Recently a number of studies have examined the efficacy of conservative treatments for knee osteoarthritis (OA). A recent blog post evaluated an interesting approach by Bennell et al 1 using a multimodal intervention program for the treatment of knee OA (http://blog.evidenceinmotion.com/evidence/2006/02/latest_research.html#comments). We want to take this opportunity to more fully explore the merits of two other studies, those conducted by Deyle et al. 2,3 We believe that, as health care professionals, it is our responsibility to critically evaluate the research and glean from it what we can in order to improve our outcomes of care.
The two studies by Deyle et al 2,3 demonstrate the efficacy of exercise combined with manual physical therapy for treatment of knee OA. As many of you blog readers know, the initial study published in Annals of Internal Medicine in 2000 2 compares outcomes for patients receiving an individualized manual physical therapy and exercise to outcomes for patients receiving placebo ultrasound. In the follow-on study,3 the researchers compared an individualized manual physical therapy and exercise program to a home exercise program (identical exercises were performed by both treatment groups).
Deyle et al,( 2005) used clinically relevant interventions and outcome measures. The WOMAC and the timed 6-minute walk test were used as primary and secondary outcome measures, respectively. For the intervention group, manual therapy procedures were selected based on examination findings for each subject and the exercise program focused on strengthening, mobility, and endurance. The control group received a home exercise program that consisted of the same exercises performed by the treatment group. The study population and methods are consistent with much of our current practice population and standards, which makes the results of this study very relevant to most clinicians’ daily practices. The results of this study show significant changes in WOMAC scores for the treatment group by 50%. The treatment group improved by 52% in contrast to 26% improvement in the HEP group. The 6-minute walk test improved significantly for both groups.
So, why is this study so important? Because it shows that impairment-based manual therapy interventions when combined with well designed exercise programs, leads to improved outcomes for patients with knee OA compared to simply performing a home exercise program! The combination of manual therapy and exercise has been shown to reduce the need for total knee replacement and steroid injections with a number needed to treat of 7 when compared with placebo intervention.3 Looking at this from a financial perspective, with an NNT of 7 and a total number of 8 visits2 and an estimated cost of $100/visit, one episode of care for these patients with knee OA would be approximately $5,600. This figure represents the estimated cost to treat 7 patients with knee OA with this treatment approach to avoid one TKA at 1 year. When contrasted with a conservative estimate4 of an average hospital cost of $17,908 plus surgeon/ anaesthesiologist charges of $4,500, the total cost of a TKA is estimated at $22,000. Manual therapy and an effective exercise program could save over $16,000 by avoiding one TKA surgery.
The “take home message” of the Deyle et al 2,3 studies is in their design and outcomes:
Deyle et al, 2005, shows the effectiveness of impairment-based manual therapy in the treatment of knee OA combined with an evidence based exercise program. The treating therapists were free to treat impairments of not only the affected knee, but lumbar spine, hip and ankle as needed. The Deyle et al, 2000 study showed that the manual therapy group was less likely to get a TKA or steroid injection at one year and demonstrated statistically significant improvement in clinically relevant and patient centered outcomes (WOMAC scores and the 6-minute walk test). Both of the Deyle et al studies 2,3 support the use of exercise for knee OA and show additional benefit from the addition of manual therapy intervention.
In these two RCTs, the results speak for themselves and answer the clinician’s question “What is appropriate, effective and evidence based treatment for OA of the knee?
1 Bennell KL, et al. Efficacy of physiotherapy management of knee joint osteoarthritis: A randomized, double blind, placebo controlled trial. Ann Rheum Dis. 2005;64:906-912.
2 Deyle GD, et al. Effectiveness of manual physical therapy and exercise in osteoarthritis of the knee: A randomized controlled trial. Ann of Intern Med. 2000;132:173-180.
3 Deyle GD, et al. Physical therapy treatment effectiveness for osteoarthritis of the knee: A randomized comparison of supervised clinical exercise and manual therapy procedures versus a home exercise program. Phys Ther. 2005; 85:1301-1317.
4 Healy et al. Clinical orthopedics and related research. 1997.
A.Y. Mitsunaga, PT
Pam Rutstein, PT
Steve Moffit, PT
Debbie Van Horn, PT