1. Knee
    1. Suprapatellar tendon rupture
      1. Maybe related to trauma, RA, renal failure, SLE, gout, corticosteroid use
    2. Patella baja
      1. Achondroplasis
      2. Paresis of quadriceps muscles (polio)
      3. JRA
    3. O'Donohue unhappy triad
      1. Combination of ACL, MCL, and medial meniscal tear results from valgus stress with rotation
    4. Widened intercondylar notch
      1. Hemophillia
  2. Femur
    1. Erlenmyer flask deformity (GOT LMN)
      1. Gaucher disease
      2. Osteopetrosis
      3. Thalassemia
      4. Lead
      5. Metaphyseal dysplasia (Pyle disease)
      6. Niemann-Pick disease
  3. Physiologic vs OCD (Laor T, MSK MRI in Children, SSR 2016