KNEE JOINT ANATOMY AND ASSESMENT

 The knee joint is one of the largest and most complex joints in the human body.

It is classified as a hinge joint and is responsible for the flexion (bending) and extension (straightening) of the lower leg.

Anatomy: The knee joint is formed by the articulation of three bones: the femur (thigh bone), tibia (shin bone), and patella (kneecap). These bones are held together by ligaments, tendons, and muscles, which provide stability and allow for movement.

Ligaments: There are four main ligaments in the knee joint:

1. •Anterior cruciate ligament (ACL): Prevents the tibia from sliding too far forward and provides rotational stability.
2. •Posterior cruciate ligament (PCL): Prevents the tibia from sliding too far backward and also provides rotational stability.
3. •Medial collateral ligament (MCL): Stabilizes the inner side of the knee, preventing it from bending inward.
4. •Lateral collateral ligament (LCL): Stabilizes the outer side of the knee, preventing it from bending outward.

Menisci: The knee joint also contains two C-shaped pieces of cartilage called menisci (singular: meniscus) that act as shock absorbers and help to distribute weight evenly across the joint. There is a medial meniscus on the inner side of the knee and a lateral meniscus on the outer side.

Muscles: Several muscles surround the knee joint and contribute to its movement.

1. •Quadriceps Femoris: This is a group of four muscles located at the front of the thigh. The quadriceps femoris consists of the rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius. These muscles are responsible for extending the knee joint.

2. •Hamstrings: The hamstrings are a group of muscles located at the back of the thigh. They consist of the biceps femoris, semitendinosus, and semimembranosus. The hamstrings play a crucial role in knee flexion and help stabilize the joint.

3. •Gastrocnemius: The gastrocnemius muscle, commonly known as the calf muscle, crosses the knee joint and plays a role in knee flexion and stability. It also acts on the ankle joint, allowing plantarflexion (pointing the toes downward).

4. •Popliteus: The popliteus muscle is a small muscle located at the back of the knee joint. It assists in knee flexion and is involved in unlocking the knee from the fully extended position.

5. •Sartorius: The sartorius muscle is the longest muscle in the body and runs diagonally across the front of the thigh. While its primary function is to flex the hip joint, it also assists in knee flexion and rotation.

6. •Gracilis: The gracilis muscle is located on the inner thigh. It helps flex the knee and also plays a role in hip adduction.

7. •Tensor Fasciae Latae (TFL): The TFL muscle is located on the outer side of the hip and runs down to the knee. It aids in knee extension and also helps stabilize the hip joint.

Common Knee Problems: The knee joint can be susceptible to various injuries and conditions, including:

1. •Ligament tears (such as ACL or MCL tears)
2. •Meniscus tears
3. •Patellar tendinitis (inflammation of the tendon connecting the patella to the shinbone)
4. •Osteoarthritis (degenerative joint disease)
5. •Bursitis (inflammation of the fluid-filled sacs that cushion the knee)
6. •Patellofemoral pain syndrome (pain around the front of the knee)
7. •Knee dislocation or subluxation (partial dislocation)

There are several tests that can be performed to assess the knee joint and evaluate various conditions and injuries.

Here are some common tests used in the examination of the knee joint:

1. •Inspection: The first step is visual inspection to assess any visible deformities, swelling, redness, or bruising around the knee joint.

   
   

2. •Palpation: The doctor or healthcare professional may use their hands to feel the knee joint and surrounding structures, checking for tenderness, warmth, or any abnormal masses or bony prominences.

   
   

3. •Range of Motion (ROM) Assessment: This involves evaluating the knee's ability to move through its full range of motion. The examiner may ask the patient to flex (bend) and extend (straighten) the knee while observing and measuring the degree of movement.

   
   

4. •Ligament Stability Tests: These tests help assess the stability of the knee ligaments, which can be injured in conditions such as ligament sprains or tears.  

    

   Examples of ligament stability tests include the Lachman test, Anterior Drawer test, and Pivot Shift test for assessing the integrity of the Anterior cruciate ligament .

   
   

   1. •Meniscus Tests: The meniscus is a C-shaped cartilage structure that acts as a shock absorber in the knee joint. Tests like the McMurray test and Apley's compression test are commonly used to assess for meniscal injuries or tears.

      
      

   2. •Patellofemoral Tests: These tests focus on evaluating the function and alignment of the patella (kneecap) in relation to the femur. Examples include the patellar apprehension test for patellar instability and the Clarke's test for patellofemoral pain syndrome.

      
      

   3. •Stability Tests: These tests assess the overall stability of the knee joint. One such test is the Varus and Valgus stress tests, which evaluate the medial (inner) and lateral (outer) collateral ligaments.

      
      

   4. Special Imaging: In some cases, imaging studies like X-rays, MRI (Magnetic Resonance Imaging), or CT (Computed Tomography) scans may be ordered to provide a more detailed view of the knee joint and its internal structures. 

      
      

      Treatment options for knee problems depend on the specific condition and severity. They can range from conservative measures like rest, physical therapy, and pain management to more invasive interventions like surgery (e.g., ACL reconstruction, meniscus repair, joint replacement).

Thank you

Dr.Rupa Bhandari 

MPT( ortho)