First Metatarsal-phalangeal (MTP) Total Joint Replacement (MOVEMENT)
This procedure uses a small, two-piece implant to cover damaged or missing articular cartilage in the MTP joint, where the base of the great toe meets the foot. The implant restores mobility to the bones of this joint, allowing them to glide smoothly against each other. This procedure is commonly used to treat hallux rigidus, also called stiff big toe.
Accessing the Joint
In preparation for the procedure, the patient is positioned and anesthetized. The surgeon makes an incision along the top of the foot to access the joint at the base of the great toe, and the joint is exposed and examined.
Preparing the Metatarsal
The surgeon begins by focusing on the metatarsal. A guide wire is inserted into the end of the metatarsal. The surgeon pushes a reamer along this wire and down to the surface of the bone. The surgeon uses the reamer to remove bone and cartilage from the head of the metatarsal, which will create a stable base for the implant. After the end is cleaned, the surgeon drills a hole into the end of the bone so the implant can be inserted. Finally, the head of the metatarsal is carefully shaped for a precise fit.
Preparing the Proximal Phalanx
After work on the metatarsal is complete, the surgeon focuses on the phalanx. The surgeon inserts a guide wire into the head of the phalanx, and uses a reamer to clean and shape the end of this bone. After the end is cleaned, the surgeon drills a hole into the end of the bone so the implant can be inserted.
Inserting the Components
The implant can now be placed within the joint. The surgeon inserts the metatarsal component and the phalangeal component, gently tapping both into place. The components are joined, and the surgeon tests the implant to ensure that the toe has a smooth range of motion.
End of Procedure and Aftercare
When the procedure is complete, the incision is closed with sutures and the foot is bandaged. The foot may be placed in a weight-bearing postoperative shoe as the toe heals, and the patient may be encouraged to begin moving the toe soon after surgery. Physical therapy may be needed.