TM USER GUIDE Device Activation and LinkStation™ Operation LB-03000-003 Rev A
INTRODUCTION The OrthoSensor™ Knee Balancer is an intelligent tibial trial that provides intraoperative data to help determine and achieve optimal soft tissue balance and component position during total knee arthroplasty (TKA). The Knee Balancer is capable of sensing dynamic loads and center of load* in the medial and lateral compartments of the operated knee through a full range of motion with the patella reduced.
LINKSTATION SET-UP STEP 1 Activate LinkStation Press and hold power button on back of computer to activate. Confirm surgeon visualization of LinkStation. Position Transceiver Power switch on back of computer Ensure Transceiver is connected directly to USB port on back of computer. Transceiver CANNOT be connected through a peripheral USB hub. Transceiver should point toward the operating table with antennae oriented in opposite directions at approximately 45º to the Transceiver.
DEVICE ACTIVATION STEP 2 Launch Application Double click the OrthoSensor icon to launch application. Activate Device A. Remove appropriate size OrthoSensor Knee Balancer and Shims from box. OrthoSensor Icon & Application Start Screen Do not remove from sterile pack. Remove outer box labels and affix to patient documentation as required. B. Place device directly over round silver magnet on LinkStation with articulating surface facing up.
LEG SELECTION STEP 3 Select LEFT or RIGHT leg The GUI will automatically prompt leg selection.
“ZERO” DEVICE STEP 4 Zero Device The OrthoSensor Knee Balancer utilizes an accelerometer to assess component position* and leg flexion angle*. The “zero” process calibrates the accelerometers to enable these functions and is accomplished in three steps. Note that the GUI prompts user to execute each step in the “Zero” process. A. Horizontal Zero, step 1 Place sterile packed device flat on LinkStation shelf Gently secure medial and lateral edges to ensure device is flat.
“ZERO” DEVICE STEP 4 (continued) C. Vertical Zero, step 3 Place sterile packed device flat against LinkStation post. Underside (non-articulating surface) of device should be placed against post with posterior edge pointing toward floor. Hold device in place and click the “Zero” button. “Device is Ready for Use” will appear on the GUI indicating completion of the “Zero” process. NOTE: This step is instantaneous and has no progress bar.
DEVICE READY FOR USE STEP 5 The OrthoSensor Knee Balancer is now ready for use. Verify Device Activation While still in sterile packaging, apply pressure on the device to verify that loads are registering on the GUI. (FIGURE I) NOTE: If loads do not register then the device may not be fully active and the following steps are recommended: FIGURE I i) Deactivate device by clicking the Power button in the lower right corner of the GUI.
ATTACH SHIMS STEP 6 The OrthoSensor Knee Balancer is packaged with four (4) shims to enable use of trial inserts with 9mm, 11mm, 13mm and 16mm thickness. A shim must be affixed to the underside of the device prior to insertion into the tibial tray. Affix Shim Affix appropriate size shim to underside of device by sliding it posterior to anterior. (FIGURE I) Shim Exchange To exchange shim size, unsnap it from anterior portion of the device and replace with desired size.
SET TIBIAL ROTATION STEP 7 Select and position appropriate size Trial Tibial Tray to achieve maximum tibial plateau coverage. The tibial tubercle mid-middle 1/3 is marked and a single anterior pin is inserted to allow rotational adjustments and maintain medial-lateral position.
DEVICE INSERTION STEP 8 The OrthoSensor Knee Balancer is inserted with appropriate sized shim affixed to replicate the thickness of the selected trial insert. In a tight knee it is often necessary to insert the tibial baseplate and the OrthoSensor Knee Balancer prior to insertion of the femoral trial. In this instance, reduce the tibia under the femur, then insert the femoral trial with minimal impaction force.
ADDITIONAL FEATURES KINETIC TRACKING™ The Kinetic Tracking function displays dynamic kinematic motion of the knee with applied loads as well as maximum and minimum load values through the complete range of motion. To enable Kinetic Tracking click the “Track” button located on the bottom edge of the GUI. NOTE: Click the “Clear” button immediately after the “Track” button to reset max/min load values.
OrthoSensor Customer Service Tel: 888-75-ORTHO (888-756-7846) OrthoSensor™ (www.orthosensor.com) is the technology leader in development of intelligent orthopedic devices that provide real-time data to surgeons and hospitals during and after surgery. OrthoSensor intelligent orthopedic devices utilize advanced sensor and communication technologies to improve healthcare outcomes and reduce the cost of treating musculoskeletal disease. The device complies with part 15 of the FCC Rules.
