Thanks to the use of UK developed CAD software, South African-based ISIQU Orthopaedics has been able to make custom-made bone and joint implants for patients with tumours and major bone loss. In most cases, the only alternative to the implants would be amputation of the affected limb.
The ISIQU process begins with information from the patient, which comes either in x-ray format, or as an MRI or 3D CT scan. If it is in the first two formats, the image is scanned and digitised, and the basic dimensions obtained to help in the design decisions.
If it is in CT scan format, it is first converted to an STL file format, which then is imported into Delcam’s CopyCAD reverse engineering software. In this software, the STL file is converted into surfaces to produce a digital model of the skeletal part that will be replaced with the implant. The surfaces produced by CopyCAD, or the dimensions from x-ray or MRI scans, are then imported into Delcam’s PowerSHAPE CAD software in which the design of the implant is completed.
The final design is then passed into the PowerMILL CAM system, which is used exclusively by ISIQU technicians to program the company’s five-axis DMG milling machine.
‘Our implants are machined exclusively from a medical grade titanium alloy,’ explained SIQU director, Dr. George Vicatos. ‘The material offers superb compatibility with the skeletal structure, not only because the body tissue accepts it, but also because of its elasticity and light weight.’
In the past three years, more than 250 people, of whom around 90 per cent were under 30 years old have had life-changing, or even life-saving, surgery from ISIQU. Typical patients include a 19-year-old woman whose arm and scapula were saved from bone cancer, and a 70-year-old man diagnosed with a malignant tumour in his lower arm.