Table I.
Un-matched patient factors and demographic information
| Variables | Controls | SLE | p-value |
|---|---|---|---|
| Number of surgeries | 503,557 | 2,284 | |
| Age, years, mean (sd) | 65.73(10.94) | 58.85(12.94) | <0.0001 |
| Sex, %(N) | <0.0001 | ||
| Male | 39.53(198,715) | 9.64(220) | |
| Female | 60.47(303,947) | 90.36(2,063) | |
| Race, %(N) | <0.0001 | ||
| White | 84.68(367,999) | 68.70(1,385) | |
| Black | 7.27(31,589) | 21.83(440) | |
| Hispanic | 4.47(19,419) | 5.26(106) | |
| Other | 3.58(15,579) | 4.22(85) | |
| Corticosteroid, %(N) | 0.72(3,612) | 12.00(274) | <0.0001 |
| Osteonecrosis of the hip, %(N) | 2.93(14,769) | 15.81(361) | <0.0001 |
| Spasm of muscle, %(N) | 0.18(888) | 0.44(10) | 0.0031 |
| Gait abnormality, %(N) | 0.58(2,928) | 0.66(15) | 0.6369 |
| Contracture of joint, pelvic region and thigh, %(N) | 0.14(726) | 0.09(2) | 0.7782 |
| Hospital region, %(N) | <0.0001 | ||
| South | 35.60(179,277) | 44.22(1,010) | |
| Northeast | 18.16(91,427) | 15.89(363) | |
| Midwest | 26.36(132,746) | 22.42(512) | |
| West | 19.88(100,107) | 17.47(399) | |
| Vitamin D deficiency, %(N) | 0.88(4,410) | 1.66(38) | <0.0001 |
| Surgery Type, %(N) | <0.0001 | ||
| THA | 31.70(159,624) | 36.56(835) | |
| TKA | 68.30(343,933) | 63.44(1,449) | |
| Charlson comorbidity index, mean(sd) | 0.63(0.95) | 1.61(0.91) | <0.0001 |