A patient sustains an injury to the popliteal artery just distal to the adductor hiatus. Despite significant reduction in direct blood flow through the popliteal artery, distal perfusion of the leg remains partially preserved through collateral vessels around the knee. Which arterial network is primarily responsible for this collateral circulation?

A 24-year-old long-distance runner develops sharp lateral knee pain that worsens during repetitive knee flexion and extension. Examination reveals tenderness over the lateral femoral epicondyle. The physician suspects inflammation in the lateral thigh. Which structure is primarily involved?

A 70-year-old woman presents with acute, severe pain and a tender mass in the groin. The mass is located inferior to the inguinal ligament and medial to the femoral vein. Imaging confirms the hernia with compromised blood flow to the herniated bowel. Through which structure does the hernia pass?

There was a lot of advice about how to be happy. Which three pieces of advice did you find the most helpful and interesting?

During repair of the posterior knee capsule, a small muscle is identified arising from the lateral femoral condyle and attaching to the posterior surface of the proximal tibia. What is the primary action of this muscle?

A 30-year-old man sustains a forceful valgus stress to the knee while his foot is planted. MRI demonstrates injury to the medial collateral ligament and an associated tear of a fibrocartilaginous structure attached to the MCL. Which structure is most likely injured?

A 29-year-old athlete has pain at the anterior hip and difficulty maintaining the thigh in a flexed, abducted, and laterally rotated position. Injury to which muscle would best explain this deficit?

A 25-year-old man is brought to the emergency department after a motor vehicle collision. On examination, his right lower extremity is shortened and held in a characteristic abnormal position. Which combination of hip position is most consistent with a posterior dislocation?

A 25-year-old man sustains a deep laceration to the anterior lower leg. After the injury, he has difficulty dorsiflexing the ankle. Which muscle is most likely affected?

A 68-year-old man presents with a pulsatile mass behind his knee and intermittent calf pain with walking. Physical examination reveals an enlarged popliteal pulse. Duplex ultrasonography confirms a popliteal artery aneurysm. Which complication is most directly associated with this condition?