Glossary of Knee Terms


Anatomical Axis – Line drawn from the center of the knee through the middle of the femur to the top of the femoral canal

Anterior – Toward the front

Anterior Cruciate Ligament (ACL) – One of the major structural ligaments of the knee providing anteroposterior (front to back) stability

Arthritis – Inflammation of the joint due to infectious, metabolic, constitutional or behavioral causes

Arthroplasty – The surgical repair of a diseased joint

Articulation – The act of motion between two or more bones within a single joint



Bilateral – Pertaining or involving both sides; bilateral knees = left and right knees

Biomechanics – The study of the action of external and internal forces on the living body



Cancellous – The softer, spongy inner matrix of bone

Capsule – Soft tissue envelope which surrounds a joint

Cartilage – A tough, rubbery supportive tissue found on the ends of bones and serving the purpose of reducing friction during movement

Condyle – A rounded prominence at the end of a bone, most often for articulation with another bone

Cortex – The outer layer

Cortical – The harder outer layer of bone

Crepitus – A creaking, squeaking or grinding sound emanating from a joint, most notable the knee joint, upon slowly flexing and extending the joint



Distal – Farthest from the point of origin



Epicondyle – A bony prominence on the condyles serving as a place for attachment for ligaments, tendons and muscles

Extension – The act of straightening a limb

External – One the outside or surface



Femur – The thigh bone, which is the largest and strongest bone in the body

Flexion – The act of bending a limb

Flexion Contracture – Soft tissue tightening resulting in loss of motion in the joint







Inferior – Lower in place or position, situated beneath another, or toward the feet

Internal – Movement toward the inside or midline of the body





Kinematics – The study of motion of the body



Lateral – Away from the median or midline of the body; toward the side

Lateral Collateral Ligament (LCL) – The ligament found on the outer side of the knee



Mechanical Axis – Line drawn from the center of the femoral head, thorugh the center of the knee, to the center of the ankle

Medial – The middle, or toward the middle

Medial Collateral Ligament (MCL) – The ligament found on the inner side of the knee and spanning the joint

Median – The midline of the body

Medullary Canal – The tubular, hollow area within long bones around which marrow is located; also called the intramedullary canal

Meniscus – Crescent shaped cartilage in the knee that acts as a cushion between bones





Osteoarthritis – A form of arthritis caused by chronic degeneration of the cartilage of the joint

Osteochondrosis – A deterioration or inflammation of the bone/cartilage surface

Osteophyte – Bony projections that form along joints



Patella – The kneecap, which is a thick circular-triangular bone that articulates with the femur and covers and protects the anterior articular surface of the knee joint

Patellofemoral Tendon – The tendon at the distal end of the quadriceps muscle group, containing the patella, and which inserts into the tibial tuberosity

Periosteum – A membrane that lines the outer surface of all bones except at the joint and serves as attachment for muscles and tendons

Posterior – Situated behind another structure; the back side

Proximal – Nearest to the point of origin or attachment



Quadriceps – The large four-part extensor muscle at the front of the femur, comprised of the rectus femoris, vastus lateralis, vastus intermedius, and the vastus medialis



Rotation – The act of turning a body part around a centrally located axis



Sagittal – Referring to the median vertical plane of the body

Sterile – Devoid of living organisms

Subluxation – A partial or incomplete dislocation of the joint

Superior – Above, higher



Tendon – A specialized connective tissue which joints muscles to bone

Tibia – The larger, heavier bone of the lower leg; shin bone

Tibial Plateau – The top or proximal portion of the tibia on which the femoral condyles articulate

Tibial Tuberosity – A bony prominence on the proximal anterior portion of the tibia which serves as the insertion of the patellofemoral tendon for the quadriceps

Tubercle – A small, rounded eminence of bone for attachment of tendons

Tuberosity – A broad, rounded eminence of bone where muscles attach





Valgus – “knock knee”

Varus – “bow legged”



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