How to place footnote outside box environment

Question

My issue is the following: The footnote gets placed inside the box. However, I want it to be placed and numbered like a normal footnote. How can that be made possible?

I provided an MWE for my specific design:

\documentclass{scrbook}
\usepackage{mdframed}
\usepackage{amsthm}
\usepackage[nopar]{kantlipsum}
\newtheorem{theorem}{Definition}
\newenvironment{ltheorem}
{\begin{mdframed}[topline=false,rightline=false,bottomline=false]
        \hspace*{-\parindent}%
        \rlap{\smash{\colorbox{white}{\strut\hspace{\parindent}}}}%
        \begin{theorem}}
        {\end{theorem}\end{mdframed}}
\begin{document}
\begin{ltheorem}[\textbf{Theorem}]
    \kant[1]\footnote{\kant[2]}
\end{ltheorem}


\end{document}

Answer 1

If you want a page-global footnote, you:

1. issue a \footnotemark in the place where you want the mark to be, and
2. issue a \footnotetext{whatever} at the page level.

Here:

\begin{document}
\begin{ltheorem}[\textbf{Theorem}]
    \kant[1]\footnotemark
\end{ltheorem}

la la la la \footnotetext{\kant[2]}


\end{document}

If you need more than one footnote, the thing get more complex; you can see for example How to make multiple \footnotemark and \footnotetext match?