GLOSSARY OF TERMS

A b c d e f g h i j k l m n o p q r s t u v w x y z

C

Cartilage

Smooth, slippery connective tissue covering, usually found at the end of bones, that allows joints to move smoothly without pain.

Conventional instrumentation

The metal guides and cutting blocks that are used in approximately 97% of TKAs. These instruments do not contain computers and are purely mechanical.

Computer assisted surgery (CAS)

In total knee arthroplasty, the term “computer-assisted surgery,” or “CAS,” describes the large computer systems (often the size of a podium) that are sometimes used in the operating room to provide the surgeon with precise information on the angles of the knee bone cuts that the surgeon is making.

Coronal plane

Also called the frontal plane, a plane that divides the body into anterior (front) and posterior (back) portions.

D

Distal

Describes the part of a bone that is further away from its attachment to the body.

F

Femoral condyles

The protrusions on the distal end of the femur.

Femur

The thighbone.

Femoral head

The top of the thighbone that sits in the hip socket.

K

KneeAlign^® 2 System

The KneeAlign® 2 system is a surgical navigation system that is equivalent to computer-assisted surgery in precisely measuring distal femoral and tibial cuts in total knee arthroplasty (TKA).

KNEE REVISION SURGERY

Knee revision surgery, which is also known as revision total knee arthroplasty, is a procedure in which the surgeon removes a previously implanted artificial knee joint, or prosthesis, and replaces it with a new prosthesis.

L

Lateral

Away from the midline of the body.

Ligaments

A strong band of connective tissue connecting bone to bone.

M

Malalignment

Occurs when the bones and joints are not lined up correctly. As a result, the body’s load (i.e. weight) is not shared evenly, but instead is carried disproportionately by the body’s other joints. Malalignment is typically described as a deviation of greater than 3º from the limb’s mechanical axis, with the mechanical axis defined as an imaginary line that runs from the center of the femoral head (in the hip socket) to the center of the ankle through the knee.

Medial

Towards the midline of the body.

Mechanical Axis

An imaginary line that runs from the center of the femoral head (in the hip socket) to the center of the ankle through the knee.

P

Partial knee replacement

A knee procedure where the medial or lateral half of the femur and tibia are replaced with an implant.

Patella

The kneecap

Posterior slope

The slope of the tibial plateau that is within the sagittal plane.

Proximal

Describes the part of a bone that is closer to its attachment to the body.

R

Resection

Cutting and removal of bone.

Sagittal plane

A plane that divides the body into left and right portions.

T

Tendon

A tough band of connective tissue connecting bones to muscles.

Tibia

The shinbone

Tibial notch

The gap on the distal femur between the condyles.

Tibial plateau

The top of the tibia where the femur moves over it.

Total knee arthroplasty

An implant that replaces the cartilage of the femur, tibia and frequently the patella.

Total knee arthroplasty (TKA)

Also known as total knee replacement, a surgical procedure in which the portions of the femur, tibia and (typically) patella that form the knee joint are replaced with plastic and metal surfaces.

V

Varus

Medial side (towards the midline)

Varus deformity

The distal part of the leg below the knee is deviated inward, resulting in a bowlegged appearance.

Valgus

Lateral side (towards the outside)

Valgus deformity

The distal part of the leg below the knee is deviated outward, resulting in a knock-kneed appearance.