This condition is also known, more technically, as Posterior Tibial Tendon Dysfunction (PTTD). It occurs when the posterior tibial tendon (which holds up your arch and provides support as you step off on your toes when walking) becomes inflamed, overstretched or torn. The result may be pain in the inner ankle and gradual loss of the inner arch on the bottom of the foot, leading to flatfoot.
Progressive flatfoot often occurs in women over 50 years of age and may be due to an inherent abnormality of the tendon. However, others factors can increase the risk of developing the condition, including obesity, diabetes and hypertension.
- Pain and swelling on the inside of the ankle
- Loss of the arch and the development of a flat foot
- Gradual development of pain on the outer side of the ankle or foot
- Weakness and an inability to stand on the toes
- Tenderness over the midfoot, especially when under stress during activity
Treatment will depend on how far the condition has progressed. In the early stages, nonsteroidal anti-inflammatory drugs such as aspirin or ibuprofen will help to relieve pain and the foot may be immobilised for six to eight weeks with a rigid below-knee cast or boot to prevent overuse. After the cast is removed, shoe inserts such as a heel wedge or arch support may be helpful.
If conservative treatments don't work, a specialist may recommend surgery. Surgical options include:
- Tenosynovectomy. In this procedure, the surgeon will clean away (debride) and remove (excise) any inflamed tissue surrounding the tendon.
- Osteotomy: This procedure changes the alignment of the heel bone (calcaneus). The surgeon may sometimes have to remove a portion of the bone.
- Tendon transfer: This procedure uses some fibres from another tendon (the flexor digitorum longus, which helps bend the toes) to repair the damaged posterior tibial tendon.
- Arthrodesis: This procedure welds (fuses) one or more bones together, eliminating movement in the joint. This stabilizes the hindfoot and prevents the condition from progressing further.