AKT · Musculoskeletal/Fractures, trauma & soft tissue

Complications of fractures

Local/systemic sequelae of fracture — compartment syndrome, AVN, non-/malunion, fat embolism, VTE

Overview

Fractures cause important complications that are heavily examined. Immediate/early: neurovascular injury, compartment syndrome, fat embolism, infection, VTE. Late: non-union, malunion, avascular necrosis (sites with precarious blood supply — femoral head, scaphoid, talus), and post-traumatic osteoarthritis. Compartment syndrome is the can't-miss emergency.

Recognise

Compartment syndrome: pain OUT OF PROPORTION, worse on passive stretch, a tense swollen compartment; paraesthesia (pulses/pallor are LATE)
Avascular necrosis: persistent pain after fracture at high-risk sites (femoral head — intracapsular NOF, scaphoid waist/proximal pole, talus)
Fat embolism: respiratory distress, petechial rash and confusion ~24–72 h after a long-bone fracture; non-union/malunion = failure of/abnormal healing

Red flags

Compartment syndrome → EMERGENCY fasciotomy; diagnosis is clinical (pain out of proportion + on passive stretch) — do NOT wait for pulselessness
Fat embolism syndrome → supportive critical care; the petechial rash + hypoxia + confusion triad

Differentials & how to tell them apart

Normal post-fracture painproportionate, eased by analgesia, no passive-stretch pain or tense compartment

DVTswelling/pain with Wells features — but always exclude compartment syndrome first

Wound infection / osteomyelitisfever, raised inflammatory markers, discharge

Investigations

Compartment syndrome is a CLINICAL diagnosis (compartment pressures only if uncertain/obtunded — don't delay); X-ray/CT for union/alignment; MRI for avascular necrosis; oxygenation/clinical picture for fat embolism.

Management

Compartment syndrome → emergency fasciotomy; otherwise treat the specific complication

1Stay alert to complications. Compartment syndrome (pain out of proportion + on passive stretch + tense compartment) is a clinical diagnosis → remove constricting casts and perform EMERGENCY fasciotomy.Gate: Do NOT wait for pulselessness/pallor in compartment syndrome — those are late signs and waiting for them costs the limb.
2Manage other complications: AVN at high-risk sites (femoral head, scaphoid, talus) with joint-preserving surgery/arthroplasty; non-/malunion with revision; VTE prophylaxis throughout; supportive care for fat embolism.

Compartment syndrome: remove tight casts, EMERGENCY fasciotomy — do not elevate above heart level; surgical decompression is definitive and time-critical

VTE prophylaxis — for immobilised/lower-limb fracture patients (LMWH per risk assessment)

AVN: analgesia, joint-preserving surgery or arthroplasty — depending on site/severity

Non-union/malunion: revision surgery, bone grafting — correct alignment and promote union

Key points

Compartment syndrome = pain OUT OF PROPORTION and on passive stretch with a tense compartment → emergency fasciotomy; pulselessness is a LATE sign, never wait for it. AVN affects the femoral head (intracapsular NOF), scaphoid and talus. Fat embolism = hypoxia + petechiae + confusion 1–3 days after a long-bone fracture.

Monitor & prognosis

Neurovascular status, union on X-ray, oxygenation (fat embolism), function.

Compartment syndrome outcome depends on time to fasciotomy; AVN and non-union may need arthroplasty/revision.

Source: BOAST; cross-ref acute_care