Orthopedics
Pseudogout and Calcium Pyrophosphate Disease
DOI: https://doi.org/10.21980/J8QG66Radiographs of the knee showed multiple radio-dense lines paralleling the articular surface (see red arrows) consistent with calcium pyrophosphate crystal deposition within the joint often seen in calcium pyrophosphate disease (CPPD) also known as pseudogout.
Lunate Dislocation
DOI: https://doi.org/10.21980/J86K56Plain film of the right wrist showed the classic “spilled teacup” consistent with a lunate dislocation. There is a loss of the normal articulation between the distal radius and lunate.
Pediatric Supracondylar Fracture
DOI: https://doi.org/10.21980/J8T88TPlain film radiography showed a displaced supracondylar fracture with disrupted anterior and posterior periostea, consistent with a type 3 supracondylar fracture.
Calcaneal Fractures and Böhler’s Angle
The right ankle lateral radiograph shows a comminuted, non-displaced fracture of the posterior calcaneus (red arrow) in addition to fracture fragments along the heel pad margin (blue arrow). The left ankle lateral radiograph shows a displaced, comminuted fracture of the mid to posterior calcaneus with extension into the subtalar joint posteriorly (purple arrow). There is subcutaneous air seen anteriorly to the tibiotalar joint space (green arrow) in addition to a joint effusion. Of note, the Böhler’s angle in the left x-ray is 16 degrees which is consistent with a fracture (see red annotation showing Böhler’s angle).
Monteggia Fracture in an Assault Patient
DOI: https://doi.org/10.21980/J81S3ZOn the axial elbow x-ray, the radial head (red arrow) is dislocated anteriorly from the humerus; the humeroulnar articulation is intact. On the AP forearm x-ray, there is a closed, displaced, comminuted fracture of the ulna (blue arrow).
Hill-Sachs Deformity
DOI: https://doi.org/10.21980/J8Z59D In the post-reduction film, there is a lateral depression in the humeral head (arrow, a Hill-Sachs deformity). A Hill-Sachs deformity is a cortical depression (fracture) in the humeral head that forms as the humeral head hits the glenoid rim during the dislocation.
Trimalleolar Fracture
DOI: https://doi.org/10.21980/J8PP46Anteroposterior (AP), lateral, and oblique x-ray views were obtained. The AP view revealed a displaced spiral fracture of the lateral malleolus (red) and a vertical fracture of the medial malleolus (blue). The lateral view revealed a displaced fracture of the posterior malleolus, tibial plafond (yellow), and the oblique view showed widening of the distal tibiofibular syndesmosis (green). CT scans confirmed trimalleolar fracture, annotated with the same colored lines (red, lateral malleolus; blue, medial malleolus; yellow, posterior malleolus).
Perilunate Dislocation
DOI: https://doi.org/10.21980/J8F59RIn the left lateral wrist x-ray, the lunate is dislocated from the rest of the wrist bones but still articulates with the radius. The capitate does not sit within the distal articulation of the lunate and is displaced dorsally. Additionally, a line drawn through the radius and lunate fails to intersect with the capitate. This is consistent with a perilunate dislocation. This is compared to a lunate dislocation, where the lunate itself is displaced and turned ventrally (spilled teacup) and the proximal aspect does not articulate with the radius.
Femoral Neck Fracture
DOI: https://doi.org/10.21980/J89G6GIn the anteroposterior view bilateral hip x-ray, there is an evident loss of Shenton’s line on the left when compared to the normal right, indicative of a fracture in the left femoral neck. This correlates with findings seen on pelvic CT, which reveals both a subcapital fracture and transcervical fracture. The neck of the femur is displaced superiorly relative to the head of the femur while the head of the femur remains in its anatomical position within the acetabulum.
Posterior Elbow Dislocation
DOI: https://doi.org/10.21980/J8X593Elbow dislocations are classified by the position of the radio-ulnar joint relative to the humerus.1 Images 1, 2, and 3 show a left posterior elbow dislocation; the radius and ulna (red lines) are displaced posteriorly with respect to the distal humerus (blue line). The lateral view of the elbow most clearly shows this: trochlear notch of the ulna (red line) is empty and displaced posteriorly relative to the trochlea (blue line). There is no associated fracture. Images 4 and 5 show the elbow status-post reduction, demonstrating proper alignment of the distal humerus (blue line) with the radius and ulna (red lines).