Based in Newcastle-upon-Tyne, ExplantLab
is an independent research organisation that is focused on improving the performance of medical implants such as hip and knee replacements.
The company combines extensive surgical, bioengineering and medical knowledge to understand the performance of medical implants that have been removed from patients’ bodies; these parts are known as ‘explants’.
Implants can fail and need to be removed from patients’ bodies for a number of reasons. When explants are submitted to ExplantLab it uses a range of technologies to reverse engineer them and to accurately determine their ‘as-new’ shape.
By comparing an explant’s reconstructed original form with its shape following removal, the amount of material that has been removed while in the patient’s body can be accurately calculated. This process allows the precise mapping of wear patterns and enables all findings to be linked to various design, surgical and patient factors.
By combining the knowledge gained from the precise examination of explants, deductions can be reached related to how and why various devices have performed well or poorly.
Given ExplantLab’s need for precision, for several years the company has used a Mitutoyo Legex 322 coordinate measuring machine (CMM) for reverse engineering explants. However, ever-increasing volumes of explants that need to be assessed recently prompted the purchase of a second CMM from Hampshire-based Mitutoyo UK Ltd
ExplantLab director David Langton said: “ExplantLab is an independent company with no contracts with manufacturers As a trusted independent investigator, our aim is to improve the quality, effective functioning and longevity of future medical devices. In addition to the knowledge and skill of our staff, the accuracy of our findings is determined by the range of technologies we use.
This includes our Mitutoyo Legex 322 CMM, which has been both accurate and reliable, so when the need arose for an additional CMM we again contacted Mitutoyo’s and together decided that a Strato Apex 574 CNC CMM with a work envelope of 500 x 700 x 400mm would meet our needs in terms of capacity, accuracy and scanning speed.
“Indeed, we can now load multiple explants onto the machine and undertake rapid, fully automated reverse engineering routines.”
A typical use for the Strato Apex 574 is the scanning of explant bearing surfaces to establish multiple data points for in-depth analysis, with automated programmes allowing the CMM to distinguish between the unworn parts of bearing surfaces and to determine their precise as-new geometries.
From unworn areas, the original geometries of the components can be reverse engineered. By comparing the actual surface (the post revision geometry) of a component to the original (as manufactured) surface, the magnitude of wear can be calculated and accurately mapped.
In conclusion, Mr Langton said: “When compared to our older CMM, we can load many more explants onto the machine, then at the press of a button start a rapid and fully automated mass scanning routine. On completion, comprehensive reports related to the precise status of each explant are then generated.
“Due to its generous capacity and excellent speed of action, our new CMM can not only handle our current requirements but also accommodate all anticipated increases in our scanning throughput.”