Table 2 Characteristics of AVN in SLE patients

Age at AVN, Median (25%, 75%IQR)

31.00 (27.19, 40.27)

Multiple locations, N (%)

58^a (82.1%)

Locations of AVN, N (%)

 Femoral head, N (%)

29^b (87.8%)

  Bilateral femoral heads, N (%)

20^b (60.6%)

 Knee joint, N (%)

9^b (27.3%)

  Bilateral knee joints, N (%)

4^b (12.1%)

Diagnostic tools

 MRI, N (%)

23^b (69.7%)

 CT only, N (%)

2^b (6.1%)

 X-ray only, N (%)

5^b (15.2%)

Femoral head replacement, N (%)

6^b (18.2%)