Pittsburgh Knee Rule

Pittsburgh Knee Rule
[select value="false=0|TRUE=1" name="fall"] <-- Recent fall or blunt-trauma mechanism.
[select value="false=0|TRUE=1" name="age"] <-- Age less than 12 years or older than 50 years.
[select value="false=0|TRUE=1" name="walk"] <-- Unable to take four weight-bearing steps in the emergency department or primary care office.
Result: [calc value="score=(fall)+(age)+(walk); score>0?'X-ray required':'X-ray not necessary'" memo="Interpretation"]
[checkbox memo="display/hide references" name="footnotes" value=""][conditional field="footnotes" condition="(footnotes).is('')"]
reference:  
[link url="//www.aafp.org/afp/2005/0315/p1169.html" memo="#1"] Ebell, MH. Am Fam Physician. 2005 Mar 15;71(6):1169-1172.
[link url="//www.ncbi.nlm.nih.gov/pubmed/14734335" memo="#2"] Bachmann LM, Haberzeth S, Steurer J, ter Riet G. The accuracy of the Ottawa knee rule to rule out knee fractures: a systematic review. Ann Intern Med. 2004;140:121–4.
[link url="//www.ncbi.nlm.nih.gov/pubmed/8060409" memo="#3"] Seaberg DC, Jackson R. Clinical decision rule for knee radiographs. Am J Emerg Med. 1994;12:541–3.
[/conditional]