The Centers for Medicare and Medicaid Services (CMS) have recommended a new HCPCS J-Code be issued on January 1, 2019 for the extended release corticosteroid, Zilretta.
New Reimbursement Code for Extended-Release Corticosteroid

Zilretta is first and only extended-release, intra-articular therapy for patients with osteoarthritis-related knee pain.
Zilretta employs proprietary microsphere technology combining triamcinolone acetonide (TA)—a short-acting corticosteroid that was first approved by the FDA in 1958—with a poly lactic-co-glycolic acid (PLGA) matrix to provide extended pain relief over 12 weeks
Importantly, the agency is recommending that Zilretta have its own separate J-code.
This is significant news for physicians looking for a longer lasting corticosteroid treatment for OA knee pain.
Zilretta, which is manufactured by Boston-based Flexion Therapeutics Inc., was officially launched into the orthopedics market in November 2017. In early April 2018, CMS issued a product-specific Q-code for Zilretta effective July 1, 2018 just for Medicare patients treated in physicians’ offices.
Clinical Data: Two Recent JBJS Published Studies
A Phase-2, double-blind, multicenter study with 228 patient enrollees with moderate to severe knee osteoarthritis pain, randomized to a single intra-articular injection of extended-release triamcinolone acetonide (TA) (testing 3 dose levels: 10, 40, or 60 mg) or 40 mg of immediate-release triamcinolone acetonide was published in the June 2015 issue of the Journal of Bone and Joint Surgery (JBJS).
The study reported that a 10-mg dose of extended release TA delivered better pain relief than immediate-release TA at two through twelve weeks, although the difference in pain relief was not significant (p ≥ 0.05).
The 40-mg dose of extended-release TA also provided better pain relief than immediate release TA at two through twelve weeks and was significantly superior at five to ten weeks (p ≥ 0.05).
Adverse events were generally mild and similar across all treatments.
A more recent study (published in JBJS on April 18,2018) tested this extended-release TA in a Phase 3 multicenter, double blinded, 24-week study of adults over 40 years of age with knee osteoarthritis (Kellgren-Lawrence grade 2 or 3) and average-daily-pain-intensity score of greater than or equal to 5 and less than or equal to 9 format.
The study enrollees were randomly selected to receive either a single intra-articular injection of extended-release triamcinolone acetonide (Zilretta) (32 mg), a saline solution placebo or non-extended release triamcinolone acetonide (TA) (40mg).
Four hundred eighty-four (484) patients were enrolled. One hundred sixty-one (161) received Zilretta. One hundred sixty-two (162) received saline-solution and 161 received TA.
The authors wrote that a lower dose of extended release TA worked as well as a higher dose of non-extended release TA.
Apparently, the extended release mechanism allows physicians to deliver effective pain relief with lower corticosteroid doses.
For more detailed information about adverse events, cautions, warnings and other clinical data, here is the link.

Discussion
This is a fascinating development. In my practice we've seen similar outcomes with the revised protocol. The key differentiator seems to be patient selection criteria. Has anyone else noticed the correlation with BMI thresholds?
Great point. I'd push back slightly on the conclusion, the sample size in the cited study is too small to draw population-level inferences. That said, the directional signal is compelling and worth a larger RCT.
We implemented a similar approach last year. Early results are promising but we're still gathering 12-month follow-up data. Happy to share our protocol if anyone is interested.
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