Posterior interosseus nerve vs. medial cutaneous nerve of the forearm: differences in digital nerve reconstruction

Digital nerve defects are common in hand trauma and for primary or secondary nerve reconstruction, the autologous nerve graft remains the gold standard. This study compares the regeneration results and donor side morbidity of either the posterior interosseus nerve (PIN) graft or the medial antebrachial cutaneous nerve (MACN) graft. 16 patients (group A, age 43 ± 13 years) with digital nerve defects were treated with a PIN graft and 12 patients (group B, age 40 ± 15 years) received a MACN graft. The average nerve gap was 22 mm in each group. After a follow-up of 15 ± 8 months in group A, S4-sensibility were measured in 9 cases, S3+ in 5 cases and in 1 case S2 and S0. Up to an inconspicuously scar in projection of the fourth extensor-tendon compartment, there was no significant donor side morbidity. In group B, a S4-senibility has been obtained in 4 cases, S3+ in 5 cases, S3, S2 and S0 in each 1 case after a follow-up of 16 ± 11 months. Regarding the donor side morbidity, almost all patients complained about a disturbing scar formation and unpleasant paresthesia at the forearm down to the rascetta. Neuroma-associated pain has been detected in 4 cases. Although there has been no significant difference in terms of nerve regeneration, we recommend the use of the PIN graft for digital nerve reconstruction, since harvesting this nerve is fast and easy and without any donor side morbidity compared to the MACN graft.