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Race, Ethnicity & Income Predict Level of Disability at Time of Total Joint Replacement

Key findings

  • This study investigated whether people of color who eventually undergo total joint arthroplasty (TJA) do so with higher levels of disability than white patients do, as measured by scores on preoperative patient-reported outcome measures (PROMs)
  • The study subjects were 3,289 patients who underwent primary TJA (hip, n=1,508; knee, n=1,781), of whom 7% were people of color
  • Higher household income was associated with better scores on PROMIS Mental Health and joint-specific PROMs; white race was associated with better scores on PROMIS Mental Health scores and the Knee injury and Osteoarthritis Outcome Score
  • 42% of patients also completed PROMs seven to 18 months postoperatively; people of color were significantly less likely than white patients to achieve the minimal clinically important difference on the PROMIS Physical Function 10a questionnaire

Multiple U.S. studies have shown lower rates of total joint arthroplasty (TJA) among people of color in the U.S. compared with white individuals. This is true despite national initiatives aimed at combatting this inequity.

Patient-related factors such as lower health literacy may contribute to the differences, but unconscious biases held by providers can't be ignored. People of color have disproportionately higher complication rates and mortality after TJA than white patients do, and in today's cost-conscious, value-driven environment for arthroplasty, the prospect of those poorer outcomes may make surgeons less likely to offer TJA to patients of color.

Massachusetts General Hospital researchers speculated that as a result of the delay, people of color are likely to have a higher incidence of preoperative disability, compared with white individuals, if they do eventually have surgery. Evidence in support of that hypothesis is presented in The Journal of Arthroplasty by Christopher M. Melnic, MD, an orthopedic surgeon in the Hip and Knee Replacement Service, Hany S. Bedair, MD, chief of the service, and colleagues.


The team identified 3,289 patients who underwent primary TJA between January 2018 and March 2021 (hip, n=1,508; knee, n=1,781). People of color represented 7.1% of the cohort (3.53% Black, 2.04% Latino/a/x, 1.37% Asian, 0.09% American Indian and 0.06% Pacific Islander).

Patients were included only if they completed patient-reported outcome measures (PROMs) within six months before surgery.

Preoperative Disability

People of color demonstrated a significantly lower preoperative score on every PROM evaluated.

In multivariable analyses:

  • Patient-Reported Outcomes Measurement Information System (PROMIS) Mental Health—White race and higher income were associated with significantly better scores
  • PROMIS Physical Function 10a (PF-10a)—Race/ethnicity was not a significant predictor
  • Hip disability and Osteoarthritis Outcome Score (HOOS)—Race/ethnicity was not a significant predictor, but higher-income was significantly associated with better scores
  • Knee injury and Osteoarthritis Outcome Score (KOOS)—White race and higher income were associated with significantly higher scores

Male gender and older age also predicted better preoperative PROM scores, whereas higher American Society of Anesthesiologists score, body mass index, and Charlson Comorbidity Index correlated with worse PROM scores. Current smoking predicted worse scores and had the largest effect across all PROMs.

Achievement of Minimal Clinically Important Difference

1,371 patients (42%) also completed PROMs postoperatively. This allowed calculation of the minimal clinically important difference (MCID) on three PROMs seven to 18 months after TJA:

  • PROMIS PF-10a—White race but not higher income was associated with a significantly greater likelihood of achieving the MCID
  • HOOS and KOOS—Neither race/ethnicity nor income predicted the likelihood of achieving the MCID


These findings show people of color and people with lower incomes had a greater disability and greater loss of function by the time they were scheduled for primary TJA. Greater awareness by individual surgeons of the potential for these discrepancies is vital to rectifying inequalities in musculoskeletal care.

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Jeffrey J. Olson, MD, and Hany S. Bedair, MD, of the Department of Orthopaedic Surgery, and colleagues found that the odds of venous thromboembolism after total hip or knee replacement were 11 times higher in HIV-positive patients than in matched HIV-negative controls.


Researchers from the Center for Hip & Knee Replacement found that higher BMI increases the risk that a patient undergoing total knee arthroplasty will not notice meaningful improvement. The risk is particularly high for high-functioning patients who have relatively low preoperative pain.