Access to joint replacement is being restricted for patients with comorbidities in a number of high-income countries. However, there is little evidence on the impact of comorbidities on outcomes. The purpose of this study was to determine the safety and effectiveness of hip and knee arthroplasty in patients with and without comorbidities. In total, 312,079 hip arthroplasty and 328,753 knee arthroplasty patients were included. A total of 11 common comorbidities were identified in administrative hospital records. Safety risks were measured by assessing length of hospital stay (LOS) and 30-day emergency readmissions and mortality. Effectiveness outcomes were changes in Oxford Hip or Knee Scores (OHS/OKS) (scale from 0 (worst) to 48 (best)) and in health-related quality of life (EQ-5D) (scale from 0 (death) to 1 (full health)) from immediately before, to six months after, surgery. Regression analysis was used to estimate adjusted mean differences (LOS, change in OHS/OKS/EQ-5D) and risk differences (readmissions and mortality).Aims
Methods
The Oxford hip and knee scores (OHS and OKS)
are validated patient-reported outcome measures used in patients undergoing
total hip replacement (THR), hip resurfacing (HR), total knee replacement
(TKR) and unicompartmental knee replacement (UKR). We analysed the
absolute OHS and OKS and change in scores following THR, HR, TKR,
and UKR performed at one specialist centre. All patients undergoing
and completing at least one Oxford score were eligible for inclusion
in the study which included 27 950 OHS and 19 750 OKS in 13 682
patients. Data were analysed using non-linear quantile regression.
The median absolute Oxford scores for THR, HR, TKR and UKR were
pre-operative 68.8% (15.0/48), 58.3% (20.0/48), 66.7% (16.0/48),
60.4% (19.0/48) respectively: and post-operative asymptote was 14.6%
(41.0/48), 5.8% (45.2/48), 31.2% (33.0/48), 29.2% (34.0/48). The
median asymptotic change from the pre-operative score for THR, HR,
TKR and UKR were 47.9% (23.0/48), 47.9% (23.0/48), 33.3% (16.0/48)
and 32.4% (15.5/48), respectively. The median time at which no further
appreciable change in score was achieved post-operatively was 0.7
years for THR, 1.1 years for HR, 0.9 years for TKR and 1.1 years
for UKR. The curves produced from this analysis could be used to educate
patients, and to audit the performance of a surgeon and an institution.
The time to achieve a stable improvement in outcome varied between
different types of joint replacement, which may have implications
for the timing of post-operative review. Cite this article:
Primary arthroplasty may be denied to very elderly patients based upon the perceived outcome and risks associated with surgery. This prospective study compared the outcome, complications, and mortality of total hip (TKR) and total knee replacement (TKR) in a prospectively selected group of patients aged ≥ 80 years with that of a control group aged between 65 and 74 years. There were 171 and 495 THRs and 185 and 492 TKRs performed in the older and control groups, respectively. No significant difference was observed in the mean improvement of Oxford hip and knee scores between the groups at 12 months (0.98, (95% confidence interval (CI) −0.66 to 2.95), p = 0.34 and 1.15 (95% CI −0.65 to 2.94), p = 0.16, respectively). The control group had a significantly (p = 0.02 and p = 0.04, respectively) greater improvement in the physical well being component of their SF-12 score, but the older group was more satisfied with their THR (p = 0.047). The older group had a longer hospital stay for both THR (5.9
