An occupational medicine expert witness has testified in the Los Angeles County Superior Court hip implant case against the DePuy Companies. DePuy provides orthopedics, spinal care, and sports medicine and is part of Johnson & Johnson. The expert described how the device failed due to the metal debris which sloughed off the implant. DePuy has recalled the metal-on-metal artificial hip implants and patients may have to undergo revision surgery within six years of their original hip surgery.