Flexor Digitorum Longus (FDL) Tendon Transfer to Posterior Tibial Tendon

Indications

This procedure is indicated for patients with a dysfunction of the posterior tibial tendon, where the tendon is either stretched out beyond its functional length or has ruptured. This is common in many aquired adult flatfoot deformity patients. Essentially, this procedure transfers the FDL so that it will do most or all of the work that the posterior tibial tendon had previously done.

Procedure

An incision is made on the inside (medial) of the ankle joint and extended down to the midfoot. After dissecting down, the posterior tibial tendon is identified. The foot is then further dissected down to locate the FDL, which can be identified as a tendon that flexes the 2nd, 3rd, 4th, and 5th toes. The FDL is then cut and transferred into the area where the posterior tibial tendon inserts, which can be done in one of two ways: the FDL can be either wrapped around and sutured to the posterior tendon or can be directly fixed with a screw or suture to the bone which the posterior tibial tendon inserts (navicular tuberosity). Once the tendon is transferred, the wound is closed up.
This procedure is almost invariably done in combination with other procedures, such as a medializing calcaneal osteotomy, a lateral column lengthening, or a gastrocnemius recession (Strayer Procedure) in order to remove the load in the area of the posterior tibial tendon.

Recovery

0-6 Weeks Post-Surgery
Since this procedure is generally done in combination with other procedures, the actual recovery of the tendon transfer is not the slowest healing process. However, patients should generally protect the repair for about 6 weeks to let the tendon transfer heal.

6 Weeks + Post-Surgery
At the 6 week postsurgical mark, patients can begin firing and moving the tendon. Until about 12 months after the surgery, patients will work on re-strengthening the muscle tendon unit. However, keep in mind that the total recovery is set by other procedures that are done.

Potential General Complications


Wound Healing Problem

Infection

Deep Vein Thrombosis (DVT)

Pulmonary Embolism (PE)

Asymmetric Gait

Potential Specific Complications

Weakness in flexion of the toes: Fortunately, this is not clinically significant. Post-surgery, the smaller muscles of the foot are now primarily responsible for flexing the 2-5 toes.

Failure of tendon transfer: If the load is not taken off the area of the transferred tendon, the graft is likely to fail. This likeliness is the reason why other procedures are performed to take off the load.