Total knee replacement (TKR) is often delayed in younger patients in an attempt to prolong the longevity of the prosthesis and avoid the risk of revision. But delaying a TKR might compromise the quality of life of young patients who are otherwise active and healthy.
We built a Markov decision model to study the simulated clinical course of a 50-year-old patient with severe unilateral knee osteoarthritis who could be either treated with conservative therapies or with a TKR at some point in time. An Indian healthcare payer perspective model was used, and lifetime costs (in Indian rupees), quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratio (ICER) were calculated.
In the base case scenario, patients who did not receive a TKR had a total lifetime cost of ₹216 709 and accumulated 13.59 QALYS in their lifetime. Those who received a TKR without delay (at age 50) accumulated 16.71 QALYS in their lifetime with an ICER of ₹9789 per QALY. When TKR was delayed, the total QALYs decreased, and ICER increased with each year of delay. But the cumulative risk of revision decreased from 27.4% when TKR was performed at 50 years to 10.0% when TKR was done at 70 years.
Our analysis found that TKR is a cost-effective procedure when the healthcare payer is willing to pay at least ₹9789 ($132) per QALY. The results also suggested that an early TKR is preferred to a delayed TKR despite the higher incidence of revisions.