PROSPECTIVE EVALUATION OF SERUM COBALT, CHROMIUM, AND TITANIUM AFTER IMPLANTATION OF METAL-ON-METAL TOTAL HIP PROSTHESES

Purpose: Serum cobalt and chromium levels after metal-on-metal implantations are not well known. There has been little data on the correlation with clinical and radiological surveillance. This prospective analysis followed the changes in serum cobalt, chromium, and titanium levels in order to ascertain the behaviour of the femoral implant and the bearing.Material and methods: The series included 292 patients followed for 27–72 months who were free of kidney failure, were not given vitamin B12 supplementation, and did not have occupational exposure. The same cemented implants were used in all patients: titanium femoral stem, Metasuly heads (28 mm). Serum samples were drawn preoperatively and at three, six and twelve months then annually (systematic activity questionnaire). The limit for detection of serum cobalt and chromium was 1 nmol/l (0.05μg/l); for titanium it was 30 nmol/l (1.4m/l).Results: The main problems encountered were two impingements and two femoral loosenings. Four patterns were identified i...