Subcutaneous botulinum toxin type a injection for chronic medial knee pain with ostheoarthritis

Ahn, Kang; Jhun, Hyung Joon; Lee, Young Jin; Kim, Eun Ha; Lim, Tae Kyun; Lee, Sangchul

Clinical Research

General Article

Anesthesia and Pain Medicine 2009;4(3):221-225.
Published online July 31, 2009.

Subcutaneous botulinum toxin type a injection for chronic medial knee pain with ostheoarthritis

Kang Ahn, Hyung Joon Jhun, Young Jin Lee, Eun Ha Kim, Tae Kyun Lim, Sangchul Lee

¹Chronic Pain Management Center, Cha Biomedical Center, Kangnam Cha Hospital, Pochon Cha University, Seoul, Korea.
²Department of Occupational and Environmental Medicine, College of Medicine, Korea University, Seoul, Korea.
³Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul, Korea. sangclee@snu.ac.kr

Abstract

BACKGROUND
This study was designed to evaluate the efficacy of subcutaneous Botulinum toxin type A (BoNT-A) injection for treating chronic medial knee pain with osteoarthritis.
METHODS
A randomized, double-blind, placebo-controlled clinical trial was conducted at a university hospital in Korea.The subjects suffering from chronic medial knee pain with osteoarthritis were randomly allocated to either the BoNT-A (treatment, n = 23) group or the normal saline (placebo, n = 27) group.Injections were given to 10 points per unilateral knee along the course of the saphenous nerve.A total of 90 units of BoNT-A (60 units at baseline and 30 units after 1 week) was given for treating unilateral knee pain and a total of 180 units of BoNT-A was given for treating bilateral knee pain.The placebo group received the same volume of normal saline.
RESULTS
The Visual Analog Scale (VAS) pain score was significantly decreased in both the BoNT-A and normal saline groups 1, 4 and 12 weeks after injection.After adjusting for covariates, BoNT-A had a 0.788 times higher effect to decrease the VAS score than did normal saline, but the effect was marginally significant (P = 0.050).
CONCLUSIONS
Subcutaneous injection along the course of the saphenous nerve significantly reduces chronic medial knee pain. The pain reduction effect of BoNT-A is higher than that of placebo, but the effect is marginally significant

Key Words: botulinum toxin, clinical trial, knee pain