Introduction
Anatomy
Cause & Symptoms
Diagnosis
Treatment
Conclusion
Flexible flatfoot in adult is quite common. About 15% of the adult population was asymptomatic flexible flatfoot. However, symptomatic adult acquired flatfoot should not be overlooked. One of the common causes for adult acquired flatfoot is inflammation of the posterior tibial tendon (posterior tibialis tendinitis).
The posterior tibial muscle attaches to the back of the shin bone. It's tendon passes behind the inner side of the ankle and attaches to the bone of the inner side of the foot. It's main function is to plantar flex your ankle and 'invert' your foot. Moreover, it is the important structure to support the medial foot arch.
Posterior tibialis tendinitis is more often seen in middle-aged obese women. overuse and trauma can cause inflammation of the tendon. Patients with this condition usually complain of pain in the inside of the foot and ankle. If untreated, the medial foot arch may become flattened (Flatfoot). This disease can be classified into 4 stages. In stage 1, there is pain along the tendon in the inner side of the foot. In stage 2, the medial foot arch is flattened and active inversion of the foot is lost. In stage 3, the flatfoot deformity is severe and rigid. If it progresses to stage 4, the ankle joint is degenerated and it is painful and deformed.
In most cases, the diagnosis of the inflammation of the posterior tibial tendon can be made clinically. X-rays are usually done to rule out bony disease, but the tendon cannot be seen on X-ray. If indicated, MRI can be done to reveal inflammation or rupture of the posterior tibial tendon clearly. Diagnostic ultrasound of the tendon is another option to assess the integrity of the tendon.
In early stage of the posterior tibialis tendinitis, the objective of treatment is to restore normal foot alignment and relieve pain. the initial treatment options include use of shoe inserts and arch supports, activity modification, rest, medication and physiotherapy. In some cases, casts are used. Local steroid injection may cause rupture of the tendon and should be avoided. If the patients are not responded to non-operative treatment, operative treatment should be considered.
In early stages of posterior tibialis tendinitis, debridement is the procedure to clean up the inflammation. In more advanced stages, the posterior tibial tendon can be reconstructed with an adjacent tendon. At the same time, bone reconstruction may be needed. In most advanced cases, the preferred treatment is fusion.
Early intervention may halt progression of the disease and prevent deformity. Once deformity sets in, it is usually worsened with time. Therefore, patients with this condition should seek early orthopaedic consultations from orthopaedic specialists for proper diagnosis and treatment.
Dr. Siu Kwai-ming