Pittsburgh Knee Rules

Original Editor - Johnathan Fahrner

Top Contributors - Johnathan Fahrner, Kai A. Sigel, Selena Horner and Claire Knott  


A clinical decision rule used to indicate the use of radiography of the knee following an injury.


Radiographs of the knee should performed if the mechanism of injury is a fall or blunt trauma and either one of the following:

1) Patient is younger than 12 or older than 50

2) Inability to walk four weight-bearing steps

These rules do not apply to individuals who present more than 6 days after injury, those with only superficial lacerations and abrasions, those with a previous history of knee injury or surgery on the affected knee, and those being reassessed for the same injury. [1]



Diagnostic Accuracy

In a study by Seaberg et al., of 934 patients evaluated the Pittsburgh knee rules applied to 745 with a sensitivity of 0.99 and a specificity of 0.60.  There was the potential to reduce radiography by 52% with one missed fracture. [3]

In a more recent study by Cheung et al., the Pittsburgh knee rules had a pooled sensitivity of 0.86 and a pooled specificity of 0.51. [4]

Recommendations for Clinical Practice

The Pittsburgh knee rules are often compared to the Ottowa knee rules.  While the Pittsburgh knee rules have a higher specificity, each have almost identical sensitivities. [3][4] The ability of these rules to rule out a condition, and thus avoid a radiograph is important and their most valuable characteristics.  With proper training either set of rules could be adopted for use. [1]

Recent Related Research (from Pubmed)


  1. 1.0 1.1 Hawley C, Rosenblatt R. Ottowa and Pittsburgh rules for acute knee injuries. The Journal of Family Practice 1998;47(4):254-255. http://www.ncbi.nlm.nih.gov/pubmed/9789509. (Accessed 25 Apr 2013).
  2. Physiotutors. The Pittsburgh Decision Rule | Knee Fracture Clinical Prediction Rule. Available: https://www.youtube.com/watch?v=TMw6SJP784U
  3. 3.0 3.1 Seaberg DC, Yealy DM, Lukens T, Auble T, Mathias S. Multicenter comparison of two clinical decision rules for the use of radiography in acute, high-risk knee injuries. Annals of Emergency Medicine 1998;32(1):8-13. http://www.ncbi.nlm.nih.gov/pubmed/9656942. (Accessed 25 Apr 2013).
  4. 4.0 4.1 Cheung TC, Tank Y, Breederveld RS, Tuinebreijer WE, de Lange-de Klerk ES, Derksen RJ. Diagnostic accuracy and reproducibility of the Ottawa Knee Rule vs the Pittsburgh Decision Rule. American Journal of Emergency Medicine 2013;31(4):641-5. http://www.ncbi.nlm.nih.gov/pubmed/23399332. (Accessed 25 Apr 2013).