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Year |
2001 |
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Question Number |
224. |
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Category |
Select |
Question
An 11-year-old girl has had progressive medial midfoot pain bilaterally for the past 6 months. Her mother states that the child’s feet appeared normal until the pain started and she is concerned about the development of flatfeet. What is the most likely diagnosis?
1. Physiologic pes planus
2. Charcot foot
3. Posterior tibial tendon insufficiency
4. Congenital vertical talus
5. Accessory navicular
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Answer (click for answer)
Answer: 5
Pes planus (or flatfoot) by convention refers to loss of the medial longitudinal arch of the foot. However, other anatomical abnormalities may be present, such as a valgus position of the heel, mild subluxation of the subtalar joint, abduction at the midtarsal joint and supination of the forefoot relative to the rearfoot
Pes planus may be congenital, that is, present from birth, or acquired. It is important to note that all children under 5 years of age have a depressed medial longitudinal arch because of the low calcaneal inclination angle. Pes planus is usually classified as flexible or rigid. Flexible pes planus is common, 15% to 20% of adults have some degree of flexible pes planus, and most of these are asymptomatic. Soft tissue structural changes are the cause of flexible pes planus, whereas, it is bony and soft tissue changes that cause a rigid pes planus foot. It is possible to clinically distinguish the two types of pes planus. If an acceptable medial longitudinal arch does not develop on non-weightbearing, the flatfoot is considered rigid
There are a number of pathologies that can cause flexible pes planus. Spastic valgus foot describes a flatfoot seen in cerebral palsy, due to spasticity of muscles. Tibialis posterior dysfunction and an accessory navicular can both lead to pes planus. But the most common cause of flexible pes planus would be secondary to, or compensation for biomechanical anomalies. Rigid pes planus is closely associated with tarsal coalitions, however, other causes may be late-stage osteoarthritis, tarsal bone fractures or congenital vertical talus.
Flexible pes planus rarely requires surgical treatment. Any procedure for the correction of flexible flatfoot should be done for disabling pain and then only after all conservative measures have been exhausted. Rigid pes planus frequently causes enough symptoms to justify an operation. In 1929, Kidner stated that the support to the medial longitudinal arch offered by the tibialis posterior tendon was compromised by its abnormal insertion into the accessory navicular. The Kidner procedure consists of excising the accessory navicular and rerouting the tibialis posterior tendon into a more plantar position. It is recommended for children under 10 to12 years of age. Permanent correction of the arch sag cannot be certain, but relief of symptoms about the prominent tuberosity and reduction or elimination of fatigue from arch strain are predictable. Prichasuk et al identified an association of pes planus and symptomatic accessory navicular. They studied the results of the Kidner procedure in 28 patients, with an average follow-up of 3.2 years. They found that 96% of patients had good results, with no patients having poor results. They also noted that only 12% of patients clinically showed an improvement of the medial longitudinal arch. They concluded that the Kidner procedure gave good results in the relief of pain and fatigue, but did not significantly restore the height of the medial arch
Physiologic pes planus is a flexible flat foot deformity that usually correct before 6 years of age . Most children are aymptomatic and require no intervention.
Charcot foot is the term given to neurogenic arthropathy that affects the joints in the foot. Neurogenic arthropathy is a rapidly progressive degenerative arthritis that results from damaged nerves (neuropathy). Charcot foot occurs most often in people with diabetes mellitus. According to the American Diabetes Association, 60%-70% of people with diabetes develop peripheral nerve damage that can lead to Charcot foot. Onset occurs after the patient has been diabetic for 15 to 20 years, usually at the age of 50 or older. The disorder occurs at the same rate in men and women. The demographics of this patient does not correlate with charcot foot.
Congenital vertical talus is a irreducible dorsal dislocation of the navicular on the talus w/ fixed talo-navicular complex. Patients demonstrate peg-leg gait (akward gait w/ limited forefoot pushoff) from the onset of bipedal ambulation.
Posterior tibial tendon insufficiency is a degenerative condition that is associated with rheumatoid arthritis and is common cause of pes planus in adults. It is often due to degenerative tears that usually occur distal to the medial malleolus, in a region which coincides with relative hypovascularity and where the sharp turn of the tendon from a verticle to a horizontal position occurs.
Reference: Prichasuk S, Sinphurmsukskul O: Kidner procedure for symptomatic accessory navicular and its relation to pes planus. Foot Ankle Int 1995;16:500-503
JA Sullivan, WA Miller. The relationship of the accessory navicular to the development of the flat foot. CORR. Vol 744. 1979. p 233-237.