Meet Our Doctor

Jaime Hernandez MD

Orthopaedic Surgeon

Computer Navigated Knee Replacement – Stryker Alignment and Sizing

A total knee replacement surgery is the last resort to relieve pain and restore function in knee damaged by arthritis or an injury when non-surgical treatments do not relieve the condition. The procedure involves replacing the damaged surfaces of the articulating bones with the artificial implant. Most of these implants wear with use. Thus, the risk of need for revision surgery is high in young and active people if the implant has to last the lifetime of the patient. The life of the implant can be extended by precise alignment of the implant and this can be achieved by the use of computer navigation for total knee replacement surgery.

Computer navigation provides the surgeon with the real time 3-D images of the mapped patient’s knee and the surgical instruments during surgery. The data for the images is provided by the infrared sensors, which are fixed to the bones of the knee and the surgical instruments. Their position is tracked by an infrared camera, which is placed above the surgical table connected to the computer. The computer than generates the real time images with the help of the appropriate software to guide the surgeon to precisely resurface and cut the bones of the knee and fix the implant precisely & accurately according to the pre-operative surgical plan. Thus, the surgery is done by the surgeon only. Computer navigation is just a tool to guide the surgeon and improve the outcome of the surgery. It cannot replace the skills of an experienced surgeon.


Computer Navigated Knee Replacement - Verasense Balance and Pressure

Dr. Hernandez was the first surgeon in Southern California to perform total knee replacement with VERASENSE technology. This new device uses microchips and pressure sensors to measure the pressure inside a patient’s knee. It provides intra-operative feedback to the surgeon to help with deciding on how to position the implants.

This Verasense System nicely complements and incorporates well with the Stryker Computer Navigation System that Dr. Hernandez utilizes in his practice. Verasense takes computerized knee replacement to the next level!

The new addition, OrthoSensor’s Verasense Knee Sensor, is an intelligent spacer block that replaces the standard plastic spacer block typically used during knee replacement surgery. The Verasense Sensor is embedded with accelerometers, microelectronics, and wireless communication technology. It transmits key data on load and balance to the computer, which features a large monitor for easy viewing by the surgeon.

Before the adoption of Intelligent Computer Assisted Orthopaedic Surgery, decisions about soft tissue balance, load, and limb alignment have varied based on a surgeon’s individual judgment, experience, and “feel”.

The real-time information provided by the Stryker Computer Navigation System with VERASENSE gives the surgeon an objective data display on a screen. This screen data is used in conjunction with the tactile information that he feels in his hands and the vision of the patient’s anatomy that he sees with his eyes.

With all of this information, surgeons are able to better understand each patient’s anatomy and then place the implants in the optimal position.