I have some problems about vertical spacing before and after some environments inside a mdframed environment. It is as if topsep=0. The insertion of \setlengh{\topsep}{8pt plus 2pt minus 4pt} fixes the problem except for the first list environment inside each mdframed environment.
\documentclass{article}
\usepackage{amsthm}
\usepackage{lipsum}
\usepackage[framemethod=tikz]{mdframed}
\newtheorem{theorem}{Theorem}
\begin{document}
\verb?\topsep?=\the\topsep
\begin{mdframed}
\verb?\topsep?=\the\topsep
\lipsum[11]
\begin{itemize}
\item \verb?\topsep?=\the\topsep
\end{itemize}
\lipsum[11]
\begin{itemize}
\item \verb?\topsep?=\the\topsep
\end{itemize}
\lipsum[11]
\begin{verbatim}
$[G\colon H\cap K] = [G\colon H][H\colon H\cap K]$
\end{verbatim}
\begin{theorem}
\lipsum[11]
\end{theorem}
\lipsum[11]
\end{mdframed}
\end{document}
