A knee mouse is a loose piece of cartilage floating free in the knee joint - more correctly called a 'loose body'.

loose body in the knee joint
Knee mice can cause giving way, catching or locking in the knee.
Loose body

Common joint surface problems in the knee

A quick overview of the problems one sees in the white joint cartilage at the end of the bones in the knee joint.



Arthroscopic removal of loose bodies using the accessory portals in the difficult locations of the knee: a case series and technical note. Chen B, Chen L, Chen H, Yang X, Tie K and Wang H. J Orthop Surg Res. 2018; 13: 258.

See also -


eBook - Common Knee Symptoms

Easy-to-read eBook about catching and other common symptoms in the knee.