The non-surgical treatments for knee osteoarthritis (OA) lack effectiveness in terms of providing complete pain relief. Therefore, scientists are exploring new treatment options to control the symptoms and maintain joint function. Intra-articular injection of hyaluronic acid (HA) offers a promising and effective nonsurgical remedy for the treatment of knee OA.

Lately, a study was performed to report long-term clinical outcomes and cost-benefit in patients who were treated with 500–730 kilodalton sodium hyaluronate. A telephone interview was conducted in patients who were recruited in a single 8-week multimodal knee OA treatment program. Participant in this study received five intra-articular knee injections of sodium hyaluronate (each injection was given one week apart), structured physical therapy, knee bracing, and patient education. Clinical outcomes were knee pain severity, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) subscores, current medication use, and history of total knee arthroplasty. Estimation of the incremental cost-effectiveness ratio (ICER) of the treatment program was done by conducting the base-case, subgroup, and sensitivity analyses and the rates were compared with historical literature controls undergoing usual care.

Long-term follow-up data was provided by a total of 218 patients (54%). It was estimated that there was 60% decrease in the knee pain severity scores. Subscores of WOMAC decreased 33%-42% compared to baseline (all p<0.001). During the follow-up knee arthroplasty was performed in about 22.8% (81/356) of knees. The treatment program was found to be highly cost-effective when compared to usual care with a base-case ICER of $6,000 per quality-adjusted life year (QALY). Subgroup analyses were found to be one-way deterministic sensitivity analyses and second-order probabilistic sensitivity analyses, and it came out with ICERs varying from $3,996 to $10,493 per QALY. The percentage of simulations with an ICER below willingness-to-pay limits was 97.2%, 98.9%, and 99.4% for the $50,000, $100,000, and $150,000 per QALY thresholds.

The study concludes that a single 8-week knee OA treatment program, which included one cycle of five intra-articular knee injections of sodium hyaluronate given at weekly intervals was found to be highly cost-effective and provides clinically useful reductions in patient symptoms that are sustained over 3.7 years mean follow-up.