What is the most complex joint in the body?

The KNEE joint

Knee joint! It takes a pounding as a hinge joint between two substantial bones… One of the most common operations performed in the U.S. – ???

Knee joint! One of the most common operations performed in the U.S. – knee arthroplasty (TKR) Total Knee Replacement

(animation ) Surgery:

THE KNEE

The knee - Largest joint in the body. -Hinge joint -greatest ROM is in flexion -highly susceptible to injury -not protected by layers of fat and muscle -easily palpable

The knee (anterior)

The knee (posterior)

Meniscus and ligaments and anatomy

Knee Meniscus

Knee ACL repair

bursas

Goniometer

Knee Flexion Testing Position: Prone with hip and knee in neutral Stabilization: Trunk and pelvis stabilized by body weight and position Goniometer Axis: Lateral epicondyle of the femur Proximal Arm: Parallel to the long axis of the femur & pointing at the greater trochanter Distal Arm: Parallel to the long axis of the fibula and pointing at the lateral malleolus Movement: The hip and knee are flexed as the heel moves toward the buttock Expected ROM: 135° *Alternate Position: Supine lying with the femur stabilized.

Alternate position

Knee Extension Testing Position: Prone with hips and knees in neutral rotation; upper leg on bolster Stabilization: Trunk and pelvis stabilized by body weight and position Goniometer Axis: Lateral Epicondyle of the femur Proximal Arm: Parallel to the long axis of the femur & pointing at the greater trochanter Distal Arm: Parallel to the long axis of the fibula and pointing at the lateral malleolus Movement: Knee extension Expected ROM: 0°. Hyperextension may be present up to -10° *Alternate Position: Supine with bolster under ankle

Alternate position- supine for knee extension

Goniometry Lab -Disadvantages:

Goniometry Lab -Disadvantages: -It is sometimes difficult to position and maintain the arms of the goniometer along the bones of the segments throughout the measurement -Intertester reliability -Coordination

Differences between R/L side measurements

Prone vs. Supine knee flexion SupineProne

Common injuries to knee

-Patellar dislocation - ACL tear -PCL tear - Collateral ligament tears -Meniscal tears -Tendon tears

Patellar dislocation

ACL tear Changing direction rapidly or landing from a jump incorrectly can tear the ACL. About half of all injuries to the ACL occur along with damage to other structures in the knee (articular cartilage, meniscus or other ligaments)

PCL tear PCL is generally injured from a blow to the front of the knee while the knee is bent. This often occurs in motor vehicle crashes and sports-related contact. PCL tears tend to be partial tears with the potential to heal on their own.

Collateral Ligament tears- lateral Injuries to the collateral ligaments are usually caused by a force that pushes the knee sideways. Injuries to the MCL are usually caused by a direct blow to the outside of the knee, and are often sports-related. Blows to the inside of the knee that push the knee outwards may injure the LCL. (LCL tears occur less frequently than other knee injuries.)

Lateral collateral ligament

Collateral Ligament tears- medial

Meniscal Tears Sudden meniscal tears often happen during sports. ◦Tears in the meniscus can occur when twisting, cutting, pivoting, or being tackled. Meniscal tears may also occur as a result of arthritis or aging. ◦Just an awkward twist when getting up from a chair may be enough to cause a tear, if the menisci have weakened with age.

Meniscal Tears

Tendon tears The quadriceps and patellar tendons can be stretched and torn. Although anyone can injure these tendons, tears are more common among middle-aged people who play running or jumping sports. Falls, direct force to the front of the knee, and landing awkwardly from a jump are common causes of knee tendon injuries.

Patellar tendon tear

Quadriceps tendon tear

Patellar tendonitis

Manual Muscle Testing

Manual Muscle testing -Knee ◦-quadriceps ◦- hamstrings

MMT- quads and hamstrings 1) Have patient go through full ROM first. 2) Then, have patient repeat full ROM while you offer resistance. 3) At the end of the motion, perform a brake test. 4) Record your results (do flexion and extension on both sides).

MMT- knee -Record your results for both the left and right LE.

Bony Landmarks of Knee -Patella -Tibial tuberosity -Femoral condyles -Tibial condyles

Stability Tests -Ligaments -Meniscus -Miscellaneous

Flexibility Tests -SLR (80-90 degrees is a desirable score) -Thomas Test

- Review medical abbreviations for quiz