TOPKAT: Partial knee replacement should be considered first choice for late-stage OA
Partial knee replacement (PKR) surgery provides similar clinical outcomes as total knee replacement (TKR) in patients with late-stage osteoarthritis (OA), although the former proves more cost-effective according to the results of the TOPKAT* trial.
TOPKAT applied a combined expertise- and equipoise-based approach. A total of 528 patients (mean age, 65 years; 58 percent male) with isolated OA of the medial compartment of the knee and who met requirements for a medial PKR were randomly assigned to receive PKR (n=264) or TKR (n=264) by surgeons who were expert in and willing to perform both surgeries or by a surgeon with particular expertise in the allocated procedure.
Operation time was around 70 min in both PKR and TKR groups. However, the length of hospital stay was markedly longer for patients who received TKR (mean, 4.3 vs 3.2 days; risk ratio [RR], 0.74, 95 percent CI, 0.63–0.87; p<0.0001).
At 5 years after surgery, the primary endpoint of Oxford Knee Score (OKS) did not significantly differ between the two groups (mean difference, 1.04, −0.42 to 2.50; p=0.159). Within-trial cost-effectiveness analysis, on the other hand, revealed PKR to be more effective (0.240 additional quality-adjusted life-years) and less expensive (−£910) than TKR during the 5 years of follow-up.
Researchers said that the cost-effectiveness finding might be attributed to slightly better outcomes, lower costs of surgery and lower follow-up healthcare costs with PKR. Therefore, PKR should be considered the first-choice procedure for late-stage OA, with the surgery done by surgeons with sufficient experience and expertise.
*Total or Partial Knee Arthroplasty Trial