Aim:
Many studies have examined the role of total hip replacement (THR) in elderly and young patients by analysing the risks of medical complications (pneumonia, pulmonary emboli, myocardial infarct, etc.), extended hospital stays, poor functional outcomes, or increased pain. Yet, many of these studies have struggled to demonstrate the effects of older age on surgical outcomes after total hip replacement (THR) in patients with rheumatoid arthritis (RA).
Methods:
Using a state-wide hospital-based (public or private) administrative database of rheumatic disease patients, in Western Australia, between 1980 – 2015, we identified patients with a diagnosis of RA who underwent THR. Next, we analysed the effects of age (<50, 50-60, 60-70,70-80, 80-90, 90-100, and 100+) on the incidence and survival of complications (infection, periprosthetic fracture, loosening, revision, and dislocation).
Results:
1572 RA patients received THR, 88% (n=1381) were over the age of 50, and 14% (n=215) were over the age of 80. After controlling for comorbidities, using a rheumatic disease version of the Charlson Comorbidity Index, age-reduced 5-year periprosthetic fracture-free survival (HR 1.02, 95% CI 1.01-1.03) and increased 5-year dislocation free survival (HR 0.99, 95% CI 0.97-1.01), but did not affect 5-year revision, infection, or loosening rates (p> 0.05). See table 1.
Conclusion:
Ageing does not increase the risk of infection, revision, loosening, or dislocation post-THR, suggesting that older RA patients can still have good long-term surgical outcomes after THR. This highlights the importance of not using age as a contraindication for THR.
Table 1: Incidence of complications vs age at THR
|
|
<50 IR, N |
50-60 IR, N, RR (95% CI) |
60-70 IR, N, RR (95% CI) |
70-80 IR, N, RR (95% CI) |
80-90 IR, N, RR (95% CI) |
p value |
|
Infection |
4.71%, 9 |
3.85%, 10, 0.82(0-1.7) |
5.46%, 23, 1.42(0.69-2.15) |
2.69%, 13, 0.49(0-1.16) |
3.55%, 7, 1.32(0.42-2.23) |
0.620 |
|
Periprosthetic fracture |
3.66%, 7 |
5.77%, 15, 1.57(0.7-2.45) |
7.6%, 32, 1.32(0.72-1.91) |
7.44%, 36, 0.98(0.52-1.44) |
8.12%, 16, 1.09(0.53-1.66) |
0.296 |
|
Loosening |
12.57%, 24 |
13.08%, 34, 1.04(0.55-1.53) |
11.16%, 47, 0.85(0.44-1.27) |
8.88%, 43, 0.8(0.4-1.19) |
6.6%, 13, 0.74(0.14-1.34) |
0.082 |
|
Revision |
5.76%, 11 |
6.15%, 16, 1.07(0.32-1.81) |
6.41%, 27, 1.04(0.44-1.64) |
3.72%, 18, 0.58(0-1.16) |
2.54%, 5, 0.68(0-1.66) |
.223 |
|
Dislocation |
15.71%, 30 |
15%, 39, 0.96(0.52-1.39) |
13.54%, 57, 0.9(0.53-1.28) |
10.12%, 49, 0.75(0.39-1.11) |
7.61%, 15, 0.75(0.2-1.31) |
.020* |
IR= Incidence rate; N= number of events; RR = relative risk (compared to previous age group); 95%CI= 95% confidence interval; P= chi square p value; *= P less than 0.05 (statistically significant)