Pes Cavus


- Discussion:
    - cavus deformity of the foot (elevated longitudinal arch) due to fixed plantar flexion of the forefoot;
    - frequency: The anatomy of cavus foot deformity
    - main type is the cavovarus; 
    - associated with spinal cerebellar degenerative dz;
    - associated deformities:
            - claw toes
    - differential dx: (commonly associatted with neurologic disorders)
            - asymmetric or unilateral deformity:
                  - cerebral palsy
                  - diastematomyelia (spinal cord dysraphism look for scoliosis)
                  - spinal cord tumor
                  - tethered cord
            - symmetric or bilateral deformity:
                  - becker muscular dystrophy
                  - cerebral palsy
                  - congenital pes cavus
                  - charcot marie tooth;
                        - Pes cavus and hereditary neuropathies: when a relationship should be suspected
                  - Dystonia musculorum deformans (equinovarus)
                  - friedreich's ataxia
                  - poliomyelitis
                  - idiopathic;


- Exam:
    - subtalar joint;
         - in pes cavus, upward axis is increased (normal 42 deg) and therefore subtalar joint allows less inversion and eversion (more internal and external rotation);
         - because longitudinal axis is closer to mid-line (less than normal 16-23 deg), less than normal dorsiflexion and plantar flexion occurs at this joint;
    - lateral block test (Coleman) assesses hindfoot flexibility of cavovarus foot (flexible feet correct to normal);
    - foot is evaluated clinically for muscle strength and for flexibility, especially of the hindfoot varus;
           - the deformity is progressive, and rigidity increases over time;
    - evaluate for scoliosis and get thorogh neuro exam;


- Radiographs:
    - angle subtended by line drawn through the axis of the talus & first metatarsal (normal = 0 degrees);


- Work Up:
    - Family history
    - Neuro Exam
    - X-rays of entire spine
    - EMG and nerve conduction studies
    - MRI myelogram


- Treatment of Early Deformity:
    - treatment involves soft-tissue releases and/or tendon transfers;
    - any proposed osseous procedures must not affect growth of the foot, such as calcaneal and/or metatarsal osteotomies;
    - planter release:
          - indicated for patients less than 10 years of age w/ cavus deformity w/ significant plantar flexion of first ray;
    - plantar medial release:
          - indicated for rigid hindfoot w/ fixed varus angulation;
          - involves planter release along w/ medial tarsal structures;
          - released medial structures include talonavicular joint capsule, superficial deltoid ligament, and possibly the long toe flexors;
    - tendon transfers:
          - indicated for patients w/ a supple inversion deformity w/ weak evertors;
          - a prerequisite for this procedure is a plantagrade foot which is achieved w/ planter release;
          - consider lateral transfer of tibialis anterior tendon into the mid-tarsal region along the long axis of third ray;

- Rigid Deformity:
    - fixed bony deformity is better managed by a combination of calcaneal and metatarsal osteotomies and may require the use of AFOs;
    - calcaneal osteotomy:
          - for correction of hindfoot varus deformity & mid-tarsal osteotomy for correction of midfoot cavus and varus deformity have been useful;
          - calcaneal osteotomy does not impede growth since it is not made thru cartilage growth surface;
          - posterior displacement calcaneal osteotomy is effective in correcting calcaneocavus deformity of the type II neuropathy;
          - in young patients w/ w/ milder deformity, translate the distal and posterior calcaneal fragment laterally w/o removal of an osseous wedge;
                 - lateral slide osteotomy is cut slightly obliquely, passing from superior position on lateral surface to a more inferior position on  medial surface;
                 - distal fragment can be translated laterally as much as 1/3 of its transverse diameter, thus allowing for conversion of wt-bearing from a
                           varus to a slight valgus position;
    - w/ severe deformity consider: triple arthrodesis



Assessment and management of pes cavus in Charcot-Marie-tooth disease.

Cavus deformity of the foot after fracture of the tibial shaft.

Effectiveness of the cavus foot orthosis

The subtle cavus foot and association with ankle instability and lateral foot overload

Association of ankle instability and foot deformity    

Idiopathic cavovarus and lateral ankle instability: recognition and treatment implications relating to ankle arthritis.

Effect of ankle arthritis on clinical outcome of lateral ankle ligament reconstruction in cavovarus feet

Effective orthotic therapy for the painful cavus foot: a randomized controlled trial

The effect of pes cavus on foot pain and plantar pressure



Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Thursday, April 12, 2012 10:26 am