Acute monoarthritis can occur as a finding in multiple conditions. Some conditions will progress to an oligo- or polyarthritis over time.
More common causes of an acute monoarthritis:
(1) avascular necrosis of bone
(2) crystal disease (monosodium urate, calcium pyrophosphate dihydrate, apatite, calcium oxalate)
(3) hemarthrosis
(4) infection (bacterial, fungal, mycobacterial, viral, Lyme's disease)
(5) internal derangement
(6) osteoarthritis
(7) osteomyelitis
(8) overuse
(9) trauma
(10) bone malignancy
(11) IBD-associated arthritis
(12) hemoglobinopathy
(13) juvenile rheumatoid arthritis
(14) loose body
(15) psoriatic arthritis
(16) rheumatoid arthritis
(17) reactive arthritis
(18) sarcoidosis
Rare causes of an acute monoarthritis:
(1) amyloidosis
(2) Behcet's syndrome
(3) Familial Mediterranean fever
(4) foreign-body synovitis
(5) hypertrophic pulmonary osteoarthropathy
(6) intermittent hydrarthrosis
(7) pigmented villonodular synovitis
(8) relapsing polychondritis
(9) Still's disease
(10) synovioma
(11) synovial metastasis
(12) vasculitis
