RESEARCH - Hyaluronan injections into OA knee can delay surgery

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Hyaluronan injections into OA knee can delay surgery

March 2, 2005 Zosia Chustecka

Washington DC - In patients with severe osteoarthritis of the knee who were

candidates for total-knee-replacement (TKR) surgery, treatment with

intra-articular injections of hyaluronan delayed the need for surgery by

nearly 4 years, according to data from a prize-winning poster presentation

at the American Academy of Orthopaedic Surgeons (AAOS) 2005 meeting. " Given

that total knee replacement is costly, can carry serious risk, and may need

revision in younger patients, hyaluronan is a viable treatment option before

last-resort surgery, " the presenters conclude.

Dr Waddel and Dr DeWayne Bricker (PAC Orthopedic Specialists of

Louisiana, Shreveport) reported a 6-year study in which patients presenting

at their practice with grade IV osteoarthritis of the knee, all of whom were

considered candidates for TKR surgery, were treated with Hylan G-F 20

(Synvisc, Genzyme) rather than be scheduled immediately for surgery. " In our

practice, patients typically undergo surgery within 3 months of being

considered a candidate, " they comment.

Patients were treated with 1 or more courses of hyaluronan (one 2-mL

intra-articular injection weekly for 3 weeks). Of 1187 knees treated, 45%

had 2 courses of treatment, 14% had 3, and a few had 4, 5, or more.

Overall, the incidence of TKR in this population was 19% (n=225 knees),

Waddel and Bricker reported. The incidence was highest in patients who were

obese or aged 60 to 69 years. Logistic regression showed that among

confounding factors of age, gender, body mass index (BMI), and effusion

history, the only significant covariate influencing the odds of having a TKR

was age (p=0.0002).

Of the 1187 knees treated, 962 had not undergone TKR by the end of the study

and a further 407 knees were no longer being seen in that practice. " Given

the assumption that patients no longer being seen in our practice had not

had a TKR during the observation period (October 1997-November 2003), then

replacement surgery was delayed by at least 1370 days (3.8 years) in 75% of

knees treated with hyaluronan, " Waddel and Bricker concluded.

" In patients who are TKR candidates, hyaluronan therapy can delay the need

for surgery, " they conclude. " This is particularly advantageous in patients

for whom TKR is not medically appropriate or patients who fear or who prefer

not to have surgery. "

Applicable to other joints?

Several other presentations at the AAOS reported on the successful use of

intra-articular injections of hyaluronan in other jointsin the hip, ankle,

shoulder, and elbow. At present, all of the hyaluronic products approved in

the US are indicated only for use in knee osteoarthritis, so these other

uses are off-label. But some of the products are already indicated for use

in these other joints in Europe and Canada, leading 1 orthopedic surgeon to

ask jokingly, " What is it that's so different about American joints? "

Results in the ankle and shoulder were presented from new clinical trials

using Hyalgan (Sanofi-Synthelabo). Dr Bob Salk (San Francisco, CA) presented

the ankle data at an oral session, from a controlled trial in 20 patients

with ankle degenerative joint disease with significant pain and disability.

After 6 months, the group treated with weekly hyaluronan injections for 5

consecutive weeks had responses that were both statistically and clinically

significant when compared with the control group treated with saline

injections, he said.

The first breaking data from a multicenter trial in chronic shoulder pain

were presented by Dr Theodore Blaine (Columbia University and New York

Presbyterian Hospital, New York, NY) at a satellite symposium sponsored by

the manufacturer. This trial involved 603 patients, and the protocol was

designed by 3 orthopedic surgeons and 2 rheumatologists in collaboration

with the FDA. Many of the patients (60%) had osteoarthritis (OA) of the

glenohumeral joint, and some had secondary arthritis due to rotator-cuff

tears and/or adhesive capsulitis. The placebo treatment was saline

injections, which had " a fairly significant effect " on pain and patient

response, but in the OA responders group the 50% improvement at 3 months was

statistically significantly better in the hyaluronan treated group (p<0.05),

Blaine noted.

" Hyaluronan products have proven to be effective in treating the pain

associated with osteoarthritis of the knee, and this would seem to be

applicable to other synovial joints, " says Dr Axe (University of

Delaware, Newark). He finds hyaluronan a very useful treatment modality " I

like to keep away from nonsteroidal anti-inflammatory drugs [NSAIDs] as much

as I can, and hyaluronan lets me do this, " but he emphasized that it forms

only part of a treatment program, which also includes nutraceuticals

(glucosamine and chondroitin supplements), may include steroid injections,

and always includes advice on weight reduction and exercise. " And here

doctors must set a good example and not be overweight and be exercising

regularly themselves, " Axe says.

I'll tell you where to go!

Mayo Clinic in Rochester

http://www.mayoclinic.org/rochester

s Hopkins Medicine

http://www.hopkinsmedicine.org