Table 1. Demographic and Clinical Characteristics of Primary THA Cohort

TABLES

Table 1. Demographic and Clinical characteristics of Primary THA cohort

Primary THAs (# patients)
Mean ± standard deviation or n (%)
Pre-operative
(n=6,168) / 2-yr FU
(n = 5,707) / 5-yr FU
(n = 3,289)
Agea / 64 ± 14 / 65 ± 13 / 65 ± 13
% female / 3,175 (52%) / 2,929 (51%) / 1,540 (53%)
BMI (kg/m2) / 29 ± 6 / 29 ± 6 / 29 ± 6
Age groupsa
≤60 yrs / 2,026 (33%) / 1,730 (30%) / 987 (30%)
>60-70 yrs / 1,844 (30%) / 1,759 (31%) / 1,059 (32%)
>70-80 yrs / 1,799 (29%) / 1,721 (30%) / 1,032 (31%)
>80 yrs / 499 (8%) / 479 (9%) / 211 (6%)
BMI (kg/m2)
25 / 1,505 (24%) / 1,387 (24%) / 799 (24%)
25-29.9 / 2,356 (38%) / 2,224 (39%) / 1,307 (40%)
30-34.9 / 1,497 (24%) / 1,361 (24%) / 757 (23%)
35-39.9 / 506 (8%) / 479 (8%) / 270 (8%)
≥40 / 279 (5%) / 228 (4%) / 136 (4%)
ASA scorea
Class I / 359 (6%) / 288 (5%) / 173 (5%)
Class II / 3,468 (56%) / 3,252 (57%) / 1,923 (59%)
Class III / 2,256 (37%) / 2,097 (37%) / 1,158 (35%)
Class IV / 59 (1%) / 41 (1%) / 14 (1%)
Implant Fixation a
Cemented / 706 (11%) / 641 (11%) / 463 (14%)
Hybrid / 3,237 (53%) / 3,053 (54%) / 1,946 (59%)
Uncemented / 2,224 (36%) / 2,013 (35%) / 880 (27%)
Underlying Diagnosesb
Rheumatoid/ inflammatory arthritis / 162 (3%) / 148 (3%) / 98 (3%)
Osteoarthritis / 5,339 (87%) / 4,944 (87%) / 2,789 (85%)
Avascular necrosis / 456 (7%) / 409 (7%) / 256 (8%)
Other a / 211 (3%) / 206 (3%) / 146 (4%)
Deyo-Charlson Index / 1 ± 2 / 1 ± 2 / 1 ± 2
Depression / 429 (7%) / 409 (7%) / 211 (6%)
Anxiety / 279 (5%) / 265 (5%) / 139 (4%)

a p<0.05 ; all characteristics were assessed at the baseline preoperative time and the their distribution is shown for the cohorts who responded to the survey preoperatively and at 2-years and 5-years post-primary THA

bThe total number of patients was as follows:

(1)Preoperative: 162 RA, 5,339 OA, 456 AVN and 211 other diagnoses

(2)2-year: 148 RA, 4,944 OA, 409 AVN and 206 other diagnoses

(3)5-year: 98 RA, 2,789 OA, 256 AVN and 146 other diagnoses

Missing: (1) Preoperative cohort: BMI, (n=25); Implant fixation (n=1); ASA score (n=26)

(2) 2-year cohort: BMI, (n=28); ASA score (n=29);

(3) 5-year cohort: BMI, (n=20); ASA score (n=21); Deyo-Charlson index (n=2);

Table 1. Characteristics of patients with OA, RA, AVN and other diagnoses

Diagnosis (%) or mean (SD)
RA
(n=162) / OA
(n = 5,339) / AVN
(n = 456) / Other
(n=211)
Agea / 56 (17) / 65 (13) / 57 (17) / 50 (15)
% female / 65% / 51% / 49% / 66%
BMI (kg/m2) / 26 (5) / 29 (6) / 27 (6) / 27 (6)
Age groupsa
≤60 yrs / 45% / 29% / 52% / 72%
>60-70 yrs / 31% / 31% / 23% / 19%
>70-80 yrs / 23% / 31% / 19% / 9%
>80 yrs / 1% / 9% / 6% / 1%
BMI (kg/m2)
25 / 46% / 23% / 32% / 40%
25-29.9 / 33% / 39% / 41% / 31%
30-34.9 / 13% / 25% / 17% / 22%
35-39.9 / 6% / 9% / 5% / 5%
≥40 / 2% / 5% / 4% / 2%
ASA scorea
Class I / 5% / 5% / 8% / 15%
Class II / 46% / 57% / 49% / 55%
Class III / 49% / 36% / 42% / 28%
Class IV / 0% / 1% / 1% / 1%
Implant Fixation a
Cemented / 8% / 12% / 12% / 8%
Hybrid / 66% / 52% / 48% / 54%
Uncemented / 26% / 36% / 41% / 38%
Deyo-Charlson Index / 1 (1) / 1 (2) / 1 (2) / 1 (2)
Depression / 7% / 7% / 8% / 4%
Anxiety / 3% / 4% / 8% / 2%
Distance Category
0-100 miles / 43% / 48% / 38% / 36%
>100-500 miles / 47% / 41% / 49% / 50%
>500 miles or Non-US / 11% / 11% / 13% / 14%

Numbers rounded to the nearest digit

Table 2. Characteristics of Non-responders for primary THA

2-years / 5-years
Variable / Events for non-responders / Odds
Ratio (95% CI) / p-value / Events for non-responders / Odds
Ratio (95% CI) / p-value
Gender
Female / 1976/4736 (41.7%) / 1244/3281 (37.9%)
Male / 1847/4418 (41.8%) / 1.0 (0.9,1.1) / 0.94 / 1130/2962 (38.1%) / 1.0 (0.9,1.1) / 0.85
Age Category
< (60 / 1176/2988 (39.4%) / 737/2075 (35.5%)
61-70 / 1204/2676 (45%) / 1.3 (1.1,1.4) / <0.01 / 791/1893 (41.8%) / 1.3 (1.1,1.5) / <.01
71-80 / 1121/2706 (41.4%) / 1.1 (1.0,1.2) / 0.12 / 706/1841 (38.3%) / 1.1 (1.0,1.3) / 0.08
>80 / 322/784 (41.1%) / 1.1 (0.9,1.3) / 0.40 / 140/434 (32.3%) / 0.9 (0.7,1.1) / 0.20
BMI Category
<25 / 935/2221 (42.1%) / 571/1570 (36.4%)
25-29.9 / 1493/3477 (42.9%) / 1.0 (0.9,1.2) / 0.54 / 954/2393 (39.9%) / 1.2 (1.0,1.3) / 0.03
30-34.9 / 907/2209 (41.1%) / 1.0 (0.8,1.1) / 0.49 / 548/1479 (37.1%) / 1.0 (0.9,1.2) / 0.70
35-39.9 / 309/786 (39.3%) / 0.9 (0.8,1.1) / 0.19 / 187/515 (36.3%) / 1.0 (0.8,1.2) / 0.98
> (40 / 161/419 (38.4%) / 0.9 (0.7,1.1) / 0.17 / 102/259 (39.4%) / 1.1 (0.9,1.5) / 0.38
ASA Score
1-2 / 2410/5608 (43%) / 1539/3950 (39%)
3-4 / 1396/3509 (39.8%) / 0.9 (0.8,1.0) / <0.01 / 823/2261 (36.4%) / 0.9 (0.8,1.0) / 0.05
Charlson Index (5 point increase) / N/A / 0.8 (0.7,0.9) / N/A / 0.9 (0.7,1.0) / 0.05
Distance Category
0-100 miles / 1785/4145 (43.1%) / 1093/2743 (39.8%)
>100-500 miles / 1531/3695 (41.4%) / 0.9 (0.9,1.0) / 0.16 / 935/2520 (37.1%) / 0.9 (0.8,1.0) / 0.05
>500 miles or Non-US / 381/988 (38.6%) / 0.8 (0.7,1.0) / 0.01 / 220/675 (32.6%) / 0.7 (0.6,0.9) / 0.01
Operative Diagnosis
Inflammatory Arthritis / 94/251 (37.5%) / 71/205 (34.6%)
AVN / 257/687 (37.4%) / 1.0 (0.7,1.4) / 0.99 / 176/519 (33.9%) / 1.0 (0.7,1.4) / 0.86
Osteoarthritis / 3355/7825 (42.9%) / 1.3 (1.0,1.6) / 0.10 / 2030/5218 (38.9%) / 1.2 (0.9,1.6) / 0.23
Other / 117/391 (29.9%) / 0.7 (0.5,1.0) / 0.05 / 97/301 (32.2%) / 0.9 (0.6,1.3) / 0.59

Table 3. Univariateassociation of diagnosis with ADL limitation and pain at 2- and 5-years after Primary THA

Diagnosis
RA/ inflammatory
arthritis / OA / AVN / Other
Overall moderate-severe ADL limitation
2-year follow-up / 67/140 (47.9%) / 1384/4714 (29.4%) / 115/389 (29.6%) / 83/192 (43.2%)
p-value compared to RA group / <0.01 / <0.01 / 0.43
5-year follow-up / 45/97 (46.4%) / 911/2648 (34.4%) / 77/246 (31.3%) / 62/139 (44.6%)
p-value compared to RA group / 0.01 / 0.02 / 0.79
Moderate-severe hip pain
2-year follow-up / 7/142 (4.9%) / 355/4676 (7.6%) / 47/378 (12.4%) / 26/194 (13.4%)
p-value compared to RA group / 0.02 / 0.24 / 0.01
5-year follow-up / 7/93 (7.5%) / 270/2651 (10.2%) / 37/244 (15.2%) / 25/142 (17.6%)
p-value compared to RA group / 0.07 / 0.41 / 0.03

*Reference category is rheumatoid arthritis/inflammatory arthritis and p-values were obtained from univariate logistic regression models

Table 4.Multivariable-adjusted association of diagnosis with ADL limitation and pain at 2- and 5-yearsafter Primary THA

OA / AVN / Other
OR* [95% CI] / p-value / OR* [95% CI] / p-value / OR* [95% CI] / p-value
Moderate-severe Overall ADL limitationa
2-years / 0.5(0.3,0.8) / 0.01 / 0.4(0.2,0.8) / 0.01 / 1.0(0.5,1.9) / 0.91
5-years / 0.7(0.4,1.4) / 0.36 / 0.9(0.4,1.8) / 0.78 / 2.1(0.9,4.8) / 0.07
Moderate-severe hip painb
2-years / 1.6(0.6,4.5) / 0.40 / 2.8(0.9,8.5) / 0.06 / 2.2(0.6,7.3) / 0.22
5-years / 2.1(0.7,6.5) / 0.22 / 4.1(1.2,14.1) / 0.02 / 4.2(1.1,16.0) / 0.04

*Reference category is rheumatoid arthritis/inflammatory arthritis.

aAdjusted for 16 additional covariates/confounders: Age, gender, BMI, Deyo-Charlson comorbidity score, ASA class, distance from the medical center, cement fixation, preoperative limitation in 7 activities, anxiety and depression

bAdjusted for 10 additional covariates/confounders: Age, gender, BMI, Deyo-Charlson comorbidity score, ASA class, distance from the medical center, cement fixation, preoperative pain, anxiety and depression

Table 5. Univariate association of diagnosis with each ADL limitation at 2- and 5-years after primary THA

2-years / 5-years
n/N (%) / OR* / 95% CI / p-value / n/N (%) / OR* / 95% CI / p-value
Limitations in
Walking
RA* / 50/141 (35.5%) / 1.0 (ref) / 38/97 (39.2%) / 1.0 (ref)
Osteoarthritis / 1298/4815 (27%) / 0.7 / (0.5,1.0) / 0.04 / 927/2723 (34%) / 0.8 / (0.5,1.2) / 0.32
AVN / 113/397 (28.5%) / 0.7 / (0.5,1.1) / 0.15 / 74/250 (29.6%) / 0.7 / (0.4,1.1) / 0.10
Other / 70/201 (34.8%) / 1.0 / (0.6,1.6) / 0.91 / 51/145 (35.2%) / 0.8 / (0.5,1.5) / 0.55
Climbing Stair
RA / 53/144 (36.8%) / 1.0 (ref) / 38/98 (38.8%) / 1.0 (ref)
Osteoarthritis / 818/4873 (16.8%) / 0.3 / (0.2,0.5) / <0.01 / 562/2739 (20.5%) / 0.4 / (0.3,0.6) / <0.01
AVN / 77/397 (19.4%) / 0.4 / (0.3,0.6) / <0.01 / 48/250 (19.2%) / 0.4 / (0.2,0.6) / <0.01
Other / 55/202 (27.2%) / 0.6 / (0.4,1.0) / 0.07 / 43/145 (29.7%) / 0.7 / (0.4,1.2) / 0.15
Putting on Socks/Shoes
RA / 57/143 (39.9%) / 1.0 (ref) / 37/97 (38.1%) / 1.0 (ref)
Osteoarthritis / 1178/4867 (24.2%) / 0.5 / (0.3,0.7) / <0.01 / 725/2733 (26.5%) / 0.6 / (0.4,0.9) / 0.02
AVN / 85/400 (21.3%) / 0.4 / (0.3,0.6) / <0.01 / 68/253 (26.9%) / 0.6 / (0.4,1.0) / 0.05
Other / 74/201 (36.8%) / 0.9 / (0.6,1.4) / 0.59 / 54/144 (37.5%) / 1.0 / (0.6,1.7) / 0.92
Picking up Objects
RA / 55/145 (37.9%) / 1.0 (ref) / 40/98 (40.8%) / 1.0 (ref)
Osteoarthritis / 1153/4873 (23.7%) / 0.5 / (0.4,0.7) / <0.01 / 730/2735 (26.7%) / 0.5 / (0.3,0.8) / <0.01
AVN / 92/399 (23.1%) / 0.5 / (0.3,0.7) / <0.01 / 63/252 (25%) / 0.5 / (0.3,0.8) / <0.01
Other / 68/203 (33.5%) / 0.8 / (0.5,1.3) / 0.41 / 50/146 (34.2%) / 0.8 / (0.4,1.3) / 0.32
Getting In/Out Car
RA / 29/144 (20.1%) / 1.0 (ref) / 21/98 (21.4%) / 1.0 (ref)
Osteoarthritis / 703/4864 (14.5%) / 0.7 / (0.4,1.0) / 0.06 / 488/2745 (17.8%) / 0.8 / (0.5,1.3) / 0.39
AVN / 63/401 (15.7%) / 0.7 / (0.4,1.2) / 0.24 / 40/251 (15.9%) / 0.7 / (0.4,1.3) / 0.26
Other / 48/202 (23.8%) / 1.2 / (0.7,2.1) / 0.43 / 36/146 (24.7%) / 1.2 / (0.6,2.3) / 0.58
Rising from Chair
RA / 25/144 (17.4%) / 1.0 (ref) / 14/98 (14.3%) / 1.0 (ref)
Osteoarthritis / 353/4852 (7.3%) / 0.4 / (0.2,0.6) / <0.01 / 272/2727 (10%) / 0.7 / (0.4,1.2) / 0.17
AVN / 39/401 (9.7%) / 0.5 / (0.3,0.9) / 0.02 / 30/252 (11.9%) / 0.8 / (0.4,1.6) / 0.55
Other / 24/201 (11.9%) / 0.6 / (0.4,1.2) / 0.16 / 18/143 (12.6%) / 0.9 / (0.4,1.8) / 0.70
Sitting Limitations
RA / 1/143 (0.7%) / 1.0 (ref) / 1/97 (1%) / 1.0 (ref)
Osteoarthritis / 44/4850 (0.9%) / 1.3 / (0.2,9.5) / 0.8 / 26/2724 (1%) / 0.9 / (0.1,6.9) / 0.94
AVN / 9/396 (2.3%) / 3.3 / (0.4, 26.3) / 0.3 / 7/251 (2.8%) / 2.8 / (0.3,22.7) / 0.35
Other / 2/200 (1.0%) / 1.4 / (0.1, 16.0) / 0.8 / 3/144 (2.1%) / 2.0 / (0.2,20.0) / 0.54

*Reference category is rheumatoid arthritis/inflammatory arthritis.

--, not applicable, since these ADLs did not have a response for mild limitation category

Table 6.Multivariable-adjusted association of diagnosis with each ADL limitation at 2- and 5-years after primary THA

2-years / 5-years
OR* / 95% CI / p-value / OR* / 95% CI / p-value
Limitations in
Walkinga
Osteoarthritis / 0.7 / (0.4,1.2) / 0.21 / 0.8 / (0.4,1.5) / 0.43
AVN / 0.8 / (0.4,1.7) / 0.63 / 0.8 / (0.4,1.8) / 0.62
Other / 1.3 / (0.6,2.7) / 0.55 / 1.2 / (0.5,3.1) / 0.67
Climbing Stairsa
Osteoarthritis / 0.6 / (0.3,1.0) / 0.07 / 0.5 / (0.3,0.9) / 0.03
AVN / 0.5 / (0.3,1.1) / 0.07 / 0.5 / (0.2,1.0) / 0.049
Other / 1.0 / (0.5,2.1) / 0.95 / 0.9 / (0.4,2.2) / 0.80
Putting on Socks/Shoesa
Osteoarthritis / 0.7 / (0.4,1.1) / 0.12 / 0.7 / (0.4,1.3) / 0.27
AVN / 0.5 / (0.3,0.9) / 0.03 / 0.9 / (0.4,1.8) / 0.72
Other / 1.6 / (0.8,3.2) / 0.16 / 2.0 / (1.0,4.4) / 0.07
Picking up Objectsa
Osteoarthritis / 0.7 / (0.4,1.1) / 0.10 / 0.6 / (0.3,1.1) / 0.09
AVN / 0.6 / (0.3,1.1) / 0.08 / 0.8 / (0.4,1.6) / 0.50
Other / 1.1 / (0.6,2.3) / 0.73 / 1.5 / (0.7,3.3) / 0.30
Getting In/Out Cara
Osteoarthritis / 1.0 / (0.5,2.0) / 0.98 / 0.8 / (0.4,1.6) / 0.53
AVN / 0.9 / (0.4,2.0) / 0.78 / 0.9 / (0.4,2.1) / 0.84
Other / 1.1 / (0.4,2.9) / 0.80 / 1.5 / (0.6,3.7) / 0.36
Rising from Chaira
Osteoarthritis / 0.4 / (0.2,0.9) / 0.03 / 1.0 / (0.4,2.5) / 0.99
AVN / 0.4 / (0.2,0.9) / 0.04 / 1.3 / (0.4,3.8) / 0.66
Other / 0.7 / (0.3,2.2) / 0.59 / 1.4 / (0.4,4.9) / 0.56
Sittinga
Osteoarthritis / N/A / N/A
AVN
Other

*Reference category is rheumatoid arthritis/inflammatory arthritis.

N/A, Not applicable, since the model did not run for sitting.