Pes Cavus / Cavovarus: Charcot Marie Tooth



- See:
       - Charcot Marie Tooth: Perineal Muscular Atrophy:
       - General Discussion of Pes Cavus:

- Discussion:
    - muscle weakness primarily affects peroneus brevis muscle and tibialis anterior, w/ relative sparing of peroneus longus (and tibialis posterior);
          - results in planatar flexion of first ray, resulting in hindfoot varus thru the tripod effect;
    - w/ platar flexed first ray and mobile lateral rays, in order for the foot to remain plantigrade, the heel must roll into varus in order to get the 
          lateral metatarsals on the ground;
    - early disease:
          - in the early stages of dz, the hindfoot is flexible;
          - deformities of the hindfoot involve malposition of the talus & calcaneus, with the latter inverted into a varus position;
    - late disease:
          - the plantar flexed position of the first ray eventually becomes rigid, which which forces the heel to remain in varus;
                - the hindfoot eventually becomes fixed in varus;
          - when deformities become rigid, neither wt-bearing nor passive manipulation fully corrects the foot;

- Exam:
    - foot is evaluated clinically for muscle strength & for flexibility, especially of the hindfoot varus;
    - lateral block test (Coleman) assesses hindfoot flexibility of cavovarus foot (flexible feet correct to normal);
          - if the hindfoot is flexible varus is a fixed deformity, it will remain in varus despite standing on the block;

- 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;
    - plantar 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 plantar 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/ plantar release;
          - consider lateral transfer of tibialis anterior tendon into the mid-tarsal region along the long axis of third ray;
          - alternatively, consider transfer of the peroneus longus to the peroneus brevis, inorder to decrease plantar flexion of the first ray;

- Rigid Deformity:
    - fixed bony deformity is better managed by a combination of calcaneal and metatarsal osteotomies and may require the use of AFO's;
    - 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;

- Pts > 10 yrs;
    - in patients who are older than ten years or who are more severely affected, a lateral closing-wedge calcaneal osteotomy with lateral translation of the distal and posterior fragments is done;
    - osteotomy is stabilized with a staple;
    - triple arthrodesis;
           - in pts who have reached skeletal maturity, who have severe deformity, and who are so severely affected neurologically that they walk w/ difficulty and cannot run, a triple arthrodesis can be performed;
           - individuals who are able to run, however imperfectly, are frequently not pleased with the result of a triple arthrodesis, as this procedure limits function, although the appearance can be good



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

Pes cavovarus. Review of a surgical approach using selective soft-tissue procedures.   

Plantar release in the correction of deformities of the foot in childhood.

Charcot-Marie-Tooth disease and the cavovarus foot.

Correction of cavovarus foot deformity in Charcot-Marie-Tooth disease.Correction of cavovarus foot deformity in Charcot-Marie-Tooth disease.

Prevalence of Charcot-Marie-Tooth disease in patients who have bilateral cavovarus feet



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

Last updated by Data Trace Staff on Thursday, May 24, 2012 2:44 pm