The Stryker Rejuvenate and ABG II — Hip Stems That Corroded for $1.4 Billion

When Howmedica Osteonics, the orthopedic subsidiary of Stryker Corporation, posted an “Urgent Field Safety Notice” on July 3, 2012 withdrawing its Rejuvenate and ABG II modular-neck hip stems, the gap between the design’s selling point and its failure was already inscribed in the chemistry: the very feature marketed as an advance — a separable, surgeon-selectable metal neck joining the femoral stem at a second taper — was the site where the device destroyed itself. The stem was titanium alloy; the neck was cobalt-chromium. The two dissimilar metals, locked at a Morse taper and loaded with every step a patient took, fretted and corroded galvanically, shedding cobalt and chromium ions and metallic debris into the hip. Roughly 20,000 of the stems had been implanted before the recall.

The harm was not mechanical loosening of the kind orthopedics had long understood. It was a slow metallic poisoning of the joint. Released cobalt and chromium provoked adverse local tissue reactions — pseudotumors, fluid collections, and necrosis of muscle and bone — while systemic ion levels rose in the bloodstream, a condition clinicians call metallosis. Patients presented with pain, swelling, and instability; many were asymptomatic until imaging or blood testing revealed elevated metal levels and tissue destruction already underway. The remedy was rarely conservative. Revision surgery — extraction of a corroded, often well-fixed stem and replacement of the damaged joint — became the common endpoint, with its own attendant risks of fracture, infection, and permanent disability.

The Rejuvenate had reached the market not through clinical trials but through the FDA’s 510(k) pathway, cleared in June 2008 as “substantially equivalent” to predicate devices already on sale; the ABG II followed in November 2009. No premarket study had been required to prove that the modular junction was durable in living bodies. By July 2014 roughly 3,700 patients had sued. The litigation consolidated into a multidistrict proceeding in federal court in Minnesota and a coordinated docket before Judge Brian R. Martinotti in Bergen County, New Jersey, and on November 3, 2014 Stryker announced a settlement paying a base award of $300,000 per failed device removed, with enhancements for complications — a program that grew, through later expansions covering revisions into December 2016, to a payout exceeding $1.4 billion. The modular hip that promised the surgeon a custom fit became the textbook case of taper-junction corrosion and the limits of clearing an implant by analogy rather than evidence.