A 30-year-old man is brought in after a high-speed motor vehicle accident. Pelvic X-ray shows bilateral pubic rami fractures anteriorly and a sacroiliac joint disruption posteriorly on one side, with an overall lateral compression pattern. According to the Tile/AO classification, this is:
- A Tile B — partially unstable, rotationally unstable but vertically stable ✓
- B Tile A — stable fracture with intact posterior sacroiliac ligaments
- C Tile C — completely unstable, both rotationally and vertically unstable
- D APC-III open book injury with complete symphyseal disruption
Correct answer: A. Tile B — partially unstable, rotationally unstable but vertically stable
Explanation
The Tile B pelvic ring injury is rotationally unstable but vertically stable because the posterior sacroiliac ligament complex (the primary vertical stabiliser) remains intact. Lateral compression injuries typically produce Tile B2 injuries. Tile C fractures involve complete disruption of the posterior ligamentous complex allowing vertical displacement. APC-III specifically describes an anterior-posterior compression mechanism with complete SI disruption, not a lateral compression pattern.
Reference: Maheshwari Essential Orthopaedics, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.