|
Year |
2003 |
|---|---|
|
Question Number |
242. |
|
Category |
Foot and Ankle |
Question
A 21-year-old woman lacerated the peroneal nerve at the level of the fibular head on a skiing accident 24 months ago. Because she does not want to continue to use an ankle-foot orthosis, treatment should consist of
1- transfer of the Achilles tendon to the peroneus longus
2- transfer of the flexor hallucis longus to the medial cuneiform
3- interosseous transfer of the posterior tibial tendon to the lateral foot
4- extensor hallucis tendon transfer
5- split anterior tibial tendon transfer
Figures
Answer (click for answer)
The answer is 3. A patient with a peroneal nerve injury will not have ankle dorsiflexion, hindfoot eversion or dorsiflexion of the great toe making walking very difficult without a brace. The overpowering of her posterior tibial tendon will bring the foot in plantarflexion and inversion.
Essentially if this patient wants to walk without a brace, then the procedure must address dorsiflexion of her foot. #1 is wrong because the Achilles tendon tranfer to the peroneus longus may help with eversion but not with dorsiflexion. #4 and #5 wont work because these tendons are out anyway and #3 does not make sense for what we are trying to obtain. The one procedure here that helps obtain a balanced foot to allow some ambulation without a brace is the tranfer of the posterior tibial tendon to the lateral foot. It is not clear from the questions if they were talking about a split transfer or not.
The posterior tibial tendon is passed from posterior to anterior through the interosseous membrane and brought to the lateral aspect of the foot, it can also be split (most commonly done) and half goes to the dorsum of the foot into bone and the other half tenodesed to the peroneal tendons. If the patient has a claw toe deformity then transferring the EHL to the 1st metatarsal and fusion of the great toe IP joint can also be done.
Reference: Lipscomb PR, Sanchez J: Anterior transplantation of the posterior tibial tendon for persistent palsy of the common peroneal nerve. J Bone Joint Surg Am 1961;43:60.
Weisseman G: Tendon transfers for peripheral nerve injuries of the lower extremity. Orthop Clin North Am 1981;12:459.
Dehne R: Congenital and acquired neurologic disorders, in Coughlin MJ, Mann RA (eds): Surgery of the Foot and Ankle, ed 7. St Louis, MO, Mosby, 1999, pp 552-557.