ANTERIOR TRANSLATION + INTERNAL/ EXTERNAL ROTATION

Graph 1 shows the results obtained after performing tests on both knees of a patient with the DYNEELAX. The graph displays the compliance curves (=opposite of stiffness curves) obtained after applying several forces on the tibia of the patient (anterior tibial translation).

The green curve represents the data collected on the healthy knee while the red curve represents the pathological knee.

This is called "dynamic analysis" because calculation of the displacements of the tibia is done while applying different forces that put the anterior cruciate ligament under stress (from 0 to 200N for example) to enable the drawing of compliance curves (=opposite of stiffness curves). As a result, the bigger the side-to-side differential, the higher the chances of an anterior cruciate ligament tear.

In comparison, other arthrometers  only collect data at a certain force (134 N for example). This is called "static analysis".

It is thus against this background that Genourob innovated while conceptualizing the DYNEELAX, the first automated tibial translation arthrometer for dynamic assessment of the anterior cruciate ligament.

Here is an example to answer this question :

The two graphs below show the results obtained on the knees of two different patients having suffered from knee ligament injuries after a DYNEELAX test. The green curves show the test results of the healthy knees whereas the red curves show the results of the pathological knees.

As 134 N is the international reference force for assessing the ACL thanks to the KT1000, let us compare the displacement differential between both knees of both patients at this force.

We can see here that the side-to-side displacement differential at 134 N is the same for both patients (1.5 mm). This should indicate that both patients are not suffering from a torn ACL. However, it not the case. The DYNEELAX indeed shows innovation & precision in this exact situation as it provide an additional diagnosis method: the analysis of the slope of the curves.

In fact, we can determine that Patient 1 has a stable knee while Patient 2 is unstable. Why?

Because on the graph of patient 1, the ACL compliance curves (=opposite of stiffness curves) are parallel and on the graph of patient 2 the ACL compliance curves (=opposite of stiffness curves) diverge.

This indeed shows that patient 1 has two stable knees with a slight side-to-side difference in laxity that remains the same eventhough the force applied on the knee increases. This indicates a stable knee. However, patient 2 clearly shows an increasing side-to-side difference in laxity correlated with the increase of the force applied on the knees, hence the objective diagnosis of an unstable knee.

This example purely states the efficiency of running dynamics tests against static tests on the knee. Considering the slope differential between both compliance (=opposite of stiffness) curves on behalf of the displacement differential between both knees ultimately leads to a much more accurate analysis of the state of the ACL in the knee.

The consequently places the DYNEELAX as the most advanced arthrometer for evaluating the state of the anterior cruciate ligament. Besides, it is also the only device capable of assessing ACL laxity very after surgery without any risk thanks to its controlled tibial translation (maximum forces applied can be chosen: 89, 100, 134, 150, 200 Newtons). 

Doctors are thus able to follow the behaviour of the ACL graft over the months following the surgery, which is key to increasing the probability of gaining knee stability. Today's surgical techniques indeed require a lot of time of recovering therefore making the DYNEELAX indispensable during anterior cruciate ligament rehabilitation (ACL Rehab).

• Over time, Genourob created several options that could be added to the GNRB such as the PCL option dedicated to analyzing the knee cruciate ligament, the posterior cruciate ligament (PCL).

• Finally, the DYNEELAX is automatically features with the LDA®Couch which provides the patient with great comfort and is specially designed for our products.
• the LDA®Trolley can also be provided for storage of the laptop and a printer for printing the results.