Flexor Hallicus Longus Tendon Transfer to the Proximal Phalanx of the Big Toe

What is a flexor hallicus longus tendon transfer?

A flexor hallicus longus (FHL) tendon transfer to the proximal phalanx of the big toe is used to treat clawing of the big toe.

What is clawing of the big toe?

Small muscles in the foot help to stabilize the big toe. When those muscles are weakened by disease, an imbalance occurs

Points of pressure resulting from clawing of the big toe.
  that leads to clawing. The clawing results in abnormal pressure to the ball of the foot and can result in the formation of an ulcer. In addition, clawing may lead to pressure on top of the toe from shoewear. Clawing is associated with a variety of underlying disorders, including Charcot-Marie-Tooth disease, diabetic neuropathy, head injury, polio and stroke.

What is the goal of an FHL tendon transfer?

The primary goal of this procedure is to decrease the abnormal pressures on the big toe both in the ball of the foot and at the tip of the toe. This will prevent ulcer formation, or in the case of an existing ulcer, promote healing. An FHL tendon transfer is often done at the same time as other foot procedures.

What signs indicate surgery may be needed?

Indications for the FHL transfer are clawing of the big toe with pain and/or ulcer formation.

When should I avoid surgery?

This procedure should not be done when there is uncontrolled infection of the soft tissue or bone of the big toe. Also, surgery is not recommended if you have poor peripheral circulation that would prevent proper healing.

General Details of the Procedure

Once the patient is under anesthesia, the surgeon makes an incision along the inside of the big toe. The surgeon takes care to protect the nearby nerve and artery. The tendon is released from its attachment and a stitch is placed into the end of it. A hole is drilled in the bone at the base of the toe close to the metatarsophalangeal (MTP) joint. The tendon is passed through the hole from the bottom of the toe up to the top of the toe, and a stitch is used to tie the tendon securely back to itself.

Although releasing the tendon can allow the toe to straighten, release of the contracted joint capsule is often necessary as well. The FHL tendon transfer is often used in combination with other procedures to correct other foot deformities.

What happens after surgery?

Typically the foot is splinted for 10 to 14 days while the incision heals. At that point stitches are removed and a walking boot is worn for four weeks. During that time weight bearing in the boot may be allowed. If there are other procedures performed at the same time, weight bearing may be further delayed and a cast may be necessary. Swelling can persist for several months.

Potential Complications

There are complications that relate to surgery in general. These include the risks associated with anesthesia, infection, damage to nerves and blood vessels, and bleeding or blood clots.
Complications specific to the tendon transfer include loss of fixation of the transfer and/or recurrence of the deformity. Stiffness at the great toe MTP joint can also be a problem.

Frequently Asked Questions

I have an ulcer on my big toe. Can I still have surgery?
While not ideal, some ulcers may not be a barrier to surgery, especially since an FHL tendon transfer usually helps with ulcer healing.
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