Metal-on-Metal Hip Device Side Effects Could Include Cysts, Lower Limb Swelling
Metal-on-Metal Hip Device Side Effects Could Include Cysts, Lower Limb SwellingDec 13, 2012
Another complication is being seen following metal-on-metal total hip arthroplasty (THA) surgeries and involves the formation of cysts and severe limb swelling.
In recent months, research has linked metal-on-metal implant devices to an array of adverse events such as tissue necrosis, pain, inflammation, swelling, metal poisoning, and high failure rates. Metal-on-metal hip devices have also been linked to pain at the implant, sometimes spreading to the groin and back, osteolysis (bone loss), and fluid collection and solid masses around the hip joint.
A new study, published in the Orthopedics Journal, discusses the case of one patient who developed an iliopsoas bursal cyst. The cyst caused venous obstruction and significant swelling in her lower limbs and was accompanied by a high level of chromium and cobalt ions; the study’s authors indicated that the woman’s condition was, in fact, the result of metallosis, which occurred due to so-called “edge loading,” related to the device’s cup liner, part of the metal-on-metal device. In this case, the patient was implanted with a DePuy Pinnacle hip implant constructed with an Ultamet Liner.
Five years after the woman was implanted with the DePuy Pinnacle hip implant, she began to experience limb swelling that worsened with walking, a result of the venous obstruction. According to the study’s authors, the woman underwent revision surgery to remove the metal-on-metal implant and was re-implanted with a ceramic-on-ceramic bearing interface. She also underwent drainage of the bursal cyst and synovectomy (removal of inflamed joint tissue).
These cysts can present as either pain or a groin mass, the author’s wrote. The vein compression and limb swelling have also been seen in metal-on-polyethylene THA devices related to these types of bursal lesions, as have pseudotumors with metal-on-metal resurfacing devices. Treatment for these types of cysts typically requires removal of the metal debris source, in this case, the metal-on-metal hip device, the study authors wrote. For the most part, this is accomplished by revision surgery to a nonmetal-on-metal bearing interface combined with cyst drainage and debridement (removal of damage tissue or foreign objects from the body).
These emerging research findings may have important implications concerning the risks to which metal-on-metal hip implant patients are exposed. DePuy Orthopaedics, a unit of Johnson & Johnson, recalled its ASR hip device and is also the maker of the Pinnacle. Other makers include Biomet, which manufactured the M2a Magnum™; Smith & Nephew, makers of the Oxinium™ and the Birmingham BHR; Zimmer, the maker of Durom; and Wright Medical Technology, which makes CONSERVE® Hip systems and the PROFEMUR®.
Metal-on-metal hip replacements gained notoriety in August 2010 when DePuy recalled 93,000 devices worldwide due to high failure rates. Since, research reveals that high revision rates were not brand or manufacturer specific, but involved the entire class of medical devices. In fact, researchers have come to believe that the metal-on-metal implants shed ions when the surfaces of the implant articulate, or rub against each other, which may lead to a number of adverse reactions