Author: Brian Wojtkielewicz, DO
Co Author #1: Brian Wojtkielewicz, DO
Co Author #2: Joseph Thomas, DO
Co Author #3: Timothy Ackerman, DO; Michael Yurkewicz, DO; Kush Patel, MD; Steven Collina, MD
Senior Editor: Carolyn Landsberg, MD
Editor: Jacob Miller, MD

Patient Presentation:
A 16-year-old male offensive linemen presented with left knee giving way and pain after an injury during a high school football game.

History:
While blocking his opponent, he was "rolled up on" but was able to walk to the huddle where he felt his knee give out. He reported a "pop" during the injury.

Upon sideline examination, he reported medial left knee pain with evolving effusion and tenderness to palpation of the medial joint line and distally along the MCL. Flexion was limited to 90 degrees with increased pain. External rotation recurvatum test was positive. Valgus stress at 0 and 30 degrees was positive. Posterior drawer test was positive. Lachman's and McMurray's tests as well as varus testing were negative. Neurovascular exam was normal.

He was referred to the ED. X-rays obtained were unremarkable. He was given an immobilizer and crutches and seen two days later at the sports medicine clinic.

Physical Exam:
Vitals: Hemodynamically stable, afebrile

L knee Exam:
Inspection: Large effusion
Palpation: Tenderness to palpation of the medial joint line and distally along the MCL.
Range of motion: Flexion to 90 degrees with increased pain.
Special tests:
External rotation recurvatum test positive.
Valgus stress at 0 and 30 degrees positive.
Posterior drawer test positive.
Lachman's, McMurray's, and varus testing negative.
Dial test normal.

Neurovascular exam was normal

Click here to continue. Challenge yourself by writing down a broad differential diagnosis before moving to the next slide.