Metallosis is the main adverse side effect cited in legal proceedings against DePuy Orthopaedics, a subsidiary of Johnson & Johnson, for faulty hip replacement surgeries. In metallosis cases, metal debris builds up in the body’s soft tissues — this is often associated with metal-on-metal hip implants. Metallosis can lead to bone and tissue death and organ damage that can require surgery to treat.

Tissue death, known medically as necrosis, can be a severe side effect related to metal hip implants, such as those produced by DePuy. When cells die as a result of necrosis, the cell membrane is unable to control the release of cell death products into intracellular spaces, which ignites an inflammatory response. If necrosis goes untreated, it can lead to a buildup of dead and decomposing tissue that can be severely detrimental and, in extreme cases, fatal.

Cobalt and chromium are particularly known for creating the toxic levels that lead to metallosis. Cobalt poisoning can lead to more serious health problems, including nerve issues and the thickening of blood. Combined cobalt-chromium toxicity can result in neurosensory, endocrine, cardiac, neurocognitive, neurological, and respiratory symptoms.

There are several precipitating side effects of cobaltism that result from the failure of DePuy products. Tinnitus is one such side effect, which is perceived ringing in the ear when there is no sound present. Vertigo is another — a type of dizziness in which a person experiences the perception of motion. Deafness, blindness, and headaches are other side effects.

Hypothyroidism is another associated side effect. This is a condition in which not enough thyroid hormone is produced by the thyroid gland — a problematic condition in that the thyroid hormone is dedicated to maintaining the body’s metabolism.

Cardiomyopathy has also been seen in DePuy cobaltism. There are different types of cardiomyopathy, although they are all generally defined by a weakening of the heart muscle or another heart muscle problem that results from the heart’s inability to pump as the body needs. In instances of cardiomyopathy, the heart muscle may become enlarged, thick, or rigid, which affects its natural rhythm. Heart failure can result in the buildup of fluids in other parts of the body, including the legs, feet and ankles, lungs, and abdomen.

Another side effect that has been seen in reparative surgeries for failed hip replacements is ruptured tendons. Tendons are the fibrous tissues that attach bones to muscle. Tendon ruptures can present serious problems that range from excruciating pain to permanent disability. Depending on the severity of the rupture, it may be treated medically or surgically.