Justin Cooper , 2025-05-14 09:30:00
Key takeaways:
- Patients with knee osteoarthritis who received intraarticular therapies but delayed physical therapy had higher risk for further injections.
- Attending 13 or more sessions decreased that likelihood.
Promptly starting physical therapy after a diagnosis of knee osteoarthritis, and attending 13 or more sessions, decreases the likelihood of subsequent intraarticular therapies, according to data published in Arthritis & Rheumatology.
“Guidelines recommend exercise and education, typically provided as part of physical therapy care, as first-line treatments for knee osteoarthritis,” Deepak Kumar, PT, PhD, associate professor of physical therapy at Boston University, told Healio. “In practice, patients are more likely to receive less effective and potentially harmful treatments, such as intra-articular corticosteroid or intra-articular hyaluronic acid injections.
“Given these facts, we were motivated to examine whether providing physical therapy care early after a diagnosis of knee osteoarthritis may reduce future use of intra-articular injections,” he added. “We also wanted to examine if there was a relation between intra-articular injections and the number of physical therapy visits and type of physicians therapy care provided.”
To accomplish this, Kumar and colleagues analyzed insurance claims from the Optum Labs Data Warehouse, specifically from adults aged 40 years or older who received physical therapy within 12 months of a knee OA diagnosis.
Using data from 67,245 patients with knee OA (mean age, 61.5 years; 61% women), the researchers compared the use of intraarticular therapy over 1 year between those who started physical therapy earlier or later, as well as those who attended more or fewer sessions.
Overall, 34,804 (51.8%) of the patients received intraarticular therapies prior to physical therapy, and 32,441 (48.2%) did not.
Among patients who received intraarticular therapies, those who waited 9 to 12 months after diagnosis to start physical therapy demonstrated a significantly increased risk for more intraarticular injections in the future (adjusted RR = 1.44; 95% CI, 1.35-1.55), compared with those who started therapy within 1 month, according to the researchers.
“We also saw that, the longer the time to starting physical therapy from the diagnosis, the greater the risk of future use of intraarticular injections,” Kumar said.
Compared with waiting 1 month or less from diagnosis, the hazard ratios increased from 1.08 (95% CI, 1.02-1.14) at 1 to 3 months, to 1.14 (95% CI, 1.07-1.22) at 3 to 6 months, and to 1.31 (95% CI, 1.22-1.4) at 6 to 9 months.
Regardless of intraarticular treatment, completing 13 or more physical therapy sessions demonstrated a significant link with a lower risk for future injections. For patients without prior injections, those who attended 13 or more sessions demonstrated a 12% lower risk (adjusted RR = 0.88; 95% CI, 0.81-0.97), while those with previous injections had a 10% lower risk (adjusted RR = 0.9; 95% CI, 0.86-0.96), according to the researchers.
“Our findings provide important support for patients, payors and providers to guide treatment decisions,” Kumar said. “Our results suggest that patients newly diagnosed with knee osteoarthritis may benefit from early referral to and initiation of physical therapy, along with optimal number of visits, to reduce reliance on less effective and potentially harmful treatments.
“We have previously reported similar results for future risk of opioid use in people diagnosed with knee osteoarthritis,” he added. “While it was a bit surprising to not see an association between type of physical therapy care and future risk of intra-articular injections, this was likely due to our limited ability to capture the type of care in more detail.”
For more information:
Deepak Kumar, PT, PhD, can be reached at kumard@bu.edu; X (Twitter): @ProfDeepakKumar.
Sources/Disclosures
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Disclosures:
This study was funded by NIH. Kumar reports receiving grants from NIH during this study and grants from the Rheumatology Research Foundation, Pfizer, Eli Lilly, MedRhythms Inc., and Adobe outside this study. Please see the full study for additional authors’ disclosures.
