# Intra-articular injections for knee osteoarthritis management: Analysis of cost-effectiveness

## TL;DR

This study compares the cost-effectiveness of different knee injections for osteoarthritis, finding that some treatments may not be worth their cost.

## Contribution

The study introduces a novel cost-effectiveness analysis of intra-articular injections for knee osteoarthritis using a validated policy model and meta-analysis.

## Key findings

- Saline injections showed the best cost-effectiveness at $8300/QALY compared to no injection.
- Platelet-rich plasma (PRP) injections exceeded accepted cost-effectiveness thresholds at $112,100/QALY.
- Corticosteroid (CS) injections could be cost-effective if they do not significantly worsen osteoarthritis progression.

## Abstract

Intra-articular injections (IAI) are commonly used to treat knee pain in persons with knee osteoarthritis (OA). We sought to determine the value of commonly used IAIs in knee OA management.

We used the validated Osteoarthritis Policy Model (OAPol) to assess the value of saline, corticosteroid (CS), hyaluronic acid (HA), and platelet-rich plasma (PRP) IAIs in knee OA management. We conducted a meta-analysis of high quality studies to estimate IAI-specific pain reduction. We assumed that repeat CS injections increase the risk of OA progression threefold in the base case. We determined the value of specific IAIs with incremental cost-effectiveness ratios (ICERs). We conducted sensitivity analyses to account for uncertainty in input parameters.

In the base case, ICERs were $8300/QALY for saline compared to no injection, $54,500/QALY for HA compared to saline, and $112,100/QALY for PRP compared to HA. CS was dominated (more costly, less effective) by saline. If saline was not included, ICER for HA was reduced to $22,400/QALY. In sensitivity analyses that assumed CS does not increase OA progression, ICERs were $6000/QALY for CS compared to no injection, HA dominated compared to CS. ICER for PRP was estimated at $151,300/QALY. ICERs for PRP were higher than currently accepted willingness to pay thresholds. PRP ICER ranges were most sensitive to discontinuation probability and cost.

CS could offer good value for knee OA management if the impact on OA progression is small. Value of PRP depends greatly on its price, with current prices leading to value exceeding well-accepted cost-effectiveness thresholds. Better data on the impact of CS on OA progression and pain efficacy related to PRP would offer critical insights for policymakers into the value of specific IAIs in the management of knee OA.