"The entity was described by the Norwegian physician Christian Magnus Falsen Sinding-Larsen (1866-1930) in 1921 5. The Swedish physician Sven Christian Johansson (1880-1959) described the same entity independently in 1922 6."
"Unlike "jumper's knee" which is seen at any age, Sinding-Larsen-Johansson disease is seen in active adolescents, typically between 10-14 years of age 1. Children with cerebral palsy are also prone to Sinding-Larsen-Johansson 4."
"patellar sleeve fractures: same age group; avulsion of inferior pole cartilage, often with small fracture fragment 2"