The washing out or cleaning out the contents (blood, fluid or loose debris) inside a joint space is generally termed as<unk> .<unk>  is a general term referring to the therapeutic washing, cleaning or rinsing.
Arthroscopic lavage
Arthrocentesis
Arthrogram
Arthroscopy
Knee replacement
Joint mobilization
Patellar tap
Ibuprofen/paracetamol