[Hereditary neuropathy with liability to pressure palsy (HNPP): a diagnostic trap].

The authors report two clinical cases of a rarely observed pathology in orthopedic surgery daily practice: hereditary neuropathy with liability to pressure palsy (HNPP), which leads to dysesthesiae, hypoesthesiae and regressive palsies. Onset, clinical signs and electromyographic abnormalities are described. Forensic consequences can occur in early postoperative period. Knowledge of this familial pathology allows precautionary measures at surgery and avoids unnecessary surgical revisions.