AAOS Updates Guidelines for Nonoperative Knee OA Treatment

Jonathan D. Gelber, MD, MS

September 28, 2021

After nearly a decade, the American Academy of Orthopaedic Surgeons (AAOS) has updated its guidance on nonoperative treatment for knee osteoarthritis (OA).

The clinical practice guidelines, released Sept. 13, 2021, is the third edition of the orthopedic society's clinical practice recommendations.

Dr Robert Brophy

According to Robert Brophy, MD, FAAOS, an orthopedic surgeon at Washington University in St. Louis, Missouri, and co-chair of the AAOS clinical practice guideline workgroup, the AAOS guidelines are a "living document" that needs periodic updating as new research comes to light.

"The methodology for maintaining the AAOS Guidelines aims to update guideline documents at least every 10 years," Brophy told Medscape Medical News. "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."

The guidelines workgroup, composed of 12 medical doctors and one physical therapist, evaluated the evidence for 29 areas of treatment.

A rating scale based on available evidence and the strength of related medical studies labeled each treatment area as demonstrating strong, moderate, or limited evidence.

Eight treatment modalities weighed in with strong evidence for or against their use: lateral wedge insoles, topical or oral NSAIDs, exercise (supervised or unsupervised), self-management programs, patient education programs, oral acetaminophen, and oral opioids.

According to Brophy, many of the recommendations assigned a strong evidence base were similar to the prior edition of the guidelines.

Oral Medications

NSAIDs and acetaminophen still remain steadfast options for the treatment of knee pain secondary to OA.

The most notable change was that opioids, which have a long history of being used to treat pain, are strongly recommended not to be used for arthritis.

"Reflecting the growing awareness of and emphasis on the opioid epidemic, one of the strongest changes between the current and prior guidelines centers on the use of opioid medications," Brophy said. "In the prior guideline, a strong recommendation was made in favor of tramadol with an inconclusive recommendation made regarding other opioid medications. The updated guideline demonstrates clearly the evidence does not support the use of opioid medications — including tramadol — to treat knee osteoarthritis."

This may require some education for both patients and doctors to buy in that knee pain can be treated adequately with NSAIDs and acetaminophen.

Patients may not understand that anti-inflammatory drugs treat the pain they are experiencing. They may equate an opioid with a "pain pill" and may need education from their doctor that NSAIDs and acetaminophen not only can relieve their pain, but also avoid potential adverse events prior to or after surgery should they progress to knee replacement surgery.

Furthermore, primary care physicians may not be looking at the long-term picture. Solving a short-term pain problem with opioids may limit the medication's ability to provide pain relief after surgery should a patient develop a tolerance to the medication's effects.

Recommendations on Hip and Foot Alignment Interventions

When it comes to alignment and joint stresses, the knee is sometimes considered the innocent bystander of hip and foot alignment.

Insoles. How the hip and foot align with each can determine the amount of weight that passes through the medial (inner) or lateral (outer) compartment of the knee. To that end, lateral foot insoles have been used in the past for unloading parts of the knee.

Nevertheless, recent evidence has failed to demonstrate a significant benefit for insoles in the setting of OA knee pain, earning the practice a strong recommendation against its use.

High-tibial osteotomy (HTO). The weight-bearing axis of the lower extremity axis can also be realigned with HTO. The procedure shifts the body's weight slightly to the opposite side of the knee.

Newer research has led the practice to be downgraded one level in the new guideline, from moderate to limited, despite its widespread use.

It will, however, likely continue to be used as an alternative to total knee replacement in younger patients and to shift weight away from an area of the knee where cartilage is being restored with a concomitant surgical procedure, according to the workgroup. They noted that additional research studies on the long-term efficacy of the procedure are still needed.

Topical treatments. The guideline authors gave these a strong recommendation. Gels with anti-inflammatory medication have long been available but were prescription only or of considerable cost. Now several affordable over-the-counter options with the same prescription strength can be found in pharmacies and supermarkets.

What makes these medications unique is that they have an NSAID medication in the formulation, which the vast majority of topical treatments found on shelves do not. They also benefit patients who are unable to tolerate oral NSAIDs due to gastrointestinal side effects.

Comparison With 2019 OARSI Recommendations

In 2019, the Osteoarthritis Research Society International (OARSI) also published guidelines for the management of Osteoarthritis of the hand, hip, and knee.

Dr Thomas Trojian

Thomas Trojian, MD, a family medicine physician with expertise in sports medicine in York, Pennsylvania, and member of both the AAOS and OARSI recommendation committees, noted that the OARSI guidelines are meant to be practical guidelines of stepwise nonoperative treatment.

He told Medscape Medical News, "the OARSI guidelines recommend dietary weight management, education, and land-based [exercise] therapy, next topical NSAIDs, then injection therapy."

Intra-articular steroids and viscosupplementation injection therapy in the form of hyaluronic acid derivatives continue to be a mainstay of treatment for both groups.

The AAOS group notably gave a moderate strength recommendation for intra-articular steroid injections with the caveat that the effects typically only last for 3 months. They also included newer extended-release steroid injections in the recommendation, stating that the evidence moderately suggests they provide more benefit than traditional short-acting steroid injections.

Methodology Differs Between Guidelines

In the areas where the guidelines don't fully line up, it is important to remember the methodology of each group often drives the guidelines and recommendations.

Dr Yale Fillingham

According to Yale Fillingham, MD, an orthopedic surgeon in group private practice in the greater Philadelphia area and the other co-chair of the AAOS guidelines committee, the biggest difference between the AAOS and OARSI guidelines is that, although the OARSI guidelines are also grounded in the literature, the recommendation level was based on voting among panel members.

"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 voting panel," Fillingham told Medscape Medical News.

He pointed out that the AAOS voting panel can alter the guideline by adjusting the strength of the recommendation but noted it was only in very clearly defined situations. Therefore, the differences in methodology between the groups make it difficult to directly compare the two guidelines.

Multiple guidelines do, however, point to the importance of the issue. Fillingham commented, "The numerous organizations that have produced guidelines on the treatment of knee osteoarthritis are a testament to the widespread and profound impact of knee osteoarthritis on our healthcare system and society."

As a member of both recommendation groups, Trojian finds both guidelines reveal the importance of understanding that knee OA is a chronic illness. "There are ways we can manage knee OA and reduce the morbidity.... The core skills of motivational interviewing are important. Open-ended questions, affirmation, reflection, and summarizing are needed to help patients find and remove roadblocks to promote lifestyle changes."

Brophy, Trojian, and Fillingham have disclosed no relevant financial relationships.

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