Posterior Tibial Tendon Dysfunction (PTTD)
What Is PTTD?
The posterior tibial tendon is one of the main supporting structures of the arch of the foot. Posterior tibial tendon dysfunction (PTTD) is a condition caused by inflammation and weakness in the tendon, impairing its ability to support the arch. This results in flattening of the foot.
PTTD is often called "adult acquired flatfoot" because it is the most common type of flatfoot developed during adulthood. Although this condition typically occurs in only one foot, some people may develop it in both feet. PTTD is usually progressive, which means it will keep getting worse, especially if it isn't treated early.
What causes of posterior tibial tendon dysfunction?
Overuse of the posterior tibial tendon is often the cause of PTTD. In fact, the symptoms usually occur after activities that involve the tendon, such as running, walking, hiking, or climbing stairs. An acute injury, such as from a fall, can tear the posterior tibial tendon or cause it to become inflamed. Once the tendon becomes inflamed or torn, the arch will slowly fall (collapse) over time.
Posterior tibial tendon dysfunction is more common in women and in people older than 40 years of age. Additional risk factors include obesity, diabetes, and hypertension.
What are the Symptoms?
- Pain along the inside of the foot and ankle, where the tendon lies. This may or may not be associated with swelling in the area.
- Pain that is worse with activity. High-intensity or high-impact activities, such as running, can be very difficult. Some patients can have trouble walking or standing for a long time.
- Pain on the outside of the ankle. When the foot collapses, the heel bone may shift to a new position outwards. This can put pressure on the outside ankle bone. The same type of pain is found in arthritis in the back of the foot.
What can be done to reduce the pain?
Because of the progressive nature of PTTD, early treatment is advised. If treated early enough, your symptoms may resolve without the need for surgery and progression of your condition can be arrested.
In contrast, untreated PTTD could leave you with an extremely flat foot, painful arthritis in the foot and ankle, and increasing limitations on walking, running, or other activities.
In many cases of PTTD, treatment can begin with non-surgical approaches that may include:
Rest: Decreasing or even stopping activities that worsen the pain is the first step. Switching to low-impact exercise is helpful. Biking, elliptical machines, or swimming do not put a large impact load on the foot, and are generally tolerated by most patients.
Anti-inflammatory Medication: Drugs, such as ibuprofen or naproxen, reduce pain and inflammation. Taking such medications about a half of an hour before an exercise activity helps to limit inflammation around the tendon. The thickening of the tendon that is present is degenerated tendon. It will not go away with medication. Talk with your primary care doctor if the medication is used for more than 1 month.
Immobilization: A short leg cast or walking boot may be used for few weeks. This allows the tendon to rest and the swelling to go down. However, a cast causes the other muscles of the leg to atrophy (decrease in strength) and thus is only used if no other conservative treatment works.
Orthotics: Most people can be helped with orthotics and braces. An orthotic is a shoe insert. It is the most common nonsurgical treatment for a flatfoot. An over-the-counter orthotic may be enough for patients with a mild change in the shape of the foot. A custom orthotic is required in patients who have moderate to severe changes in the shape of the foot. The custom orthotic is more costly, but it allows the doctor to better control the position the foot.
Braces: A lace-up ankle brace may help mild to moderate flatfoot. The brace would support the joints of the back of the foot and take tension off of the tendon. A custom-molded leather brace is needed in severe flatfoot that is stiff or arthritic. The brace can help some patients avoid surgery.
Physical Therapy: Physical therapy that strengthens the tendon can help patients with mild to moderate disease of the posterior tibial tendon.
PRP Injection: Recent reports with PRP injections are encouraging, however there is no evidence to support its routine use. Cortisone injection into the posterior tibial tendon is not normally done. It carries a risk of tendon rupture.
When Is Surgery Needed?
In cases of PTTD that have progressed substantially or have failed to improve with non-surgical treatment, surgery may be required. For some advanced cases, surgery may be the only option. Your foot and ankle surgeon will determine the best approach for you.
The following is a list of the more commonly used operations. Additional procedures may also be required:
Lengthening of the Achilles Tendon or Gastrocnemius Recession
This is a surgical lengthening of the calf muscles. It is useful in patients who have limited ability to move the ankle up. This surgery can help prevent flatfoot from returning, but does create some weakness with pushing off and climbing stairs. Complication rates are low but can include nerve damage and weakness. This surgery is typically performed together with other techniques for treating flatfoot.
Tenosynovectomy (Cleaning the Tendon)
This surgery is used when there is very mild disease, the shape of the foot has not changed, and there is pain and swelling over the tendon. The surgeon will clean away and remove the inflamed tissue (synovium) surrounding the tendon. This can be performed alone or in addition to other procedures. The main risk of this surgery is that the tendon may continue to degenerate and the pain may return.
Tendon transfer can be done in flexible flatfoot to recreate the function of the damaged posterior tibial tendon. In this procedure, the diseased posterior tibial tendon is removed and replaced with another tendon from the foot, or, if the disease is not too significant in the posterior tibial tendon, the transferred tendon is attached to the preserved (not removed) posterior tibial tendon.
One of two possible tendons are commonly used to replace the posterior tibial tendon. One tendon helps the big toe point down and the other one helps the little toes move down. After the transfer, the toes will still be able to move and most patients will not notice a change in how they walk.
Although the transferred tendon can substitute for the posterior tibial tendon, the foot still is not normal. Some people may not be able to run or return to competitive sports after surgery. Patients who need tendon transfer surgery are typically not able to participate in many sports activities before surgery because of pain and tendon disease.
Osteotomy (Cutting and Shifting Bones)
An osteotomy can change the shape of a flexible flatfoot to recreate a more "normal" arch shape. One or two bone cuts may be required, typically of the heel bone (calcaneus).
If flatfoot is severe, a bone graft may be needed. The bone graft will lengthen the outside of the foot. Other bones in the middle of the foot also may be involved. They may be cut or fused to help support the arch and prevent the flatfoot from returning. Screws or plates hold the bones in places while they heal.
X-ray of a foot as viewed from the side in a patient with a more severe deformity. This patient required fusion of the middle of the foot in addition to a tendon transfer and cut in the heel bone.
Sometimes flatfoot is stiff or there is also arthritis in the back of the foot. In these cases, the foot will not be flexible enough to be treated successfully with bone cuts and tendon transfers. Fusion (arthrodesis) of a joint or joints in the back of the foot is used to realign the foot and make it more "normal" shaped and remove any arthritis. Fusion involves removing any remaining cartilage in the joint. Over time, this lets the body "glue" the joints together so that they become one large bone without a joint, which eliminates joint pain. Screws or plates hold the bones in places while they heal.
What are the Complications of surgery?
The most common complication is that pain is not completely relieved. Nonunion (failure of the body to "glue" the bones together) can be a complication with both osteotomies and fusions. Wound infection is a possible complication, as well.
Is the surgery successful?
Most patients have good results from surgery. The main factors that determine surgical outcome are the amount of motion possible before surgery and the severity of the flatfoot. The more severe the problem, the longer the recovery time and the less likely a patient will be able to return to sports. In many patients, it may be 12 months before there is any great improvement in pain.