During fracture healing, which phase is characterized by the formation of a fibrocartilaginous callus and is typically seen 1–3 weeks after injury?

Question

Accepted Answer

D. Soft callus (reparative) phase. ## Fracture Healing — Phases Overview

**Key Point:** Fracture healing progresses through four distinct phases, each with characteristic cellular and tissue changes.

### Phase-by-Phase Timeline

| Phase | Timing | Key Features | Callus Type |
|-------|--------|--------------|-------------|
| **Inflammatory** | 0–3 days | Hematoma formation, inflammatory cell infiltration, necrotic tissue removal | None yet |
| **Soft Callus (Reparative)** | 1–3 weeks | Fibroblasts and chondrocytes proliferate; fibrocartilaginous matrix laid down; angiogenesis | Fibrocartilaginous |
| **Hard Callus (Bridging)** | 3–12 weeks | Endochondral ossification; woven bone replaces cartilage; fracture site becomes rigid | Bony |
| **Remodeling** | Months to years | Woven bone → lamellar bone; restoration of medullary canal; return to normal architecture | Mature bone |

**High-Yield:** The **soft callus phase (1–3 weeks)** is when fibrocartilaginous callus forms—this is the bridge between inflammation and hard bone formation. The callus is still pliable and not yet rigid.

**Clinical Pearl:** On X-ray, soft callus is often not visible because it is radiolucent (not calcified). Hard callus becomes radiographically apparent as ossification begins around week 3–4.

**Mnemonic:** **I-S-H-R** = Inflammatory → Soft callus → Hard callus → Remodeling. Think: "Soft comes before Hard."

### Why This Phase Matters

During the soft callus phase:
- Fracture site is still mobile and vulnerable to re-injury.
- Callus is composed mainly of fibrocartilage, not bone.
- Endochondral ossification has not yet begun in significant amounts.
- External callus is visible clinically (swelling) but not yet on plain radiographs.

![Fracture Healing — Stages diagram](https://mmcphlazjonnzmdysowq.supabase.co/storage/v1/object/public/blog-images/explanation/3538.webp)

Answer

A. Remodeling phase

Answer

B. Inflammatory phase

Answer

C. Hard callus (bridging) phase

During fracture healing, which phase is characterized by the formation of a fibrocartilaginous callus and is typically seen 1–3 weeks after injury?

Explanation

Fracture Healing — Phases Overview

Phase-by-Phase Timeline

Why This Phase Matters

Practice similar questions

Join our NEET PG community

Phase	Timing	Key Features	Callus Type
Inflammatory	0–3 days	Hematoma formation, inflammatory cell infiltration, necrotic tissue removal	None yet
Soft Callus (Reparative)	1–3 weeks	Fibroblasts and chondrocytes proliferate; fibrocartilaginous matrix laid down; angiogenesis	Fibrocartilaginous
Hard Callus (Bridging)	3–12 weeks	Endochondral ossification; woven bone replaces cartilage; fracture site becomes rigid	Bony
Remodeling	Months to years	Woven bone → lamellar bone; restoration of medullary canal; return to normal architecture	Mature bone