Aim: We studied changes in opioid prescriptions and corticosteroid injection use for knee osteoarthritis patients before and after intra-articular hyaluronic acid (HA) use and opioid prescriptions before and after knee arthroplasty (KA). Materials & methods: A total of 1,017,578 knee osteoarthritis members were ascertained from a commercial claims database (Health Intelligence Company LLC, IL, USA) using ICD9/ICD10 diagnosis codes. Results: Eighty two percent of HA patients did not fill opioid prescriptions postinjection, with 54% of opioid users discontinuing fills. Two-thirds of KA patients filled opioid prescriptions within 6 months postsurgery, with 78% of opioid users continuing fills and 62% of nonusers initiating use. Conclusion: Alternative therapies, such as HA, that reduce opioid use may alleviate opioid addiction risks for KA patients who use opioids in the pre- and postoperative periods.

Background

Several nonoperative options have been recommended for the treatment of knee osteoarthritis (OA), with varying degrees of evidence. Adhering to the American Academy of Orthopaedic Surgeons clinical practice guidelines has been suggested to decrease direct treatment costs by 45% in the year before knee arthroplasty, but this does not consider the cost of the entire episode of care, including the cost of surgery and postsurgery care.

Objectives

To analyze the total treatment costs after a diagnosis of knee OA, as well as the proportion of arthroplasty interventions as part of the total knee OA-related costs, and whether the total costs differed for patients who received intra-articular hyaluronic acid and/or had knee arthroplasty.

Methods

We identified patients newly diagnosed with knee OA using the 5% Medicare data sample from January 2010 to December 2015. Patients were excluded if they were aged <65 years, had incomplete claim history, did not reside in any of the 50 states, had claim history <12 months before knee OA diagnosis, or did not enroll in Medicare Part A and Part B. The study analyzed knee OA-related costs from a payer perspective in terms of reimbursements provided by Medicare, as well as the time from the diagnosis of knee OA to knee arthroplasty for patients who had knee arthroplasty, and the time from the first hyaluronic acid injection to knee arthroplasty for those who received the injection. We compared patients who received hyaluronic acid and those who did not receive hyaluronic acid injections. Patients who received hyaluronic acid injection who subsequently had knee arthroplasty were also compared with those who did not have subsequent knee arthroplasty.

Results

Of the 275,256 patients with knee OA, 45,801 (16.6%) received a hyaluronic acid injection and 35,465 (12.9%) had knee arthroplasty during the study period. The median time to knee arthroplasty was 16.4 months for patients who received hyaluronic acid versus 5.7 months for those who did not receive hyaluronic acid. Non-arthroplasty-related therapies and knee arthroplasty accounted for similar proportions of knee OA-related costs, with hyaluronic acid injection comprising 5.6% of the total knee OA-related costs. For patients who received hyaluronic acid injections and subsequently had knee arthroplasty, hyaluronic acid injection contributed 1.8% of the knee OA-related costs versus 76.6% of the cost from knee arthroplasty. Patients who received hyaluronic acid injections and did not have knee arthroplasty incurred less than 10% of the knee OA-related costs that patients who had surgery incurred.

Conclusion

Although limiting hyaluronic acid use may reduce the knee OA-related costs, in this study hyaluronic acid injection only comprised a small fraction of the overall costs related to knee OA. Among patients who had knee arthroplasty, those who received treatment with hyaluronic acid had surgery delayed by a median of 10.7 months and associated costs for a significant period. The ability to delay or avoid knee arthroplasty altogether can have a substantial impact on healthcare costs.