Botox for Knee Arthritis
This off label use for Arthritis is offered at our clinic by Dr. Esmond. The cost is $400 which covers the cost of therapeutic botox needed to treat one knee. To book your appointment, please call 905 808 7546.
Intra-articular injections of botulinum A toxin (Botox, Allergan) decrease refractory joint pain and improve function, according to the first-ever study looking at the use of this toxin in joints. The new findings were reported at the American College of Rheumatology 2004 meeting.
In this open-label, pilot study, 7 frail elderly patients with shoulder pain received intra-articular injections of 50 to 100 units of Botox into the joint and 5 patients with refractory lower-joint pain received intra-articular injections of 25 to 50 units of the toxin.
"There was a striking decrease in pain within 4 to 6 weeks after injection, and several people's pain continued decreasing until after 2 months. Thereafter, there was a gradual increase in pain," says Dr Marin L Mahowald (University of Minnesota Medical School, Minneapolis)."This may be an interim treatment to delay surgery."
Overall, pain relief lasted 3 to 12 months, according the 1-year follow-up data. Three patients had a slow increase in pain, but not to the pre-injection levels of severity.
Among shoulder-pain patients, there was a 71% mean maximum decrease in shoulder pain 4 to 12 weeks after injection, dropping from 8.2 to 2.4 on a 0-10 score of ascending pain severity. In addition, this group showed a 67% increase in degree of forward flexion and a 42% increase in degree of active abduction. Patients who had injections in their lower-extremity joints had a 55% mean maximum decrease in joint pain and severity 4 to 12 weeks after injection. This group also achieved a 36% improvement in the time to perform sit-to-stand exercises 10 times, down from 36 seconds before to 23 seconds after the injection.
Mahowald injected a total of 15 joints (9 shoulders, 3 knees, and 3 ankles). There were 9 male and 2 female patients, with an age range of 42 to 82, including 5 rheumatoid arthritis (RA) patients, 1 psoriatic arthritis patient, and 5 osteoarthritis (OA) patients. In the study, 14 of 15 joints injected achieved a 30% reduction in pain and 10 of 15 joints had a 50% or greater pain reduction. Patients requested reinjection of 2 shoulders at 3 months, 2 shoulders at 9 months, and a knee at 10 months. Botox was effective on reinjection. Since completing this study, Mahowald says that she has even done 1 injection into a hip joint, and "it worked."
Exactly how this toxin works to reduce joint pain is not known, but Mahowald suspects it inhibits the release of neuropeptides involved in pain production and transmission. She initiated the trial without any pharmaceutical support based on preliminary data in animals showing it may have an effect, positive reports of its use in cervical dystonia, and its serendipity as a migraine treatment.
Safety "was a big concern," she says, especially given its off-label use and the unique mode of injection used in this study. However, there was no increase in joint swelling, erythema, tenderness, fatigue, or dyspnea. In addition, no adverse events were seen among patients who were reinjected.
"These encouraging results must be verified by randomized placebo-controlled trials, which are under way," Mahowald cautions. The new study involves injecting of 100 units of Botox or saline into shoulders and knees.
The primary outcome is pain at 1 month. If there is no reported pain relief, subjects can roll over into an open-label trial. The new trial will also assess function with the Western Ontario and McMaster University Osteoarthritis Index (WOMAC), and SF-36 will be used to measure quality of life. Currently, Botox is US FDA-approved to treat strabismus, blepharospasm, hemifacial muscle spasm, glabellar lines, and severe primary axillary hyperhidrosis.
Botox has been used by other investigators for both low back and neck disorders. It is injected directly into the muscle and appears to work by eliminating the severe muscle spasm which affects many patients who have osteoarthritis in both the neck and low back.