case_images: PMC5553490_01
case_images: Anteroposterior X-ray of the right knee showing an avulsion fracture on the medial femoral condyle (arrow).
case_images: 10-1055-s-0037-1599256-i1600037cr-1.jpg
case_images: PMC5553490_01_10-1055-s-0037-1599256-i1600037cr-1.jpg
case_images: FI1600037cr-1
case_images:  Anteroposterior and lateral X-rays of the knee were performed in the emergency room, showing an avulsion fracture on the medial femoral condyle ( Fig. 1 ).
case_images: T2-weighted magnetic resonance imaging of the injured knee. (
  A
  ) Coronal view: arrow, avulsion of the medial collateral ligament in the medial femoral condyle; asterisk, trabecular fractures with cortical collapse; arrowhead, altered imaging of the anterior cruciate ligament (keeping a normal route). (
  B
  ) Axial view: arrow, avulsion of the medial collateral ligament in the medial femoral condyle. (
  C
  ) Sagittal view: arrow, complete rupture of the posterior cruciate ligament.
case_images: 10-1055-s-0037-1599256-i1600037cr-2.jpg
case_images: PMC5553490_01_10-1055-s-0037-1599256-i1600037cr-2.jpg
case_images: FI1600037cr-2
case_images: His magnetic resonance imaging (MRI) findings were as follows: avulsion of the MCL's origin in the medial femoral condyle with the bone fragment rotated and retracted together with the MCL, trabecular fractures adjacent to the posterolateral tibial spine with a minimum cortical collapse and a severe bone edema, altered imaging of the anterior cruciate ligament (ACL) keeping a normal route, which could be explained by a partial tear of the ligament, and complete rupture of the PCL with its proximal part retracted ( Figs. 2 and 3 ). 
case_images: Magnetic resonance imaging of the injured knee showing the partial tear of the anterior cruciate ligament and the complete rupture of the posterior cruciate ligament.
case_images: 10-1055-s-0037-1599256-i1600037cr-3.jpg
case_images: PMC5553490_01_10-1055-s-0037-1599256-i1600037cr-3.jpg
case_images: FI1600037cr-3
case_images: His magnetic resonance imaging (MRI) findings were as follows: avulsion of the MCL's origin in the medial femoral condyle with the bone fragment rotated and retracted together with the MCL, trabecular fractures adjacent to the posterolateral tibial spine with a minimum cortical collapse and a severe bone edema, altered imaging of the anterior cruciate ligament (ACL) keeping a normal route, which could be explained by a partial tear of the ligament, and complete rupture of the PCL with its proximal part retracted ( Figs. 2 and 3 ). 
case_images: postoperative X-rays at the last follow-up.
case_images: 10-1055-s-0037-1599256-i1600037cr-4.jpg
case_images: PMC5553490_01_10-1055-s-0037-1599256-i1600037cr-4.jpg
case_images: FI1600037cr-4
case_images:  At the last follow-up, 2 years after surgery, the patient enjoyed a 0/140-degree range of motion for flexion/extension ( Figs. 4 and 5 ).
case_images: Magnetic resonance imaging showing the resolution of the bone edema.
case_images: 10-1055-s-0037-1599256-i1600037cr-5.jpg
case_images: PMC5553490_01_10-1055-s-0037-1599256-i1600037cr-5.jpg
case_images: FI1600037cr-5
case_images:  At the last follow-up, 2 years after surgery, the patient enjoyed a 0/140-degree range of motion for flexion/extension ( Figs. 4 and 5 ).