[Simple decompression of the ulnar nerve in cubital tunnel syndrome with and without morphologic changes. Report of experiences based on 523 cases].

The transposition of the ulnar nerve has proved to be an effective therapy in ulnar neuritis at the elbow but has also many risks and technical problems. In contrast the simple decompression or release of the nerve within the cubital tunnel which was first described by Osborne and Feindel and Stratford is an operation which is free of complications and postoperative morbidity and can be performed in local anesthesia. According to the results of a former study of 139 cases and this follow-up study of further 523 cases the simple decompression proved to be an efficacious and almost entirely substitute for the more complicated and extensive procedure of volar transposition-not only for the "idiopathic" cubital tunnel syndrome but also for the "symptomatic" forms as tardy ulnar palsy, luxation of the ulnar nerve or other abnormalities i.e. epitrochleoanconeus muscle, ganglia, lipomas, bursitis. Depending on the severity of nerve damage and duration of symptoms but widely independent from etiology the electroneurographic follow-up study indicated a significant improvement of conduction velocity in about 90% of cases and was therefore a good indicator for successful decompression. It is suggested to give up the concept of different etiologies especially the widely used "sulcus-ulnaris-syndrome" and to replace it by the term "cubital tunnel syndrome" (with or without morphological alterations). Most important for the outcome of surgery is an early operation. Once muscle atrophy has developed the prognosis will be poor. This is also true for cases with concomitant polyneuropathy. Anterior transposition may be restricted to very few cases of extreme cubitus valgus.