Table 1.
Clinical and demographic characteristics of patients
| Primary TKA, na (%) unless specified otherwise | ||
|---|---|---|
| 2 years (n = 7, 139) | 5 years, (n = 4, 234) | |
| Men/women | 3, 162 (44.3%)/3, 977 (55.7%) | 1903 (44.9%)/2, 331 (55.1%) |
| Age, mean ± SD | 68.4 ± 10.0 | 68.4 ± 9.6 |
| Age groups, n (%): | ||
| ≤ 60 years | 1, 313 (18.4%) | 745 (17.6%) |
| > 60 to 70 years | 2, 531 (35.5%) | 1, 576 (37.2%) |
| > 70 to 80 years | 2, 734 (38.3%) | 1, 617 (38.2%) |
| > 80 years | 561 (7.9%) | 296 (7.0%) |
| Body mass index, kg/m2: | ||
| < 25 | 934 (13.1%) | 566 (13.4)% |
| 25 to 29.9 | 2, 479 (34.7%) | 1, 525 (36.0%) |
| 30 to 34.9 | 2, 092 (29.3%) | 1, 250 (29.5%) |
| 35 to 39.9 | 976 (13.7%) | 573 (13.5%) |
| ≥ 40 | 605 (8.5%) | 303 (7.2%) |
| ASA score: | ||
| Class I to II | 4, 115 (57.6%) | 2, 467 (58.3%) |
| Class III to IV | 3, 006 (42.1%) | 1, 741 (41.1%) |
| Deyo-Charlson Index, mean ± SD | 1.2 ± 1.9 | 1.1 ± 1.9 |
| Key Deyo-Charlson comorbidities: | ||
| Myocardial infarction | 341 (4.8%) | 202 (4.8%) |
| Peripheral vascular disease | 370 (5.2%) | 190 (4.5%) |
| Renal disease | 397 (5.6%) | 175 (4.1%) |
| Chronic obstructive pulmonary disease | 762 (10.7%) | 408 (9.6%) |
| Diabetes | 669 (9.4%) | 349 (8.2%) |
| Connective tissue disease | 520 (7.3%) | 352 (8.3%) |
| Anxiety | 465 (6.5%) | 220 (5.2%) |
| Depression | 741 (10.4%) | 334 (7.9%) |
| Distance from medical center: | ||
| 0 to 100 miles | 3, 669 (51.4%) | 2, 080 (49.1%) |
| > 100 to 500 miles | 2, 731 (38.3%) | 1, 653 (39.0%) |
| > 500 miles | 541 (7.6%) | 327 (7.7%) |
| Diagnosis: | ||
| Inflammatory arthritis | 256 (3.6%) | 189 (4.5%) |
| Osteoarthritis | 6, 710 (94.0%) | 3, 922 (92.6%) |
| Other | 172 (2.4%) | 123 (2.9%) |
aMissing values for 2-year cohort: 27 were missing body mass index (BMI), 18 were missing American Society of Anesthesiologists (ASA) class, 3 were missing Charlson Index scores, 198 were missing the distance variable, 1 was missing operative diagnosis. Missing values for 5-year cohort: 17 were missing BMI, 26 were missing ASA class, 174 were missing the distance variable, 23 were missing operative diagnosis.