A 23-year-old man comes to the urgent care center due to a knee injury 2 days ago. He was playing basketball when he was hit on the left side by an opposing player while running. The patient attempted to continue playing, but his left knee felt tight and he had to sit out the rest of the game. Over the last 2 days, the pain has been persistent and only partially relieved with ice and ibuprofen. He also has been using a knee brace for improved stability. Examination shows mild soft-tissue swelling of the left knee without a significant joint effusion. There is tenderness at the medial joint line but no locking or catching. Range of motion of the knee is near normal. Abduction (valgus) stress test shows some left knee laxity but is limited by pain. X-ray of the knee is normal. Which of the following is the most likely diagnosis in this patient?

Question

A 23-year-old man comes to the urgent care center due to a knee injury 2 days ago.  He was playing basketball when he was hit on the left side by an opposing player while running.  The patient attempted to continue playing, but his left knee felt tight and he had to sit out the rest of the game.  Over the last 2 days, the pain has been persistent and only partially relieved with ice and ibuprofen.  He also has been using a knee brace for improved stability.  Examination shows mild soft-tissue swelling of the left knee without a significant joint effusion.  There is tenderness at the medial joint line but no locking or catching.  Range of motion of the knee is near normal.  Abduction (valgus) stress test shows some left knee laxity but is limited by pain.  X-ray of the knee is normal.  Which of the following is the most likely diagnosis in this patient?

Quizplus · Accepted Answer

11ec25c8_d2bc_37a1_bc81_3162f60aaca6_MD0003_00 Medial collateral ligament (MCL) tear is a common knee injury caused by severe valgus stress (eg, blow to the lateral knee) or twisting injury. Examination findings may include local swelling, ecchymosis, and joint line tenderness at the medial knee. Appreciable laxity when the leg is forced into abduction (valgus stress test) is helpful for diagnosis but may be masked by swelling and muscle spasm. Acute effusion/hemarthrosis is uncommon unless there is concurrent injury to the anterior cruciate ligament. MRI is the most sensitive test for diagnosis but is generally reserved for patients being considered for surgical intervention. Patients with uncomplicated MCL tears can be managed nonoperatively with rest, ice, compression, and elevation (RICE measures) and analgesics with progressive return to activity as tolerated. MRI (Choice A) Injury to the anterior cruciate ligament will produce acute, often dramatic hemarthrosis with an effusion on physical examination. The tibia will show anterior rather than valgus laxity. (Choice B) Injuries to the lateral collateral ligament are uncommon but are occasionally seen following high-velocity trauma. The knee will have varus laxity. (Choice D) The medial meniscus and MCL are intimately associated and may be injured together. A meniscus injury may show joint line tenderness, but there is typically also a small joint effusion and crepitus, locking, or catching with range of motion. Meniscal tears often occur when patients pivot on a flexed knee while the foot is planted. (Choice E) Patellar tendonitis ("jumper's knee") is a chronic overuse injury characterized by anterior knee pain and tenderness. Stress testing of the ligaments is normal. (Choice F) Tibial plateau fractures can occur due to contact sports, falls, or motor vehicle accidents. However, most patients with such fractures are unable to bear weight on the knee. Educational objective: Medial collateral ligament tear is caused by valgus stress or severe twisting injury and can be associated with injury to the medial meniscus. Findings include tenderness at the medial knee and valgus laxity. MRI is the most sensitive test, and most patients are managed nonoperatively. References: Structure and function, injury, pathology, and treatment of the medial collateral ligament of the knee. (http://www.ncbi.nlm.nih.gov/pubmed/22890899)

A 23-Year-Old Man Comes to the Urgent Care Center Due