Dr. Kevin Yip

Dr Kevin Yip
Orthopaedic Surgeon
MBBS(UK), FRCS(EDIN), FAM(SING), FHKCOS(ORTHO)

Featured on Channel NewsAsia

Flatfoot

Basics
Description
  • Flatfoot, or pes planus, is a deformity of the foot in which the normal medial longitudinal arch of the foot has been lost.
  • It may present as an asymptomatic incidental finding or as a painful condition secondary to an associated anatomic abnormality or pathologic condition of the foot.
  • Classification:
    • Rigid versus flexible:
      • A flexible flatfoot lacks an arch only when patient is weightbearing, not when nonweightbearing or toe-standing.
      • A rigid flatfoot lacks an arch at all times.
    • Pediatric versus adult:
      • Onset may indicate underlying potential cause.
Epidemiology
Incidence
  • Congenital flexible flatfoot after infancy:
    • Is a trait that often runs in families, although the pattern of inheritance is not known
    • Is present in ~15% of adults
  • Tarsal coalition, the most common type of congenital rigid flatfoot, is inherited in an autosomal dominant pattern.
    • The exact overall incidence is unknown, but it is <1%.
  • PTT deficiency is the most common cause of acquired flatfoot in adults, although its precise incidence is not known.
  • The exact incidence of other patterns of acquired flatfeet is not known.
Risk Factors
  • For persistent congenital flexible flatfoot: Other family members with the same condition
  • For congenital rigid flatfoot secondary to tarsal coalition: Female gender and other family members with the same condition
  • For acquired flexible flatfoot secondary to PTT synovitis or rupture: Hypertension, diabetes, and a history of trauma
  • Other conditions that can lead to flatfoot:
    • Tight Achilles tendon
    • Neurologic diseases (e.g., poliomyelitis, spina bifida, myelodysplasia, NF, stroke)
    • Osteoarthritis, posttraumatic arthritis, or inflammatory arthritis
    • Charcot arthropathy secondary to diabetes or other peripheral neuropathy
Etiology
  • Congenital flexible flatfoot and tarsal coalition are the result of genetic inheritance.
  • PTT dysfunction is secondary to tendon degeneration and attenuation.
  • Flatfoot deformity from Charcot neuroarthropathy is secondary to bone fragmentation, resorption, and fracture.
  • Other causes to consider: Congenital vertical talus, peroneal spastic flatfoot, and trauma
Diagnosis
Signs and Symptoms
  • Flatfoot with low or no arch
  • Pain over medial arch
  • Deformity may progress with time.
  • May be exacerbated by walking, sports, high level of activity, or traumatic event
  • Abnormal shoe wear pattern
History
  • The onset of deformity, family history, associated diseases, activity level, and history of previous trauma should be noted for all patients.
  • The patient or parents may complain of tenderness and swelling along the medial part of the foot, a diminished endurance in the foot, a decreased ability to participate in sports, and, eventually, a progressive difficulty in ambulating.
  • Increased wear on medial aspect of the shoe
  • Pediatric flatfoot deformity often is present from an early age.
  • Adult acquired flatfoot caused by arthritis or rupture of the PTT presents as a gradual, progressive aching and swelling along the medial aspect of the foot and ankle.
Physical Exam
  • Of primary importance is the determination of whether the condition is rigid or flexible.
    • Rigid flatfoot:
      • Loss of the normal longitudinal arch of the foot at all times
      • Restricted motion of the hindfoot
    • Flexible flatfoot:
      • Loss of arch only on standing on the affected foot, with reconstitution of the arch when the foot is dependent or when the patient toe-stands
      • Normal motion of the hindfoot
  • Increasing severity is associated with forefoot abduction and the too many toes sign when the patient is viewed from behind.
  • Inversion against resistance may be absent or diminished in patients with PTT dysfunction.
    • The patient may have pain or difficulty when attempting a single-limb heel rise on the affected side.
  • The foot should be inspected for deformity or swelling and then palpated for tenderness.
  • Gait pattern should be assessed.
    • An antalgic gait may indicate a painful condition such as arthritis or tendinitis.
    • The patient may have impaired propulsion with PTT abnormality.
    • An awkward, foot-slapping gait may suggest a neurologic or neuromuscular disease (e.g., spina bifida or poliomyelitis).
  • The Achilles tendon should be examined to test whether the heel cord is tight.
Tests
Imaging
  • Radiography:
    • 3 standing radiographic views of the patient’s ankle (AP, lateral, and mortise) and 3 views of the patient’s foot (AP, lateral, and oblique) should be obtained.
    • The calcaneal pitch is diminished and may approach 0° with more severe flatfoot deformity.
    • The talus-1st metatarsal angle increases with loss of arch.
      • This angle should normally be 0° with the talus and metatarsal collinear.
      • Angle measurements: <15°, minor pes planus deformity; 15-30°, moderate deformity; >30°, severe deformity
    • When tarsal coalition is suspected:
      • Assess oblique radiograph for a calcaneonavicular coalition.
      • Obtain a CT scan to rule out a talocalcaneal coalition.
    • Assess the degree of hindfoot or midfoot arthritis.
    • Rule out bony fragmentation indicative of Charcot arthropathy.
  • An MRI scan may be useful for visualizing PTT abnormality.
Pathological Findings
  • Secondary to underlying cause:
    • Charcot arthropathy: Fragmentation, resorption of bone
    • PTT dysfunction: Degeneration, tearing, hypertrophy
    • Tarsal coalition: Fibrous, fibrocartilaginous, or osseous coalition
Differential Diagnosis
  • Pediatric flatfoot:
    • Benign flexible flatfoot
    • Tarsal coalition
    • Congenital vertical/oblique talus
    • Accessory navicular
  • Adult acquired flatfoot:
    • PTT dysfunction or tear
    • Midfoot arthritis
    • Charcot arthropathy
    • Neuromuscular disorders
Treatment
General Measures
  • No treatment needed if asymptomatic
  • Pediatric:
    • Benign flexible flatfoot:
      • Shoes with good arch support
      • Consider orthotic device (e.g., prefabricated or custom-made medial arch support).
    • Tarsal coalition:
      • Initially, immobilization with a below-the-knee cast or boot brace
      • Rest and temporary activity restriction
    • Flatfoot secondary to a tight Achilles tendon may be relieved by physical therapy and heel-cord stretching.
  • Adult:
    • PTT dysfunction or tear:
      • NSAIDs and rest
      • Short-term immobilization with a below-the-knee cast or boot brace
      • Long-term maintenance with custom orthotic arch support or ankle-foot orthosis (brace)
      • Injection of corticosteroids is not recommended because it may weaken or rupture the tendon.
      • Weight loss
    • Midfoot arthritis:
      • Orthotic arch support
      • NSAIDs
      • Foot wear modifications (e.g., rocker-bottom and steel shank)
      • Intra-articular corticosteroid injections
    • Charcot arthropathy:
      • Acutely: Total contact cast and restricted weightbearing
      • Long-term: Orthotics and/or bracing
    • Surgical treatment is indicated for failure of nonoperative treatment.
Special Therapy
Physical Therapy
  • Physical therapy can be used to increase ankle and foot ROM and to stretch a tight Achilles tendon.
  • Orthotists can fabricate appropriate orthotic devices.
Medication
  • NSAIDs:
    • Can be used if swelling and pain are substantial
    • Are most useful for acute injuries or for patients with posterior tibial tendinitis.
Surgery
  • Indicated for failure of nonoperative treatment, progression of deformity, or instability
    • Surgical treatment may entail fusion, osteotomies, and possible soft-tissue procedures.
    • Age, activity level, degree of deformity, and comorbid conditions play a role in determining the extent of surgical treatment.
  • Pediatric flexible flatfoot:
    • Surgical treatments usually consist of osteotomies that realign the foot to correct valgus and improve mechanical alignment of the foot and ankle.
  • Rigid flatfoot from tarsal coalition:
    • Resection of tarsal coalition with interposition of fat or muscle
    • For patients with talocalcaneal coalition involving >50% of the joint surface or those with degenerative joint arthritis, subtalar arthrodesis is indicated.
  • Flatfoot secondary to a tight Achilles tendon:
    • Tendon lengthening involves a Z-lengthening procedure or partial sectioning of the tendon.
  • Acquired flatfoot secondary to PTT synovitis:
    • In early stages of the disease, synovectomy may be sufficient.
    • Flexible deformities are corrected with tendon transfers, calcaneal and midfoot osteotomies, and/or limited hindfoot arthrodesis.
  • Fusion is necessary for arthritis or rigid flatfoot deformity.
Follow-up
Prognosis
Most patients do not develop progressive deformities and do not need corrective surgery.
 
Complications
  • Most patients have little risk of complications with nonoperative treatment.
  • 1 major exception is patients with PTT dysfunction (acquired flatfoot) because they may develop a rigid flatfoot.
Patient Monitoring
Patients should be followed at 3-month intervals to monitor their discomfort and function and to check whether their deformity is stable or progressive.
 
Miscellaneous
Codes
ICD9-CM
  • 734.0 Acquired flat foot
  • 754.61 Congenital flat foot
Patient Teaching
  • Patient education is crucial because cosmesis in the absence of symptoms is not an appropriate indication for surgery.
  • Stretching exercises can help patients with tight Achilles tendons, and foot orthoses may be useful for patients who want to be active.
FAQ
Q: What are 3 causes of flatfoot deformity in pediatric patients?
A: Benign flexible flatfoot, tarsal coalition, and congenital vertical talus.
 
Q: What are 3 causes of flatfoot deformity in adults?
A: PTT dysfunction (most common cause of adult acquired flatfoot), neuroarthropathy, and degenerative or inflammatory arthritis.

1 comment to Flatfoot

  • Sharmi Banerjee

    Hi my son is going to be 14 years old on June 19th, 2013. He has flat foot problem and have is unable to walk for long hours. Please let me know how long is the treatment? what kind of cost we are looking at? Can I make an appointment in the evening after my son is back from School?
    Thanks and regards-
    Sharmi Banerjee.