Extensor digiti minimi transfer for thumb extension in a patient with hypoplastic thumb extensor tendons and absent extensor indicis proprius

Bilateral Digital Extensor Hypoplasia Correction: A Case Report and Systematic Review

Digital extensor hypoplasia (DEH) is a rare malformation that presents with loss of active finger extension at the metacarpophalangeal (MCP) joints. Descriptions of optimal treatment and outcomes in this population are sparse. We describe successful operative treatment of a child with DEH involving the extensor digitorum communis, extensor digiti minimi, and the extensor indicis proprius tendons. The 5-year-old male patient was referred for severe limitation on bilateral finger extension since birth. He had been previously diagnosed with arthrogryposis and managed conservatively. Due to lack of improvement, magnetic resonance imaging was done evidencing hypoplasia/aplasia of the extensor tendons. The patient underwent successful tendon transfers using extensor carpi radialis longus to the common extensor tendons, and one hand required an additional tenolysis procedure. 2 years postoperatively, his MCP position and finger extension are markedly improved, and he is able to grip objects without limitation or difficulty. The patient returned to full activity without restriction.

[Secondary reconstruction in zones V-VII in extensor tendon injuries]

BACKGROUND

Due to various functional impairments after primary extensor tendon repair or lack of treatment, secondary tendon reconstruction is often required. Anatomical considerations, the outcome of the injury and its treatment and the patients' individual demands on the function of the hand affect the choice of the procedure.

OBJECTIVE

Description of techniques for secondary reconstruction after extensor tendon injury in zones V-VII.

MATERIAL AND METHODS

Overview of surgical treatment concepts for secondary extensor tendon repair in zones V-VII of the extensor tendons of the fingers and thumb. Discussion of alternative surgical techniques for secondary extensor tendon repair.

RESULTS

While techniques for reconstruction of sagittal band injuries are predominant in zone V, side-to-side tendon transfers, the use of tendon grafts and end-to-end tendon transfers prevail in zones VI-VII. The reconstruction of the extensor pollicis longus tendon function using transfer of the extensor indicis proprius tendon is the standard procedure.

CONCLUSION

For secondary repair of an extensor tendon function, anatomical features and functional interaction of the extrinsic and intrinsic hand musculature need to be considered depending on the zone affected.