In anatomical studies the deepest soft tissue layer, related to the deep rectus femoris tendinous fibers, has been described as the “prepatellar quadriceps continuation”. This paper presents an unusual case of an isolated prepatellar continuation rupture, which is thought by the authors the first described case in the literature. Injuries to the extensor mechanism may include isolated rupture of the prepatellar continuation with intact quadriceps and patellar tendons. Diagnosis could be challenging with ultrasound scan and requires MRI scan for confirmation. Appropriate clinical assessment and regular physiotherapy lead to a full functional recovery.