The Gantzer transfer - Assessment of the feasibility of using the nerve supplying the Gantzer muscle for end-to-side supercharging of the ulnar nerve.

Our study aimed at assessing the anatomical feasibility of using the nerve supplying the Gantzer muscle (GM) to supercharge the ulnar nerve following injury. The GM nerve was dissected and measured in 36 forearms. The distance between its origin and the lateral epicondyle of humerus and between the GM nerve and the ulnar nerve was measured. The GM was present in 15 forearms (47%). The average distance between the origin of the GM nerve and the lateral epicondyle was 7.34 cm (range 3.3-9.1 cm). The average length of the GM nerve was 3.05 cm (range 1.6-4.5 cm) from origin to neuromuscular junction. The average distance from the ulnar nerve was 2.56 cm (range 1.8-13 3.4 cm). The length of the GM nerve was significantly greater (p < 0.05) than the perpendicular distance between its origin and the ulnar nerve, allowing ample margin for side-to-side or end-to-side supercharging of the ulnar nerve with minimal or no need for further translocation or dissection. The use of the GM nerve as donor following ulnar nerve injury may provide an alternative to the pronator quadratus nerve for supercharged end-to-side transfer, or as an addition, thus supercharging the ulnar nerve twice.

Supercharge End-to-Side Nerve Transfer: Systematic Review.

Background: To decrease the time to reinnervation of the intrinsic motor end plates after high ulnar nerve injuries, a supercharged end-to-side (SETS) anterior interosseous to ulnar motor nerve transfer has been proposed. The purpose of this study was to compile and review the indications, outcomes, and complications of SETS anterior interosseous to ulnar motor nerve transfer. Methods: A literature search was performed, identifying 73 papers; 4 of which met inclusion and exclusion criteria, including 78 patients. Papers included were those that contained the results of SETS between the years 2000 and 2018. Data were pooled and analyzed focusing on the primary outcomes: intrinsic muscle recovery and complications. Results: Four studies with 78 patients met inclusion and exclusion criteria. Most patients (33.3%) underwent SETS for an ulnar nerve lesion in continuity, the average age was 46.5 years, and the average follow-up was 10 months. The average duration of symptoms before surgery was 99 weeks, all patients had weakness and numbness, nearly all (96%) had atrophy, and half (53%) had pain. Grip and key pinch strength improved 202% and 179%, respectively, from the preoperative assessment. The vast majority (91.9%) recovered intrinsic function at an average of 3.7 months. Other than 8% of patients who did not recover intrinsic strength, no other complications were reported in any of the 78 patients. Conclusions: The SETS is a successful procedure with low morbidity, which may restore intrinsic function in patients with proximal nerve injuries.