Tile/AO Classification
Tile classification divides pelvic fractures into three basic types according to stability based on the integrity of the posterior sacroiliac complex. Here is a mnemonic that can be used to remember tile classification.
Tile A: Anterior arch only (Posterior arch intact)
- Avulsion injury (3 spines – ASIS, AIIS or pubic spine)
- Anterior arch or Ala of ilium (Iliac wing)
- Across (transverse fracture) the Ala of sacrum or coccyx
Tile B: Borderline stable (Posterior arch – incomplete disruption)
- Book (Open): External rotation – Pubic diastasis > 2.5 cm +/- SI joint widening
- Book (Closed): Internal rotation – Lateral compression injury
- Book – Bilateral B injuries
Type C: Completely unstable (Complete disruption of posterior arch)
- One side C
- One side B, One side C
- Both side C
Young Burgess Classification
It is based on injury mechanism.
Antero-posterior compression (APC): There is diastasis of pubic symphysis without anterior fractures. This can cause substantial hemorrhage.
- Pubic diastasis <2.5 cm (stable)
- Pubic diastasis >2.5 cm with widening of anterior SI joint (rotationally unstable)
- Pubic diastasis >5 cm with widening of both anterior and posterior SI joint (globally unstable)
Lateral compression (LC): There is transverse overlapping obturator ring fracture +
- Sacral impaction fracture with intact ligaments (stable)
- 1 + Posterior SI ligament disruption with or without iliac crescent fracture (rotationally unstable)
- LC type 1 or 2 on one side and APC on other side (globally unstable)
Vertical shear (VS): Vertical displacement of hemipelvis (malgaigne fractures). These fractures involve pubic rami and disruption of SI joint or fracture through sacral wing or through posterior iliac wing.
Combined
WSES (World Society of Emergency Surgery) Classification
It uses Young-Burgess classification and hemodynamic stability to classify and guide pelvic fracture management. Hemodynamic stability is the condition in which the patient achieve a constant or an amelioration of blood pressure after fluids with a blood pressure >90 mmHg and heart rate <100 bpm.
Hemodynamic instability:
- Admission systolic blood pressure <90 mmHg, or > 90 mmHg but requiring bolus infusions/transfusions and/or vasopressor drugs OR
- Admission base deficit (BD) >6 mmol/l OR
- Shock index > 1 OR
- Transfusion requirement of at least 4–6 Units of packed red blood cells within the first 24 h
WSES grade | Young-Burgess classification | Haemodynamic | Mechanic | CT-scan | First-line Treatment | |
| MINOR | I | APC I – LC I | Stable | Stable | Yes | Conservative |
| MODERATE | II | LC II/III – APC II/III | Stable | Unstable | Yes | Pelvic Binder in the field ± Angioembolization (if blush at CT-scan) Operative – Anterior External Fixation |
| III | VS – CM | Stable | Unstable | Yes | Pelvic Binder in the field ± Angioembolization (if blush at CT-scan) Operative – C-Clamp | |
| SEVERE | IV | Any | Unstable | Any | No | Pelvic Binder in the field Preperitoneal Pelvic Packing ± Mechanical fixation (see over) ± REBOA (Resuscitative Endo-aortic balloon) ± Angioembolization |
Further reading: Coccolini, F., Stahel, P.F., Montori, G. et al. Pelvic trauma: WSES classification and guidelines. World J Emerg Surg 12, 5 (2017). https://doi.org/10.1186/s13017-017-0117-6
Cause of hemorrhage:
- Stable pelvic fractures: ~70% due to associated injuries and 30% due to pelvic fracture
- Unstable pelvic fracture: ~70% due to pelvic fractures and 30% due to associated injuries
Further reading: Montmany S, Rebasa P, Luna A, Hidalgo JM, Cánovas G, Navarro S. Source of bleeding in trauma patients with pelvic fracture and haemodynamic instability. Cir Esp. 2015 Aug-Sep;93(7):450-4. English, Spanish. doi: 10.1016/j.ciresp.2015.01.011. Epub 2015 Mar 21. PMID: 25804517.
