Implant failure of the gamma nail

The gamma nail is a temporary implant characterised by a limited life expec tancy under continuous dynamic stress. We reviewed a series of 839 patients with gamma nail stabilisation and found two fatigue fractures (0.2%) at th e aperture of the distal locking holes. This complication has not been desc ribed in the literature. Metallurgic and scanning electron microscopic examinations proved that the fatigue zones occurred at the clover-leaf grooves, which is where the diame ter of the gamma nail is reduced. The clover-leaf diameter is of no biomech anical use in gamma nail stabilisation. We suggested product modification b f the gamma nail to produce implants with a round diameter instead of a clo ver-leaf shape. A modified implant is already in use at our institution. (C ) 1999 Elsevier Science Ltd. All rights reserved.