Developing an algorithm to predict risk of joint replacement failure

Over 160,000 NHS patients undergo knee and hip arthroplasty surgery each year. A number of these surgeries will fail, requiring costly and complex revision surgery, which carries an increased risk for the patient.

An increasing body of scientific evidence suggests metal allergies are responsible for many of these failures. Wear and tear metal-containing implants causes metal debris to be released, whilst electrochemical processes releases metal ions that travel into the bloodstream and collect in organs. Localised cellular reactions and inflammatory responses underpin a pathophysiology that leads to adverse reaction to metal debris (ARMD). This is strongly correlated with loosening of implants in the joint and ultimate failure of the implanted metal device.

There is currently no method recommended for preoperative screening of patients for metal allergies as a predictor of future metal implant failure, representing a significant unmet need. The only option for sensitivity testing available prior to implantation is a skin-based Patch Test, which is highly limited in its predictive value (due to skin responses to allergens being different to that within bodily tissues) and is thus not used.

PXD Ltd have undertaken proprietary research and isolated biomarkers that are detectable preoperatively that are associated with metal allergies and post-operative joint failure. In this project, they will develop an algorithm to analyse these biomarkers in the context of other clinical data and use this to generate a low/medium/high risk stratification of patients. The screening service proposed by PXD Limited, underpinned by the algorithms generated in this project, represents a novel opportunity for orthopaedic surgeons to use data generated using patient-specific biomarkers preoperatively to assess which implant will give the best possible patient outcomes.