Address: for Samples:
Sandwell & West Birmingham Hospitals NHS Trust,
Pathology Department, Dudley Road,
Birmingham, B18 7QH
Contact Points
Email:
Laboratory Tel: 0121 507 5345
Chromium & Cobalt for Metal on Metal (MoM)
Wear Checking
Page last updated: 03 March 2023
Test
TPMT
In some individuals with metal-on-metaL (MoM) replacement hip joints, and similar prostheses, it has become evident that
release of metal debris from the devices may occur, leading to elevated blood metal ion concentrations and local soft tissue
reactions. These can result in destruction of nearby muscle and bone and in a small number of cases, complete failure of the
joint. In response to concerns regarding this, the MHRA issued a Medical Devices Alert (MDA/2010/033) in 2010. This
recommended That certain groups of patients deemed to be at high risk of soft tissue reactions, undergo regular monitoring,
including measuring blood concentrations of cobalt and chromium. If the metal ionconcentrations exceed the MHRA
threshold of 7 ppb (135 nmol/L for chromium or 120 nmol/L for cobalt), repeat testing 3 months later is advised together with
other further investigations (e.g., imaging studies)
Chromium & Cobalt
