16/09/2026
Question :@ Postoperative Complications @ Surgical Infection
A 67-year-old man with poorly controlled diabetes undergoes an above-knee amputation for an ischaemic, infected limb. Eighteen hours later he develops rapidly increasing pain at the stump and becomes tachycardic and hypotensive. Examination shows tense oedema of the stump with dusky skin discolouration, haemorrhagic bullae and palpable crepitus.
What is the single most likely diagnosis?
A. Clostridial myonecrosis
B. Necrotising fasciitis
C. Deep incisional surgical-site infection
D. Postoperative stump haematoma
E. Acute pulmonary embolism
Correct answer: A. Clostridial myonecrosis
Explanation:
Clostridial myonecrosis (gas gangrene) is a rapidly progressive, toxin-mediated infection of skeletal muscle, most commonly caused by Clostridium perfringens. The combination of very rapid postoperative deterioration, severe increasing pain, tense oedema, skin discolouration, haemorrhagic bullae, crepitus and cardiovascular collapse is characteristic.
This is a surgical emergency requiring immediate resuscitation, broad-spectrum intravenous antibiotics and urgent radical surgical debridement; amputation may be required when infection is extensive.
Why the other options are incorrect
B. Necrotising fasciitis: Can cause severe pain, systemic toxicity and skin necrosis, but predominantly tracks along fascial planes. The very rapid progression with prominent muscle involvement, gas formation and profound toxicity favours clostridial myonecrosis.
C. Deep incisional surgical-site infection: Usually develops less explosively and does not typically produce extensive crepitus, haemorrhagic bullae and rapid cardiovascular collapse within hours.
D. Postoperative stump haematoma: May cause swelling and pain but would not explain crepitus, haemorrhagic bullae and severe infective toxicity.
E. Acute pulmonary embolism: Could cause tachycardia and hypotension after major surgery but would not account for the rapidly progressive local stump abnormalities.