Key Insights On Conservative Care For Adult Flatfoot

Patrick DeHeer, DPM, FACFAS, FASPS, and Aaron Warnock, DPM

Although a variety of surgical treatments are available for adult flatfoot, conservative treatments such as night splints and orthoses can be effective in managing the deformity. These authors provide keys to a thorough clinical exam of these patients, insights on accessing the severity of the flatfoot deformity and a review of conservative treatment options.

The adult flatfoot deformity is a condition that lends itself to many treatment options whether they are conservative or surgical. Formulating a proper treatment must begin with evaluating and categorizing the deformity.

   The evaluation of an adult flatfoot requires ascertaining a pertinent patient history that includes the onset of the deformity, the timing of symptoms and the severity of past and current symptoms. One may elicit a family history of flatfoot deformity. Van Boerum and colleagues showed that associated conditions including rheumatoid arthritis, seronegative arthropathies, hypertension or diabetes may be significant in the adult patient with flatfoot.1 Occupation, activity level and obesity are other possible contributory factors. Footwear, the history of trauma and previous treatment are other significant factors. The authors also emphasize a pertinent review of systems.

   We can categorize the flatfoot deformity as either a residual flatfoot deformity from a developmental etiology or an acquired deformity. Myerson showed that developmental causes include abnormal joint development, tarsal coalition, a congenital vertical talus, accessory navicular and generalized ligamentous laxity from Marfan’s syndrome or Ehlers-Danlos syndrome.2 As Myerson notes, the acquired flatfoot condition is associated with posterior tibial tendon dysfunction (PTTD), midfoot laxity, subluxation of the talus, traumatic deformities, a ruptured plantar fascia or Charcot foot as well as neuromuscular imbalances from polio, cerebral palsy, closed head injuries or following a cerebrovascular accident.

   Importantly, tightness of the triceps surae complex and isolated gastrocnemius tightness have a profound effect on the longitudinal medial arch. Johnson and Christensen performed a three dimensional evaluation of the first ray in cadaver models with variable Achilles tendon tension.3 They found the influence of the peroneus longus on the medial column diminishes with increasing Achilles load. Equinus on an intact longitudinal arch seems to affect the distal components of the medial column, primarily in the frontal plane. Furthermore, the authors say with increased pull on the Achilles, a measurable arch flattening effect occurs with plantarflexion of the talus and navicular, and dorsiflexion of the first metatarsal and cuneiform.

Assessing The Extent Of The Deformity

When assessing the extent of flatfoot, clinicians should perform a thorough clinical examination in conjunction with plain film X-rays. With the patient seated in the exam chair, one can focus on the neurological and musculoskeletal portions of the clinical exam. The musculoskeletal examination should account for any gross deformities, symptomatic sites or malalignments. Perform a comprehensive non-weightbearing biomechanical exam including the Silfverskiöld test for equinus, subtalar range of motion and neutral position, forefoot to rearfoot alignment, forefoot hypermobility and first metatarsophalangeal joint range of motion. When it comes to these biomechanical exams, perform these exams with the forefoot both loaded and unloaded.

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