Combined nerve and tendon transfer strategy for the restoration of grasp in tetraplegia; a case report.

Introduction: By combining nerve and tendon transfer procedures, a more versatile hand function can be expected. Here we report the long-term outcomes of novel, individualized reconstruction strategies using combined nerve and tendon transfer procedures (CNaTT) to restore prehension and grasp in two patients with tetraplegia.

Case Presentation: Two women, 45 years of age, underwent bilateral nerve transfer according to the Bertelli S-PIN (supinator to posterior interosseous nerve transfer) procedure. The grip reconstruction included tendon transfers using brachioradialis to flexor pollicis longus and extensor carpi radialis longus to flexor digitorum profundus, as well as balancing tenodesis, arthrodesis procedures and intrinsic reconstruction. At 6 months, the patients' pinch and grasp strength ranged between 1.0-2.0 and 2.2-5.0 kg, respectively, concomitant with improvements in activity and occupational performance. At 4-7 years after the grip reconstruction, both patients had full metacarpophalangeal (MCP) extension scoring M5 and M4, as well as full thumb extension scoring M5 and M4 on the right side. On the left side, MCP extension was weaker for both patients (M1/M2), whereas the thumb could extend against gravity (M3/M4). The maximal 1 webspace opening measured between 5 and 11 cm. Pinch strength measured between 1.25 and 2.6 kg, and whole hand grip strength between 3.9 and 7.8 kg. The patients' grasps could fit around 80 and 50 mm wide cylinders using a normal right-handed grasp.

Discussion: The CNaTT procedure successfully restored useful grasp and release function with long-lasting effects. A large-scale controlled study is needed to confirm these findings.