CAD/CAM Delivers an Alternative to Amputation

A range of Delcam's CAD/CAM software is being used by ISIQU Orthopaedics to design and manufacture custom-made bone and joint implants in patients with tumors and major bone loss. In most cases, the only alternative to the implants would be amputation of the affected limb.

In the past three years, more than 250 people, of which around 90% were under 30 years old, have had life-changing or even life-saving surgery from ISIQU, based near Cape Town, South Africa. Some of the typical patient cases 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 tumor in his lower arm.

PowerSHAPE converts the CopyCAD surfaces into a final design.

"We have been using Delcam products since the start of ISIQU's manufacturing customized implants operations," explains Director, Dr. George Vicatos. "With the complexity of our work, we didn't have a big selection of CAD/ CAM products from which to choose. The way that representatives from software reseller Aztech presented the software made all the difference. In my mind, there were no other products in the market that offered the versatility, power and precision needed for our work."

The ISIQU process begins with information from the patient, which comes either in X-ray format, or as a MRI or 3D CT scan. If it is in the first two formats, the image is scanned and digitized, and the basic dimensions are obtained to help in the design decisions. If it is in CT scan format, it is first converted to an STL file format, which is then imported into Delcam's CopyCAD reverse engineering software. In this program, 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 imported into the PowerSHAPE CAD program in which the design of the implant is completed.

The final design is passed into Delcam's PowerMILL CAM system, which is used exclusively by ISIQU technicians to program the company's 5-axis milling machine. "I do not believe that any other software in the market could create the programs as quickly and as easily as PowerMILL, especially with the complexity of the surfaces that we machine," Vicatos comments. "The programming and machining times for our implants are crucial. We always produce custom implants and sometimes we have only two days notice before the operation.

"Our implants are machined exclusively of a medical grade titanium alloy," Vicatos adds. "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."

All machining at ISIQU is programmed with PowerMILL.

However, it's an unforgiving material if any aspect of the machining is not perfect. ISIQU has studied technology that has been developed for cutting titanium in other industries when setting speeds and feeds.

"As well as having the best software, we use the best cutting tools that the market can provide," Vicatos says. "The time constraints that we work under mean that the complete process from receiving the patient's data, to the design, the programming, the machining and to the finished implant has to have no surprises that would delay the process.

Although the process seems to be complicated, with the Delcam software, it is in fact straightforward and fast. "Most importantly, I feel comfortable that the patient will get exactly the implant I have designed, and this is what counts. It would be difficult to undertake any of the surgeries we perform without the software – in many cases it would be impossible," Vicatos concludes.

Delcam Inc.,
Windsor, Ontario
delcam.com

ISIQU Orthopeadics
Cape Town, South Africa
isiqu.co.za