A Probing Device for Quantitatively Measuring the Mechanical Properties of Soft Tissues during Arthroscopy

The main advantage of this device is that, it allows us to measure the resistance of soft tissue in a quantitative manner. The device conform closely to the shape of conventional probe, uses the consecutive parameter and the correct data in the known unit Newtons. All measurements of the resistance force of the acetabular labrum by pool probing.

First fix a phantom hip consisting of the left pelvis and femur bone, major muscles of the hip, acetabular labrum, hip capsule, and articular cartilage of the hip joint onto a standard fixation device. Unlock the connecting part of the fixation device. Then abduct and internally rotate the femur bone slightly to distance it from the pelvis and to generate joint space to mimic hip arthroscopy.

To prepare the arthroscope, connect a portable arthroscopy camera light source to a four millimeter 70 degree autoclavable direct view arthroscope and connect USB cables from the arthroscopy camera and light source to a computer. Then open the advanced screen recording software for the arthroscopy view. To generate the first portal, insert a cannulated needle and guidewire into the hip joint.

From the tip of the greater trochanter to make a normal anterolateral portal. Insert a 5.5 millimeter cannula with an obturator along the guidewire. Then remove the obturator and then insert the 70 degree arthroscope and camera along the cannula then confirmed that the capsular triangle between the labrum and femoral head, can be observed in the view from this portal and create the second portal as a modified anterior portal.

When the anterior portal has been generated, retain the arthroscope in the anterolateral portal. Insert a 4.5 millimeter cannula with an obturator along the guidewire. Remove the obturator and then insert an arthroscopic scalpel from the anterior portal.

Perform a Periportal Capsulotomy around the anterior portal, moving the scalpel, medially and laterally to generate more space for the anterior portal in the hip capsule and place the arthroscope into the anterior portal. Rotate the camera view of the arthroscope until the cannula can be visualized at the anterolateral portal and insert the arthroscopic scalpel from the anterolateral portal. Then perform a transverse 15 millimeter long inter portal capsulotomy connecting the two portals five millimeters from the labram from approximately 10 o'clock to two o'clock.

To set up the probing device, connect the power supply unit and computer with a USB cable and switch on the power supply. Open the software for the probing device and input the matrix data, which is pre-calculated during the calibration of the strain gauge sensor. Immediately before measurement, reset the measuring force value to zero and check the functionality of the foot switch connected to the recording system of the probing device.

To measure the resistance of the intact labram, switch the arthroscope into the anterolateral portal from the anterior portal. Insert switching stick, remove the cannula and insert another cannula. Finally, insert the probing device through the anterior portal into the hip joint until the tip of the device is below the inner side of the acetabular labrum.

Be sure to always confirm that that this riding aspect of the device works before probing Then retract the tip of the probing device in the direction of the joint while pressing the foot pedal to obtain the force resistance value. To measure the force reaction of a mock cartilage sample, place a freshly prepared a 15 by 20 by three millimeter mock cartilage plate onto a base plate with a tiny stopper toward the side of the push probing and fix the position and orientation of the probing device such that the tip of the device almost touches the surface of the mock cartilage sample at a 30 degree tilt to the horizontal line. After zeroing the setting, press the foot pedal three times to push and pull the tip of the probing device on the mock cartilage sample.

When the force resistance of all the samples has been measured, use a classical indentation device to measure the conventional elastic modulus and stiffness of the sample. In this representative analysis, the highest mean result in forces of Y and Z for the acetabular labrum for the three steps, were 4.4 Newtons at the intact labrum, 1.6 Newtons at the cut labrum and 4.6 Newtons at the repair labrum. In addition, a significant positive correlation between the probing sensor force and the elastic modulus was obtained.

Take care to maintain your arm position while probing, especially when pushing or pulling softer tissues as riding of this probe tip can affect the accuracy of the data. In future studies, artificial intelligence may be a useful tool for identifying the condition of the soft tissues as well as for acquiring quantitative parameters.