Clinical findings with a septic joint:
(1) persistent swelling of the joint
(2) intense pain in the joint
(3) restricted range of motion, resulting in decreased function (with limp if in the lower extremity, etc.)
(4) local warmth to the touch (calor)
(5) fever
(6) signs of sepsis (hypotension, prostration, etc)
(7) draining sinus near the joint (especially near a prosthetic joint)
Risk factors for a septic arthritis:
(1) recent trauma at or near the joint
(2) prosthetic joint (see section on periprosthetic infection, 23.57)
(3) recent arthrocentesis or joint surgery
(4) recent bacteremia or risk factors for bacteremia
Differential diagnosis:
(1) gout
(2) postinfectious (reactive arthritis)
(3) rheumatoid or other autoimmune arthritis
(4) hemarthrosis
