Abstract
Objective:
To determine the accuracy of Ottawa knee Rule (OKR) to rule out knee fractures in adult patients presenting with acute knee injury in Pakistani population at the Emergency department (ED) of the Indus Hospital and Health Network (IHHN), keeping knee radiograph as the gold standard.
Methods:
A Descriptive Cross-Sectional study was conducted at the ED of tertiary care teaching hospital, after approval from Institutional Review Board (IRB). The time duration of the study was 6 month, from 16th Nov, 2021 up to 16th May 2021. A total of 194 patients with acute knee injury, using non probability consecutive sampling technique, meeting inclusion criteria, were enrolled in this study after verbal informed consent. Patients’ medical information was recorded on a pre-designed questionnaire. Demographic details like age and gender were noted with details of mechanism of injury. Patients were assessed by ED doctors on five variables of the OKR and also underwent knee radiograph followed by orthopedic consultation. Outcome measures of this study were: sensitivity, specificity, positive predictive value and negative predictive value and predicting accuracy of the OKR.
Results:
In a sample of 194 patients (average age 35), 55 (28.35%) had a positive Ottawa Knee Rule (OKR) score (≥ 1). OKR accurately predicted the need for knee radiographs in 46 patients with fractures but yielded nine false positives. For the remaining 137 patients, OKR effectively ruled out the need for radiographs, with two false negatives. Overall, OKR demonstrated a sensitivity of 95.83%, specificity of 93.83%, positive predictive value of 83.63%, negative predictive value of 98.56%, and predicted accuracy of 94.32% in assessing acute knee injuries. Employing the OKR in our study brought about a substantial 70.62% reduction in the overall use of radiographs.
Conclusion:
In patients with acute knee injury, OKR has significant applicability in accurately predicting those who need knee radiographs and in excluding the probability of bony involvement

Key words: Traumatic Knee Injury, Ottawa Knee Rules, X-ray Knee