Team DFTB. Don’t Forget The Christmas Quiz: the picture round answers, Don't Forget the Bubbles, 2020. Available at:
Here are the answers to the picture round. How did you do?
a) What name is given to this two-piece intra-articular fracture of the base of the 1st metacarpal of the thumb?
This is a Bennett fracture: an intra-articular 2-part fracture of the base of 1st metacarpal bone, named after Edward Hallaran Bennett, an Irish surgeon from Dublin.
Thumb metacarpal base fractures require surgical opinion. Disruption of carpometacarpal joint congruity can result in significant functional impairment.
A similar intra-articular fracture-dislocation of the base of the 5th metacarpal bone is called a reverse Bennett fracture. This fracture pattern is inherently unstable.
b) If the fracture was in three parts, what would it be called?
Rolando fractures of the base of the 1st metacarpal are similar to Bennett fractures, but with at least 3 parts, and a less favourable prognosis.
Read more about bony finger (and thumb) injuries in this bony finger injuries post.
What tendon is being tested in this image?
Flexor digitorum superficialis (FDS). FDS and flexor digitorum profundus (FDP) tendons should be tested individually.
To check FDS function, hold all adjacent fingers in extension and then release the finger you want to assess. Ask the child to flex the free digit at the PIP joint.
To examine FDP, hold the middle phalanx in extension and ask the child to flex the DIP joint.
For more finger examination tips, including digital cascade, wrist tenodesis and assessment of extensor tendon function check out the tendon and ligaments finger injuries post.
What type of injury is demonstrated below?
This is a mallet injury. The top image is a ligamentous mallet injury due to rupture of the extensor tendon. The lower image is a bony mallet injury due to an avulsion fracture of the insertion point of the terminal extensor tendon at the distal phalangeal epiphysis – this is the more common injury type in children. Children present with a flexion deformity and inability to extend at the distal interphalangeal joint. These injuries must be managed by hand specialists, either with 6-8 weeks of splinting if the injury is closed, or operatively if the injury is open, or if the avulsion fragment is larger than 30-50% of the articular surface.
a) What are the names of the three highlighted areas in this shoulder x-ray?
b) What injury is demonstrated in this x-ray?
This is a Y-view of the shoulder. The humeral head is no longer sitting over the glenoid and is instead sat under the coracoid process. This is an anterior shoulder dislocation. Bonus points to anyone who noted flattening of the humeral head suggesting a Hill Sachs lesion (and those are real bonus points as the shoulder dislocation post hasn’t yet been published – but watch this space!)
For more tips on interpreting shoulder x-rays, check out our shoulder x-ray post.
This child presents with worsening foot pain with no history of trauma. Which bone is affected and what is this condition called?
The x-ray shows thinning and sclerosis of the navicular bone. This is Kohler’s Disease, an osteochondrosis of the navicular. Osteochondrosis is a disorder of bone growth primarily involving the ossification centres at the epiphysis. It commonly begins in childhood and results in osteonecrosis of the growth plate. This can lead to altered bone and cartilage formation beyond the growth plate. A better known osteochondrosis is Perthe’s Disease of the femoral head.
Although often confused with apophysitis, which is more clearly due to traction overuse injuries, osteochondrosis is often described as idiopathic osteonecrosis as there has been no definite cause found. There have been some links showing genetic factors and high activity levels can increase a person’s risk of developing osteochondrosis. Read more about the different osteochondroses in our ostrochondrosis post.
This child has been complaining of heel pain. What does his x-ray show and what is this condition called?
This x-ray shows an increased density of the calcaneal apophysis, typically seen in children aged between 7 and 14 years with Sever’s Disease. Apophysitis is a term used to describe a group of overuse traction injuries which commonly cause pain in adolescents. The most common is Osgood Schlatter disease, but other common anatomical areas of apophysitis include the inferior pole of patella (Sinding-Larsen-Johansson), calcaneal tuberosity (Sever’s), medial epicondyle of the elbow (within spectrum of Little League elbow) and various sites on the pelvis. They’re subtly different from osteochondrosis, which is instead due to changes in the epiphyseal ossification centre. Read more about apophysitis in our apophysitis post.
Describe this fracture.
What type of fracture is this? (Clue: it involves a dislocation. Bonus points if you can name the injured joint)
This is a Galeazzi fracture-dislocation – a fracture of the radius (usually distal third) with dislocation of the distal radio-ulnar joint (DRUJ). They’re often missed but must be checked for – the DRUJ dislocation must be reduced before casting. Always examine the DRUJ on x-ray in any child with an isolated radius fracture.
Read more about Galeazzi fracture dislocations and other wrist injuries in our wrist injuries module.
What type of fracture is this?
This is a Tillaux fracture: a Salter-Harris III fracture at the anterolateral distal tibial epiphysis. There is usually avulsion of the tibial fragment by the tibiofibular ligament, attaching it to the fibula.
This is different to a Triplane fracture because there is no fracture through the coronal plane.
Tillaux and Triplane fractures are seen in adolescents. If not recognised and therefore no managed correctly they can be associated with long term morbidity.
Name the Christmas movie
Love, Actually (Ed: Both Andy and Dani profess to loving this movie)
Thank you to @leejrichardson3 for our very own DFTB Lego version