odds ratio = 17.88 [8.66, 43.43]; P < .001). Proportions of acute kidney injury (13.5 versus 26.7%; P < .001) were also lower. There was no difference in relative proportions of metabolic acidosis (4.4 versus 3.7%; P = .831), LOS (2.0 versus 2.0 days; P = .259), or early postoperative complications.

CONCLUSIONS

Continuing home oral antidiabetic medications after primary TKA was associated with lower BG levels without an associated worsening creatinine or increase in metabolic acidosis.

LEVEL III EVIDENCE

Retrospective Cohort Study.

Racial and Ethnic Minority Patients Have Increased Complication Risks When Undergoing Surgery While Not Meeting Clinical Guidelines

BACKGROUND

Clinical guidelines for performing total joint arthroplasty (TJA) have not been uniformly adopted in practice because research has suggested that they may foster inequities in surgical access, potentially disadvantaging minority sociodemographic groups. The aim of this study was to assess whether undergoing TJA without meeting clinical guidelines affects complication risk and leads to disparities in postoperative outcomes.

METHODS

This retrospective cohort study evaluated the records of 11,611 adult patients who underwent primary TJA from January 1, 2010, to December 31, 2020, at an academic hospital network. Based on self-reported race and ethnicity, 89.5% of patients were White, 3.5% were Black, 2.9% were Hispanic, 1.3% were Asian, and 2.8% were classified as other. Patients met institutional guidelines for undergoing TJA if they had a hemoglobin A1c of <8.0% and a body mass index of <40 kg/m 2 and were not currently smoking. A logistic regression model was utilized to identify factors associated with complications, and a mixed-effects model was utilized to identify factors associated with not meeting guidelines for undergoing TJA.

RESULTS

During the study period, 11% (1,274) of the 11,611 adults who underwent primary TJA did not meet clinical guidelines. Compared with the group who met guidelines, the group who did not had higher proportions of Black patients (3.2% versus 6.0%; p < 0.001) and Hispanic patients (2.7% versus 4.6%; p < 0.001). An increased risk of not meeting guidelines at the time of surgery was demonstrated among Black patients (odds ratio [OR], 1.60 [95% confidence interval (CI), 1.22 to 2.10]; p = 0.001) and patients insured by Medicaid (OR, 1.75 [95% CI, 1.26 to 2.44]; p = 0.001) or Medicare (OR, 1.22 [95% CI, 1.06 to 1.41]; p = 0.007). Patients who did not meet guidelines had a higher risk of reoperation than those who met guidelines (7.7% [98] versus 5.9% [615]; p = 0.017), including a higher risk of infection-related reoperation (3.1% [40] versus 1.4% [147]; p < 0.001).

CONCLUSIONS

We found that patients who underwent TJA despite not meeting institutional preoperative criteria had a higher risk of postoperative complications. These patients were more likely to be from racial and ethnic minority groups, to have a lower socioeconomic status, and to have Medicare or Medicaid insurance. These findings underscore the need for surgery-related shared decision-making that is informed by evidence-based guidelines in order to reduce complication burden.

LEVEL OF EVIDENCE

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

The influence of mental health on early outcomes following total hip arthroplasty

BACKGROUND

Poor mental health is difficult to recognize and as a result, its association with recovery from total joint arthroplasty is difficult to assess. The purpose of this study was to investigate the relationship between overall mental health scores and outcomes in the early postoperative period following unilateral total hip arthroplasty (THA).

METHODS

This is a retrospective review of prospectively collected data involving 142 patients who underwent primary unilateral THA. Independent variables included patient demographics and preoperative Patient-Reported Outcomes Measurement Information System (PROMIS), Global Physical Health (GPH) and Global Mental Health (GMH) and Hip Disability and Osteoarthritis Outcome Score, Joint Replacement (HOOS JR) scores as well as diagnoses of depression or anxiety. Dependent variables included length of stay (LOS), disposition at discharge, narcotic consumption until discharge, 6-week postoperative GPH, GMH and HOOS JR scores and magnitude of change compared to preoperative scores. Preoperative GMH and postoperative outcomes were compared using Pearson correlation coefficient, independent t-tests, Pearson's Chi-Square test, and univariate logistic regression.

RESULTS

Patients with preoperative GMH scores below the 25% quartile were less likely to be discharged home and resulted in lower GPH, GMH and HOOS JR scores at 6-week follow-up compared to patients with preoperative GMH scores in the top 25% quartile. However, patients with low preoperative GMH scores demonstrated a greater magnitude of improvement in both the GPH and GMH scores compared to patients in the top 25% quartile. There was no difference in opioid consumption or LOS between either groups. When comparing patients with and without depression/anxiety, no difference was seen in any of the outcomes measured.

CONCLUSION

Unilateral THA offers significant improvements in both physical and mental function to patients with hip osteoarthritis and poor mental health, though overall scores remain lower than in those with better mental health.

Mental Health Effects on the Minimal Clinically Important Difference in Total Joint Arthroplasty

INTRODUCTION

The effect of mental health on patient-reported outcome measures is not fully understood in total joint arthroplasty (TJA). Thus, we investigated the relationship between mental health diagnoses (MHDs) and the Minimal Clinically Important Difference for Improvement (MCID-I) and Worsening (MCID-W) in primary TJA and revision TJA (rTJA).

METHODS

Retrospective data were collected using relevant Current Procedural Terminology and MHDs International Classification of Diseases, 10th Revision, codes with completed Hip Disability and Osteoarthritis Outcome Score-Physical Function Short Form, Knee Injury and Osteoarthritis Outcome Score-Physical Function Short Form, Patient-reported Outcomes Measurement Information System (PROMIS)-Physical Function Short Form 10a, PROMIS Global-Mental, or PROMIS Global-Physical questionnaires. Logistic regressions and statistical analyses were used to determine the effect of a MHD on MCID-I/MCID-W rates.

RESULTS

Data included 4,562 patients (4,190 primary TJAs/372 rTJAs). In primary total hip arthroplasty (pTHA), MHD-affected outcomes for Hip Disability and Osteoarthritis Outcome Score-Physical Function Short Form (MCID-I: 81% versus 86%, P = 0.007; MCID-W: 6.0% versus 3.2%, P = 0.008), Physical Function Short Form 10a (MCID-I: 68% versus 77%, P < 0.001), PROMIS Global-Mental (MCID-I: 38% versus 44%, P = 0.009), and PROMIS Global-Physical (MCID-I: 61% versus 73%, P < 0.001; MCID-W: 14% versus 7.9%, P < 0.001) versus pTHA patients without MHD. A MHD led to lower rates of MCID-I for PROMIS Global-Physical (MCID-I: 56% versus 63%, P = 0.003) in primary total knee arthroplasty patients. No effects from a MHD were observed in rTJA patients.

DISCUSSION

The presence of a MHD had a prominent negative influence on pTHA patients. Patients who underwent rTJA had lower MCID-I rates, higher MCID-W rates, and lower patient-reported outcome measure scores despite less influence from a MHD.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Semaglutide Use Prior to Total Hip Arthroplasty Results in Fewer Postoperative Prosthetic Joint Infections and Readmissions

BACKGROUND

Semaglutide, a novel diabetes management medication, is known for its efficacy in inducing weight loss. Despite this, its impact on outcomes after total hip arthroplasty (THA) remains unclear. The aim of this study was to evaluate if THA patients on semaglutide demonstrate: (1) fewer medical complications; (2) fewer implant-related complications; (3) fewer readmissions; and (4) lower costs.

METHODS

Using a national claims database from 2010 to 2021, we retrospectively examined diabetic patients prescribed semaglutide who underwent primary THA. This yielded 9,465 patients (Semaglutide = 1,653; Control = 7,812). Multivariable logistic regression was used to evaluate the following outcomes: 90-day postoperative medical complications, 2-year implant-related complications, 90-day readmissions, in-hospital lengths of stay, and day-of-surgery and 90-day episode of care costs.

RESULTS

Semaglutide users exhibited lower 90-day readmission rates (6.2 versus 8.8%; odds ratio 0.68; P < .01) and reduced prosthetic joint infections (1.6 versus 2.9%; odds ratio 0.56; P < .01). However, medical complication rates, hospital stays, same-day surgical costs, and 90-day episode costs showed no significant differences.

CONCLUSIONS

This study highlights semaglutide users undergoing THA with fewer 90-day readmissions and 2-year prosthetic joint infections. Although no variance appeared in medical complications, hospital stays, or costs, the medication's notable glycemic control and weight loss benefits could prompt pre-surgery consideration. Further research is essential for a comprehensive understanding of semaglutide's impact on post-THA outcomes.

Strategies for Perioperative Optimization in Upper Extremity Fracture Care

Perioperative optimization in upper extremity fracture care must balance the need for timely treatment with the benefits of medical optimization. Care pathways directed at optimizing glycemic control, chronic anticoagulation, smoking history, nutrition, and frailty can reduce surgical risk in upper extremity fracture care. The development of multidisciplinary approaches that tie risk modification with risk stratification is needed.

Zucker Diabetic-Sprague Dawley Rats Have Impaired Peri-Implant Bone Formation, Matrix Composition, and Implant Fixation Strength

An increasing number of patients with type 2 diabetes (T2DM) will require total joint replacement (TJR) in the next decade. T2DM patients are at increased risk for TJR failure, but the mechanisms are not well understood. The current study used the Zucker Diabetic-Sprague Dawley (ZDSD) rat model of T2DM with Sprague Dawley (SPD) controls to investigate the effects of intramedullary implant placement on osseointegration, peri-implant bone structure and matrix composition, and fixation strength at 2 and 10 weeks post-implant placement. Postoperative inflammation was assessed with circulating MCP-1 and IL-10 2 days post-implant placement. In addition to comparing the two groups, stepwise linear regression modeling was performed to determine the relative contribution of glucose, cytokines, bone formation, bone structure, and bone matrix composition on osseointegration and implant fixation strength. ZDSD rats had decreased peri-implant bone formation and reduced trabecular bone volume per total volume compared with SPD controls. The osseointegrated bone matrix of ZDSD rats had decreased mineral-to-matrix and increased crystallinity compared with SPD controls. Osseointegrated bone volume per total volume was not different between the groups, whereas implant fixation was significantly decreased in ZDSD at 2 weeks but not at 10 weeks. A combination of trabecular mineral apposition rate and postoperative MCP-1 levels explained 55.6% of the variance in osseointegration, whereas cortical thickness, osseointegration mineral apposition rate, and matrix compositional parameters explained 69.2% of the variance in implant fixation strength. The results support the growing recognition that both peri-implant structure and matrix composition affect implant fixation and suggest that postoperative inflammation may contribute to poor outcomes after TJR surgeries in T2DM patients. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Rural-Urban Differences in Hospital and Patient-Reported Outcomes Following Total Hip Arthroplasty

Background

Rural patients have unique health-care factors influencing outcomes of arthroplasty, hypothetically putting these patients at increased risk for complications following total joint arthroplasty. The aim of this study is to better understand differences in patient outcomes and satisfaction between rural and urban patients receiving care in an urban setting and to provide more equitable care.

Methods

A retrospective chart review was performed on patients undergoing primary total hip arthroplasty at a single large academic center between January 2013 and August 2020. Demographic, operative, and hospital outcomes were obtained from the institutional electronic medical record. Rurality was determined by rural-urban code (RUC) classifications by zip code with RUC codes 1-3 defined as urban and RUC 4-10 defined as rural.

Results

Patients from urban areas were more likely to visit the emergency department within 30 days postoperatively (P = .006) and be readmitted within 90 days (P < .001). However, unplanned (P < .001) admissions were higher in the rural group. There was no statistical difference in postoperative complications (P = .4). At 6 months, rural patients had higher patient-reported outcome measures (PROMs) including Hip Disability and Osteoarthritis Outcome Score total (P = .05), Hip Disability and Osteoarthritis Outcome Score interval (P = .05), self-reported functional improvement (P < .05), improvements in pain (P < .05), and that the surgery met expectations (P < .05). However, these values did not reach minimal clinically important difference.

Conclusions

There may be differences in emergency department visits, readmissions, and PROMs in rural vs urban populations undergoing total hip arthroplasty in an urban setting. Patient access to care and attitudes of rural patients toward health care may underlie these findings. Understanding differences in PROMs, satisfaction, and hospital-based outcomes based on rurality is essential to provide equitable arthroplasty care.

Risk factors for complications within 30 days of operatively fixed periprosthetic femur fractures

BACKGROUND

With a rising number of periprosthetic femur fractures (PPFFs) each year, the primary objective of our study was to quantify risk factors that predict complications following operative treatment of PPFFs.

METHODS

A retrospective cohort study of 231 patients with a periprosthetic femur fracture was conducted at an Academic, Level 1 Trauma Center. The main outcome measurement of interest was complications, as defined by the ACS-NSQIP, within 30 days of surgery.

RESULTS

56 patients had 96 complications. Bivariate analyses revealed ASA score, preoperative ambulatory status, length of stay, discharge disposition, time from admission to surgery, length of surgery, perioperative change in hemoglobin, Charlson comorbidity index, cerebral vascular accident/transient ischemic attack, chronic obstructive pulmonary disease, diabetes mellitus, and receipt of a blood transfusion were associated with development of a complication (p < 0.1). Multivariate logistic regression showed length of stay (OR 1.11, 95% CI 1.03-1.19; p = 0.006), receipt of a blood transfusion (OR 2.48, 95% CI 1.14-5.42; p = 0.02), and diabetes mellitus (OR 2.17, 95% CI 1.03-4.56; p = 0.04) remained independently predictive of complication.

CONCLUSIONS

Length of stay, receipt of a blood transfusion, and diabetes were associated with increased perioperative risk for developing a complication following operative treatment of periprosthetic femur fractures. Methods to decrease length of stay or transfusion rates may mitigate complication risk in these patients.

LEVEL OF EVIDENCE

Prognostic, Level III.

Team Approach: Preoperative Management of Metabolic Conditions in Total Joint Replacement

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Total joint arthroplasties (TJAs) of the knee and hip have been considered 2 of the most successful surgical procedures performed to date.

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Frailty is defined as increased vulnerability to adverse outcomes with physiologic stress.

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Preoperative optimization of frailty and metabolic bone conditions, including osteoporosis, vitamin D deficiency, and diabetes, through a multidisciplinary approach can help improve outcomes and minimize costs after TJA.

Is Uncontrolled Diabetes Mellitus Associated with Incidence of Complications After Posterior Instrumented Lumbar Fusion? A National Claims Database Analysis

BACKGROUND

Previous research has shown that diabetes mellitus (DM) is associated with postoperative complications, including surgical site infections (SSIs). However, evidence for the association between diabetes control and postoperative complications in patients with DM is mixed. Prior studies relied on a single metric for defining uncontrolled DM, which does not account for glycemic variability, and it is unknown whether a more comprehensive assessment of diabetes control is associated with postoperative complications.

QUESTIONS/PURPOSES

(1) Is there a difference in the incidence of SSI after lumbar spine fusion in patients with uncontrolled DM, defined with a comprehensive assessment of glycemic control, compared with patients with controlled DM? (2) Is there a difference in the incidence of other select postoperative complications after lumbar spine fusion in patients with uncontrolled DM compared with patients with controlled DM? (3) Is there a difference in total reimbursements between these groups?

METHODS

We used the PearlDiver Patient Records Database, a national administrative claims database that provides access to the full continuum of perioperative care. We included 46,490 patients with DM undergoing posterior lumbar fusion with instrumentation. Patients were required to be continuously enrolled in the database for at least 1 year before and 90 days after the index procedure. Patients were divided into uncontrolled and controlled DM cohorts, as defined by ICD-9 diagnostic codes. These are based on a comprehensive assessment of glycemic control, including consideration of patient self-monitoring of blood glucose levels, hemoglobin A1c, and the presence/severity of diabetes-related comorbidities. The cohorts differed only by age, insurance type, and Elixhauser comorbidity score. The primary outcome was the incidence of SSI, divided into superficial and deep, within 90 days postoperatively. Secondary complications included the incidence of cerebrovascular events, acute kidney injury, pulmonary embolism, pneumonia, urinary tract infection, blood transfusion, and total reimbursements. These are the sum of reimbursements occurring within 90 days of surgery, which capture the total professional and facility cost burden to the health payer (such as the insurer). We constructed multivariable logistic regression models to adjust for the effects of age, insurance type, and comorbidities.

RESULTS

After adjusting for potentially confounding variables including age, insurance type, and comorbidities, we found that patients with uncontrolled DM had an odds ratio for deep SSI of 1.52 (95% confidence interval 1.16 to 1.95; p = 0.002). Similarly, patients with uncontrolled DM had adjusted odds ratios of 1.25 (95% CI 1.01 to 1.53; p = 0.03) for cerebrovascular events, 1.36 (95% CI 1.18 to 1.57; p < 0.001) for acute kidney injury, 1.55 (95% CI 1.16 to 2.04; p = 0.002) for pulmonary embolism, 1.30 (95% CI 1.08 to 1.54; p = 0.004) for pneumonia, 1.33 (95% CI 1.19 to 1.49; p < 0.001) for urinary tract infection, and 1.27 (95% CI 1.04 to 1.53; p = 0.02) for perioperative transfusion. Patients with uncontrolled DM had higher median 90-day total reimbursements than patients with controlled DM: USD 27,915 (interquartile range 5472 to 63,400) versus USD 10,263 (IQR 4101 to 49,748; p < 0.001).

CONCLUSION

Our findings encourage surgeons to take a full diabetic history beyond the HbA1c value, including any self-monitoring of glucose measurements, time in acceptable range for continuous glucose monitors, and/or consideration of the presence/severity of diabetes-related complications before lumbar spine fusion, as HbA1c does not fully capture glycemic control or variability. We emphasize that uncontrolled DM is a clinical, rather than laboratory, diagnosis. Comprehensive diabetes histories should be incorporated into existing preoperative diabetes care pathways and elective surgery could be deferred to improve glycemic control. Future development of an index measure incorporating multidimensional measures of diabetes control (such as continuous or self-glucose monitoring, diabetes-related comorbidities) is warranted.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Regional Variation in Rates of Total Knee Arthroplasty Among Medicare Beneficiaries

IMPORTANCE

Rates of total knee arthroplasty vary widely across the United States. Whether this variation is associated with differences in patient characteristics or physician practice is unknown.

OBJECTIVES

To determine regional variations in rates of total knee arthroplasty after accounting for the prevalence of knee arthritis and other potentially associated patient risk factors and to assess the correlation of these variations with measures of access to care and surgical indications.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective national cohort study used Medicare data on more than 24 million deidentified beneficiaries annually from 2011 to 2015. Individuals included had fee-for-service coverage, were 65 to 89 years of age, and resided in 1 of 306 health referral regions. Data were analyzed from September 13, 2018, to August 15, 2019.

MAIN OUTCOMES AND MEASURES

Rate of primary total knee arthroplasty indexed to the national rate using observed to expected ratios. The expected numbers of arthroplasty procedures were derived from estimates based on beneficiaries' demographic and clinical characteristics. Observed to expected ratios were confounded by race/ethnicity; thus race/ethnicity-stratified analyses were conducted.

RESULTS

In 2011, there were 218 282 total knee arthroplasty procedures among 24 583 706 white Medicare beneficiaries (mean [SD] age 74.2 [6.9] years; 54.6% women). The rate of arthroplasty during the study period (5 years) was 9.3 per 1000 person-years. Adjustment for clinical characteristics reduced the spread in observed to expected ratios among regions by 29% compared with adjustment for age and sex alone. However, substantial variation remained, with observed to expected ratios that ranged from 0.61 in Newark, New Jersey, to 1.82 in Idaho Falls, Idaho. High ratios were primarily present in the upper Midwest, Great Plains, and Mountain West regions. Higher ratios were associated with regions where beneficiaries had fewer outpatient visits (Spearman correlation [r], -0.64; 95% CI, -0.70 to -0.56) and with regions having more surgeons per capita who performed knee arthroplasty (r = 0.27; 95% CI, 0.16-0.37). Higher ratios were associated with higher rates of arthroplasty procedures among beneficiaries with dementia (r = 0.36; 95% CI, 0.25-0.46), peripheral vascular disease (r = 0.52; 95% CI, 0.42-0.61), and skin ulcers (r = 0.43; 95% CI, 0.32-0.53), which are relative contraindications to arthroplasty.

CONCLUSIONS AND RELEVANCE

Substantial regional variation in rates of total knee arthroplasty remained after adjustment for patient characteristics. Coexistence of high observed to expected ratios and high rates among patients at greater surgical risk suggested overuse of knee arthroplasty in some regions.

Validated Risk-Stratification System for Prediction of Early Adverse Events Following Open Reduction and Internal Fixation of Closed Ankle Fractures

BACKGROUND

As orthopaedic surgery moves toward bundled payments, there is growing interest in identifying patients at high risk of early postoperative adverse events. The purpose of this study was to develop and validate a risk-stratification system for the occurrence of early adverse events among patients treated with open reduction and internal fixation (ORIF) for a closed fracture of the ankle.

METHODS

Patients undergoing ORIF for a closed ankle fracture during the period of 2006 to 2017, as documented by the American College of Surgeons National Surgical Quality Improvement Program, were identified. For the 60% of patients randomly selected as the development cohort, multivariate Cox proportional hazards modeling was used to identify factors that were independently associated with the occurrence of adverse events (including events such as reoperation, surgical site infection, and pulmonary embolism). On the basis of these results, a nomogram analysis was used to generate a point-based risk-stratification system. To evaluate the validity of the point-based system, the system was applied to the remaining 40% of patients constituting the validation cohort and tested for its ability to predict adverse events.

RESULTS

Of the 7,582 patients in the development cohort, 455 developed an adverse event (estimated adverse event risk of 6%). On the basis of Cox proportional-hazards regression, patients were assigned points for each of the following significant risk factors: +1 point for age of 40 to 59 years, +3 points for age of 60 to 79 years, +5 points for age of ≥80 years, +1 point for female sex, +2 points for chronic obstructive pulmonary disease (COPD), +2 points for insulin-dependent diabetes, +3 points for anemia, and +4 points for end-stage renal disease. The validation cohort included 5,263 patients. Among this second cohort, the risk-stratification system predicted the risk of early adverse events (p < 0.001; Harrell C = 0.697).

CONCLUSIONS

The occurrence of early adverse events following ORIF for closed ankle fractures was associated with greater age, female sex, COPD, insulin-dependent diabetes, anemia, and end-stage renal disease. We present and validate a simple point-based risk-stratification system to predict the risk of early adverse events.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Defining and Optimizing Value in Total Joint Arthroplasty From the Patient, Payer, and Provider Perspectives

BACKGROUND

The purpose of this study is to define value in bundled total joint arthroplasty (TJA) from the differing perspectives of the patient, payer/employer, and hospital/provider.

METHODS

Demographic, psychosocial, clinical, financial, and patient-reported outcomes (PROs) data from 2017 to 2018 elective TJA cases at a multihospital academic health system were queried. Value was defined as improvement in PROs (preoperatively to 1 year postoperatively) for patients, improvement in PROs per $1000 of bundle cost for payers, and the normalized sum of improvement in PROs and hospital bundle margin for providers. Bivariate analysis was used to compare high value vs low value (>50th percentile vs <50th percentile). Multivariate analysis was performed to identify predictors.

RESULTS

A total of 280 patients had PRO data, of which 71 had Medicare claims data. Diabetes (odds ratio [OR], 0.45; P = .02) predicted low value for patients; female gender (OR, 0.25), hypertension (OR, 0.17), pulmonary disease (OR, 0.12), and skilled nursing facility discharge (OR, 0.17) for payers (P ≤ .03 for all); and pulmonary disease (OR, 0.16) and skilled nursing facility discharge (OR, 0.19) for providers (P ≤ .04 for all).

CONCLUSION

This is the first article to define value in TJA under a bundle payment model from multiple perspectives, providing a foundation for future studies analyzing value-based TJA.

Influence of Diabetes Mellitus on the Recovery Trajectories of Function, Strength, and Self-Report Measures After Total Knee Arthroplasty

OBJECTIVE

As the proportion of individuals with diabetes mellitus (DM) in the aging population and the number of total knee arthroplasties (TKAs) both continue to grow, understanding the outcomes for these patient populations is critical. The purpose of this study was to determine whether patients with and without DM differed in the recovery of 3 physical performance measures during the first 90 days following a TKA.

METHODS

Data collected at ATI Physical Therapy from 169 patients (37 with DM, and 132 without) were available. Physical performance measures included the 4-meter walk test, the 30-second sit-to-stand test (30STS), and the timed-up-and-go test (TUG). A mixed-effects model was performed to determine differences in the rate of recovery and 90-day postoperative scores for all measures.

RESULTS

Both groups had similar baseline values for all measures. Patients with DM demonstrated a slower rate of recovery for the 4-meter walk test, and worse scores for the 4-meter walk test, 30STS, and TUG at the end of 90 days when accounting for significant covariates.

CONCLUSION

Our findings show a negative relationship between the presence of DM and the recovery trajectories of all physical performance measures. Clinicians should closely monitor patients with DM, knowing that they are at higher risk for sustained functional deficits and early complications.

Increased postoperative glucose variability is associated with adverse outcomes following orthopaedic surgery

Aims

The aim of this study was to examine the association between postoperative glycaemic variability and adverse outcomes following orthopaedic surgery.

Patients and Methods

This retrospective study analyzed data on 12 978 patients (1361 with two operations) who underwent orthopaedic surgery at a single institution between 2001 and 2017. Patients with a minimum of either two postoperative measurements of blood glucose levels per day, or more than three measurements overall, were included in the study. Glycaemic variability was assessed using a coefficient of variation (CV). The length of stay (LOS), in-hospital complications, and 90-day readmission and mortality rates were examined. Data were analyzed with linear and generalized linear mixed models for linear and binary outcomes, adjusting for various covariates.

Results

The cohort included 14 339 admissions, of which 3302 (23.0%) involved diabetic patients. Patients with CV values in the upper tertile were twice as likely to have an in-hospital complication compared with patients in the lowest tertile (19.4% versus 9.0%, p < 0.001), and almost five times more likely to die compared with those in the lowest tertile (2.8% versus 0.6%, p < 0.001). Results of the adjusted analyses indicated that the mean LOS was 1.28 days longer in the highest versus the lowest CV tertile (p < 0.001), and the odds of an in-hospital complication and 90-day mortality in the highest CV tertile were respectively 1.91 (p < 0.001) and 2.10 (p = 0.001) times larger than the odds of these events in the lowest CV tertile. These associations were significant even for non-diabetic patients. After adjusting for hypoglycaemia, the relationships remained significant, except that the CV tertile no longer predicted mortality in diabetics.

Conclusion

These results indicate that higher glycaemic variability is associated with longer LOS and in-hospital complications. Glycaemic variability also predicted death, although that primarily held for non-diabetic patients in the highest CV tertile following orthopaedic surgery. Prospective studies should examine whether ensuring low postoperative glycaemic variability may reduce complication rates and mortality. Cite this article: Bone Joint J 2018;100-B:1125–32.

Inadequate Glycemic Control Is Associated With Increased Surgical Site Infection in Total Joint Arthroplasty: A Systematic Review and Meta-Analysis

BACKGROUND

The association between inadequate glycemic control and surgical site infection (SSI) following total joint arthroplasty (TJA) remains unclear. The aim of this study is to assess the relationship between perioperative glycemic control and the risk for SSI, mainly periprosthetic joint infection.

METHODS

We searched OVID-MEDLINE, Embase, and Web of Science from inception up to June 2017. The main independent variable was glycemic control as defined by glycated hemoglobin (HbA1C) or perioperative glucose values. The main outcome was SSI. Publication year, location, study design, sample population (size, age, gender), procedure, glycemic control assessment, infection outcome, results, confounders, and limitations were assessed. Studies included in the meta-analysis had stratified glycemic control using a distinct HbA1C cut-off.

RESULTS

Seventeen studies were included in this study. Meta-analysis of 10 studies suggested that elevated HbA1C levels were associated with a higher risk of SSI after TJA (pooled odds ratio 1.49, 95% confidence interval 0.94-2.37, P = .09) with significant heterogeneity between studies (I² = 81.32%, P < .0001). In a subgroup analysis of studies considering HbA1C with a cut-off of 7% as uncontrolled, this association was no longer noticed (P = .50). All 5 studies that specifically assessed for SSI and perioperative hyperglycemia showed a significant association, which was usually attenuated after adjusting for covariates.

CONCLUSION

Inadequate glycemic control was associated with increased risk for SSI after TJA. However, the optimal HbA1C threshold remains contentious. Pooled data does not support the conventional 7% cut-off for risk stratification. Future studies should examine new markers for determining adequate glycemic control.

Serum Fructosamine: A Simple and Inexpensive Test for Assessing Preoperative Glycemic Control

BACKGROUND

Although the medical community acknowledges the importance of preoperative glycemic control, the literature is inconclusive and the proper metric for assessment of glycemic control remains unclear. Serum fructosamine reflects the mean glycemic control in a shorter time period compared with glycated hemoglobin (HbA1c). Our aim was to examine its role in predicting adverse outcomes following total joint arthroplasty.

METHODS

Between 2012 and 2013, we screened all patients undergoing total joint arthroplasty preoperatively using serum HbA1c, fructosamine, and blood glucose levels. On the basis of the recommendations of the American Diabetes Association, 7% was chosen as the cutoff for HbA1c being indicative of poor glycemic control. This threshold correlated with a fructosamine level of 292 μmol/L. All patients were followed and total joint arthroplasty complications were evaluated. We were particularly interested in retrieving details on surgical-site infection (superficial and deep). Patients with fructosamine levels of ≥292 μmol/L were compared with those with fructosamine levels of <292 μmol/L. Complications were evaluated in a univariate analysis followed by a stepwise logistic regression analysis.

RESULTS

A total of 829 patients undergoing primary total joint arthroplasty were included in the present study. There were 119 patients (14.4%) with a history of diabetes and 308 patients (37.2%) with HbA1c levels in the prediabetic range. Overall, 51 patients had fructosamine levels of ≥292 μmol/L. Twenty patients (39.2%) had a fructosamine level of ≥292 μmol/L but did not have an HbA1c level of ≥7%. Patients with fructosamine levels of ≥292 μmol/L had a significantly higher risk for deep infection (adjusted odds ratio [OR], 6.2 [95% confidence interval (CI), 1.6 to 24.0]; p = 0.009), readmission (adjusted OR, 3.0 [95% CI, 1.1 to 8.1]; p = 0.03), and reoperation (adjusted OR, 3.4 [95% CI, 1.2 to 9.2]; p = 0.02). In the current study with the given sample size, HbA1c levels of ≥7% failed to show any significant correlation with deep infection (p = 0.14), readmission (p = 1.0), or reoperation (p = 0.7).

CONCLUSIONS

Serum fructosamine is a simple and inexpensive test that appears to be a good predictor of adverse outcome in patients with known diabetes and those with unrecognized diabetes or hyperglycemia. Our findings suggest that fructosamine can serve as an alternative to HbA1c in the setting of preoperative glycemic assessment.

LEVEL OF EVIDENCE

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