Cavus foot

Disease Description (Causes and Symptoms)

• Definition: Cavus foot is a condition in which the medial longitudinal arch of the foot is excessively high, causing the sole to curve upward. Weight cannot be distributed evenly across the entire foot, so the load is concentrated on the heel and forefoot.
• Main causes: In most cases, secondary changes caused by neuromuscular diseases (e.g., Charcot–Marie–Tooth disease, sequelae of poliomyelitis), congenital deformities, trauma (deformity after a fracture), sequelae of compartment syndrome caused by severe swelling, cerebral palsy, cerebellar diseases, and others. In adults, trauma and neuromuscular lesions are common.
• Summary of pathophysiology: Muscle imbalance (e.g., weakness of the dorsiflexor muscles and relative shortening of the peroneal/calf muscles) → increased height of the medial longitudinal arch → concentration of load on the forefoot and hindfoot → calluses, pain, toe deformities (claw toes/hammer toes), ankle instability, and gait disturbance. If neuropathy is present, the risk of ulcers increases due to reduced sensation.
• Clinical symptoms: Forefoot and hindfoot pain, thickening of the sole (calluses), difficulty walking and abnormal gait, claw toes or hammer toes, ankle sprains and instability, and chronic lower back pain (caused by changes in gait pattern).

Treatment Methods

• Conservative treatment
  • Custom orthoses: Metatarsal pads, medial and lateral support and insoles (pressure redistribution), rocker-sole shoes, and other options can relieve pain and improve gait.
  • Physical therapy and stretching: Stretching of the calf (Achilles) and plantar fascia, and muscle strengthening (especially strengthening of the dorsiflexor and lateral muscles).
  • Medication: Analgesic and anti-inflammatory drugs such as NSAIDs for acute pain; medications for neuropathic pain, such as gabapentin and pregabalin, may be considered if neuropathic pain is suspected.
  • Activity modification and appropriate footwear: Shoes with good shock absorption; avoid pointed shoes.
  • Management of the underlying disease: If a neuromuscular disease is the cause, neurological evaluation and specialized treatment (rehabilitation, medication, genetic counseling, etc.) are needed.
• Surgical treatment (when symptoms are severe or cannot be controlled with conservative treatment)
  • Soft-tissue surgery: Plantar fascia release, tendon release (e.g., Achilles tendon lengthening), and other procedures.
  • Tendon transfer: The position of a tendon is changed to compensate for muscle imbalance.
  • Bone correction surgery, including osteotomy, hindfoot correction (calcaneal osteotomy), and metatarsal correction.
  • Arthrodesis: Fusion surgery may be performed in cases of extensive arthritis or severe deformity.
  • The surgical method is determined individually according to the location and cause of the deformity (whether neuropathy is present) and the condition of the joints.
• Precautions / Risk of complications / Self-management
  • Without early treatment, foot deformity, chronic pain, calluses and ulcers, arthritis, and gait disturbance may worsen or progress.
  • If reduced nerve sensation is present, take care when managing wounds and ulcers (risk of infection and gangrene).
  • After surgery, infection, nerve damage, nonunion, and recurrence are possible.
  • Regular monitoring is recommended even during conservative treatment (observing changes in foot shape, skin, and sensation). Appropriate shoes and insoles and weight management can help relieve symptoms.

Checklist Before an Outpatient Visit (Including Sample Questions)

• Items to prepare
  • A list of medications currently being taken (including prescription drugs, OTC medications, and supplements)
  • Previous test results (foot X-rays, CT, MRI, EMG/nerve conduction study results, etc.) and surgical records, if available
  • The time symptoms began, how they have progressed, the location and intensity of pain (pain diary), changes in symptoms during the day, and aggravating factors (walking, exercise, and shoes)
  • Photos of shoes (shoes normally worn) and photos of the bare foot from the side (for observing foot shape)
  • Family history (especially peripheral neuropathy and genetic diseases), history of previous trauma, and nervous-system-related symptoms (numbness and weakness)
• Information to tell the doctor in advance during the outpatient visit (examples)
  • Whether pain is present and its severity (visual pain scale), and the degree to which daily activities are limited
  • The effects of orthoses, insoles, and physical therapy tried previously
  • Sensory abnormalities (tingling and numbness) and whether muscle weakness is present

Examples of General Questions to Ask the Doctor

• "What are the side effects or precautions for this medication (or the prescribed orthosis)?"
• "What is the likelihood that my foot deformity will progress (what is the prognosis)?"
• "Can my symptoms be controlled with conservative treatment without surgery? How long is the recommended treatment period?"
• "What should I be careful about in daily life and during exercise?"
• "If I undergo surgery, approximately how long will rehabilitation take, and when can I return to daily activities?"

Examples of Condition-Specific Questions

• "What additional tests (such as EMG or genetic testing) should I undergo to determine whether my cavus foot is associated with a neuromuscular disease (e.g., Charcot–Marie–Tooth disease)?"
• "What surgical method is recommended for my current deformity (or X-ray findings), and what is the likelihood of recurrence and the risk of complications?"