Pes Planus

ICD-9	Classification / Treatment
Etiology / Epidemiology / Natural History	Associated Injuries / Differential Diagnosis
Anatomy	Complications
Clinical Evaluation	Follow-up Care
Xray / Diagnositc Tests	Review References

synonyms: flatfoot

Flatfoot ICD-9

• 734 (flat foot)

Flatfoot Etiology / Epidemiology / Natural History

• may be caused by rupture of the posterior tibial tendon, degenerative arthritis of the midfoot or hindfoot, diabetic Charcot neuroarthropathy, or inflammatory arthritis of the hindfoot.

Flatfoot Anatomy

• Posterior tibial tendon insufficiency, the most frequent cause of flatfoot deformity, leads to attenuation of the medial supporting structures of the foot, lowering of the longitudinal arch, heel valgus alignment, and ultimately hindfoot and ankle arthritis.

Flatfoot Clinical Evaluation

Flatfoot Xray / Diagnostic Tests

• Weight-bearing A/P, lateral and oblique xrays indicated: generally show lowering of the longitudinal arch, decrease in calcaneal pitch, increase of the talometatarsal angle, and uncovering of the talonavicular joint with increasing forefoot abduction.
• Advanced cases, attenuation of the deltoid ligament leads to valgus tilting of the ankle mortise.

Flatfoot Classification/Treatment

• Stage I:pain and swelling of the medial ankle region, with pain progressing into the arch.
• Stage II:dynamic hindfoot valgus deformity, attenuation of the spring ligament, and progressive flattening of the longitudinal arch.
• Stage III: fixed hindfoot valgus deformity.
• Stage IV: secondary changes of the ankle joint and stretching of the deltoid ligament.
• Flexible (arch reconstitutes with NWB)-RX=shoe with supportive arch or molded arch support of both, +/- gastroc/soleus stretching
• Rigid-subtalar and midtarsal joints cannot reach neutral.  Forefoot pronated.  Can be undiagnosed tarsal coalition.  RX=medial sole and heel wedges (1/8-3/16”).  Semirigid molded insoles. Gastroc-soleus stretching.  If severely painful-double-upright brace with a locked ankle, inside T-strap, and rigid rocker sole (or similar AFO).  Subtalar vs triple arthrodesis.

Associated Injuries / Differential Diagnosis

Flatfoot Complications

Flatfoot Follow up  care

The painful flatfoot deformity

Physical examination reveals the inability to perform a single leg heel rise with the affected limb. Late symptoms include lateral calcaneofibular impingement with collapse of the arch and difficulty with ambulation. Variable amounts of forefoot abduction occur, leading to the "too many toes" sign. Etiology is related to obesity, diabetes, accessory navicular, inflammatory arthritis, and steroid injections.

Treatment of posterior tibial tendon insufficiency consists of immobilization and nonsteroidal antiinflammatory drugs (NSAIDs) for the stage I patient who has pain but no deformity. Custom-molded orthotic insoles or a University of California Biomechanics Laboratory type orthosis also may be useful. Surgical treatment is indicated if nonsurgical measures have failed. There may be a limited role for posterior tibial tendon débridement or flexor digitorum longus transfer alone in patients with tenosynovitis and preserved architecture of the hindfoot. Once the heel has progressed into valgus deformity, a flexor digitorum tendon transfer to the navicular along with a medial calcaneal slide osteotomy to shift the axis of the Achilles tendon medially may be performed. Repair of the attenuated spring ligament and deltoid ligament may be useful in correction of hindfoot alignment, but this method is controversial. A lengthening of the Achilles tendon may be indicated if contracture is present. In patients with a rigid deformity and arthritis of the hindfoot, arthrodesis is often necessary. Fusion of the subtalar, talonavicular, calcaneocuboid joints, or combinations of these are used to stabilize the hindfoot. Lateral column lengthening through an osteotomy of the calcaneal neck or calcaneocuboid fusion may also be useful in conjunction with flexor digitorum longus tendon transfer.

Flatfoot References

1. Evans D: Calcaneo-valgus deformity.  J Bone Joint Surg 1975;57B:270-278.
2. Horton GA, Olney BW: Triple arthrodesis with lateral column lengthening for treatment of severe planovalgus deformity.  Foot Ankle Int 1995;16:395-400.
3. Mosca VS: Calcaneal lengthening for valgus deformity of the hindfoot: Results in children who had severe, symptomatic flatfoot and skewfoot.  J Bone Joint Surg 1995;77A:500-512.