The investigators aim to determine the cause of failure of orthopaedic implants using multi-disciplinary analysis of data from patients who have undergone revision.

The following tests will then be arranged:

• Tribological assessment. The investigators will measure the wear of the explants using: 1) 'out of roundness'; and 2) Coordinate measuring. Semi-quantitative assessment of damage to the explants will also be conducted
• Histological assessment. Tissue sent in formalin may determine the biomarker of diagnosis of metal ion synovitis where applicable
• Metal ion measurement in body fluids where applicable (in patients with metal implants)
• Diamond Light Source (this was approved in the 1st amendment). The tests will involve subjecting formalin fixed tissue to the high energy electron beam of the Diamond Light Source
• Destructive testing of the implant is allowed by the patient (after all non-destructive tests have been performed)
• Protein analysis of fluid and tissue if provided
• Titanium levels from blood samples if provided
• Gene expression testing to assess and understand mechanism of inflammation where applicable

Inclusion Criteria:

• All patients undergoing revision of an orthopaedic implant (previously this was limited to metal hips but this has now expanded to other orthopaedic implants)

Exclusion Criteria:

• Patients not consenting to the study

Patients will be both male and female, aged between 11-70 years.