Templates Provide Greater Accuracy for Orthopedic Surgeons

An innovative technique helps orthopedic surgeons customize artificial knee implants and align the knee joint properly, thus reducing the need for future revision surgeries.

The OtisKnee technique is used to precisely match the size and placement of the implant to the patient's unique and normal (non-arthritic) knee anatomy, by manufacturing a custom cutting blocks for each patient. Prior to surgery, a magnetic resonance imaging (MRI) scan is performed to take very precise measurements of the patient's arthritic knee. Second, proprietary computer software creates a three dimensional (3D) image of that knee, and then virtually corrects the deformity to return the knee to its pre-arthritic state. A computerized 3D image of the implant to be used in the patient's surgery is then shape-matched to the anatomically correct virtual knee model.

Lastly, using all of this information, special cutting template guides are created for the surgeon to use during the procedure. These patient-specific cutting guides, which are accurate to within a few millimeters, indicate to the surgeon exactly where to make bone cuts so that the knee replacement is customized for the individual patient. By thus narrowing the margin of error, post-operative pain is relieved and patients can achieve a better balance of the ligaments, and a good chance of resuming normal activities earlier. The new technique was developed by OtisMed (Alameda, CA, USA), a Stryker Corporation (Kalamazoo, MI, USA) company, in collaboration with orthopedic surgeon Stephen Howell, M.D, of The Methodist Center for Orthopaedic Surgery (Methodist, Houston, TX, USA).

"It's the same as aligning the wheels of a car. You can get the wheel on the car, but the better it is aligned, the longer it will last and the more effective it will be,” said Kenneth Mathis, M.D., chairman of Methodist. "In the next ten years, we will see a more than 600% increase in revision knee replacement surgeries. Some of this is because we are doing them in younger patients, but the majority of cases I see for revision are from alignment and implantation errors.”

Related Links:
OtisMed
Stryker Corporation
The Methodist Center for Orthopaedic Surgery