According to the Gustilo classification, a Type III open fracture is further subdivided into three categories (IIIa, IIIb, IIIc). Which of the following defines Type IIIb?

Explanation

## Gustilo Classification of Open Fractures **Key Point:** The Gustilo classification stratifies open fractures by soft tissue injury severity and vascular compromise, which directly predicts infection risk and functional outcome. ### Type III Subdivisions | Type | Soft Tissue Injury | Periosteal Stripping | Vascular Status | Infection Risk | | --- | --- | --- | --- | --- | | **IIIa** | Extensive | Present | Intact / no vascular repair needed | 10–15% | | **IIIb** | Extensive + periosteal stripping/loss | Yes | **No vascular injury requiring repair** | 25–50% | | **IIIc** | Any soft tissue injury | Any | **Arterial injury requiring repair** | Highest | **High-Yield:** Type IIIb is defined by *extensive soft tissue injury with periosteal stripping* (often requiring local or free-flap coverage) but **without** a vascular injury requiring repair. The presence of a vascular injury requiring repair defines **Type IIIc**, not IIIb. This is the critical distinction that the original explanation had reversed. **Clinical Pearl:** Type IIIb fractures typically require plastic surgical reconstruction (e.g., rotational or free flaps) for soft tissue coverage due to periosteal stripping and bone exposure. Type IIIc adds an arterial injury requiring vascular repair, carrying the highest amputation risk (>50%). **Mnemonic:** **IIIb = Big soft tissue loss + Bone exposed, no vascular Bypass needed** | **IIIc = Cut artery requiring repair** ### Key Distinguishing Features 1. **IIIa:** Extensive soft tissue damage with periosteal stripping, but adequate soft tissue coverage remains; no vascular repair needed. 2. **IIIb:** Extensive soft tissue loss with periosteal stripping and bone exposure requiring reconstructive coverage — **no vascular injury requiring repair** (Option A). 3. **IIIc:** Any soft tissue injury **+ arterial injury requiring repair** — vascular compromise alone defines this category. *Reference: Gustilo RB, Mendoza RM, Williams DN. Problems in the management of type III (severe) open fractures. J Trauma. 1984; as cited in Rockwood & Green's Fractures in Adults, 9th ed.*