An apparatus for forming a weld between a first portion of a biocompatible conductive thermoplastic material and a second portion of a biocompatible conductive thermoplastic material comprises a first electrode, a second electrode, and a structure for holding said first and second electrodes in opposition to one other with a space therebetween for receiving said first portion and said second portion in contact with one another. The structure is electrically non-conductive and an electrical circuit comprising a power source and a switch arranged such that closure of said switch applies a voltage potential across said first electrode and said second electrode so as to generate heat via electrical resistance, the heat being sufficient to melt regions of said first and second portions.