Thirty-one cases of failed metal-backed patellar components requiring revision surgery are reviewed. Two modes of implant failure onset were noted. Within each group, delays in patient presentation and diagnosis of the failed component were encountered. The syndrome of the failed metal-backed patellar component is proposed. The authors conclude that: (1) more of these failures will be seen in the future; (2) this patient population needs appropriate counsel concerning the signs and symptoms of this syndrome as well as more frequent follow-up evaluations; (3) surgeons treating this complication should be prepared to revise all components; and (4) the use of metal-backed patellar components should be discontinued.