Wound drainage after metal-on-metal hip arthroplasty secondary to presumed delayed hypersensitivity reaction.

An emerging concern with metal-on-metal total hip arthroplasty is metal-induced hypersensitivity. Currently, this is a diagnosis of exclusion in patients with groin pain after metal-on-metal total hip arthroplasty. We describe a patient presenting nearly a year after arthroplasty with incisional drainage. Infection was presumed; but preoperative studies were nondefinitive, and the wound was explored. The operative cultures were negative; the histology revealed lymphocytic vasculitis. The patient recovered uneventfully after exchange to a metal polyethylene bearing couple. We believe that metal-induced hypersensitivity should be considered with draining wounds with this bearing couple if infection cannot be proven.