Author: Jacob Gianuzzi, BS, OMS-III
Co Author #1: Eric Hemler DO - University of Minnesota Family Medicine Residency
Co Author #2: Amanda Honsvall Hoeffler MD - University of Minnesota Family Medicine Residency
Co Author #3: William Knopp MD - University of Minnesota Dept. of Family Medicine
Senior Editor: Warren Bodine, DO, FAMSSM
Editor: James Robinson, MD

Patient Presentation:
A high school quarterback was injured his knee after being tackled and was initially evaluated on the field.

History:
A 17 year old male quarterback with possession was sprinting downfield when two opponents collided with him. He had planted his left foot and begun push-off phase when the tackle occurred. The first opponent dove in low from the patient's right side, stabilizing the left tibia from forward motion. The second opponent tackled the patient's torso from the posterior left side, causing axial loading and forward fall. The combination produced extreme left knee hyper-extension to approximately 60 degrees.

Immediate on-field evaluation revealed left knee flexed to 30 degrees with distal leg internally rotated. The patella was superolaterally displaced and the lateral tibial plateau was palpated anterior to the lateral femoral condyle. His patella and tibia easily reduced with gentle knee extension. He was carried off the field. He was in a pain in fully evaluated on the sideline.

Physical Exam:
*Post-reduction sideline assessment*
General: Tearful, in distress
Musculoskeletal Left Knee Exam:
Left knee with mild effusion without overlying erythema or ecchymosis. Tenderness to palpation over medial and lateral joint lines. Active and passive ROM limited secondary to pain and apprehension. Lachman and pivot test 3+. Anteromedial drawer 3 to 4+. Valgus stress test 3+ in extension and flexion. Varus stress test and posterior drawer normal.
Pelvis non-tender to compression. Hips with normal, non-painful ROM.
Ankles non-tender with full ROM, 5/5 ankle dorsi- and plantarflexion.
Neuro: A&O x4. Sensation intact to light touch.
Skin: Extremities warm, well-perfused.
Vasc: DP and PT pulses 2+ bilaterally

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