decortication: removal of the outer covering of an organ or part
operation: a medical procedure involving an incision with instruments; performed to repair damage or arrest disease in a living body
becker muscular dystrophy: a form of muscular dystrophy that sets in in adolescence or adulthood and progresses slowly but will affect all voluntary muscles; characterized by generalized weakness and muscle wasting that affects limb and trunk muscles first; similar to Duchenne's muscular dystrophy but less severe; inheritance is X-linked recessive (carried by females but affecting only males)