Pediatric musculoskeletal disorders: Pathology review

A 13 year old boy named Lucas comes to the clinic complaining of right knee pain, which gets worse when he is running, jumping, or climbing stairs. Upon further questioning, Lucas mentions that he plays basketball for his school team, and recently, he started training more intensely for an upcoming tournament. On physical examination, you are able to move his hip in all directions with no resistance or pain, but you notice that his right knee has a more prominent tibial tubercle, which is also tender to the touch.

Some days later, a 4 year old girl named Sophia is brought to the clinic by her mother. Earlier that day, Sofia’s older brother was swinging her by the arms. Since then, Sofia has been experiencing pain in her right arm when she tries to move it. On physical examination, you notice that Sophia is holding her arm by her body, and cries when you try to move it. You decide to quickly hyperpronate her arm, after which Sophia becomes able to use her arm again without pain.

Okay, both Lucas and Sophia seem to have some form of pediatric musculoskeletal condition, meaning a condition that commonly affects the muscles, bones, or cartilage of individuals younger than 18 years. For your tests, the most high yield pediatric musculoskeletal disorders include developmental dysplasia of the hip, Legg-Calvé-Perthes disease, slipped capital femoral epiphysis, Osgood-Schlatter disease, patellofemoral syndrome, radial head subluxation, and a variety of bone fractures.

Okay, let’s start with developmental dysplasia of the hip, or DDH, which is also known as congenital hip dysplasia. In DDH, the femoral head dislocates out of the acetabulum during development in utero. For your exams, it’s important to keep in mind that this is more common in twin or multiple pregnancies, where the fetuses have to share the space within the uterus, which may put a lot of pressure on them; as well as in firstborns, because the mother’s uterus is not as stretched out; or when the fetus is lying in a breech position within the mother’s uterus, with its buttock near the cervix at the time of delivery. Another situation that can lead to DDH is oligohydramnios, when there’s not enough amniotic fluid to expand the uterine cavity so that the fetus can have enough room.