MSK: Fractures for the ABR Core Exam Part 2
Review of fractures for radiology board exams. The Radiology Review Podcast was recently named #2 on the Top 5 Radiology Podcasts You Must Follow in 2020! Link here: https://blog.feedspot.com/radiology_podcasts/
Show Notes/Study Guide:
Are avulsion fractures more common in adults or kids? Answer is kids. In adults, bones are typically stronger then tendons so you will tear the tendon first. In kids, tendons may be stronger then bones so you will avulse the bone before you tear a tendon.
An avulsion fracture of the lesser trochanter in an adult should make you think of what? Answer is a pathologic fracture…because adults don’t normally get an avulsion fracture (see above).
Name the muscle causing the avulsion fracture
Iliac crest = abdominal muscles
Pubic symphysis = adductor muscles
Anterior superior iliac spine = sartorius
Anterior inferior iliac spine = rectus femoris
Ischial tuberosity = hamstrings
Greater trochanter = gluteal muscles
Lesser trochanter = iliopsoas
Honda sign denotes which fracture? Sacral insufficiency fracture. Increased risk after pelvic radiation or hip arthroplasty. Look for this sign on a bone scan.
Avulsion fracture of the lateral tibial plateau = Segond fracture.
Segond fracture is a sign of what additional injury? ACL tear (75%), occurs with internal rotation
Medial tibial plateau avulsion fracture = reverse segond fracture
Reverse segond fracture is a sign of what additional injury? PCL tear, occurs with external rotation
Tibial plateau fractures are most common laterally or medially? Lateral tibial plateau fractures are most common
Classification system for tibial plateau fractures? Schatzker classification (Types 1 through 6), Type 2 is most common which is a split and depressed lateral tibial plateau fracture
The most common long bone fracture is = tibial shaft fracture
Salter-Harris type 3 fracture through the anterolateral aspect of the distal tibial ephiphysis = Tillaux fracture
Mechanism is that the medial growth plate fuses in a teenager before the lateral growth plate so the lateral aspect is prone to avulsion as it is not fully fused
Salter-Harris type 4 fracture with a vertical component through the tibial ephiphysis, a horizontal component through the physis, and an oblique component through the metaphysis = Triplane fracture
Unstable fracture involving the medial tibial malleolus and/or disruption of the distal tibiofibular syndesmosis (deep deltoid ligament) consider which fracture= Maisonneuve fracture. Look for a widened medial ankle mortis. If you see this the next step is? Get radiographs of the proximal fibula to show the fracture of the proximal fibular shaft. Maisonneuve fracture is an unstable medial malleolar fracture with associated proximal fibular shaft fracture.
