In a retrospective review of 1,967 patients with acute knee injuries by Stiell et al [2], 74.1% of patients had knee radiography, and only 5.2% of these had fractures. Therefore, to avoid a large number of negative radiographic studies, development of the inclusion criteria for obtaining knee radiographs in the setting of the acute trauma was needed. The two most commonly used clinical decision criteria, the Ottawa Knee Rule and the Pittsburgh Decision Rule, can help to decide when to perform radiographs in acute knee trauma [5,6,8]. Pittsburgh Decision Rule The Pittsburgh Decision Rule states that patients with acute knee trauma who are <12 years old or >50 years old should have radiographs as well as patients who cannot take 4 weight-bearing steps in the emergency department [5,6]. In their prospective study in 178 patients with acute knee trauma with the Ottawa rule criteria applied, Jenny et al [8] found a 35% decrease in the number of radiographic examinations with 100% sensitivity for detecting knee fracture. Similarly, Cheung et al [6] found a 23% reduction of knee radiographs in 90 patients if the Ottawa rule criteria were applied, although they did report 1 patient who had a fracture and did not meet any of the clinical criteria, but this fracture was radiographically occult and visible only by MRI. In their retrospective study on 106 acute knee trauma patients, Konan et al [5] evaluated the role of the Ottawa and Pittsburgh rules to reduce the unnecessary use of radiographs following knee injury. One hundred and one patients (95%) had radiographs of their injured knees. Only 5% of these patients had a fracture on radiographs, all with Ottawa and Pittsburgh knee rules fulfilled. Using the Ottawa rules, 27 radiographic studies (25%) could have been Acute Trauma to the Knee avoided without missing a fracture. Using the Pittsburgh rules, 32 radiographic studies (30%) could have been avoided.
Acute Trauma to the Knee. In a retrospective review of 1,967 patients with acute knee injuries by Stiell et al [2], 74.1% of patients had knee radiography, and only 5.2% of these had fractures. Therefore, to avoid a large number of negative radiographic studies, development of the inclusion criteria for obtaining knee radiographs in the setting of the acute trauma was needed. The two most commonly used clinical decision criteria, the Ottawa Knee Rule and the Pittsburgh Decision Rule, can help to decide when to perform radiographs in acute knee trauma [5,6,8]. Pittsburgh Decision Rule The Pittsburgh Decision Rule states that patients with acute knee trauma who are <12 years old or >50 years old should have radiographs as well as patients who cannot take 4 weight-bearing steps in the emergency department [5,6]. In their prospective study in 178 patients with acute knee trauma with the Ottawa rule criteria applied, Jenny et al [8] found a 35% decrease in the number of radiographic examinations with 100% sensitivity for detecting knee fracture. Similarly, Cheung et al [6] found a 23% reduction of knee radiographs in 90 patients if the Ottawa rule criteria were applied, although they did report 1 patient who had a fracture and did not meet any of the clinical criteria, but this fracture was radiographically occult and visible only by MRI. In their retrospective study on 106 acute knee trauma patients, Konan et al [5] evaluated the role of the Ottawa and Pittsburgh rules to reduce the unnecessary use of radiographs following knee injury. One hundred and one patients (95%) had radiographs of their injured knees. Only 5% of these patients had a fracture on radiographs, all with Ottawa and Pittsburgh knee rules fulfilled. Using the Ottawa rules, 27 radiographic studies (25%) could have been Acute Trauma to the Knee avoided without missing a fracture. Using the Pittsburgh rules, 32 radiographic studies (30%) could have been avoided.