PATHOANATOMIC FINDINGS IN RADIOHUMERAL EPICONDYLOPATHY - A COMBINED ANATOMIC AND ELECTROMYOGRAPHIC STUDY

Several authors believe that a compression syndrome of the radial nerv e or its muscle branches is responsible for the clinical picture of ra diohumeral epicondylopathy. Various structural and functional stenoses have been discussed as possible causes. We performed systematic elect romyographies (EMGs) on the extensors subdividing from the radial epic ondyle and found significant changes (P < 0.05) in 27/51 patients rega rding latency, velocity of nerve conduction and rate of polyphasic pot entials. Especially affected were the extensor carpi radialis brevis a nd the extensor digitorum muscle. In order to clarify causal anatomic correlations, we performed a longitudinal and cross-sectional study on a total of 40 arms from cadavers. We found constant variations from t he topographic anatomy published in the standard literature which corr esponded to the EMG results in the area between the epicondyle and pla ce of entry into the supinator muscle. In addition, we observed a regu lary occurring ulnar deviation from the distal part of the extensor ca rpi radials brevis origin which protrudes over the plane of insertion of the joint extensor tendon aponeurosis and forms in most cases the a rcade of Frohse. Because the deep radial branch and its parallel muscu lar branches cross this part at an obtuse angle, we think that dynamic pressure on a nerve without structural influences is the pathoanatomi c result of this heterogeneously interpreted clinical picture.