Botulinum Toxin's Orthopedic Applications
BY ARIELLA P. GOLOMB, MD, AUGUST 22, 2006
You've heard about Botox being used to reduce wrinkles, but did you know it can also be used by orthopedic surgeons?
"Botulinum toxin and its orthopaedic applications" was reviewed in this month's British volume of the Journal of Bone and Joint Sugery in an article by Drs. M. Ramachandran and D.M. Eastwood. We've summarized some of the highlights from the review article below.
What is it?
Clostridium botulinium bacteria got its name in the late 19th century from the Latin word for sausage, botulus, after a neurotoxin caused an outbreak of food poisining from blood sausages. There are seven types of the neurotoxin, BTX, released by the bacteria. BTX can cause a fatal condition in humans resulting in flaccid paralysis and subsequent respiratory failure following exposure from contaminated food, wound infections or the intestinal botulism toxin found in infants. However, the neurotoxin has been isolated for beneficial clinical uses; BTX-A has been studied most widely and is currently available commercially as Allergan's Botox and Ipsen's Dysport.
How does it work?
BTX prevents the release of acetylchonline at the neuromuscular junction. Its effects (chemodenervation with muscle relaxation) last for 12 to 16 weeks, and it takes at least six months for restoration at the cellular level. When administering BTX, the toxin must be injected within the fascial compartment of the muscle in sufficient quantity to reach the neuromuscular junctions without unwanted spread. Unlike simple palpation techniques used in cosmetic procedures, electrical stimulation or other guided techniques have been recommended in orthopedics to localize the individual target muscle for needle placement. There is still uncertainty surrounding the ideal location, number and volume of injections within the muscle.
How can it be used in orthopedics?
The licensed (or on label) uses for orthopedics are few. The majority of use takes place "off-licence". BTX is a popular treatment for dystonic or spastic muscles and often requires concomintant physiotherapy and/or splinting. Treatment has the potential to prevent deformity, relieve pain, improve range of movement and aid control of bladder function. The authors point out that little is known about the long-term effects of regular use.
Potential indications include:
*Cerebral palsy and other central nervous system (CNS) conditions such as multiple scelerosis, stroke, head injury and spinal injury.
*Other pediatric orthopedic conditions including congenital talipes equinovarus (clubfoot), idiopathic toe walking, congenital and acquired muscular torticollis (wryneck) and neonatal injury to the brachial plexus.
*Other potential indications include pain syndrome secondary to muscle spasm (such as in whiplash and low back pain), lateral epicondylitis (tennis elbow) and tendon repair (to "protect" repairs in rehabilitation of children or other patients with difficult compliance).
