Chopart Amputation


- See:
      - Syme's Amputation
      - Transmetatarsal Amputation

- Discussion:
    - Francis Chopart first described disarticulation thru midtarsal joint;
    - Chopart amputation removes the forefoot and midfoot, saving talus and calcaneus;
    - Chopart amptutations should not performed for ischemia;
    - this is a very unstable amputation, noting that most of the tendons which act around the ankle joint have lost their insertion into foot and 
           the heel remains unstable;
    - has a pronounced tendency to go into equinus and must usually be fitted with a prosthesis that extends upto the patellar tendon level;
    - if the ankle joint is in a neutral position and good ankle motion is present, AFO derivatives or boot type prostheses may be required;
    - technical considerations:
          - rebalancing is required to prevent equinus and varus deformities, and can be accomplished by Achilles tenotomy, anterior tibialis or
                 extensor digitorum transfer to the talus, and post op casting;
          - transfer of the tibialis anterior to the talar neck is necessary to control the deformity of the hindfoot;
                 - tendon of the tibialis anterior is detached from its insertion and is passed thru a hole drilled in the neck of the talus;
                 - tendon is then sutured upon itself and the extensor tendons are carefully sutured to the fascia and soft tissues of the
                        sole of the foot;
                 - note that rupture of the transposed tibialis anterior tendon is common after many years of use;
          - some say the ankle joint should be fused;
    - complications:
         - Robert Jones believed that Chopart's procedure invariably failed because of progressive equinovarus deformity - as was Lisfranc's 
                  amputation;
         - in the chopart amputation, the stump goes into equinus, so that the  preserved heel cushion is not used and the pressure is on the
                 anterior end of the os calcis;
                 - transfer of the anterior tibial tendon has an insufficient moment arm to prevent this;
                 - initial release of the tendo achilles may reduce this problem;
         - with all amputations of the foot, there will be some loss of normal arch of the foot



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

Last updated by Data Trace Staff on Monday, May 14, 2012 9:58 am