Knee A to Z

A joint is a junction between two bones.

Joint cartilage is the shiny white gristle covering the contact surfaces of the bones in articulating (moving) joints.

Joint distraction is when a joint is kept pulled out under slight tension in an effort to improve cartilage healing.

Joint line tenderness indicates possible damage to the meniscus.

Replacing damaged joint surfaces with biological structures rather than metal and plastic.

Joint replacement is removing damaged joint cartilage and underlying bone and replacing it with metal and plastic.

Joint space narrowing is when the bones of femur and tibia are closer together than normal, recognised on an X-ray taken from the front.

JRA is an abbreviation of 'juvenile rheumatoid arthritis'.

The J-sign is when the kneecap 'pops out' (subluxes) to the outer side each time the knee moves into the fully straight position (terminal extension). Page updated March 2024 by Dr Sheila Strover (Clinical Editor)

Jumper's knee is an overuse condition, also called patellar tendinitis, tendinopathy or tendinosis, where the area of attachment of the patellar tendon to the patella becomes painful.