A Gustilo Type III open fracture is further subdivided into three categories (IIIa, IIIb, IIIc). Which of the following is the defining characteristic of a Type IIIc fracture?

## Gustilo Type III Open Fracture Subclassification **Key Point:** Gustilo Type IIIc is defined by **vascular injury requiring repair**, not soft tissue extent or bone loss alone. This is the critical distinguishing feature that determines limb salvageability and prognosis. ### Type III Subdivisions | Subtype | Defining Feature | Soft Tissue Injury | Vascular Status | Prognosis | |---------|------------------|-------------------|-----------------|----------| | **IIIa** | Adequate soft tissue coverage despite extensive contamination | Extensive but periosteum intact | Intact | Better | | **IIIb** | Periosteal stripping with bone exposure; severe contamination | Massive muscle devitalization | Intact | Guarded | | **IIIc** | **Arterial injury requiring vascular repair** | Variable extent | **Compromised** | Poor; high amputation risk | **High-Yield:** Type IIIc fractures carry the **highest amputation rate (11–45%)** and worst functional outcomes. The vascular injury is the defining criterion, regardless of soft tissue damage severity. **Clinical Pearl:** A Type IIIc fracture requires immediate vascular surgery consultation. Ischemia time >6–8 hours significantly increases amputation risk; therefore, vascular repair takes priority over fracture fixation in the operative sequence. **Mnemonic:** **IIIc = Circulation compromised** — the "c" stands for vascular compromise, the worst prognostic factor.