A 28-year-old female presents 10 days after a closed fracture of the distal radius managed with closed reduction and plaster immobilization. Examination reveals significant swelling, pain at the fracture site, and warmth over the cast. Plain radiographs confirm fracture alignment is maintained. The patient reports severe pain despite analgesia. What is the most appropriate immediate next step in management?

Explanation

## Clinical Context The patient is at **10 days post-fracture**, which is within the **inflammatory phase** (0–3 weeks). The constellation of severe swelling, pain, warmth, and pain unresponsive to analgesia raises concern for **compartment syndrome** or excessive swelling within the rigid cast. ## Fracture Healing Phases and Swelling | Phase | Duration | Edema Status | Management Implications | |-------|----------|--------------|------------------------| | **Inflammatory** | 0–3 weeks | Maximal swelling (peaks day 2–3) | Risk of compartment syndrome, cast splitting essential | | **Soft callus** | 1–3 weeks | Swelling resolving | Cast may become loose; padding adjustment needed | | **Hard callus** | 3–12 weeks | Minimal swelling | Stable immobilization | | **Remodeling** | 3–12 months | Normal | Progressive loading | ## Key Point: **Severe pain, swelling, and warmth within 10 days of fracture immobilization suggest compartment syndrome or excessive pressure necrosis.** Immediate cast splitting is the standard emergency response to prevent irreversible tissue damage. ## High-Yield: - **Compartment syndrome is a surgical emergency** that can develop within hours to days of fracture or immobilization. - Classic signs: pain out of proportion, pain on passive stretch, paresthesias, pallor, pulselessness (late). - Cast splitting/bivalving is the **first-line emergency measure** to decompress and assess; fasciotomy may follow if symptoms persist. - The inflammatory phase (first 3 weeks) carries the highest risk of compartment syndrome due to maximal edema. ## Clinical Pearl: **"Pain out of proportion to clinical findings" is the most sensitive early sign of compartment syndrome.** In a post-fracture patient with a cast, severe pain unresponsive to analgesia should trigger immediate cast removal/splitting, not further imaging. ## Warning: ~~Do not delay treatment with imaging (MRI, CT) when compartment syndrome is suspected.~~ Clinical examination and immediate decompression take priority. Imaging is not needed to diagnose compartment syndrome—clinical suspicion + emergency decompression is the standard. ## Mnemonic: **5 P's of Compartment Syndrome** — Pain (out of proportion), Pressure (tense compartment), Paresthesias, Pallor, Pulselessness (late). The first two are most reliable early signs.