Knee A to Z

Sometimes a knee can make a clicking noise, and this may be painless or accompanied by discomfort or true pain.

'Clinical' means 'medical'.

A clinical sign is a sign that is evident to a doctor examining a patient and which points to the underlying diagnosis.

A clinician is a professional dealing with a patient's medical condition, eg a doctor, nurse, physiotherapist.

Closed chain exercises are those where the moving limb forms an unbroken chain with another surface.

Closed chain exercises are those rehabilitation exercises where the moving limb is continually in contact with the surface of the exercise equipment, eg cycling. Page updated May 2024 by Dr Sheila Strover (Clinical Editor)

A closing wedge osteotomy is an operation to change the angulation of a bone (eg femur or tibia) by cutting a wedge out of one side and closing the gap.

The Cochrane database is a collection of several databases that contain different types of high-quality, independent evidence to inform healthcare decision-making.

Coefficient of friction is a measure of the 'slipperiness' of something, for example the cartilage at the end of bone.

Collagen matrix is an insoluble fibrous protein that forms part of the background material of connective tissue.