arthrocentesis

noun

ar·​thro·​cen·​te·​sis ˌär-(ˌ)thrō-sen-ˈtē-səs 

plural arthrocenteses -ˌsēz 

: surgical puncture of a joint especially for aspiration of fluid from the joint

Arthrocentesis of the right elbow joint was performed in the emergency department; the aspirate was orange-tinted, with 17,250 white cells per cubic millimeter …

—Benjamin T. Davis and Mark S. Pasternack, The New England Journal of Medicine

I asked him to do an arthrocentesis—put a needle in the ankle and get a sample of the suspicious fluid causing the swelling.

—Rahul Parikh, The Los Angeles Times