Conservative treatment may yield positive results for patients with knee OA

Some studies have shown hyaluronic acid, PRP and stem cell treatment have a positive effect on knee OA.

Prior to surgical intervention, patients with knee osteoarthritis may benefit from conservative treatment with such modalities as steroid injection, platelet-rich plasma or PRP, stem cells and hyaluronic acid or HA, according to a review article published in Orthopedics.

Perspective from Thomas A. Einhorn, MD

“It is not uncommon for me to see patients come into the office who have not had an extensive conservative treatment protocol prior to being scheduled for a total knee replacement,” Jack M. Bert, MD, of Minnesota Bone and Joint Specialists Ltd. and adjunct clinical professor at University of Minnesota, told Orthopedics Today. “I feel it is important to at least discuss with the patient the various treatment modalities that should be tried prior to subjecting someone to a TKR with its attendant risks and complications. Furthermore, there are currently 14 published articles confirming that TKR only has an 80% to 82% patient satisfaction rate at 1 year.”

Steroids’ role in inflammatory response

Steroid injections inhibit prostaglandins, as well as metalloproteoglycan chondrolytic enzyme levels in osteoarthritic cartilage, and thus can be used to reduce inflammatory response from OA. Unfortunately, there is a dramatic efflux of injected steroids from the knee joint at 18 to 20 days post-injection, according to Bert.

He said Zilretta (triamcinolone acetonide extended-release injectable suspension, Flexion Therapeutics Inc.), which was FDA-approved in 2017 to treat OA knee pain, has been shown to provide long-lasting pain relief due to an increase in joint residence time of the injected steroid.

“I use [Zilretta] in my older patients with significant disease who do not want to go on to have TKR and it can be used in diabetics because it does not result in a significant increase in blood glucose after injection,” said Bert, who is an Orthopedics Today Editorial Board Member.

Results with HA

Although the American Academy of Orthopaedic Surgeons recommends against the use of viscosupplementation as conservative treatment for knee OA, high molecular-weight hyaluronic acid (HA) has been found to be safe, efficacious and cost-effective in several published studies, including a 2016 review article by Johan and colleagues in Journal of Bone and Joint Surgery, according to Bert.

Bert and colleagues noted in the article that high-molecular weight/crosslinked HA has an increased residence time and a half-life of up to 8.8 days.

“[Hyaluronic acid] is for patients that do not have complete collapse of their joint space,” Bert said.

He continued, “There is some evidence in those patients, if injected every 6 months, that high-molecular weight/crosslinked HA will prevent arthritis from progressing.”

Although results using PRP and stem cells for knee OA are “all over the board” with improvement in symptoms from 50% to 75%, these results are promising, Bert noted.

“We are not sure how well they work because we cannot legally manipulate stem cells once they are removed from the body, but we know that adipose tissue and bone marrow seem to be the optimal sites for their removal. Bone marrow cells must be concentrated prior to injection to exert optimal effect,” Bert said. – by Casey Tingle

References:

Bert JM, et al. Orthopedics. 2018;doi:10.3928/01477447-20180828-08.

Johal H, et al. JBJS Rev. 2016;doi:10.2106/JBJS.RVW.15.00098.

Flexion Therapeutics announces FDA approval of Zilretta (triamcinolone acetonide extended-release injectable suspension) for osteoarthritis (OA) knee pain. Available at: http://ir.flexiontherapeutics.com/news-releases/news-release-details/flexion-therapeutics-announces-fda-approval-zilrettatm. Accessed Oct. 17, 2018.

For more information:

Jack M. Bert, MD, can be reached at 2025 Woodlane Dr., Woodbury, MN 55125; email: bertx001@gmail.com.

Disclosure: Bert reports he is a speaker for Flexion Therapeutics Inc.

Perspective

Thomas A. Einhorn, MD

Bert and colleagues have suggested that OA of the knee will soon reach epidemic proportions affecting millions of Americans. As a consequence, the number of knee replacements expected to be performed within the next decade is staggering. Many of these patients seem to be afflicted with a low-grade form of this condition and thus are not necessarily in need of TKR now. Identifying such patients, modifying their lifestyles and employing novel therapies to prevent progression is the current way forward.

First, because many patients with OA of the knee have an elevated BMI, methods to reduce obesity in this population are paramount. Optimizing nutrition and maintaining a near normal body mass are critical for preventing OA and enhancing its management.

A lot has been heard about glucosamine and chondroitin sulfate, as well as COX-2 inhibitors, for initial treatment. However, there are minimal data to support these treatment modalities right now and the enthusiasm that they enjoyed several years ago seems to have waned.

The article by Bert and colleagues, if nothing else, provides good references for further investigation. There are references on steroid injections, PRP, stem cell implantation and HA. Note, however, the AAOS still has not changed its 2013 position statement against viscosupplementation.

According to Bert and colleagues, “The conservative treatment of OA of the knee is important and should be exhausted prior to total knee replacement.” I could not agree more.

Thomas A. Einhorn, MD

NYU Langone Health

New York

Disclosures: Einhorn reports no relevant financial disclosures.