AAOS Updates Knee OA Guideline, Highlights Zilretta®

Eight years after the last update, The American Academy of Orthopaedic Surgeons (AAOS) Board of Directors has updated its evidence-based clinical practice guideline for treating painful osteoarthritis (OA) of the knee. With changes to 19 of the 29 recommendations from the previous guideline, the new document focused only on less invasive non-arthoplasty treatments.  Notably, the guidelines mentioned a relatively new treatment, a time-release corticosteroid, Zilretta^®.

Robert H. Brophy, M.D., FAAOS, co-chair of the clinical practice guideline workgroup and member of the AAOS Committee on Evidence-Based Quality and Value, put the new guidelines into context saying, “The AAOS guidelines are a ‘living document’ that needs to be updated periodically as we learn more through new research. The methodology for maintaining the AAOS Guidelines aims to update guideline documents at least every 10 years. Since the last edition was from 2013, it was time to provide an updated guideline on this very important topic that affects such a high percentage of our patients and providers.”

What, OTW asked, were points of debate during the committee’s deliberations? Yale Fillingham, M.D., co-chair of the clinical practice guideline workgroup and member of the AAOS Committee on Evidence-Based Quality and Value, answered, “The AAOS methodology requires the recommendation and strength of the recommendation to be dictated primarily by the best available evidence in the literature and much less on the expertise and opinion of the workgroup members.”

“The workgroup can alter the guideline through adjustment of the strength of the recommendation but only in very clearly defined situations. Therefore, much of the discussion among the workgroup centers around the wording of the recommendations to provide concise and clearly written statements for providers and patients to understand and implement in the care of knee osteoarthritis.”

“For instance, a significant amount of work went into writing the recommendation regarding arthroscopic partial meniscectomy. After evaluation of the evidence on the topic, two important points were noted:

1. The studies did not include patients with end-stage grade 4 bone on bone osteoarthritis, and
2. The comparator to arthroscopic partial meniscectomy was other non-surgical treatment options.

As a result, it is important to emphasize that patients with severe arthritis are not included in the recommendation. Additionally, recognizing the clinical equipoise between operative and non-operative treatments, less invasive options are appropriate before considering surgery. Therefore through careful discussion among the workgroup, the final recommendation was written.”

As in the previous version of the document, the new guideline suggests that patients with symptomatic OA of the knee receive one of the following for pain (barring any contraindications):

• Acetaminophen (not to exceed 3,000 mg per day)
• For short-term pain relief, intra-articular corticosteroids and made specific mention of Zilretta^®, a time-release corticosteroid
• Oral anti-inflammatory drugs (NSAIDs)

It does not recommend the following treatments or evidence is inconsistent/limited:

• Custom made lateral wedge insoles
• Glucosamine and/or chondroitin sulfate or hydrochloride
• Needle lavage (aspiration of the joint with injection of saline) and/or debridement

In devising the update, AAOS worked alongside the American Association of Hip and Knee Surgeons, The Knee Society, the American Academy of Family Physicians, the American Physical Therapy Association, the Arthroscopy Association of North America, the International Cartilage Repair Society, the American Medical Society for Sports Medicine, and the American Society of Regional Anesthesia and Pain Medicine.

Highlighting the Role of Extended-Release Corticosteroids

Addressing the decision to include Zilretta^® in the guideline, Dr. Brophy explained to OTW, “The main recommendation is for the use of corticosteroid injections in the treatment of knee osteoarthritis. The discussion in the rationale behind the main recommendation mentions extended-release corticosteroids because of emerging evidence that extended-release intra-articular corticosteroid injections provide another evidence-based option for symptomatic relief from knee osteoarthritis.

However, the literature and FDA guidelines on extended-release intra-articular corticosteroid injections have not proven the safety and effectiveness of repeat injections. The next update may be able to shed further light on this option.”