Sleeve fracture of the adult patella: Case report and review of the literature.

RATIONALE: The patellar fractures are common in adults, but rare in children. As a particular type of patellar fracture, however, sleeve fractures are almost always limited to children in the under 16's group.

PATIENT CONCERNS: Herein, we report a rare case of a 19-year-old healthy adult female who presented sleeve fracture at the superior pole of the left patella. The clinical and radiological features are found including joint effusion, anterior tilt of the patella and a shell of bone lying proximally to the patella.

DIAGNOSES: Computed tomography and magnetic resonance imaging examination have been performed to further confirm the diagnosis of sleeve fracture, rupture of the quadriceps tendon and the cartilaginous injury.

INTERVENTIONS: Under general anaesthesia, she underwent open surgical procedures for reconstituting anatomically the fracture and repairing the rupture of the quadriceps tendon.

OUTCOMES: Six months after the operation, she could fully use her left knee without any pain and disability.

LESSONS: Sleeve fractures of the patellar in adults are extremely rare, and our case is of interest for the first time occurring in healthy female adults. Our case report and literature review was aim to describe the clinic and imaging characteristics of superior pole sleeve fractures in adults, and highlight that physicians must be aware of this entity in adults so as to reduce misdiagnosis due to unfamiliarity.