Essential knee terminology
J-sign search for term

The J-sign is when the kneecap subluxes laterally each time the knee moves into terminal extension.

Page updated January 2024 by Dr Sheila Strover (Clinical Editor)

Joint search for term

A joint is a junction between two bones.

Joint cartilage search for term

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

Joint distraction search for term

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

Joint line tenderness search for term

Joint line tenderness indicates possible damage to the meniscus.

Joint reconstruction search for term

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

Joint replacement search for term

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

Joint space narrowing search for term

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 search for term

JRA is an abbreviation of 'juvenile rheumatoid arthritis'.

Jumper's knee search for term

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.

Juvenile rheumatoid arthritis search for term

Juvenile rheumatoid arthritis is arthritis affecting a child (under 16) in several joints where evidence exists that the condition is autoimmune - ie the child's own immune system is attacking its joints.

Juvenile traction osteochondritis search for term

Juvenile traction osteochondritis is an overuse syndrome where jumping activities in a young person causes excessive pulling of the patellar tendon on the tibial tubercle.