Direct plantar approach to Henry's knot for flexor hallucis longus transfer.

Background: Transfer of the flexor hallucis longus (FHL) tendon is an established method to replace a dysfunctional Achilles tendon. When using a single incision, the FHL tendon has to be transferred as a single stranded graft into the calcaneus and the distal FHL stump cannot be directly attached to the flexor digitorum longus tendon (FDL). Another concern with tendon retrieval is neurovascular damage.