Delayed Presentation of a Retained Knife Fragment Following Penetrating Abdominal Trauma and Exploratory Laparotomy.

This case report describes a rare delayed presentation of a retained knife fragment following penetrating abdominal trauma and prior exploratory laparotomy. A 23-year-old male patient presented seven months after sustaining a stab wound with progressive left lower abdominal, buttock, and radicular leg pain, along with new-onset testicular discomfort. His initial injury required emergent laparotomy for multiple small bowel and mesenteric injuries. Despite an initially uncomplicated postoperative course, persistent and worsening symptoms prompted reevaluation. Computed tomography (CT) revealed a 10-cm retained knife fragment within the left gluteal musculature extending toward the ischium. The patient underwent operative removal of the blade under fluoroscopic guidance, with a small distal fragment left embedded in bone. He recovered well and was discharged the following day. Retained foreign bodies after penetrating trauma are uncommon but clinically significant, with potential for delayed complications including pain, infection, and organ dysfunction. This case underscores the importance of maintaining a high index of suspicion in patients with persistent or unexplained symptoms after trauma, even months following initial management. Imaging, particularly CT, plays a critical role in identifying and localizing retained objects to guide safe surgical intervention. Additionally, this case highlights the need for meticulous intraoperative exploration and consideration of postoperative imaging in select high-risk patients to prevent missed foreign bodies and associated morbidity.