Cortical Window Osteotomy for Diagnostic Biopsy in Iliac Osteomyelitis: A Case Report and Technical Note

Iliac osteomyelitis is a rare and often overlooked condition because of its deep anatomical location and vague clinical presentation. Patients commonly present with persistent groin or pelvic pain and minimal systemic symptoms, frequently resulting in delayed diagnosis. Obtaining adequate tissue for microbiological and histopathological evaluation in such deep-seated lesions can also be challenging. We report a case of subacute iliac osteomyelitis managed using a cortical window osteotomy technique for diagnostic biopsy and curettage.

A 19-year-old male presented with a 6-month history of progressively worsening right groin pain associated with intermittent low-grade fever and difficulty in walking. Laboratory investigations revealed elevated inflammatory markers. Magnetic resonance imaging demonstrated marrow edema and cortical irregularity involving the right ilium with extension into the iliacus muscle, suggestive of subacute osteomyelitis. Computed tomography further defined the cortical involvement and assisted in surgical planning. Considering the deep location of the lesion and the need for adequate tissue sampling, an open biopsy was performed using a cortical window osteotomy approach. A hinged cortical flap was created to access the lesion, allowing curettage and collection of multiple tissue samples. The cortical segment was subsequently repositioned and fixed with cortical screws. Although microbiological investigations were negative, histopathology showed chronic inflammatory changes. The diagnosis was supported by the radiological findings, intraoperative appearance, elevated inflammatory markers, and the patient's favorable clinical response to treatment. At follow-up, the patient had complete resolution of symptoms with maintained pelvic stability.

Cortical window osteotomy provided safe and satisfactory exposure for biopsy and curettage in this case while preserving pelvic integrity through anatomical reconstruction of the cortical segment. This technique may serve as a useful alternative in selected deep-seated iliac lesions where percutaneous biopsy is unlikely to provide adequate tissue.