Secondary reconstruction of lost muscle function in brachial plexus injuries is performed by dynamic muscle and tendon transposition, by free microvascular muscle transplantation and by static surgical procedures. In cases of weak function of the finger flexors, static opponensplasty is required. In these cases our procedure is the internal fixation of the base of the metacarpal I to the base of the metacarpal II without stabilisation of cancellous bone. From 1987 to 1992 we operated 15 patients by this procedure. Results are showing sufficient stabilisation and good function.