Treatment varies depending on the severity of the condition and may include rest, immobilization, medication, and surgery.
This article explains what this condition is, how it occurs, the symptoms to watch out for, and how to treat it.
Posterior Tibial Tendon Anatomy
The posterior tibial muscle attaches to the back of the shin bone. The posterior tibial tendon connects this muscle to the bones of the foot. A tendon is a thick cord of tissue that attaches a muscle to a bone.
The posterior tibial tendon passes down the back of the leg, not far from the Achilles tendon. It then turns under the inner side of the ankle. Here, it attaches to the bone of the inner side of the foot, just next to the arch of the foot.
Posterior tibial tendon problems usually occur just underneath the inner side of the ankle, called the medial malleolus. The medial malleolus is the end of the shin bone (the tibia). It’s the big bump you feel on the inside of your ankle. The posterior tibial tendon wraps just underneath the medial malleolus.
Posterior Tibial Tendonitis Symptoms
Most commonly, people with posterior tibial tendonitis:
Feel pain on the inner side of the foot and ankleMay have an unsteady gait May have trouble maintaining stability while walking
Many people with this condition report having had a recent ankle sprain. However, some will have had no recent injury. The tendon can also be damaged from overuse.
As the condition gets worse, the foot’s arch can flatten, and the toes begin to point outwards. This is the result of the posterior tibial tendon not doing its job to support the arch of the foot.
Adult-Acquired Flatfoot Deformity
When left untreated, posterior tibial tendonitis can gradually bring on a problem called adult-acquired flatfoot deformity (AAFD), also known as a “fallen arch.” This condition typically begins with pain and weakness of the tendon.
As AAFD advances, the ligaments of the foot are affected. The foot joints may no longer line up correctly and may become set in the wrong position. For this reason, most physicians prefer early treatment before the later stages of AAFD.
Diagnosis
A podiatrist, or doctor who specializes in foot and ankle problems, can diagnose posterior tibial tendonitis by physical examination. People with the condition have:
Tenderness and swelling along the posterior tibial tendonWeakness when trying to point their toes inwardTrouble standing on their toes on the affected side
If the examination is unclear or your doctor is considering surgical repair, they may order a magnetic resonance imaging (MRI) scan. The MRI can determine whether the tendon has ruptured, and where. It can also show inflammation surrounding the tendon.
Stages
Posterior tibial tendonitis is classified according to the stage of the condition. Stage 1 through stage 4 indicate increasing deformity (abnormal shape) of the foot as the condition progresses:
Stage 1: The earliest stage is having pain and swelling along the tendon. The foot may appear completely normal. On the other hand, some people may notice their foot has a mild flatfoot deformity. This may be something they feel they have always had. Stage 2: As the condition progresses, the arch of the foot begins to collapse. When they stand, the foot appears flat along its inner side. At this stage, it may be possible to correct the flattened arch. Stage 3: In stage 3 of the condition, called a rigid flatfoot deformity, a physician cannot easily correct the foot. Stage 4: In stage 4, not only is the foot involved, but the adjacent ankle joint also is affected by the condition.
As these stages progress, more extensive treatments are needed to correct the problem.
Posterior Tibial Tendonitis Treatment
Treatment varies depending on the stage of the tendonitis. In the early stage, it mostly involves rest. Later, it may require surgery.
Early Treatment
The initial treatment of posterior tibial tendonitis is rest so that the tendon can heal. Unfortunately, even normal walking may get in the way of allowing the tendon to heal adequately.
Options for early treatment include:
Shoe inserts and arch supports, which prevent motion between the middle and back of the foot and decrease inflammation Walking boots, which can help decrease inflammation Casts, which are the safest method to ensure the tendon is adequately rested Anti-inflammatory medications, which help reduce inflammation around the tendon Limiting activity, which can help the tendon rest and reduce inflammation around it Cortisone shots, which may be injected around the posterior tibial tendon to reduce inflammation and pain Physical therapy, which may include stretching and strengthening exercises, as well as massage
Research also suggests that taping may help reduce improper movement of a functional posterior tibial tendon and slightly increase muscle activity for the first 15 minutes of running.
Surgical Options
Surgical treatment of posterior tibial tendonitis is controversial. Surgical options vary depending on the extent of the condition and include:
Debridement: In the early stage, some surgeons may recommend a procedure to clean up the inflammation. During debridement, the inflamed tissue and abnormal tendon are removed. This allows for the healing of the damaged tendon. Reconstruction: In more advanced stages, the arch of the foot collapses and your doctor may surgically reconstruct the area. This involves using a neighboring tendon, called the flexor digitorum longus, to replace the damaged posterior tibial tendon. Bones in the foot may be cut and reshaped to create a new arch, as well. Fusion: Finally, in the most advanced cases, when the foot’s arch has become rigid, doctors often prefer a fusion procedure, where the bones and joints in the foot are fixed in place to restore the arch.
Summary
Posterior tibial tendonitis is a condition that results in pain on the inner side of the foot and ankle. It may cause instability while walking. Over time, the condition can lead to the arches becoming flattened, a condition called adult-acquired flatfoot deformity (AAFD).
Your doctor will diagnose this condition based on a physical examination and imaging techniques. Treatment depends on how advanced the condition is.
A Word From Verywell
Posterior tibial tendonitis and adult-acquired flatfoot deformity can be frustrating problems. Often, people feel their discomfort and instability are ignored by a doctor who may not recognize the problem.
However, it’s best to treat the condition early, before it gets worse. So, it’s important to find a doctor who will listen to you and take your symptoms seriously.
Once in the later stages, surgery is usually needed, and you may lose some function in your foot. For these reasons, early treatments such as wearing a cast, boot, or brace and getting physical therapy are important.
