Most all metal implants are constructed of cobalt and chromium, although many have a titanium stem (another potential problem regarding mismatched metals). Patients with particular sensitivities to cobalt and chromium may experience significant adverse health effects at relatively low levels of metal exposure while others may have dangerously high levels of cobalt and chromium, yet remain asymptomatic. While cobalt and chromium toxicity have many of the same symptoms, there are important differences as well...

Cobalt and chromium ions which enter the surrounding hip tissues can cause chronic pain in the hip, groin or thigh, inflammation, loosening of the Pinnacle implant, deterioration of the bone and tissue, and the necessity for revision surgery. Despite the fact that the FDA has received over 1300 adverse reports related to the Pinnacle, DePuy and its parent company, Johnson & Johnson...

Recipients of metal-on-metal hip implants have been forced to deal with scores of side effects resulting from metallosis or chromium and cobalt poisoning. Many of these metal hips have been recalled, although many more are still being marketed and implanted. The process by which many metal hip implants gained approval...

In medical terms, metallosis is defined as aseptic fibrosis or local necrosis caused by corrosion of a metal device implanted in the body and the subsequent release of metal ion debris. Metallosis has also been described also as the macroscopic staining of the soft tissues…associated with abnormal wear. When metal surfaces come in contact with one another during periods of activity on the part of the patient—or when the polyethylene liner between the two metal components has degraded, allowing unintended contact between the metal parts—corrosion, fretting and excess wear can occur.

Regardless of the type of material used in the hip replacement surgery, there are certain risks associated with the procedure. Blood clots in the legs which travel to the lungs are known as pulmonary emboli, and, while relatively rare, can lead to respiratory failure and even death of the patient. The following complications can also occur in those who undergo hip replacement surgery...