Endoscopic anatomical nerve observation and minimally invasive management of cubital tunnel syndrome.

Experience with the use of the Universal Subcutaneous Endoscope (USE) system in surgical treatment of cubital tunnel syndrome in 35 patients is reported. Patients included in the study had pre- and postoperative clinical and electrophysiological data, and had undergone a minimum follow-up period of 13 months. Mean patient age was 59.5 years and the mean follow-up period was 25.9 months. The operation was performed under local anaesthesia without pneumatic tourniquet and on an out-patient basis. A 1.5 cm portal is made at the cubital tunnel and the USE system is inserted next to the ulnar nerve, first distally and then proximally. The nerve is endoscopically assessed and only the tissue that compresses the nerve is released, in keeping with the principles of minimally invasive treatment. Preoperative tingling sensations disappeared postoperatively in 63% of cases. Pain and sensory disturbance recovered to normal in 92% and 89% of cases, respectively. Abnormal motor nerve conduction velocities improved in 77%. Abductor digiti minimi weakness MMT 0, 1, 2 in 16 hands recovered to MMT 4 or 5 in eight. First-dorsal interosseous weakness in 18 hands recovered to MMT 4 or 5 in seven. There were no complications in this series. The endoscopic approach facilitates inspection of the ulnar nerve so that selective release of the tissue that compresses the nerve can readily be performed. The technique has proven effective in the treatment of cubital tunnel syndrome.