A 26-year-old man in a hip spica cast for a femoral shaft fracture develops recurrent vomiting, epigastric discomfort worse after meals, and abdominal distension. A contrast study shows dilatation of the proximal duodenum with abrupt cut-off at its third part. The underlying mechanism is:

• A Compression of the third part of the duodenum between the aorta and the superior mesenteric artery ✓
• B Paralytic ileus from retroperitoneal haematoma
• C Obstruction of the pyloric canal by cast pressure
• D Acute gastric volvulus secondary to hyperlordotic positioning

Explanation

Cast syndrome is superior mesenteric artery syndrome caused by body casts or hip spicas that produce hyperlordosis and weight loss, narrowing the aortomesenteric angle and compressing the third part of the duodenum. It presents with proximal duodenal obstruction. Management is cast splitting, nasogastric decompression, fluids and nutritional support. Paralytic ileus would show diffuse gas without the characteristic abrupt duodenal cut-off on contrast study.

Reference: Campbell's Operative Orthopaedics, 14th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.