Hip Pain Secondary to Small Bowel Fistula to Pelvis

A 26-year old man presented to the emergency department for two months of worsening right hip and thigh pain. He complained of radicular pain from his buttocks to his calf and has difficulty bearing weight on his right leg. He denies a history of trauma, fever, prior surgery, or arthritis. In addition, he was being evaluated by a gastroenterologist for recurrent diarrhea. In the middle of his encounter, the radiologist called to discuss a result of his computed tomography (CT) performed three days prior. CT images showed inflamed loops of bowel involving the distal ileum and rectum. A fistula is seen from the rectum, extending into the distal ileal loop and the posterior pelvis (Figures 1 and 2). An abscess was found between the piriformis and gluteus medius. He was admitted for intravenous antibiotic therapy, including a consultation with general surgery for Chrohn’s Disease (CD). He responded well to antibiotics and was discharged six days later.

Figure 1.

Axial computed tomography of the pelvis with oral and intravenous contrast material, at the level of the greater sciatic foramen, demonstrating a sinus tract extending to the right piriformis (red arrow), originating from a segment of the distal ileum (not shown). Segmental, transmural distal ileal wall thickening is also shown (blue arrows). Patient also has multiple ileocolic fistulae (not shown).

Figure 2.

Coronal reformat better demonstrating the oblique, presacral course of the sinus tract along the piriformis (circle).

Extraintestinal manifestations of CD are known to occur with arthropathies occurring in twenty percent of patients.⁴ Common among this group are sacroilitis, or ankylosing spondylitis. Purulent musculoskeletal complications, while rare, have been described.¹ In this study, twenty-three of 552 patients were found to have a musculoskeletal abnormality in CT scans during a 7-year period. Only four of the patients presented with gluteal muscle abscess/fistula. However, twenty-two of these patients were known to have CD at the time of the abnormality. Solitary involvement of the piriformis has also been identified in a patient with a known case of CD.² Similar to the case above, this patient developed difficulty walking and bearing weight. Purulent complications can extend further from the abdominopelvic area with fistula communicating along fascial planes of the thigh into the knee compartment.³ Unfortunately, the patient died from complications and CD was diagnosed post-mortem.