We report a rare case of complete avulsion of the quadriceps tendon in an 8-year-old child with juvenile idiopathic arthritis (JIA). Our patient presented with acute onset of pain and effusion with a history of feeling a "pop" in the knee after a fall while playing kickball. Although knee radiographs showed a cortical irregularity involving the superior patellar pole, it was assumed that the symptoms were a result of a JIA flare rather than an acute injury. Complete quadriceps disruption was later diagnosed by magnetic resonance imaging, and surgical repair was performed.
Complete rupture of the quadriceps tendon is an unusual, disabling injury in children that necessitates prompt diagnosis and early surgical repair. High index of suspicion and thorough physical evaluation are essential for the diagnosis of such injuries, especially in children with complex medical conditions.