Acquired Flat Foot Deformity  [Tibialis Posterior Insufficiency]

 

 

Clinical Presentation

• pain along the inside of the ankle and arch of the foot

• pain may be temporary relieved by rest

• tenderness below medial malleolar area

• pain elicited by everting a plantarflexed inverted foot

• ”too many toes“ sign (forefoot abductus)

• medial talonavicular joint prominence (increase bulging inside of the ankle)

• flattening of the medial longitudinal arch

• heel may be twisted inwards (everted - valgus)

• unable to perform single heel rise test

• initially flexible deformity (stages I-II) which progressively stiffens (stages III-IV)

• lateral ankle pain (subfibular impingement) in pes planovalgus (severe flat foot with twisted heel)

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Non-operative Management of the Flexible Deformity (stages I-II)​

• Aims at unloading the tendon and progressively reload in a controlled way to allow healing and strengthening of the tendon without further deterioration

• Includes functional foot orthotics (UCBL orthotics), stretching, eccentric and strengthening exercises

• Functional foot orthotics reduce stress on the tibialis posterior tendon by increasing the ground reaction forces on the inside of the foot thus reducing overpronation during gait. To optimise function, the foot should be corrected in a position that allows efficient transition of body weight from heel to toes

• Medial arch support +/- medial forefoot post

• Medial heel lift wedge/skive

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Non-operative Management of the Stiff Deformity (stages III-IV)

• Aims at providing accommodation and some degree of support to the stiff flat foot

• Includes the use of accommodative total contact foot orthotics +/- rocker soled shoes/boots

• Intra-articular steroid infiltrations for symptomatic arthritic joints (most commonly the subtalar joint)

 

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Operative treatment is indicated at any stage of the deformity

if non-operative management fails to provide symptomatic relief.