**Core Concept**
The patient's presentation of joint swelling, pain, and radiographic evidence of joint effusion in the absence of a fracture suggests a diagnosis of acute crystal-induced arthritis, likely due to gout. The presence of rhomboid crystals with weak-positive birefringence in the joint fluid is a key diagnostic feature of gout.

**Why the Correct Answer is Right**
The correct answer involves the administration of colchicine, a medication that inhibits microtubule polymerization and reduces the production of pro-inflammatory cytokines. This leads to a decrease in inflammation and pain in patients with acute gout attacks. Colchicine is typically used in the initial management of acute gout attacks, especially in patients who are intolerant of NSAIDs or have contraindications to NSAID use. The mechanism of action of colchicine is distinct from NSAIDs, which are often used in the treatment of gout but can have significant gastrointestinal side effects.

**Why Each Wrong Option is Incorrect**
**Option A:** Corticosteroids, such as prednisone, can be used in the treatment of acute gout, but they are not the first-line treatment and may be reserved for patients who are intolerant of NSAIDs or colchicine. Corticosteroids can also be used to reduce joint inflammation in the absence of an acute gout attack.
**Option B:** Oral NSAIDs, such as ibuprofen or naproxen, are often used in the treatment of acute gout attacks, but they may not be suitable for patients with renal impairment or those who are intolerant of NSAIDs. Additionally, NSAIDs can have significant gastrointestinal side effects.
**Option C:** Intra-articular corticosteroid injections are sometimes used in the treatment of chronic gout or in patients who have failed other treatments. However, they are not typically used as the initial treatment for acute gout attacks.
**Option D:** Oral allopurinol is used in the long-term management of gout to decrease serum urate levels and prevent future attacks, but it is not typically used in the treatment of acute gout attacks.

**Clinical Pearl / High-Yield Fact**
It is essential to note that the diagnosis of gout can be challenging, and the presence of rhomboid crystals in the joint fluid is a key diagnostic feature. However, not all patients with acute gout attacks will have crystals visible in the joint fluid, and a diagnosis of gout can be made clinically based on the presence of characteristic symptoms and signs, such as sudden onset of intense pain, redness, and swelling in the affected joint.

**Correct Answer:** C. Intra-articular corticosteroid injections are sometimes used in the treatment of chronic gout or in patients who have failed other treatments. However, they are not typically used as the initial treatment for acute gout attacks.