What is a first MTP joint interposition arthroplasty?

The first MTP, also called the first metatarsophalangeal joint, is the big toe joint. A first MTP joint interposition arthroplasty is a surgical procedure to treat arthritis of the big toe. The treatment can stop pain at the base of the big toe by preventing the surfaces of the bones from rubbing together. It also can preserve some motion in the big toe.

Symptoms

The main symptoms of arthritis are pain and loss of motion at the joint between the big toe and the foot. Your foot and ankle orthopaedic surgeon will examine you and take X-rays to determine the extent of your arthritis. If it is severe, this procedure may be an option.

Patients with infection or blood vessel disease should not be considered for this surgery. Young age and poor skin around the joint or large deformities are sometimes barriers to surgery. Diabetics should consult their doctor before this surgery.

Treatment

An incision is made over the first MTP joint and carried down to the joint. The joint surfaces along with a small amount of bone are removed. The remaining space can be treated in two different ways.

In one method, a sheet of tissue is placed over the bone and stitched into place to resurface the joint. This material can come from another part of your body, a donor or a graft made from animal or synthetic materials.

A newer technique uses a synthetic cartilage implant plug made out of polyvinyl alcohol as a spacer, without covering the surface area of the joint. This procedure requires less bone removal and is easier to convert to fusion if it fails. It also has shown to be as effective as fusion in relieving pain, while preserving motion of the joint. This is a newer procedure; however, current studies have demonstrated good results that appear likely to hold up over time. Many foot and ankle orthopaedic surgeons find this procedure helpful but at present it is not universally accepted. 

Recovery

After surgery, a gauze dressing and a wrap such as elastic bandages are placed over the toe and foot. The joint should be immobilized followed by early motion to prevent stiffness. Physical therapy may be used to improve motion and strength. Patients should keep their foot elevated as much as possible to reduce swelling. There may be a brief period of time where you should not weight bear but in general you will get back to limited walking within a few weeks of your surgery. Stitches generally are removed after 10 to 15 days, depending on the condition of the skin. Patients are encouraged to wear a hard-soled shoe.

Risks and Complications

All surgeries come with possible complications, including the risks associated with anesthesia, infection, damage to nerves and blood vessels, and bleeding or blood clots. 

One of the most frequent complications of first MTP joint interposition arthroplasty is failure to relieve pain or preserve motion. Another complication is rejection of the tissue placed in the gap, which may require further surgery. Other complications can include pain at the base of the second toe, delayed wound healing, recurrent deformity, bony overgrowth, disintegration of bone around the graft, implant displacement, instability of the joint and injury to the nerves of the big toe.

FAQs

When can I return to work?
It depends on the physical requirements of your work and your individual pain tolerance. When you can tolerate pain without pain medication and you can walk without assistive devices you can return to a sedentary occupation (desk work, etc.). For more physically strenuous occupations, it could take as much as 12 weeks to safely return to work. You and your orthopedic foot and ankle surgeon can decide when it is right for you to return to work.

Can I play sports after first MTP joint interposition arthroplasty?
Strenuous physical activity such as running, jumping and rock climbing is thought to lead to early failure of the procedure. Light activity, such as walking and cycling, can be performed after the initial healing without significant risk of early failure. Again, this is a matter to be discussed with your orthopedic foot and ankle surgeon.

Will first MTP joint interposition arthroplasty improve my range of motion? 
It is unlikely that you will regain more motion than you had prior to surgery.

The American Orthopaedic Foot & Ankle Society (AOFAS) offers information on this site as an educational service. The content of FootCareMD, including text, images, and graphics, is for informational purposes only. The content is not intended to substitute for professional medical advice, diagnoses or treatments. If you need medical advice, use the "Find a Surgeon" search to locate a foot and ankle orthopaedic surgeon in your area.