Explant Analysis from a Patient Exhibiting Rapid Acceleration of Parkinson Disease Symptoms and Hypercobaltemia Following Metal-on-Metal Total Hip Arthroplasty

Case: A 46-year-old man developed rapidly progressing Parkinson disease symptoms after metal-on-metal total hip arthroplasty, worsening to the extent that he underwent implantation of a right subthalamic deep brain stimulator (DBS). A serum cobalt level of 116 μg/L was measured shortly after DBS implantation, and revision arthroplasty was performed using ceramic-on-polyethylene bearings. After revision, the patient’s serum cobalt level fell below 1 μg/L, the Parkinson disease symptoms improved, and he reduced the DBS to its lowest setting. Explant analysis showed substantial material loss from the bearing surfaces of one hip. Conclusion: Future studies should evaluate the possible link between Parkinson disease symptoms and prosthesis wear-induced hypercobaltemia.