Revers End to Side Nerve Transfer for the Partial Injury of the Ulna Nerve. Our Experience

Introduction: We introduce our experience about the revers end to side transfer from AIN to the motor fascicular group of ulna nerve to improve the partial injury of this nerve

Methodology and Material: 7 patients were undergone to surgery in our service. All of them had been diagnosed of axonotmesis involved the ulna nerve as a consequence of severe entrapment at the elbow. All patients showed atrophy of the dorsal interossis muscles as in their hipotenar compartment. Before the treatment patients were studied with electromiographic registers to establish the number of unit motor and action potential in abductor digiti minimi and the first dorsal interossis muscles. That register were performed with stimulation of the median and the ulna nerve The treatment was the revers transfer from AIN to motor fascicle of the ulna nerve plus releasing of motor branch of ulna nerve at Guyon canal.

When the release at the elbow had not been performed before, an exoneurolysis at this level was performed in the same surgery (4 cases) After 2 weeks the patients started a program of rehabilitation to improve the interossis muscles of the hand and the synergism between the pronation and abduction movement.

Results:

The average was 50 years old.

All patients were sent to home in the same day of the surgery.

All patients improved the force for abduction and adduction of his/her fingers and most of them recovered the atrophy of the interossis muscles, mainly of the first dorsal interossi muscle.

Preoperative registers of motor activities were 2.51mV and 1.75mV in hipotenar muscles and first interosseous dorsal muscle. After 22.53 months of follow up, the motor activities were 5.18mV and 5.18mV respectively. The sensitive recorder in the fifth finger was 0.87mV before the surgery and 3.14microV after the surgery.

The electromiographic recording after 6 months of the surgery showed activity in the first interosseus muscle and abductor digiti minim when the median nerve was stimulated proximally to the suture No complications were observed during the postoperative period.

Conclusions: The revers nerve transfer for partial injury of the ulna nerve is a good treatment to recover the force of interossis muscles.

This kind of transfer opens new options of treatment for other axonotmesis in different places.

Nevertheless, further studies are necessaries to know the real role of the transfer in the recovery of the ulna nerve