Monoarticular hip involvement in pseudogout

Area of Science:

• Rheumatology
• Geriatric Medicine
• Diagnostic Imaging

Background:

• Pseudogout (calcium pyrophosphate deposition disease) is a common cause of acute arthritis in the elderly.
• While typically polyarticular, pseudogout can present as monoarticular arthritis, often mimicking infectious or degenerative joint diseases.
• Monoarticular hip pseudogout is rare and has historically been misdiagnosed as septic arthritis.

Purpose of the Study:

• To report a unique case of monoarticular hip pseudogout.
• To highlight its presentation mimicking a soft tissue abscess.
• To emphasize the importance of accurate diagnosis in preventing unnecessary interventions.

Main Methods:

• Case report of a patient with suspected hip infection.
• Diagnostic workup included ultrasonography of the hip joint.
• Synovial fluid analysis encompassing pathological and biochemical testing.

Main Results:

• Ultrasonography revealed findings consistent with pseudogout.
• Synovial fluid analysis confirmed calcium pyrophosphate crystals.
• The patient's condition was diagnosed as monoarticular hip pseudogout, not infection or abscess.

Conclusions:

• Monoarticular hip pseudogout can present atypically, mimicking soft tissue abscesses.
• Ultrasonography and synovial fluid analysis are essential for accurate diagnosis.
• Correct diagnosis prevents unnecessary surgical and medical treatments for pseudogout.