Hip and knee replacement: benefits of computer-assisted surgery
7 Dec 2020

Hip and knee replacements are among the most commonly performed orthopedic procedures and their number continues to grow worldwide. Significant improvements in implant design and materials have been observed over the past decade.

However, surgical technique and accurate positioning of the implants remain critical in order to achieve successful results. Surgical navigation (computer-assisted surgery) represents a major advance in improving accuracy and is therefore expected to improve both functional results and implant longevity. 

When should I consult a hip or knee replacement specialist?

“More and more people are suffering from their hip or knee joints nowadays. Osteoarthritis is the most common reason and is related to increased life expectancy, a more active lifestyle, and the increased incidence of obesity. Joint pain progressively restricts walking distance due to limping. Additionally, a restricted range of motion gradually makes daily activities more difficult to perform. Such situations with altered quality of life require a specialist opinion with physical examination and imaging in order to determine whether joint replacement may be the best option or not. Such a procedure should not be considered too early, nor too late.”

What are the major advances in the field of hip and knee replacement over the past decade?

“Better knowledge of joint biomechanics and material properties have led to significant improvement in implant design and wear resistance. Additionally, significant advancements in perioperative management of pain and blood loss have also been observed, and fast recovery programs have emerged. However, despite these improvements, complications may still occur and accurate positioning of the implants remains critical to reduce the likelihood of failures. The development of computer-assisted surgery, especially surgical navigation, represents a major advance as it provides the surgeon with continuous real-time feedback during the procedure.”

What are the advantages of using navigation systems in orthopedic surgery? 

“Basically, navigation systems have been developed in order to improve the accuracy of the surgical procedure, allowing for a less invasive approach and reduced morbidity. They were first introduced in neurosurgery in the early 1990s. Progressively, orthopedic surgery has become the main field of investigation. Using markers located by infrared cameras on bones and surgical instruments, the navigation system enables the surgeon to access real-time information about the 3D location and orientation of instruments and implants. In the same manner as a GPS helps the driver to reach the destination, navigation is a tool that assists the surgeon during the procedure to achieve the pre-operative planning, thus increasing the likelihood of successful clinical results and longevity of the implants. Using navigation, the procedure becomes more accurate and reproducible.”

Which kind of orthopedic surgery is done with this system? 

“Navigation offers major benefits in the field of joint replacement. For knee replacement, such a system helps the surgeon to intraoperatively control lower limb alignment, ligament balancing, and patellar tracking. For hip replacement, navigation enables the surgeon to control stability (to avoid dislocation), leg length and the abductor muscle tension. All these parameters are known to be highly correlated with successful results. Encouraging results of navigation for joint replacement has led not only to the use of this technology for other procedures including osteotomies, ligament repair, and traumatology, but has also led to the recent development of “active” systems with the current emergence of robotic surgery.”

* Prof. Olivier Guyen is specialist in hip and knee replacement at Clinique de Genolier.
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