Removing each knee ligament to test its function

Now that you're familiar with the normal motions, you're ready to knock out some ligaments. On page 1 of the activity worksheet, you'll find a table. There's a row for each of the motions that you practiced in the previous step and a column for each of the major ligaments of the knee. For this experiment, you'll remove each ligament (individually, not more than one at a time) and then go down the column, checking whether the motion corresponding to each row is normal or abnormal.

If you observe abnormal motion with the removal of a ligament, that means that ligament functions to limit that particular motion. For example, if you remove a ligament and the tibia is now able to laterally rotate about its long axis laterally beyond whatits isnormal normal,range, the ligament that you removed functions to limit lateral longitudinal rotation.

ForIn addition, this experiment,result you'llalso completetells theyou tablethat onextreme pagelateral 1longitudinal ofrotation yourcan worksheet,injure removing each remove eachthat ligament and determineonce whetherthat ligament is injured, there will be pain and/or instability with lateral longitudinal rotation.

This guide will walk you through the resultingfirst motionligament, isthe normalIliotibial or(IT) abnormaltract/band, .so Anythat abnormalyou motionscan check your work and make sure you are on the right track before continuing with the remaining ligaments.

Knocking out your knee kit's ligaments

Knocking out the iliotibial (IT) tract/band

You can knock out the IT tract by simply unhooking it from its attachment on the tibia. Using the forceps can help in grabbing and pulling the "tail" of the cord.

Video of unhooking the IT tract from its attachment on the tibia by pulling on the tail of the cord.

Knocking out the other ligaments

To knock out the other ligaments, follow the steps below.

1. Locate the access door on the posterior aspect of the femur. 
   
   

   

   Caption

   
   
2. Use the Allen wrench to remove the screw from the access door.
   
   

   

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   Inside you'll see

2. To remove a 

Testing ligament function

Iliotibial (IT) band/tracttract/band

Lateral collateral ligament (LCL)

Anterior cruciate ligament (ACL)

Posterior cruciate ligament (PCL)

Medial collateral ligament (MCL)