Table 1.
Patients, procedures, implants, and surgeon and hospital characteristics, listed according to bearing surface
| Total cohort | CoCr-HXLPE | CoCr-CPE | OZ-CPE | ||
|---|---|---|---|---|---|
| (n = 62,177) | (n = 7,618) | (n = 49,055) | (n = 1,066) | p-value | |
| n (%) | n (%) | n (%) | n (%) | ||
| Patient characteristics | |||||
| Female a | 38,828 (62.4) | 4,692 (61.6) | 30,864 (62.9) | 608 (57.0) | < 0.001 |
| Mean age (SD), years a | 67.5 (9.3) | 65.7 (9.4) | 67.8 (9.2) | 59.7 (8.4) | < 0.001 |
| ASA score | |||||
| 1 or 2 | 37,090 (59.7) | 4,536 (59.5) | 29,196 (59.5) | 656 (61.5) | 0.002 |
| > 3 | 23,593 (37.9) | 2,719 (35.7) | 18,910 (38.5) | 373 (35) | |
| Unknown | 1494 (2.4) | 363 (4.8) | 949 (1.9) | 37 (3.5) | |
| BMI, kg/m2 | |||||
| < 30 | 2,6314 (42.3) | 2,882 (37.8) | 21,028 (42.9) | 339 (31.8) | < 0.001 |
| 30–35 | 18,066 (29.1) | 2,251 (29.5) | 14,191 (28.9) | 323 (30.3) | |
| ≥ 35 | 16,597 (26.7) | 2,396 (31.5) | 12,840 (26.2) | 385 (36.1) | |
| Unknown | 1,200 (1.9) | 89 (1.2) | 996 (2.0) | 19 (1.8) | |
| Race | |||||
| Asian | 3,034 (4.9) | 274 (3.6) | 2,563 (5.2) | 28 (2.6) | < 0.001 |
| Black | 4,868 (7.8) | 783 (10.3) | 3,718 (7.6) | 153 (14.4) | |
| White | 41,640 (67) | 5,217 (68.5) | 32,483 (66.2) | 646 (60.6) | |
| Hispanic | 7,633 (12.3) | 843 (11.1) | 6,187 (12.6) | 134 (12.6) | |
| Other b | 1,282 (2.1) | 148 (1.9) | 1,057 (2.2) | 12 (1.1) | |
| Unknown | 3,720 (6.0) | 353 (4.6) | 3,047 (6.2) | 93 (8.7) | |
| Diabetes | 16,465 (26.5) | 2,036 (26.7) | 13,012 (26.5) | 275 (25.8) | 0.8 |
| Procedure/implant characteristics | |||||
| Bilateral | 5,311 (8.5) | 510 (6.7) | 42,74 (8.7) | 113 (10.6) | < 0.001 |
| Mean operative time (SD), min a | 95.1 (32.5) | 96.8 (31.7) | 95 (32.6) | 105 (36.8) | < 0.001 |
| Implant fixation | |||||
| Uncemented | 1,874 (3.0) | 207 (2.7) | 969 (2.0) | 3 (0.3) | < 0.001 |
| Hybrid | 3,137 (5.0) | 570 (7.5) | 2,447 (5.0) | 8 (0.8) | |
| Cemented | 53,379 (85.9) | 6,263 (82.2) | 42,785 (87.2) | 989 (92.8) | |
| Unknown | 3787 (6.1) | 578 (7.6) | 2854 (5.8) | 66 (6.2) | |
| Mobility and stability | |||||
| Fixed: Cruciate retaining | 15,811 (25.4) | 3,922 (51.5) | 10,736 (21.9) | 404 (37.9) | < 0.001 |
| Fixed: Posterior stabilized | 38,516 (61.9) | 3,695 (48.5) | 31,377 (64.0) | 662 (62.1) | |
| Rotate: Cruciate retaining | 858 (1.4) | 0 (0.0) | 856 (1.7) | 0 (0.0) | |
| Rotate: Low contact stress | 1,040 (1.7) | 0 (0.0) | 1,020 (2.1) | 0 (0.0) | |
| Rotate: Posterior stabilized | 5,096 (8.2) | 0 (0.0) | 5,063 (10.3) | 0 (0.0) | |
| Unknown | 856 (1.4) | 1 (0.0) | 3 (0.0) | 0 (0.0) | |
| High flexion | 7,583 (12.2) | 3,363 (44.1) | 3,659 (7.5) | 443 (41.6) | < 0.001 |
| Surgeon/hospital characteristics | |||||
| Joint arthroplasty fellowship training a | 21,551 (34.7) | 2,404 (31.6) | 17,254 (35.2) | 430 (40.3) | < 0.001 |
| Surgeon volume, cases/year a | |||||
| < 10 | 1,092 (1.8) | 184 (2.4) | 791 (1.6) | 35 (3.3) | < 0.001 |
| 10–49 | 26,447 (42.5) | 3,231 (42.4) | 21,040 (42.9) | 516 (48.4) | |
| ≥ 50 | 34,638 (55.7) | 4,203 (55.2) | 27,224 (55.5) | 515 (48.3) | |
| No. of cases performed by surgeon, median (IQR) | 95 (33–205) | 39 (13–98) | 117 (48–235) | 14 (5–40) | < 0.001 |
| Hospital volume, cases/year a | |||||
| < 99 | 2,022 (3.3) | 438 (5.7) | 1442 (2.9) | 63 (5.9) | < 0.001 |
| 100–199 | 11,443 (18.4) | 1,082 (14.2) | 9,604 (19.6) | 264 (24.8) | |
| ≥ 200 | 48,712 (78.3) | 6,098 (80) | 38,009 (77.5) | 739 (69.3) |
a Missing data: sex < 0.1%, age < 0.1%, operative time 17.7%, fellowship training 0.1%.
b Includes native American, multi-race, and other.
ASA: American Society of Anaesthesiologists score; BMI: body mass index; HXLPE: highly crosslinked polyethylene;
CoCr: cobalt-chromium; CPE: conventional polyethylene; OZ: oxidized zirconium.