Solution to Unknown Case #17 – Short 4th and 5th Metacarpals Differential Diagnosis
History: 15 year old boy with hand pain. This is a case of short 4th and 5th metacarpals. Shortened 4th and 5th metacarpals is diagnosed by the metacarpal sign, which involves drawing a line through the heads of the 4th and 5th metacarpals. If the line intersects the head of the third metacarpal, then it […]
Solution to Unknown Case #16 – Solitary (Unicameral) Bone Cyst
History: Adolescent Male with knee pain. This is a case of a solitary or unicameral bone cyst. A solitary bone cyst (also called a juvenile bone cyst, unicameral bone cyst, essential bone cyst, or simple bone cyst) is a benign lytic bone lesion that is fluid filled. The most common location that solitary bone cysts […]
Solution to Unknown Case #15 – Osteogenesis Imperfecta and the Differential Diagnosis of Gracile Diaphyses
History: 17 year old female. History withheld. This is a case of osteogenesis imperfecta. Osteogenesis imperfecta is a genetic defect in forming type 1 collagen. There are multiple subtypes of osteogenesis imperfecta, which are divided according to the Silence classificaiton system as follows: Type 1 – Autosomal Dominant, blue sclerae, mildest form (often called osteogenesis […]
Solution to Unknown Case #14 – Iliac Horn Syndrome or Nail Patella Syndrome or Hereditary Osteo-Onychodysplasia
History: 10 year old female with this Aunt Minnie finding on scout KUB for a retrograde voiding cystourethrogram. This is a case of Iliac Horn Syndrome, also called Nail Patella Syndrome or Hereditary Osteo-Onychodysplasia. The finding in the image above of iliac horns is pathognomonic (an aunt minnie for Iliac Horn syndrome). The reason why […]
Solution to Unknown Case # 13 – Fibrous Dsyplasia of the Skull Base
History: 10 year old girl with headaches and facial deformity. This is a case of fibrous dysplasia of the skull base. Fibrous dysplasia is a congenital bone disease resulting from abnormal osteoblast differentiation which results in the replacement of normal bone with a mixture of fibrous tissue and immature woven bone. It usually occurs in […]
Solution to Unknown Case # 12 – Avulsion Fracture of the Anterior Superior Iliac Spine
History: Adolescent with hip pain. This is an avulsion fracture of the left anterior superior iliac spine, which is due to the sartorius muscle pulling off a fragment of bone at the apophysis, which is a growth center at the tendon attachment to bone. Other common areas of seeing avulsion fractures in pediatric patients include […]
Solution to Unknown Case # 11 – Differential Diagnosis of a Cystic Pediatric Neck Mass
History: 5 year old male with a midline neck mass. This is the appearance of a lymphatic malformation, which use to be termed “cystic hygroma.” A lymphatic malformation is a congenital malformation of lymph channels which collect into embryonic lymphatic sacs. They can virtually be found in any head and neck location, and are characteristically […]
Solution to Unknown Case # 10 – Boxer’s Fracture
History: Adolescent boy with hand pain. This is called a boxer fracture, which is a transverse fracture through the fifth metacarpal neck. Only the collateral ligaments remain attached, and therefore the typical finding is volar angulation (or dorsal apex angulation) of the metacarpal head. Boxer’s Fracture Causes Boxer’s fractures received their name from one of […]
Solution to Unknown Case # 9 – Radial Head Dislocation and Ulnar Acute Plastic Bowing – Monteggia?
History: child with limited range of motion of the right forearm. This is a radial head dislocation with acute plastic bowing of the ulna. Acute plastic bowing is a plastic response to a longitudinal stress that is frequently seen in young children ages 2-5 years old. In the image above, normally the ulnar cortical surface […]
Solution to Unknown Case # 8 – Luckenschadel Skull versus Copper Beaten Skull
History: Infant with a congenital anomaly. This is the appearance of a Luckenschadel (or lacunar) skull. Luckenschadel skull is a congenital defect in the skull that results from abnormal membranous ossification. It is associated with Chiari II malformations, which includes the following features: 1. Cerebellar tonsil herniation through foramen magnum due to a small posterior […]