A patient presents with knee pain and instability following a twisting injury during sports activity. MRI reveals a tear involving the anterior cruciate ligament (ACL). Which surgical procedure is commonly performed to reconstruct the ACL?

Correct Answer: C

Rationale: Anterior cruciate ligament (ACL) reconstruction is a common surgical procedure performed to repair a torn ACL. This procedure involves replacing the damaged ACL with a graft, often using a portion of the patient's own patellar tendon, hamstring tendon, or an allograft (donor tissue). ACL reconstruction is typically indicated for patients with ACL tears that result in knee instability and functional limitations, especially in active individuals who participate in sports or activities requiring pivoting and cutting movements. Arthroscopic surgery is commonly used to perform ACL reconstruction, allowing for smaller incisions and faster recovery compared to traditional open surgeries. Post-operative rehabilitation and physical therapy are crucial components of the recovery process following ACL reconstruction surgery to optimize outcomes and return to pre-injury activity levels.

Correct Answer: C

Rationale: Sevelamer is a medication commonly prescribed to reduce serum phosphate levels in patients with chronic kidney disease. Sevelamer is a phosphate binder that works by binding to dietary phosphate in the gut, preventing its absorption into the bloodstream. By reducing serum phosphate levels, sevelamer helps manage complications associated with hyperphosphatemia in chronic kidney disease patients, such as mineral and bone disorders. Other medications like epoetin alfa are used to treat anemia commonly seen in chronic kidney disease patients, while cinacalcet is used to manage secondary hyperparathyroidism. Allopurinol, on the other hand, is used to treat gout by reducing uric acid levels and is not indicated for reducing serum phosphate levels in chronic kidney disease patients.

Correct Answer: B

Rationale: The patient's presentation with renal failure, confusion, seizures, asterixis, and a sweet odor to the breath, along with laboratory findings of severe metabolic acidosis, hyperkalemia, and elevated BUN and creatinine levels, is consistent with uremic encephalopathy. Uremic encephalopathy is a neurological complication of acute or chronic renal failure resulting from the buildup of uremic toxins in the blood, leading to various neurological symptoms such as confusion and seizures. The sweet odor to the breath can be attributed to the presence of urea, a waste product that accumulates in renal failure. Other metabolic abnormalities like hyperkalemia and severe metabolic acidosis are also common in renal failure. It is crucial to promptly recognize and manage uremic encephalopathy to prevent further neurological complications.

Correct Answer: D

Rationale: Nephrolithiasis refers to the formation of stones within the kidney or urinary tract. The most common types of kidney stones are either composed of calcium oxalate or calcium phosphate. When these stones form within the renal collecting system, they can lead to symptoms such as flank pain, hematuria, and urinary obstruction. Ureteropelvic junction (UPJ) obstruction and ureterovesical junction (UVJ) obstruction are specific types of blockages within the urinary system that can be caused by kidney stones but are not characteristic of the stone formation itself. Renal colic is the term used to describe the severe pain associated with the passage of a kidney stone through the ureter.

Correct Answer: A

Rationale: The clinical presentation of fever, chills, headache, and myalgia following a trip to sub-Saharan Africa is highly suggestive of malaria, which is caused by the Plasmodium species. Specifically, the presence of intraerythrocytic ring forms and trophozoites on blood smear examination points towards Plasmodium falciparum as the most likely causative agent.