A medical dictionary laying on a table

Glossary of Terms

Below you will find a list of terms commonly heard in the context of hip preservation, and their meanings, in simple terms.

If there are any other terms that you would like to see explained here, please contact ISHA at member@isha.net.


Where the body mistakenly targets healthy tissues.

Autologous graft

A graft taken from the patient’s own body.


Substances/medicines isolated from natural sources.

Bone oedema

Or more accurately bone marrow oedema, which describes the build up of fluid within the bone marrow. This can occur in conditions such as stress fractures, osteoarthritis and trauma, and is visible on MRI.


Any damage to the articular cartilage is repaired and reshaped.


The removal of damaged tissue.

Eccentric loading

Muscle contraction which occurs as it lengthens.


Once damaged, articular cartilage has limited potential to repair itself.  Following any repair to articular cartilage, tissue develops during the healing process which is mechanically inferior and is known as fibrocartilage.

Hyaline cartilage

Smooth, slippery cartilage which covers joint surfaces providing lubrication and frictionless movement, also referred to as articular cartilage.

Hyaluronic acid

Naturally occurring gel like substance which cushions and lubricates and is used to treat painful joints.


The ability to perform joint movements beyond what is expected, taking into consideration inherent ethnic differences as well as age, gender, and abilities acquired through training.

Interventional radiology

Minimally invasive image guided procedures such as injections and aspirations.

Magnetic resonance arthrogram (MRA)

MRI with prior injection of contrast dye to enable better visualisation of certain tissues and structures.


Drilling into the bone to stimulate release of stem cells from bone marrow to promote healing. The resulting fibrocartilage would not be the same as the original but will be preferable to exposed bone.

Open surgery or procedure

This involves surgery via a larger incision/cut and does not involve the use of arthroscopy equipment.


Reshaping of articular surfaces to their original shape.


Surgery involving the cutting and reshaping of bone to repair a damaged joint or alter weight distribution to off load a damaged area of bone.


Also known as avascular necrosis, which is characterised by the death of bone cells.


Fluid in the blood which carries platelets, and red and white blood cells.


Carried in the blood and are responsible for blood clotting. They are made in the bone marrow.

Platelet rich plasma (PRP)

Blood is taken from the patient and the concentration of platelets is increased before reinjection, with the aim of assisting in the healing of injuries.


After surgery.


Before surgery.


Commonly known as radiotherapy; a cancer treatment using high doses of radiation to kill cancer cells and hence reduce the size of tumours.


A small cut, or partial removal of fibrous tissue that may be causing friction and inflammation.

Sickle cell anaemia

Blood disorder where the normal rounded shape of red blood cells is lost and instead the cells are shaped like crescent moons. They do not flow as easily and become the cause of many symptoms and severe disease.

Stem cells

Human cells with the ability to develop into many different cell types, ranging from muscle cells to cartilage and brain cells. They also regulate metabolism and immune function via their secretory abilities.


Inflammation of the joint lining, also known as the synovium. This can cause severe pain and prevent normal joint movement.