New patient-specific drill guide revolutionizes orthopaedic surgeries to benefit younger active patients

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The commercial licensing of a patient-specific guide for orthopaedic surgery developed by researchers at the Human Mobility Research Centre, a joint venture between Kingston General Hospital and Queen’s University, has the potential to bring the benefit of advanced computer assist surgery to regular operating rooms around the world.

This revolutionary surgical tool is an innovative drill template created by using three-dimensional computer models from a patient’s computed tomography, or CT scan (CT scans use diagnostic imaging to produce precise, detailed cross-sectional images of anatomical structures.) With specially engineered computer software, these images are then used to build a plastic drilling template that exactly fits the patient’s bone structure. These patient-specific molds include a novel verification component that enables surgeons to precisely and accurately align and place the metallic implants used in hip resurfacing and other related surgeries.

“The three-dimensional advantage of the CT scan is incorporated into the design to create a customized form – a drill guide – that increases accuracy and efficiency in the OR,” says Dr. John Rudan, orthopaedic surgeon at Kingston General Hospital and Professor of Surgery at Queen’s University. Dr. Rudan is also Vice President of Clinical Relations at iGO Technologies Inc., the Kingston-based medical technology firm that assisted with the customized surgical planning software development.

Dr. Rudan originally designed the drill template for a procedure known as hip resurfacing arthroplasty, a relatively new procedure which preserves more of the bone structure than with traditional hip replacements. With this technique, only the damaged cartilage on the femur head is removed, instead of the whole joint. It is then replaced with a metal cap, providing a more natural range of motion for the patient and a faster return to normal activity levels. To date the guide has been successfully used in over 50 hip resurfacing procedures at Kingston General Hospital.

A significant challenge with this unique form of joint surgery is that precise placement of the metal implant is critical to prevent undue strain on the remaining healthy bone structure. There are few surgeons in the world skilled enough in “freehand” drilling to accomplish this precision, so computer-assist surgery systems are used. With the development of this new patient-specific drill template, orthopaedic surgeons are able to quickly and accurately align the metal cap, thereby reducing operating room time and postoperative complications for improved patient outcomes.

Most important, thanks to the licensing agreement established by the university’s technology transfer office, PARTEQ Innovations, this drill template allows surgeons at hospitals anywhere to perform this advanced surgical procedure without the complex and expensive computer-assist operating room infrastructure usually found only at health sciences and research centres.

The drill template has applications in other orthopaedic procedures, such as knee and ankle replacements and shoulder surgeries similar to hip resurfacing arthoplasty. All of these procedures are geared towards younger, more active patients who would otherwise outlive traditional total joint replacements and be left with permanent impaired mobility and decreased quality of life.

The guide was created at the Human Mobility Research Centre by Dr. Rudan and Dr. Manuela Kunz, the mechanical and software engineer behind this exciting and innovative tool. This world-class research facility is shared by a multidisciplinary group of leading clinician-scientists, basic scientists and engineers interested in the mechanisms of musculoskeletal diseases and disorders.

With the licensing agreement now in place, patients and surgeons around the world will benefit from this important advancement in orthopaedic surgery,” says Dr. Kunz. “This is a completely new way of performing navigational surgery, allowing patients and surgeons access to the most advanced techniques outside of the clinical research setting,” she explains. “It is very rewarding to see the results of research commercialized to allow a greater number of patients to ultimately benefit.”