PT vs. Steroid Injections for Knee OA
Physical Therapy versus Glucocorticoid Injection for Osteoarthritis of the Knee.
Deyle GD, Allen CS, Allison SC, et al.
N Engl J Med. 2020 Apr 9;382(15):1420-1429. [Full text]
There are numerous physical, psychosocial, and mind-body approaches that are strongly recommended by guidelines for osteoarthritis of the knee, including weight loss, exercise, Tai Chi, and tibiofemoral braces [1]. Often, a pharmacological intervention is favored by a treating provider as adherence may be less in question. Intrarticular (IA) glucocorticoid (GC) injections are one such intervention which is “strongly recommended” by the American College of Rheumatology (ACR). A recent small randomized trial noted that IA GCs resulted in significantly greater cartilage volume loss and no significant difference in knee pain compared to a saline injection [2].
A physical therapy (PT) referral is a manner in which a provider can improve adherence of non pharmacologic approaches. For example, exercise programs are more effective if supervised by a physical therapist [1]. This trial directly compared PT with IA GC injections.
Patient population and Design
Patients recruited were 38 years of age or older and presented to one of two large military hospitals from October 2012 through May 2017. Eligible patients met ACR clinical classification criteria for osteoarthritis of the knee and had radiographic evidence of osteoarthritis, Kellgren–Lawrence grade 1-4 (see image).
(B) KL classification Grade 2, possible narrowing of the joint space with definite osteophyte formation.
(C) KL classification Grade 3, definite narrowing of joint space, moderate osteophyte formation, some sclerosis, and possible deformity of bony ends.
(D) KL classification Grade 4, large osteophyte formation, severe narrowing of the joint space with marked sclerosis, and definite deformity of bone ends.
Patients were excluded if they had received a glucocorticoid (GC) injection or had undergone PT for knee pain in the previous year.
Patients were assigned in a 1:1 ratio to receive a GC injection (40 mg triamcinolone mixed 1:7 with 1% lidocaine) or undergo PT (without a placebo injection). Research assistants who were not investigators performed outcome assessments and were unaware of the trial-group assignments. Patients with symptoms in both knees received treatment in both knees, but trial outcomes were assessed only in the knee with worse symptoms at baseline.
The patients undergoing PT underwent up to eight treatment sessions over the initial 4-to-6-weeks, and could attend an additional 1-3 sessions at the 4-month and 9-month reassessments.
Outcomes
The primary outcome was the total WOMAC score at 1 year. The WOMAC score includes subscales assessing pain, physical function, and stiffness. Higher scores indicate worse symptoms.
Secondary outcomes were the Global Rating of Change scale (range −7 to +7, positive values indicating more improvement and negative worsening symptoms), the 1-year cost of knee-related health care utilization, and the results of the Timed Up and Go test and the Alternate Step Test (mean of three attempts).
Adverse events included death, infection, and fracture, in addition to a persistent worsening of symptoms resulting in additional treatment outside the trial.
Results
From October 2012 through May 2017, 156 patients were enrolled. The mean age of the patients was 56.1 yrs, 48% identified as female, and the mean BMI of the entire cohort was 31.5. More patients in PT group had a Kellgren–Lawrence grade of 3 or 4, or radiographically worse disease.
A total of 78 patients were randomly assigned to each group. Patients in the GC injection group received a mean of 2.6 injections (range, 1 to 4). Patients in the PT group attended a mean of 11.8 treatment visits (range, 4 to 22).
The mean WOMAC scores at 1 year were worse in the GC injection group (55.8±53.8) compared to the PT group 37.0±30.7 with a mean between-group difference 18.8 points (95% CI, 5.0 to 32.6; P=0.008).
At 1 year, the median score on the Global Rating of Change scale was +5 (“quite a bit better”) in the physical therapy group and +4 (“moderately better”) in the GC injection group. Patients in the PT group performed better in the Alternate Step Test, mean difference 1.0 s (95% CI, 0.3 to 1.6), and the Timed Up and Go test, difference 0.9 s (95% CI, 0.3 to 1.5) at 1 year. One patient in the GC group fainted while receiving an injection, otherwise there were no other adverse events.
The mean cost for all knee-related medical care during the 1-year trial period was similar in the two groups ($2,113 in the GC injection group and $2,131 in the PT group)
Discussion
In this small, single center, open label trial of IA GC knee injections compared to PT, the PT group had a better WOMAC score at 1 year, a higher Global Rating of Change, faster Alternate Step Test and Timed Up and Go test results with similar health care cost ($2,113 vs. $2,131). It should be noted that patients in the PT group had considerably greater contact time with providers than patients in the GC injection group. Additionally, the therapists were all board certified in orthopedic physical therapy, but the individualized treatment plans were not discussed or standardized, making replicating the results in real world practice more challenging. The results took a median of 11.8 PT visits, hence it should be stressed to patients that participating in only a few PT sessions may not be sufficient to receive benefit.
In the accompanying editorial, Bennell and Hunter stress that “the results do not exclude a role for joint injection for treatment of a flare of acute pain”. Instead, they suggest these results should favor PT as first line, and that IA GC injections should not be used in place of PT [3]. In a health care system that can tend to have better remuneration for procedural intervention, affecting clinical practice may require systemic change to achieve this.
| F: Follow up | 12 mo |
| R: Randomization | Yes |
| I: Intention to treat | Yes |
| S: Similar at baseline | NO, more patients in PT group had a Kellgren–Lawrence grade of 3 or 4 |
| B: Blinding | NO |
| E: Equal treatment | N/A |
| S: Source (funding) | Not discussed |
- Kolasinski SL, Neogi T, Hochberg MC, et al,; Reston J. 2019 American College of Rheumatology/Arthritis Foundation Guideline for the Management of Osteoarthritis of the Hand, Hip, and Knee. Arthritis Rheumatol. 2020 Feb;72(2):220-233.
- McAlindon TE, LaValley MP, Harvey WF, et al.; Effect of Intra-articular Triamcinolone vs Saline on Knee Cartilage Volume and Pain in Patients With Knee Osteoarthritis: A Randomized Clinical Trial. JAMA. 2017 May 16;317(19):1967-1975.
- Bennell KL, Hunter DJ. Physical Therapy before the Needle for Osteoarthritis of the Knee. N Engl J Med. 2020 Apr 9;382(15):1470-1471.
