Key terms
Femur - A bone of the leg situated between the pelvis and knee in humans. It is the largest and strongest bone in the body.
Bursa - A sac or saclike bodily cavity, especially one containing a viscous lubricating fluid and located between a tendon and a bone or at points of friction between moving structures.
Synovial membrane - The connective-tissue membrane that lines the cavity of a synovial joint and produces the synovial fluid. Also called synovium. This will thicken following acute injuries and chronic conditions (synovitis)
Articular cartilage - The joint surfaces covering the inside surfaces of the bones forming a synovial joint. Also called arthrodial cartilage, diarthrodial or investing cartilage.
Capsule - a tough, flexible connective tissue layer that site around the whole knee joint.
Tibia - The inner and larger of the two bones of the lower human leg, extending from the knee to the ankle.
Patella - A flat triangular bone located at the front of the knee joint. Also called kneecap.
Synovial fluid - A clear, viscid lubricating fluid secreted by membranes in joint cavities, sheaths of tendons, and bursae.
Synovium - The inner lining of all mobile, synovial joints. This is a specialised tissue which will inflame in the presence of acute or chronic injury
Meniscus - A cartilage disk that acts as a cushion between the ends of bones that meet in a joint.
Patellar tendon - The part of the tendon of the extensor mechanism that extends from the patella to the tibia, sometimes called the patellar ligament.
Quadriceps tendon - The tendon attaching the bulk of muscles at the front of the thigh to the top of the kneecap.
Anterior Cruciate Ligament (ACL) - one of two deep central ligaments within the knee which is frequently invloved in significant twiting knee injuries.
Medial Collateral Ligament (MCL) - The most frequently injured ligament lies on the inner side of the knee.
Posterior Cruciate Ligament (PCL) - The other, slightly larger and less commonly injured central knee ligament.
Lateral Collateral Ligament (LCL) - The main ligament complex on the outer side of the knee.
Postero-Lateral Corner (PLC) Ligament - an additional complex of 3 ligaments at the back/other side of the knee.
Postero-Medial Corner (PMC) Ligament - a capsular condensation on the back, inner side of the knee.