Overview
Adult-acquired flatfoot or collapsed arch occurs because the large tendon on the inside of the ankle - the posterior tibial tendon - becomes stretched out and no longer supports the foot?s arch. In many cases, the condition worsens and and the tendon thickens, becoming painful, especially during activities. Flatfoot or collapsed arch is also known as posterior tibial tendon dysfunction. This condition is different than having flat feet since birth (known as congenital flatfoot), although sometimes these patients develop similar symptoms and require similar treatments.
Causes
The posterior tibial tendon, which connects the bones inside the foot to the calf, is responsible for supporting the foot during movement and holding up the arch. Gradual stretching and tearing of the posterior tibial tendon can cause failure of the ligaments in the arch. Without support, the bones in the feet fall out of normal position, rolling the foot inward. The foot's arch will collapse completely over time, resulting in adult acquired flatfoot. The ligaments and tendons holding up the arch can lose elasticity and strength as a result of aging. Obesity, diabetes, and hypertension can increase the risk of developing this condition. Adult acquired flatfoot is seen more often in women than in men and in those 40 or older.
Symptoms
The symptom most often associated with AAF is PTTD, but it is important to see this only as a single step along a broader continuum. The most important function of the PT tendon is to work in synergy with the peroneus longus to stabilize the midtarsal joint (MTJ). When the PT muscle contracts and acts concentrically, it inverts the foot, thereby raising the medial arch. When stretched under tension, acting eccentrically, its function can be seen as a pronation retarder. The integrity of the PT tendon and muscle is crucial to the proper function of the foot, but it is far from the lone actor in maintaining the arch. There is a vital codependence on a host of other muscles and ligaments that when disrupted leads to an almost predictable loss in foot architecture and subsequent pathology.
Diagnosis
Starting from the knee down, check for any bowing of the tibia. A tibial varum will cause increased medial stress on the foot and ankle. This is essential to consider in surgical planning. Check the gastrocnemius muscle and Achilles complex via a straight and bent knee check for equinus. If the range of motion improves to at least neutral with bent knee testing of the Achilles complex, one may consider a gastrocnemius recession. If the Achilles complex is still tight with bent knee testing, an Achilles lengthening may be necessary. Check the posterior tibial muscle along its entire course. Palpate the muscle and observe the tendon for strength with a plantarflexion and inversion stress test. Check the flexor muscles for strength in order to see if an adequate transfer tendon is available. Check the anterior tibial tendon for size and strength.
Non surgical Treatment
The following is a summary of conservative treatments for acquired flatfoot. Stage 1, NSAIDs and short-leg walking cast or walker boot for 6-8 weeks; full-length semirigid custom molded orthosis, physical therapy. Stage 2, UCBL orthosis or short articulated ankle orthosis. Stage 3, Molded AFO, double-upright brace, or patellar tendon-bearing brace. Stage 4, Molded AFO, double-upright brace, or patellar tendon-bearing brace.
Surgical Treatment
If conservative treatments don?t work, your doctor may recommend surgery. Several procedures can be used to treat posterior tibial tendon dysfunction; often more than one procedure is performed at the same time. Your doctor will recommend a specific course of treatment based on your individual case. 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 fibers from another tendon (the flexor digitorum longus, which helps bend the toes) to repair the damaged posterior tibial tendon. Lateral column lengthening, In this procedure, the surgeon places a small wedge-shaped piece of bone into the outside of the calcaneus. This helps realign the bones and recreates the arch. 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.
Adult-acquired flatfoot or collapsed arch occurs because the large tendon on the inside of the ankle - the posterior tibial tendon - becomes stretched out and no longer supports the foot?s arch. In many cases, the condition worsens and and the tendon thickens, becoming painful, especially during activities. Flatfoot or collapsed arch is also known as posterior tibial tendon dysfunction. This condition is different than having flat feet since birth (known as congenital flatfoot), although sometimes these patients develop similar symptoms and require similar treatments.
Causes
The posterior tibial tendon, which connects the bones inside the foot to the calf, is responsible for supporting the foot during movement and holding up the arch. Gradual stretching and tearing of the posterior tibial tendon can cause failure of the ligaments in the arch. Without support, the bones in the feet fall out of normal position, rolling the foot inward. The foot's arch will collapse completely over time, resulting in adult acquired flatfoot. The ligaments and tendons holding up the arch can lose elasticity and strength as a result of aging. Obesity, diabetes, and hypertension can increase the risk of developing this condition. Adult acquired flatfoot is seen more often in women than in men and in those 40 or older.
Symptoms
The symptom most often associated with AAF is PTTD, but it is important to see this only as a single step along a broader continuum. The most important function of the PT tendon is to work in synergy with the peroneus longus to stabilize the midtarsal joint (MTJ). When the PT muscle contracts and acts concentrically, it inverts the foot, thereby raising the medial arch. When stretched under tension, acting eccentrically, its function can be seen as a pronation retarder. The integrity of the PT tendon and muscle is crucial to the proper function of the foot, but it is far from the lone actor in maintaining the arch. There is a vital codependence on a host of other muscles and ligaments that when disrupted leads to an almost predictable loss in foot architecture and subsequent pathology.
Diagnosis
Starting from the knee down, check for any bowing of the tibia. A tibial varum will cause increased medial stress on the foot and ankle. This is essential to consider in surgical planning. Check the gastrocnemius muscle and Achilles complex via a straight and bent knee check for equinus. If the range of motion improves to at least neutral with bent knee testing of the Achilles complex, one may consider a gastrocnemius recession. If the Achilles complex is still tight with bent knee testing, an Achilles lengthening may be necessary. Check the posterior tibial muscle along its entire course. Palpate the muscle and observe the tendon for strength with a plantarflexion and inversion stress test. Check the flexor muscles for strength in order to see if an adequate transfer tendon is available. Check the anterior tibial tendon for size and strength.
Non surgical Treatment
The following is a summary of conservative treatments for acquired flatfoot. Stage 1, NSAIDs and short-leg walking cast or walker boot for 6-8 weeks; full-length semirigid custom molded orthosis, physical therapy. Stage 2, UCBL orthosis or short articulated ankle orthosis. Stage 3, Molded AFO, double-upright brace, or patellar tendon-bearing brace. Stage 4, Molded AFO, double-upright brace, or patellar tendon-bearing brace.
Surgical Treatment
If conservative treatments don?t work, your doctor may recommend surgery. Several procedures can be used to treat posterior tibial tendon dysfunction; often more than one procedure is performed at the same time. Your doctor will recommend a specific course of treatment based on your individual case. 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 fibers from another tendon (the flexor digitorum longus, which helps bend the toes) to repair the damaged posterior tibial tendon. Lateral column lengthening, In this procedure, the surgeon places a small wedge-shaped piece of bone into the outside of the calcaneus. This helps realign the bones and recreates the arch. 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.