ESSENTIALS OF DIAGNOSIS
Can have a wide array of complaints, including arch pain, pain along course of posterior tibial tendon, muscle fatigue, heel pain, or lateral ankle pain.
Inability to perform or pain upon performing a single-leg heel raise.
Decreased medial longitudinal arch height.
Difficulty in walking.
Difficulty with shoe wear.
Flatfoot deformity is a very common problem, but a majority of flatfeet are asymptomatic. Flatfoot is also known as adult acquired flatfoot, pes planus, or pes planovalgus. There is a wide range of presenting ages and complaints. Flatfoot is a progressive deformity characterized by the collapse of the medial longitudinal arch with forefoot abduction and hindfoot valgus (Figures E5–6 and E5–7). There are numerous causes of flatfoot including rearfoot equinus, tendon laceration, tarsal coalition, arthritis, neuroarthropathy, muscle imbalances, ligamentous laxity, and neurologic weakness. Most cases of flexible pes planus are associated with generalized ligamentous laxity.
Weight-bearing examination of collapse of the medial longitudinal arch and the foot in a pronated position. (Used, with permission, from C. Parks, DPM.)
“Too many toes” sign with the forefoot abduction where the lesser toes are visible laterally. Also seen is the hindfoot valgus deformity. (Used, with permission, from C. Parks, DPM.)
The most common etiology of flatfoot deformity is posterior tibial tendon dysfunction. Even with most causes associated with posterior tibial tendon dysfunction, it is still necessary to evaluate patients for other possible causes to ensure optimal treatment. Patients with congenital ligamentous laxity secondary to Down syndrome, Marfan syndrome, or Ehlers-Danlos syndrome are susceptible to developing flatfoot. Ligamentous laxity seen in pregnancy may also cause flatfoot, but this usually corrects itself soon after delivery. Patients with degenerative or inflammatory arthropathies, rheumatoid arthritis, or seronegative arthropathies are at higher risk for developing flatfoot. A common result in Charcot neuroarthropathy leads to midfoot collapse with a rigid rocker-bottom flatfoot.
Flatfoot is fairly common in the first decade of life, when most infants are born with flatfeet and develop a medial arch during their first decade of life. Children and early adolescents are prone to flatfeet because of ligamentous laxity and lack of neuromuscular control. Most instances of flatfoot in children are flexible, meaning there is an arch present without weight bearing but collapses with weight bearing. Younger patients with rigid flatfoot should be screened for tarsal coalition, congenital vertical talus, accessory navicular, or other hindfoot pathologies. Studies support the theory that asymptomatic flatfoot can progress into symptomatic flatfoot over time as ongoing degenerative processes change flexible deformities into a rigid deformity.
The flatfoot may or may ...