Background
Methods
Data source and study population
Outcome of interest
Predictors of interest and covariates
Statistical analyses
IRB approval
Results
Primary TKA | Revision TKA | |||
---|---|---|---|---|
2-year (n = 7,139) | 5-year (n = 4,234) | 2-year (n = 1,533) | 5-year (n = 881) | |
Mean age (±standard deviation)
| 68 ± 10 | 68 ± 10 | 69 ± 10 | 69 ± 10 |
Men/Women (%)
| 44%/56% | 45%/55% | 49%/51% | 51%/49% |
Age groups (%)
| ||||
≤60 yrs
| 18% | 18% | 20% | 20% |
>60-70 yrs
| 35% | 37% | 29% | 31% |
>70-80 yrs
| 38% | 38% | 42% | 41% |
>80 yrs
| 8% | 7% | 9% | 8% |
Body mass index (%)
| ||||
<25 kg/m
2
| 13% | 13% | 13% | 14% |
25-29.9 kg/m
2
| 35% | 36% | 36% | 39% |
30-34.9 kg/m
2
| 29% | 43% | 29% | 27% |
35-39.9 kg/m
2
| 14% | 7% | 14% | 14% |
≥40 kg/m
2
| 9% | 7% | 7% | 5% |
American Society of Anesthesiologists (ASA) cass
| ||||
Class I-II
| 58% | 58% | 50% | 53% |
Class III-IV
| 42% | 41% | 50% | 47% |
Deyo-Charlson index, mean (±standard deviation)
| 1.2 ± 1.9 | 1.1 ± 1.9 | 1.0 ± 1.7 | 1.0 ± 1.4 |
Deyo-Charlson comorbidities (%)
| ||||
Myocardial infarction
| 5% | 5% | 4% | 4% |
Congestive heart failure
| 4% | 3% | 4% | 2% |
Peripheral vascular disease
| 5% | 4% | 3% | 2% |
Cerebrovascular disease
| 7% | 7% | 7% | 6% |
Dementia
| 0.2% | 0.1% | 0.2% | 0.1% |
Chronic Obstructive Pulmonary Disease (COPD)
| 11% | 10% | 9% | 9% |
Ulcer disease
| 8% | 9% | 7% | 7% |
Mild liver disease
| 2% | 2% | 1% | 2% |
Diabetes
| 9% | 8% | 10% | 7% |
Diabetes with organ damage
| 2% | 2% | 2% | 2% |
Hemiplegia
| 0.3% | 0.2% | 0.4% | 0.3% |
Moderate/severe renal disease
| 6% | 4% | 4% | 2% |
Moderate/severe liver disease
| 0.4% | 0.2% | 0.5% | 0.5% |
Metastatic solid tumor
| 3% | 3% | 1% | 1% |
AIDS
| 0% | 0% | 0.1% | 0.1% |
Rheumatologic disease
| 7% | 8% | 8% | 8% |
Other cancer
| 14% | 13% | 10% | 7% |
Psychological comorbidity (%)
| ||||
Anxiety
| 6% | 5% | 5% | 3% |
Depression
| 11% | 8% | 8% | 5% |
Distance from medical center
| ||||
<100 miles
| 53% | 51% | 32% | 34% |
100-500 miles
| 39% | 41% | 57% | 54% |
>500 miles
| 8% | 8% | 11% | 12% |
Implant fixation (cement status)
| ||||
Uncemented
| 98% | 99.7% | 0% | 0% |
Cemented/hybrid
| 2% | 0.3% | 100% | 100% |
Operative diagnosis
| ||||
Osteoarthritis
| 94% | 93% | ||
Rheumatoid arthritis
| 4% | 4% | ||
Loosening/wear/osteolysis
| 57% | 61% | ||
Dislocation/fracture/instability/non-union
| 22% | 20% | ||
Failed prior arthroplasty with components removed/infection
| 21% | 19% | ||
Other
| 2% | 3% |
2-yr primary TKA | 5-yr primary TKA | 2-yr revision TKA | 5-yr revision TKA | |||||
---|---|---|---|---|---|---|---|---|
Events for non-responders (3818/ 10957) | OR (95%)) CI) | Events for non-responders (3170/7404) | OR (95%)) CI) | Events for non-responders (1162/2695) | OR (95%)) CI) | Events for non-responders (961/1842) | OR (95%)) CI) | |
Gender
| ||||||||
Women | 2184/6161 (35.4%) | 1860/4191 (44.4%) | 621/1402 (44.3%) | 509/944 (53.9%) | ||||
Men | 1634/4796 (34.1%) | 0.94 (0.86,1.03) | 1310/3213 (40.8%) |
0.86
‡
(0.78,0.96)
| 541/1293 (41.8%) | 1.10 (0.94, 1.29) | 452/898 (50.3%) | 0.87 (0.72,1.05) |
Age groups n (%)
| ||||||||
≤60 yrs | 841/2154 (39%) | 728/1473 (49.4%) | 283/587 (48.2%) | 241/413 (58.4%) | ||||
>60-70 yrs | 1273/3804 (33.5%) |
0.79
‡
(0.69,0.89)
| 1065/2641 (40.3%) |
0.69
‡
(0.60,0.80)
| 365/816 (44.7%) | 0.87 (0.70,1.08) | 281/555 (50.6%) |
0.73* (0.56,0.96)
|
>70-80 yrs | 1387/4121 (33.7%) |
0.79
‡
(0.70,0.89)
| 1142/2759 (41.4%) |
0.72
‡
(0.63,0.83)
| 391/1034 (37.8%) | 0.65‡ (0.53,0.81) | 350/714 (49%) |
0.69
‡
(0.53,0.89)
|
>80 yrs | 317/878 (36.1%) | 0.88 (0.74,1.05) | 235/531 (44.3%) | 0.81 (0.65,1.01) | 123/258 (47.7%) | 0.98 (0.72,1.32) | 89/160 (55.6%) | 0.89 (0.61,1.31) |
BMI Categorized
| ||||||||
≤24.9 | 514/1474 (34.9%) | 452/1018 (44.4%) | 172/375 (45.9%) | 136/258 (52.7%) | ||||
25-29.9 | 1287/3766 (34.2%) | 0.97 (0.84,1.11) | 1061/2586 (41%) | 0.87 (0.74,1.02) | 375/925 (40.5%) | 0.80 (0.63,1.03) | 310/655 (47.3%) | 0.81 (0.60,1.09) |
30-39.9 | 1644/4712 (34.9%) | 1.00 (0.87,1.15) | 1346/3169 (42.5%) | 0.92 (0.79,1.08) | 485/1149 (42.2%) | 0.86 (0.68,1.09) | 423/784 (54%) | 1.05 (0.79,1.41) |
≥40 | 355/960 (37%) | 1.10 (0.91,1.32) | 299/602 (49.7%) | 1.24 (0.99,1.55) | 123/229 (53.7%) | 1.37 (0.98,1.91) | 89/136 (65.4%) |
1.70* (1.09,2.66)
|
ASA
| ||||||||
1-2 | 2021/6136 (32.9%) | 1771/4238 (41.8%) | 505/1270 (39.8%) | 432/899 (48.1%) | ||||
3-4 | 1772/4778 (37.1%) |
1.20
‡
(1.10,1.31)
| 1388/3129 (44.4%) |
1.11* (1.00,1.23)
| 651/1414 (46%) |
1.29
‡
(1.10,1.51)
| 523/933 (56.1%) |
1.38
‡
(1.15,1.66)
|
Deyo-Charlson index (5 point increase)
|
1.30
‡
(1.17,1.44)
| 1.07 (0.93,1.22) | 1.16 (0.93,1.44) |
1.63
‡
(1.21,2.20)
| ||||
Income
| ||||||||
>$45 K | 1035/3099 (33.4%) | 720/1665 (43.2%) | 236/548 (43.1%) | 163/304 (53.6%) | ||||
≤$35 K | 699/2098 (33.3%) | 1.00 (0.87,1.14) | 736/1841 (40%) | 0.87 (0.75,1.02) | 254/595 (42.7%) | 1.98 (0.77,1.25) | 243/488 (49.8%) | 0.86 (0.64, 1.15) |
>$35 K-$45 K | 1347/4044 (33.3%) | 1.00 (0.89,1.11) | 1058/2541 (41.6%) | 0.94 (0.82,1.07) | 450/1050 (42.9%) | 0.99 (0.80,1.23) | 363/677 (53.6%) | 1.00 (0.76,1.32) |
Distance
| ||||||||
0-100 miles | 1785/5454 (32.7%) | 1443/3523 (41%) | 390/865 (45.1%) | 284/571 (49.7%) | ||||
>100-500 miles | 1435/4166 (34.4%) | 1.08 (0.98,1.19) | 1218/2871 (42.4%) | 1.06 (0.95,1.19) | 602/1449 (41.5%) | 0.87 (0.72,1.03) | 535/993 (53.9%) | 1.18 (0.95, 1.46) |
>500 miles or Non-US | 476/1017 (46.8%) |
1.81
‡
(1.55,2.11)
| 382/709 (53.9%) |
1.68
‡
(1.40,2.03)
| 129/293 (44%) | 0.96 (0.73,1.27) | 103/200 (51.5%) | 1.07 (0.77, 1.50) |
Underlying diagnoses
| ||||||||
Inflammatory arthritis | 172/428 (40.2%) | 155/344 (45.1%) | ||||||
Osteoarthritis | 3480/10190(34.2%) |
0.77* (0.62,0.97)
| 2872/6794 (42.3%) | 0.89 (0.70,1.14) | ||||
Other | 166/338 (49.1%) |
1.44* (1.05,1.96)
| 143/266 (53.8%) |
1.42* (1.00,2.01)
| ||||
Loosening/wear or osteolysis | 584/1453 (40.2%) | 475/1015 (46.8%) | ||||||
Dislocation, bone or prosthesis fracture, instability, non-union | 254/597 (42.5%) | 1.10 (0.91,1.34) | 216/393 (55%) |
1.39
‡
(1.10,1.76)
| ||||
Failed prior arthroplasty with components removed or infection | 324/645 (50.2%) | 1.50‡ (1.24,1.82) | 270/434 (62.2%) |
1.87
‡
(1.48,2.36)
|
Depression, anxiety and Improvement in Knee Function after Primary TKA
2-year | 5-year | ||||||
---|---|---|---|---|---|---|---|
Variable | Overall knee statusa
| Overall knee status n/N (%) | Odds ratio (95% CI) | p-value | Overall knee status n/N (%) | Odds ratio (95% CI) | p-value |
Deyo-Charlsonb
| Better | Not applicable | 1.0 (0.7, 1.6) | 0.88 | Not applicable | 1.1 (0.7, 1.6) | 0.72 |
Deyo-Charlsonb
| Much better | Not applicable | 0.7 (0.5, 1.1) | 0.10 | Not applicable | 0.8 (0.6, 1.1) | 0.14 |
Anxiety: No | Better | 299/3,115 = 9.6% | 1.0 | 481/5076 = 9.5% | 1.0 | ||
Yes | Better | 24/163 = 14.7% | 1.1 (0.5, 2.2) | 0.87 | 40/351 = 11.4% | 1.0 (0.5, 1.8) | 0.94 |
Anxiety: No | Much better | 2657/3,115 = 85.3% | 1.0 | 4407/5076 = 86.8% | 1.0 | ||
Yes | Much better | 127/163 = 77.9% | 0.6 (0.3, 1.2) | 0.14 | 295/351 = 84.0% | 0.8 (0.5, 1.3) | 0.37 |
Depression: No | Better | 290/3,008 = 9.6% | 1.0 | 450/4851 = 9.3% | 1.0 | ||
Yes | Better | 33/270 = 12.2% | 0.7 (0.4, 1.2) | 0.15 | 71/576 = 12.3% | 1.1 (0.7, 1.8) | 0.62 |
Depression: No | Much better | 2572/3,008 = 85.5% | 1.0 | 4222/4851 = 87.0% | 1.0 | ||
Yes | Much better | 212/270 = 78.5% |
0.5 (0.3, 0.8)
|
<0.01
| 480/576 = 83.3% | 0.8 (0.5, 1.3) | 0.35 |
Overall knee status at 2 years | p-value | Overall knee status at 5 years | p-value | ||
---|---|---|---|---|---|
Odds ratio (95% CI) | Odds ratio (95% CI) | ||||
Primary TKA
| |||||
Deyo-Charlson index (5-point increase) | |||||
Better | 1.0 (0.6 to 1.7) | 0.90 | 1.0 (0.6 to 1.5) | 0.94 | |
Much better | 0.9 (0.6 to 1.3) | 0.47 | 0.8 (0.6 to 1.2) | 0.25 | |
Anxiety | |||||
Better | 1.3 (0.6 to 2.8) | 0.58 | 0.9 (0.5 to 1.8) | 0.83 | |
Much better | 0.9 (0.4 to 1.8) | 0.71 | 0.8 (0.5 to 1.5) | 0.50 | |
Depression | |||||
Better | 0.6 (0.3 to 1.2) | 0.17 | 1.1 (0.7 to 2.0) | 0.61 | |
Much better |
0.5 (0.3 to 0.9)
|
0.02
| 0.9 (0.5 to 1.4) | 0.55 | |
Revision TKA
| |||||
Deyo-Charlson index (5-point increase) | |||||
Better | 1.5 (0.8 to 2.7) | 0.21 | 0.4 (0.2 to 1.1) | 0.07 | |
Much better | 1.2 (0.7 to 2.1) | 0.48 |
0.5 (0.2 to 1.0)
|
0.05
| |
Anxiety | |||||
Better | 1.3 (0.5 to 3.3) | 0.60 | 1.8 (0.4 to 8.0) | 0.45 | |
Much better | 0.9 (0.4 to 2.0) | 0.75 | 0.6 (0.1 to 2.9) | 0.56 | |
Depression | |||||
Better | 1.0 (0.5 to 2.0) | 0.98 | 1.1 (0.4 to 3.2) | 0.86 | |
Much better | 0.6 (0.4 to 1.2) | 0.17 | 0.5 (0.2 to 1.4) | 0.21 |
Depression, anxiety and improvement in knee function after revision TKA
2-year | 5-year | ||||||
---|---|---|---|---|---|---|---|
Variable | Overall knee status categorya
| Overall knee status n/N (%) | Odds ratio (95% CI) | p-value | Overall knee status n/N (%) | Odds ratio (95%) CI) | p-value |
Deyo-Charlson indexb
| Better | Not applicable | 1.4 (0.8, 2.4) | 0.24 | Not applicable | 0.5 (0.2, 1.1) | 0.08 |
Deyo-Charlson indexb
| Much better | Not applicable | 1.2 (0.7, 1.9) | 0.50 | Not applicable | 0.6 (0.3, 1.2) | 0.13 |
Anxiety: No | Better | 241/1,257 = 19.2% | 1.0 | 151/727 = 20.8% | 1.0 | ||
Yes | Better | 18/58 = 31.0% | 1.6 (0.7, 3.6) | 0.28 | 8/18 = 44.4% | 2.0 (0.5, 7.6) | 0.33 |
Anxiety: No | Much better | 827/1,257 = 65.8% | 1.0 | 465/727 = 64.0% | 1.0 | ||
Yes | Much better | 31/58 = 53.4% | 0.8 (0.4, 1.7) | 0.54 | 7/18 = 38.9% | 0.6 (0.1, 2.2) | 0.40 |
Depression: No | Better | 231/1,212 = 19.1% | 1.0 | 147/707 = 20.8% | 1.0 | ||
Yes | Better | 28/103 = 27.2% | 1.1 (0.6, 2.1) | 0.67 | 12/38 = 31.6% | 1.0 (0.4, 2.3) | 0.91 |
Depression: No | Much better | 802/1,212 = 66.2% | 455/707 = 64.4% | 1.0 | |||
Yes | Much better | 56/103 = 54.4% | 0.7 (0.4, 1.1) | 0.13 | 17/38 = 44.7% |
0.4 (0.2, 1.0)
|
0.05
|