Infection of ulnar bursa is diagnosed by –
**Core Concept**
The ulnar bursa, also known as the cubital bursa, is a synovial fluid-filled sac located between the ulna bone and the medial epicondyle of the humerus. Infection of this bursa, known as septic bursitis, is a type of inflammatory condition that requires prompt diagnosis and treatment.
**Why the Correct Answer is Right**
Septic bursitis of the ulnar bursa is typically diagnosed based on clinical findings, such as pain, swelling, and warmth over the affected area. The diagnosis is often confirmed by aspiration of the bursa fluid, which is then sent for culture and sensitivity testing. This allows for the identification of the causative organism and guides antibiotic therapy.
**Why Each Wrong Option is Incorrect**
**Option A:** Magnetic Resonance Imaging (MRI) may be used to evaluate the extent of bursitis and surrounding soft tissue involvement, but it is not the primary method for diagnosing septic bursitis.
**Option B:** Ultrasound may be used to guide aspiration of the bursa fluid, but it is not the primary diagnostic tool for septic bursitis.
**Option C:** Blood cultures may be performed to identify systemic infection, but they are not specific for diagnosing septic bursitis.
**Clinical Pearl / High-Yield Fact**
It is essential to differentiate septic bursitis from other causes of bursitis, such as gout or pseudogout, as the treatment approach differs. Aspiration of the bursa fluid is a critical step in diagnosing septic bursitis and guiding treatment.
**Correct Answer:** D. Aspiration of the bursa fluid