Upper pole sleeve fracture of the patella secondary to patellar dislocation: A case report

RATIONALE: Upper pole sleeve fractures of the patella are rare in adolescents; however, they are serious injuries that require early diagnosis and treatment. PATIENT CONCERNS: We present a rare case of a 15-year-old girl who suffered a sleeve fracture at the superior pole of the right patella. The patient had a history of dislocation of the patella 2 weeks ago. Physical examination showed tenderness on palpation over the upper pole of the patella and absence of active movement of the knee accompanied by swelling and joint effusion. A plain radiograph showed an avulsed fragment of the superior pole of the patella. DIAGNOSES: Magnetic resonance imaging showed a superior pole patellar avulsion fracture and dysfunction of the knee extensor mechanism. INTERVENTIONS: Under general anesthesia, the patient underwent open surgery for reduction of the patellar fracture and reconstruction of the knee extension apparatus through an anterior approach. OUTCOMES: Six months after the operation, the knee function was fully restored, there was absence of pain and swelling, and the patient was able to return to sports. LESSONS: Upper pole sleeve fracture of the patella is usually serious and it needs to be diagnosed and treated as soon as possible, the sports medicine practitioner must be aware of this type of injury.