Orthotype: Next-generation orthopaedics

The unique preoperative test that predicts the likelihood of chronic pain and implant failure in patients

First of its kind
'host response' focused test

Despite most implants containing cobalt chrome, it is now known that even a blood concentration of just two micrograms per litre can cause an aggressive inflammatory response in some patients.

Our test uses a patient's genotype to identify potential intolerance to certain metals. Surgeons can then use these personalised results to choose the most compatible implant for their patients and significantly reduce the risk of unexplained chronic pain or implant failure.

Host Response
With no two patients the same, many manufacturers will offer 'patient specific' implants. However, these tend to overlook the crucial host immune response, despite it playing a huge role in determining the success of the implant.

Orthotype
Developed to be used pre- or post-op to help surgeons and patients wherever they are on the implant journey

Pre-op

Samples can be taken via saliva or blood, with a saliva test done either at home or in clinic. We then carry out genetic sequencing to predict the likelihood of a metal sensitivity reaction developing following surgery.

Post-op

We provide testing kits for two blood samples. We can then carry out genetic sequencing with ICP-MS to determine blood metal concentrations.

Ortho Analysis

Next-generation DNA sequencing

As patients move, particles are generated from the implant surfaces. These particles are then taken up by antigen-presenting cells where they are digested in the lysosome and broken down into their constituent peptides.

These peptides then compete to occupy the binding grooves of the major histocompatibility complexes (MHCs), which is a critical trigger to stimulating the patient's immune system.

By using next-generation gene sequencing, we can precisely identify a patient's MHC structures, and, therefore, determine the probability of an adverse reaction.

The MHC complex

The MHC complex is encoded by the human leukocyte antigen (HLA) genes.

And it is the three dimensional structure of these MHC complex that determines which peptides are more likely to be present on the cell surface.

However, certain peptide fragments have greater immunogenicity than others.

Peptide determination

If the peptide presented at the cell surface is recognised as foreign, lymphocytes may be activated to combat the antigen. This, in turn, sets off a chain reaction that results in fluid accumulation and tissue destruction.

Through genotyping, we can determine which peptides a patient is more likely to present.

Blood metal ion analysis

For patients who have already undergone joint replacement surgery, we use inductively coupled plasma mass spectrometry (ICP-MS) to measure the level of cobalt and chromium in the bloodstream. It is widely accepted a level of 7 micrograms per litre indicates an increased risk of an adverse reaction.

However, our research has shown that a significant number of patients may develop destructive tissue lesions at concentrations as low as 2 micrograms per litre.

Orthotype incorporates blood metal ion testing and high resolution genotyping to help identify the patients at greatest risk of adverse tissue responses.

As there can be a significant time delay in the appearance of inflammation following surgery, an Orthotype test report will also provide the clinician with a time-dependent risk profile.

Helping orthopaedic professionals create a complete patient picture with a comprehensive, easy to read report

Combining the results of DNA testing and metal ion analysis, we can identify the likelihood of a delayed type metal allergy being present in a patient.

We recommend Orthotype before revision surgery to give the patient a greater chance of a successful outcome with their new implant. Our Orthotype report is provided within 2 weeks of testing to indicate:

A risk estimate of an active sensitivity to metal

A risk estimate of future issues occurring

A comparative population evaluation

Older Man Post Implant Surgery
Tailored decision making for long term gain. By predicting the likelihood of post-surgery complications, Orthotype can reduce the possibility of revision surgery, chronic pain and implant failure.
39%
increase in revision surgery for total knee arthroplasty (2006 vs 2010)*
Stats

Helping surgeons make
better-informed decisions for the benefit of their patients

By giving surgeons a more detailed picture and greater understanding of their patients, right down to their genotype profile, we can significantly increase the chances of a positive post-op outcome. While at the same time allowing this approach to 'personalised medicine' to integrate seamlessly into the current process.


See our papers