Can extant comorbidity indices identify patients who experience poor outcomes following total joint arthroplasty?

INTRODUCTION: It is uncertain if generic comorbidity indices commonly used in orthopedics accurately predict outcomes after total hip (THA) or knee arthroplasty (TKA). The purpose of this study was to determine the predictive ability of such comorbidity indices for: (1) 30-day mortality; (2) 30-day rate of major and minor complications; (3) discharge disposition; and (4) extended length of stay (LOS). METHODS: The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was retrospectively reviewed for all patients who underwent elective THA (n = 202,488) or TKA (n = 230,823) from 2011 to 2019. The American Society of Anesthesiologists (ASA) physical status classification system score, modified Charlson Comorbidity Index (mCCI), Elixhauser Comorbidity Measure (ECM), and 5-Factor Modified Frailty Index (mFI-5) were calculated for each patient. Logistic regression models predicting 30-day mortality, discharge disposition, LOS greater than 1 day, and 30-day major and minor complications were fit for each index. RESULTS: The ASA classification (C-statistic = 0.773 for THA and TKA) and mCCI (THA: c-statistic = 0.781; TKA: C-statistic = 0.771) were good models for predicting 30-day mortality. However, ASA and mCCI were not predictive of major and minor complications, discharge disposition, or LOS. The ECM and mFI-5 did not reliably predict any outcomes of interest. CONCLUSION: ASA and mCCI are good models for predicting 30-day mortality after THA and TKA. However, similar to ECM and mFI-5, these generic comorbidity risk-assessment tools do not adequately predict 30-day postoperative outcomes or in-hospital metrics. This highlights the need for an updated, data-driven approach for standardized comorbidity reporting and risk assessment in arthroplasty.

Comorbidity indices in orthopaedic surgery: a narrative review focused on hip and knee arthroplasty.

Comorbidity indices currently used to estimate negative postoperative outcomes in orthopaedic surgery were originally developed among non-orthopaedic patient populations.While current indices were initially intended to predict short-term mortality, they have since been used for other purposes as well.As the rate of hip and knee arthroplasty steadily rises, understanding the magnitude of the effect of comorbid disease on postoperative outcomes has become increasingly more important.Currently, the ASA classification is the most commonly used comorbidity measure and is systematically recorded by the majority of national arthroplasty registries.Consideration should be given to developing an updated, standardized approach for comorbidity assessment and reporting in orthopaedic surgery, especially within the setting of elective hip and knee arthroplasty. Cite this article: EFORT Open Rev 2021;6:629-640. DOI: 10.1302/2058-5241.6.200124.

What Is the 30-Day Mortality Burden After Elective Total Hip Arthroplasty? An Analysis of 194,062 Patients.

BACKGROUND: This study aims to answer the following questions regarding elective total hip arthroplasty (THA): What is (1) the overall 30-day mortality rate; (2) the mortality rate when stratified by age, comorbidities, and preoperative diagnosis; and (3) the distribution of patient demographics, comorbidities, and preoperative diagnoses between the mortality and mortality-free cohorts? METHODS: The American College of Surgeons National Surgical Quality Improvement Program database was reviewed for all patients undergoing elective primary THA (2011-2018). A total of 194,062 patients were categorized based on the incidence of 30-day mortality (mortality: n = 206 vs mortality-free: n = 193,856). Patient demographics, comorbidities, and preoperative diagnosis (osteoarthritis [OA] vs non-OA) were recorded. Age category, American Society of Anesthesiologists (ASA) score, and modified Charlson Comorbidity Index (CCI) scores were normalized per 1000 and stratified by preoperative diagnosis. RESULTS: The 30-day mortality rate was 0.11%. The percentage of deaths per age group (normalized per 1000) was 0% (18-29 years), 0% (30-39 years), 0.049% (40-49 years), 0.052%(50-59 years), 0.071% (60-69 years), 0.133% (70-79 years), and 0.352% (80-89 years). The percentage of deaths per ASA score was 0% (ASA I), 0.035% (ASA II), 0.174% (ASA III), and 1.008% (ASA IV). The percentage of deaths per CCI score was 0.09% (CCI = 0), 0.23% (CCI = 1), 0.74% (CCI = 2), 3.21% (CCI = 3), 4.76% (CCI = 4), and 0.57% (CCI ≥ 5). Non-OA diagnoses were significantly more frequent in the mortality cohort (16.0% vs 7.6%; P < .001). CONCLUSION: The risk of mortality was highest in patients aged 80-89, patients of ASA class IV, patients with a CCI score of 4, and patients with a non-OA diagnosis. The overall rate of death was higher in the non-OA cohort compared to the OA cohort. LEVEL OF EVIDENCE: III.

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.

Perioperative Outcomes and Complications After Primary Total Hip Arthroplasty in Patients With Disproportionately Short Stature: A Matched Cohort Analysis.

BACKGROUND: This study compared (1) perioperative outcomes, (2) postoperative complications, and (3) reoperation rates after primary total hip arthroplasty (THA) between short stature patients and matched control patients. METHODS: A review of primary THA patients from 2012 to 2017 using an institutional database was conducted. This yielded 12,850 patients of which 108 were shorter than 148 cm. These patients were matched 1:1 by age (P = .527), gender (P = .664), and body mass index (P = .240) to controls. The final study population with minimum 1-year follow-up that was included for analysis comprised 47 patients in the short stature cohort and 57 patients in the control cohort. The following outcomes/complications were compared: operative times, lengths of stay (LOSs), intraoperative fractures, minor complications, 90-day readmissions, and revisions. RESULTS: Operative times were significantly longer in the short stature cohort than in the matched control cohort (133 ± 65 minutes vs 104 ± 30 minutes, P = .005). In addition, hospital LOS was slightly longer in the short stature group than in the matched control groups (3.2 ± 1.5 days vs 2.6 ± 1.0, P = .017). Rates of intraoperative fractures (P = 1.000), minor complications P = .406), 90-day readmissions (P = .5000), and revision (P = .202) were similar between the short stature and control cohorts. CONCLUSION: Patients with disproportionately short stature had longer operative times and slight longer LOS. However, complication and readmission rates were similar. Future studies with larger sample sizes are warranted to confirm these findings and further evaluate implant survivorship in this unique THA patient population.