Peroneal Tendons Injection

Acute or chronic tendinopathy

Causes and findings:
• Overuse
• Pain at lateral side of ankle or foot
• Painful: resisted eversion of the foot
• Tender area above, behind or below the lateral malleolus

Equipment:
Syringe - 1ml
Needle - 25G 0.5 inches (16mm) orange
Kenalog 40 - 10 mg
Lidocaine - 0.75 ml 2%
Total volume - 1 ml

Anatomy:
The peroneus longus and brevis run together in a synovial sheath behind the lateral malleolus. The longus then divides to pass under the arch of the foot to insert at the base of the big toe, and brevis inserts into the base of the fifth metatarsal. The division of the two tendons is the entry point for the needle and can be found by having the patient hold the foot in strong eversion and palpating for the V-shaped fork of the tendons.

Technique:
• Patient lies supine with foot supported in some medial rotation
• Identify and mark division of the two tendons
• Insert needle perpendicularly at this point, turn and slide horizontally under skin towards malleolus
• Deposit solution into combined tendon sheath. There should be minimal resistance and often a sausage-shaped bulge is observed

Aftercare:
Avoid any overuse for about 1 week. Resolution of symptoms should then lead to consideration of change in footwear, orthotics and strengthening of the evertors.

Comments:
Occasionally the tendinopathy occurs at the insertion of the peroneus brevis. The same amount of solution is then peppered into the teno-osseous junction by inserting the needle parallel to the skin to touch the base of the fifth metatarsal.