The predictive value and reliability of ultrasound-guided synovial aspiration and biopsies for diagnosing periprosthetic shoulder infections.

Introduction: Preoperative diagnosis of periprosthetic shoulder infections (PSI) is difficult. Infections are mostly caused by low virulence bacteria and patients do not show typical signs of infection. The aim of this study was to determine the diagnostic value and reliability of ultrasound-guided biopsies for cultures alone and in combination with multiplex polymerase chain reaction (mPCR), serum markers, and/or synovial markers for the preoperative diagnosis of PSI in patients undergoing revision shoulder surgery.

[Various manifestations of calcium pyrophosphate-associated arthritis].

In calcium pyrophosphate (CPP)-associated arthritis, deposits of calcium pyrophosphate lead to acute attacks of painful joint inflammation. The disease may present with signs of systemic inflammation such as fever, mimicking an infectious disease. Early recognition and treatment of this disease can prevent overdiagnosis and joint damage.

[Unexplained pain in the ankle and foot. Consider transient osteoporosis].

Transient osteoporosis is an increasingly recognized condition that causes severe pain in weight-bearing joints and is characterized by otherwise unexplained bone-marrow oedema on MRI. We present two patients, a 40-year-old man and a 60-year-old woman, with longstanding severe pain in the foot and ankle. Both had invalidating pain with only mild swelling of the foot or ankle.

[A man with swollen fingers].

A 28-year-old man was referred to our hospital because of localised swelling of his fingers, with suspicion of arthritis of the proximal interphalangeal (PIP) joints. At physical examination we observed a swelling, superficial to the PIP joints. Ultrasonography revealed a hypo-echoic structure above the extensor tendon, typical for knuckle pads.