This is a great video showing how the medial side of the knee opens up when  the medial collateral ligament is sprained.Embedded VideoBlogged with the Flock Browser

This is a nice short animation demonstrating a method for completing a Bone-Tendon-Bone Anterior Cruciate Ligament Reconstruction.Embedded VideoBlogged with the Flock Browser

    This is a good video demonstrating a Posterior Cruciate Sprain. Embedded VideoBlogged with the Flock Browser

Click to Play The Anterior Drawer Test for the knee is used to examine the integrity of the anterior cruciate ligament. The patient is placed supine on the table with the knee in 90 degrees of flexion and the hip flexed approximately 45 degrees. The examiner places her hands around the proximal tibial with her thumbs crossing the anterior joint line. The patient's foot is anchored in a neutral position by the examiner's thigh. The examiner tells the patient to relax her hamstrings. This suggestion is enhanced through a light tapping with the examiners fingers on the tendons of the hamstrings just behind the knee. Once the patient is relaxed the examiner attempts to pull the tibia anteriorly. Instability is determined by examining bilaterally and comparing the amount of excursion present.

Click to Play Apley's distraction test is commonly performed in conjunction with Apley's compression test. The patient starting position is the same (prone with the knee flexed to 90 degrees). The examiner will apply traction to the lower leg while rotating the tibia medially and laterally. Pain with this maneuver can indicate a ligamentous injury of the knee.

Click to Play Apley's Compression test is used to assess the menisci of the knee. The patient is place prone on the exam table with her knee flexed to 90 degrees. The examiner applys a downward compressive force through the lower leg while laterally rotating the lower leg. Pain with this maneuver can indicate an injury of either meniscus.

Click to Play The Lachman's test (aka Ritchie test) is the preferred method of assessing for instability of the anterior cruciate ligament.  The patient is supine on the table with their knee flexed approximately 20-30 degrees.  The examiner grasps the medial proximal tibia with one hand and the distal thigh with the other.  The examiner then applies a posteromedial to anterolateral force to the knee, essentially pulling the tibia anteriorly on the femur.  The amount of translation is compared bilaterally to determine the presence and/or extent of instability.  Alternative methods have been developed to accomodate examiners with small hands and for use with patients with large extremities.

Click to Play The Slocum Drawer test is used to assess for medial and lateral rotary instabilities of the knee.  The exam is administered similarly to the anterior drawer test with the exception that the tibia is rotated medially and laterally to assess for anterolateral and anteromedial instability respectively.  The knee is placed in approximately 90-degrees of flexion with the foot flat on the table.  Thirty-degrees of medial rotation is applied to the tibia by rotating the foot and the examiner pulls anteriorly on the tibia to assess for anterolateral rotary instability.  To examine anteromedial rotary instability the tibia is laterally rotated approximately 15-degrees and the tibia is once again pulled anteriorly.  Results are compared bilaterally.

Click to Play The Acute Patella Injury Test (aka Apprehension Test) is used to assess the possibility that the patient may have sustained a patellar dislocation which spontaneously reduced.  This test provokes the same sensations which would have been present when the dislocation occured and therefore will elicit a reactive contraction of the quadriceps muscles by the patient in an attempt to avoid a recurrance of the dislocation.  This reaction is referred to as an apprehension sign.  The patient lies supine on the table with the knee in 20-30 degrees of flexion and the quadriceps relaxed.  The examiner carefully glides the patella laterally observing for the apprehension sign.  A positive test is the presence of this reaction by the patient.

Click to Play The posterior sag test (also known as the gravity drawer test, drop back sign, or Godfrey's test) is used to assess posterior cruciate ligament laxity.  The patient is supine with her hips and knees bent to ninety-degrees.  The examiner supports the patient's legs at the ankles and observes for an indication that the tibia has shifted posteriorly (toward the table) as compared to the uninvolved knee.