Flatfoot
Posterior tibial tendon dysfunction
The posterior tibial tendon runs along the inside (medial) aspect of the ankle. Its purpose is to support the arch of the foot. In some patients, this tendon can become inflamed (tendonitis), enlarged (tendinotic), or torn. All of these cause pain on the inside of the ankle. Once the tendon is torn, it can no longer do its job of supporting the arch of the foot, and the foot flattens.
Patients who are born with flat feet are predisposed to developing posterior tibial tendon dysfunction because their flat feet put more tension on the tendon. This is a bit of a vicious cycle, in that the tendon then tears, and the arch falls further.
We will review here the diagnostic and treatment modalities for posterior tibial tendon dysfunction and adult flatfoot disorder.
Diagnosis
The diagnosis is made with x-rays and physical exam.
On examination, the arch will be fallen, and the posterior tibial tendon will usually be swollen, tender, warm, and weak. Sometimes the foot gets so flat that the heel bone bumps into the fibula and causes pain, which will be evident on exam.
On x-ray, the foot will be flat, and any arthritis of the hindfoot will be visible. The x-ray helps to characterize the severity of the deformity.
An MRI is often used to confirm the diagnosis and aid in preoperative planning if nonsurgical treatment is not successful. CT may be used to characterize any arthritis in the hindfoot and guide the specifics of the surgical procedure to be performed.
Nonsurgical treatment
Nonsurgical treatment depends on the duration and severity of the symptoms and the goals of the patient. They can include the following:
Immobilization in a boot or brace
Anti-inflammatory medications (both oral and topical)
Physical therapy
Dr. Bohl will continue with nonsurgical treatment as long as you desire. Many patients — especially those with a short duration of symptoms — are able to get through an acute episode and avoid surgery altogether. Other patients — usually those with a longer duration of symptoms — are able to delay surgery with nonsurgical treatment, but operative treatment is ultimately desired.
Flatfoot without arthritis
For adult patients who have posterior tibial tendon dysfunction, fallen arches, and no arthritis of the hindfoot, Dr. Bohl recommends “joint-sparing” reconstruction. The purpose of this procedure is to take pressure off the diseased posterior tibial tendon, reconstruct the arch of your foot, and relieve your pain. This procedure consists of multiple components tailored to your specific condition:
Reshaping the heel bone (calcaneus) to rebuild the back portion of your arch. This is fixed with metal screws.
Reshaping a midfoot bone (the medial cuneiform bone) to rebuild the front portion of your arch.
Reconstructing a ligament (the spring ligament) on the inside (medial side) of your foot that supports your arch.
Moving the flexor digitorum longus tendon from its normal attachment to the toes to a midfoot bone (the navicular) in order to substitute for the diseased posterior tibial tendon.
After surgery, you will be placed in a splint for 2 weeks. You will then be placed in a cast for 4 weeks. After that, you can begin putting weight on your foot, but you must wear a boot for an additional 4 weeks.
Results of this procedure are excellent in terms of pain relief, function, and maintenance of the arch. Patients are usually able to return to most of the activities that they enjoy.
Flatfoot with arthritis
For adult patients who have posterior tibial tendon dysfunction, fallen arches, and a stiff or arthritic hindfoot, Dr. Bohl recommends fusion of the hindfoot joints. This may involve fusion of just the subtalar joint, in which case it is combined with the flexor digitorum longus tendon trasnfer described above. Or it may involve fusion of the subtalar, talonavicular, and calcaneocuboid joints, in which case it is termed a “triple arthrodesis.”
Fusion of the hindfoot in this manner allows the entire foot to be powerfully shaped, so it is particularly advantageous in patients with severe flatfoot. Fusion of the joints eliminates the posterior tibial tendon as a pain generator, and also relieves any pain due to arthritis. After surgery, you will be palced in a splint for 2 weeks. You will tehn be placed in a cast for 4 weeks. After that, you can begin putting weight on your foot but you must wear the boot for an additional 4 weeks.
Patients are typically extremely happy with the outcome and able to return to wearing regular shoes without the use of a brace and most of the activities they enjoy.