Knee

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Anatomy

The Knee joint

The knee joint is the largest joint in the body, consisting of 3 bones and an extensive network of ligaments and muscles.

The 3 main bones are: the Femur, the Tibia and Patella. The fibula is not involved in the knee joint. The main movements of the knee joint occur between the femur, patella and tibia. They are covered in articular cartilage which is an extremely hard, smooth substance designed to decrease the friction forces. Friction forces occur when there is movement between two bones. The patella lies in an indentation of the femur known as the intercondylar groove. At the outer surface of the tibia lies the fibula, a long thin bone that travels right down to the ankle joint. The knee joint consists of the patellafemoral articulation and the tibiofemoral articulation. The first articulation contains the patella and the femur and the second articulation contains the tibia and the femur.

Ligaments of the knee joint

Knee Ligaments

The ligaments of the knee maintain the stability of the knee. Each ligament has a particular function in helping to maintain optimal knee stability.

1. Medial Collateral Ligament (MCL) - This band runs from the medial epicondyle of the femur to the medial condyl and the superior part of the medial surface of the tibia. In the middle of the ligament the deep fibers are attached to the medial meniscus. MCL resists forces acting from the outer surface of the knee, valgus forces.
2. Lateral Collateral Ligament (LCL) – a cord like ligament that begins on the lateral epicoondyle of the femur to the lateral surface of the fibula head. It resists impacts from the inner surface of the knee, varus forces.
3. Anterior Cruciate Ligament (ACL) - The ACL is one of the most important structures in the knee. The cruciate ligaments are so called because they form a cross in the middle of the knee joint. The ACL, runs from the anterior of the tibia to the posterior of the femur and prevents the tibia moving forward. It is most commonly injured in twisting movements.
4. Posterior Cruciate Ligament (PCL) - This ligament runs from the posterior surface of the tibia to the anterior surface of the femur and so wraps around the ACL. The PCL limits anterior rolling of the femur on the tibial plateau during extension.

Menisci

Knee Menisci

The medial meniscus appears ‘C’ shaped while the lateral meniscus appears more ‘O’ shaped. The surface of each meniscus is concave superiorly, providing a congruous surface to the femoral condyles and is flat inferiorly to accompany the relatively flat tibial plateau. The medial meniscus is much less mobile during joint motion than the lateral meniscus owing in large part to its firm attachment to the knee joint capsule and medial collateral ligament (MCL). On the lateral side the meniscus is less firmly attached to the joint capsule and has no attachment to the lateral collateral ligament. In fact, the posterior horn of the lateral meniscus is separated entirely from the posterolateral aspect of the joint capsule by the tendon of the popliteus muscle as it descends from the lateral epicondyle of the femur.

Muscle Groups surrounding the knee joint.

The two main muscle groups of the knee knee joint are the quadriceps and the hamstrings.
• M. Quadriceps
• M. Biceps femoris
• M. Semimembranosus
• M. Semitendinosus
• M. Gracilis
• M. Sartorius
• M. Triceps Surae
• M. Plantaris

Motions Available:

Flexion and extension are the main movements. There is a little rotation when the knee flexes.

Closed Packed Position:

Near full extension. There is a medial rotation of the femoral condyles on the tibial plateau.

Open Packed Position:

Midrange flexion.

Clinical Examination

• Knee Examination
• Special Tests
  • McMurray's Test
  • Apley's Test
  • Steinman's Test
  • Ege's Test
  • Ely's Test
  • LCL Test
  • MCL Test
  • Anterior Draw
  • Lachman Test
  • Pivot Shift
  • Slocum's Test
  • Posterior Drawer Test
  • Dial Test
  • Muller's Test
  • Patellar Apprehension Sign
  • Patellar Grind Test
  • Thessaly's Test

• Outcome Measures
  • Knee Injury and Osteoarthritis Outcome Score

Conditions

• Anterior Cruciate Ligament Injury
  
• Articular Cartilage Lesions
• Baker's Cyst
• Chondromalacia Patellae
  
• Femoral Fractures
• Hamstring Strain
• Iliotibial Band Syndrome
• Knee Osteoarthritis
• Knee Bursitis
  
• Lateral Collateral Ligament Injury
  
• Medial Collateral Ligament Injury
  
• Meniscal Lesions
• Ober's Test
• Osteochondritis Dissecans of the Knee
• Osgood-Schlatter's Disease
• Plica Syndrome
• Quadriceps Muscle Strain
• Quadricpes Muscle Contusion
  
• Patellofemoral Pain Syndrome
• Patellofemoral Instability
• Patellar Tendinitis
• Patellar Fractures
• Pes Anserinus Bursitis
• Plica Syndrome
• PrePatellar Bursitis
• Popliteus Tendinitis
• Posterior Cruciate Ligament Injury
  
• Sinding Larsen Johansson Syndrome
• Tibial Plateau Fractures

Procedures

• Arthroscopic Meniscectomy
• Meniscal Repair
• Articular Cartilage Debridement & Microfracture
• ACL Reconstruction
  • Patellar Tendon Autograph
    
  • Hamstring Tendon Autograph
    
  • Allograph
• PCL Reconstruction
• ORIF Post-Fracture
• Arthroscopic Debridement & Manipulation
• Lateral Release of the Patella
• Tibial Osteotomy
  

Interventions

• Therapeutic Exercise: Knee
• Manual Therapy: Knee
• ACL Rehabilitation
• Patellar Taping