Differences in radiographic features of knee osteoarthritis in African-Americans and Caucasians: the Johnston County Osteoarthritis Project

Abstract

Summary Objective To examine racial differences in tibiofemoral joint (TFJ) and patellofemoral joint (PFJ) radiographic osteoarthritis in African-American (AA) and Caucasian men and women. Method Multiple logistic regression was used to evaluate cross-sectional associations between race and tibiofemoral osteoarthritis (TF-OA) and the presence, severity and location of individual radiographic features of tibiofemoral joint osteoarthritis [TFJ-OA] (osteophytes, joint space narrowing [JSN], sclerosis and cysts) and patellofemoral joint osteoarthritis (PFJ-OA) (osteophytes, JSN and sclerosis), using data from the Johnston County Osteoarthritis Project. Proportional odds ratios (POR) assessed severity of TF-OA, TFJ and PFJ osteophytes, and JSN, adjusting for confounders. Generalized estimating equations accounted for auto-correlation of knees. Results Among 3187 participants (32.5% AAs; 62% women; mean age 62 years), 6300 TFJ and 1957 PFJ were included. Compared to Caucasians, AA men were more likely to have TF-OA (adjusted odds ratio [aOR] = 1.36; 95% CI, 1.00–1.86); tri-compartmental TFJ and PFJ osteophytes (aOR = 3.06; 95%CI = 1.96–4.78), and TFJ and PFJ sclerosis. AA women were more likely than Caucasian to have medial TFJ and tri-compartmental osteophytes (aOR = 2.13; 1.55–2.94), and lateral TFJ sclerosis. AAs had more severe TF-OA than Caucasians (adjusted cumulative odds ratio [aPOR] = 2.08; 95% CI, 1.19–3.64 for men; aPOR = 1.56; 95% CI, 1.06–2.29 for women) and were more likely to have lateral TFJ JSN. Conclusions Compared to Caucasians, AAs were more likely to have more severe TF-OA; tri-compartmental disease; and lateral JSN. Further research to clarify the discrepancy between radiographic features in OA among races appears warranted.

Racial Differences in Knee Osteoarthritis Pain: Potential Contribution of Occupational and Household Tasks

“…These results suggest that among adults with knee OA who are still working, greater exposure to lower extremity joint loading is an important contributor to racial differences in pain severity. While occupational tasks performed at the longest job were not substantial contributors to racial differences in current pain severity, these results do not rule out the possibility that lifetime occupational exposures contribute to racial differences in radiographic knee OA prevalence or severity, as previously reported 11,19 . However, these previous, more longterm occupational exposures do not appear to be a major factor in explaining racial differences in current pain severity.…”

Longitudinal analysis of cartilage T2 relaxation times and joint degeneration in African American and Caucasian American women over an observation period of 6 years – data from the Osteoarthritis Initiative

“…Analyzing the distribution of degeneration according to medial and lateral disease we did not find a significant discrepancy between the ethnic groups. Particularly we did not find a predominance of lateral disease in African American knees as described in Braga et al 23 who analyzed knee X-rays of more than 3187 participants of the Johnston County osteoarthritis project. The reason for this may be that we included only subjects with no or doubtful signs of radiographic knee OA.…”

Position statement: the epidemiology, pathogenesis and risk factors of osteoarthritis of the knee

“…The pattern of OA is also different with African-Americans tending to have more tri-compartmental disease and more severe radiographic changes in the tibiofemoral joint, and lateral joint space narrowing 20. Suggested reasons include differences in genetics, obesity, bone mineral density, occupational physical demands, diet and other lifestyle factors 20…”