Question

A 17 year old basketball player comes to the physican after "twisting" his knee in a game one week ago. After jumping to catch a pass, he twisted on his flexed right knee and felt a sharp pain. He denies any joint dislocation or popping sounds or sensations, but was scarcely able to bear weight after the injury and had to be helped off the court. The following morning, his knee was swollen, and although his pain has improved, he has had several episodes where his knee "locks" into an extended position. On physical examination, there is a moderate effusion of the right knee and tenderness to palpation along the medial joint line. Extending the fully-flexed knee while applying a moderate varus stress causes an

audible click and reproduces the patient's pain. With the knee flexed to ninety degrees, there is no movement of the tibia on the femur when the lower leg is pulled anteriorly. Which of the following is the most likely diagnosis in this patient?
A. Osgood-Schlatter disease
B. Torn ACL
C. IT band syndrome
D. Slipped capital femoral epiphysis
E. Meniscal injury

Answer 1

The most likely diagnosis in this patient is a meniscal injury. Symptoms and physical examination findings support this diagnosis. Imaging studies, such as MRI, may be ordered for confirmation.

Step-by-step explanation:

The most likely diagnosis in this patient is a meniscal injury. A meniscal injury occurs when there is a tear in the fibrocartilage pads in the knee, known as the menisci. The symptoms described by the patient, such as a twisting mechanism of injury, sharp pain, swelling, and locking of the knee, are consistent with a meniscal injury.

The physical examination findings also support a meniscal injury, such as tenderness along the medial joint line and an audible click when extending the fully-flexed knee while applying varus stress. The absence of movement of the tibia on the femur when the lower leg is pulled anteriorly at a 90-degree knee flexion further suggests a meniscal injury.

To confirm the diagnosis, imaging studies like MRI may be ordered to visualize the meniscal tear.