Essential knee terminology
Sag sign search for term

The sag sign indicates a possible incompetency of the posterior cruciate ligament.

Sagittal plane search for term

If there was a very thin gap between two glass doors, and you turned sideways, holding out your arms out to the side up to shoulder height, to slip through the gap, then the glass doors would be considered to be in the sagittal plane in relation to your body.

Salvage search for term

Salvage procedures attempt to make the best of what is already a very bad situation.

Saphenous nerve search for term

A nerve branching off from the larger femoral nerve, and which transmits sensation in the side of the leg. 

Scaffold search for term

A framework that is used to facilitate building another structure.

Schatzker classification search for term

A system for the classification of tibial plateau fractures. I - VI

Schenck Classification search for term

A classification of degrees of knee dislocation based on the number of ligaments damaged, and the presence of associated fractures.

Screw home mechanism search for term

The screw home mechanism is a key element to knee stability for standing upright, and is a rotation between the tibia and femur occurring at the end of knee extension, between full extension (0 degrees) and 20 degrees of knee flexion.

Second look arthroscopy search for term

A 'second look' arthroscopy is when a patient is pro-actively booked to have an arthroscopy just to check up on a previous surgical procedure.

Segond Fracture search for term

A Segond Fracture is an avulsion of a small chip of bone off the lateral side of the femur, commonly seen in association with an anterior cruciate ligament rupture. 

Semi-lunar cartilage search for term

A semi-lunar cartilage is the old-fashioned name for a meniscus. 'Semi-lunar' means 'half-moon' and refers to the shape of the meniscus.

Semimembranosus search for term

The semimembranosus muscle is one of the three hamstrings muscles.

Semitendinosus search for term

The semitendinosus muscle is one of the hamstrings muscles.

Semitendinosus graft search for term

A graft for transplant derived from the tendon of the semitendinosus muscle.

Semitendinosus tenodesis search for term

One of several surgical procedures to re-align the patella.

Sherman Classification search for term

The Sherman classification is a classification based upon the situation of an ACL (anterior cruciate ligament) tear.

Shin bone search for term

The larger bone of the lower leg.

Short arc extensions search for term

Short arc extensions are knee rehabilitation exercises to re-trigger quads activity.

Side-stepping search for term

A knee rehabilitation exercise.

Sign search for term

Something that you can see which gives an idea about diagnosis of a medical problem.

Single-bundle ACL graft search for term

Reconstruction of the anterior cruciate ligament using a 'single-bundle' graft.

Single-photon-emission computed tomography search for term

Single-photon-emission computed tomography is a radioactive imaging technique to give information about blood flow in the body.

Slocum test search for term

The Slocum test is a modification of the anterior drawer test and is a test of anteromedial rotary instability and anterolateral rotary instability of the knee.

Small-incision knee replacement search for term

A small-incision knee replacement is a knee replacement performed with a smaller incision than traditionally, and using special techniques and instruments.

Snapping search for term

A sharp noisy snap of structures usually at the outer side or back of the knee.

SPECT search for term

Abbreviation of 'single-photon-emission computed tomography'.

Sports therapist search for term

Sports Therapy is an aspect of healthcare that is specifically concerned with the prevention of injury and the rehabilitation of the patient back to optimum levels of functional, occupational and sports specific fitness.

SPP search for term

Abbreviation of 'suprapatellar plica'.

Spurs search for term

Small and sometimes sharp abnormal bony outgrowths at the joint edges, usually associated with osteoarthritis.

Squats search for term

With your arms out in front of you, bending as if you are going to sit, but then straightening up again.

Squinting patellae search for term

When the two kneecaps face towards each other when the patient stands comfortably facing forwards.

Standing wall slides search for term

A knee rehabilitation exercise.

Staple search for term

Staples for ACL graft fixation are made of cobalt chrome with two sharp leg spikes for easier penetration into the bone without predrilling.

Static bicycle search for term

An exercise bicycle on a stand, where the wheels turn but the bicycle stays still.

Static bike search for term

Useful equipment item for knee rehabilitation.

Static quads search for term

Static quads are very early knee rehabilitation exercises to activate the quadriceps muscle of the lap.

Stem cell search for term

A stem cell is an unspecialised cell with a remarkable ability to divide over and over and become differentiated into another type of cell, replacing damaged body tissue.

Stem cell line search for term

A culture of stem cells all derived from the same original cell source, which has been allowed to multiply.

Stem cell therapy search for term

Repairing damaged body tissues with the use of stem cells.

Stem cells search for term

Stem cells are unspecialised cells with a remarkable ability to reproduce and become differentiated into another type of cell, replacing damaged body tissue.

Step ups search for term

A knee rehabilitation exercise.

Steroids search for term

Corticosteroids are drugs used to suppress inflammation.

Straight leg raise search for term

A straight leg raise is knee rehabilitation exercise to strengthen the quads muscles, but it is also used by surgeons to give a quick idea of the activity of the quads after surgery.

Stutter test search for term

A test for the presence of a medial synovial plica.

Subchondral search for term

An adjective referring to the layer of bone immediately under the articular cartilage.

Subchondral drilling search for term

A surgical procedure where small holes are drilled through damaged joint cartilage into the bone marrow of the underlying bone.

Subcutaneous search for term

Subcutaneous means 'under the skin'.

Subluxation search for term

Subluxation is when the bones of a joint nearly leave their normal alignment, but then return to a normal position, eg patellar subluxation.

Sudek's atrophy search for term

Tissue wasting secondary to complex regional pain syndrome.

Sulcus angle search for term

This is a measurement of the steepness of the walls of the groove in which the kneecap rides (the trochlear groove).

Superficial peroneal nerve search for term

The superficial branch of the common peroneal nerve.

Superior search for term

Superior is a positional word, meaning 'above'.

Suprapatellar search for term

A positional word meaning 'above the patella' (kneecap).

Suprapatellar bursa search for term

An extension of the joint cavity above the kneecap.

Suprapatellar plica search for term

A suprapatellar plica is a membrane - possibly an embryonic remnant - that stretches across the joint cavity in the pouch above the kneecap.

Suprapatellar pouch search for term

The suprapatellar pouch is the extension of the knee joint cavity above the patella.

Surface replacement search for term

A surface replacement involves an implant usually used on the surface of the condyles (end of the femur) or for the damaged kneecap and groove in which the kneecap (patella) runs.

Swelling search for term

Swelling is an abnormal enlargement of a part of the body, typically as a result of an accumulation of fluid.

Sympathetic nervous system search for term

The nerve system that controls things like heart rate and blood pressure.

Symptom search for term

A symptom is a discomforture felt by the patient - for example pain, giving way, catching.

Syndrome search for term

Signs and symptoms often found in association with one another.

Synovectomy search for term

A surgical procedure to remove excessive joint lining (synovium).

Synovial fluid search for term

The fluid washing the inside of the joint, secreted by the synovium - the cells of the joint lining.

Synovial joint search for term

Synovial joints are movable joints that contain a lubricating fluid called synovial fluid and have articular cartilage to keep the ends of the moving bones separate from each other.

Synovial membrane search for term

Thin cell lining around the inside of lubricated joints.

Synovial plica search for term

A synovial plica is an infold of the joint lining or synovium - it is a normal anatomical structure but can sometimes become problematic.

Synovitis search for term

Synovitis is inflammation of the joint lining (synovium).

Synovium search for term

The synovium is the cell layer that constitutes the inner lining of the knee joint and other joints.

Synthetic search for term

'Synthetic' means 'artificial'.

Synthetic graft search for term

A graft using artificial materials, eg Gore-Tex.

Systemic search for term

Affecting the whole body.