Usefulness of skyline view in the evaluation of acute patellar dislocation: A case study

Skyline view is routinely used for the evaluation of patellofemoral abnormalities in general practitioner, orthopaedic and rheumatology patients but rarely forms part of the trauma radiographic series. A 16-year-old male was referred for an x-ray of the right knee after patellar dislocation following a football injury. The lateral view showed an osteochondral lesion in the lateral femoral condyle and a skyline was suggested to be performed. Despite the patient could manage only 70° of flexion from full extension, a skyline view was obtained by adapting the standard technique which revealed an avulsion fracture at the medial aspect of the patella. Advanced imaging is used for further evaluation when x-ray findings are equivocal, or as a management or intervention tool(s). But not every patient is referred for advanced imaging unless there is an informed clinical reason. Skyline view should therefore be performed as part of trauma knee radiographic series when it is clinically indicated that patellar dislocation has occurred. When the standard skyline view positioning technique is not possible due to limited flexion, it can still be achieved depending on the degree of flexion at the knee.