Score:
0
/ 9
00:00
Small Fragment Osteosynthesis
1. The drill bit size used for the gliding hole of a 3.5 mm cortical screw.
Rationale:
For a 3.5mm cortical screw, the pilot (threaded) hole is 2.5mm, but the gliding hole in the near cortex must be the same as the screw diameter: 3.5mm.
2. The drill bit size used for a 3.5 mm locking screw.
Rationale:
3.5mm locking screws have a larger core than cortical screws; they require a 2.8mm drill bit.
Trauma Scoring & Classification
3. Mirel's score for an intertrochanteric lytic lesion, <1/3 width, with moderate pain.
Rationale:
Site: Peritrochanteric (3), Pain: Moderate (2), Lesion: Lytic (3), Size: <1/3 (1). Total = 9. Prophylactic fixation is indicated (Score ≥9).
4. Vancouver classification for a periprosthetic fracture around a loose stem with poor bone stock.
Rationale:
Type B2 is a loose stem with good bone; Type B3 is a loose stem with inadequate (poor) proximal bone stock.
Cervical Spine Injuries
5. A 19-year-old with painful neck following an axial compression (diving) injury.
Rationale:
A Jefferson fracture is a burst fracture of C1 caused by axial loading.
6. An 18-year-old following a fall; lateral X-ray shows the "bow tie" sign.
Rationale:
The "bow tie" appearance on a lateral X-ray is pathognomonic for a Unilateral Facet Dislocation.
