Background: Opponensplasty is a salvage tendon transfer procedure to restore thumb opposition function, tip and key pinch in median nerve palsy. The present work aimed to compare between two techniques of Opponensplasty (using flexor digitorum superficialis (FDS) tendon versus extensor indicis (EI) proprius tendon) to know which one is better in improving the thumb function.

Methods: Twenty-four patients with late median nerve palsy of thumb who were admitted to the emergency unit of the Plastic and Reconstructive Surgery Department in Zagazig University Hospitals were enrolled in this prospective comparative study, they were categorized into 2 groups (n=12 patients in each group): Group I: was operated using flexor digitorum superficialis tendon and Group II was operated using extensor indicis proprius tendon.

Results: We found that 25% of the cases in Group I had complications (thumb hyperflexion, wound infection and donor site morbidity) while 16.7% in Group II had complications (all had donor site morbidity%). The mean Kapandj scoring system in Group I pre & post operative respectively were 0.5±0.80 & 7.46±2.5 and in Group II 0.33±0.49 & 7±1.98.

Conclusion: The use of opponensplasty is an effective surgical intervention to restore thumb functions among patients with median nerve palsy. The choice between FDS and EI tendon transfers were almost comparable with no upper hand of any one on the other, it should be individualized based on the patient's clinical presentation, with consideration given to the potential complications and long-term functional outcomes