Basics and Beyond ® Anatomy of the Upper Extremity

True:  For example, if a patient presents with a cast and the MCP joints are straight and the IP joints are flexed then you must get the cast cut back to allow full MCP joint flexion. Otherwise, the MCP joint collateral ligaments will become shorter and stout, causing active/passive MCP joint flexion to become painful and difficult, if not impossible. Also, in this position you will cause interossei tightness and perhaps lumbrical tightness.  In the same breath, if the PIPJ and DIPJ collateral ligaments are not respected and left to flex or dangle over the edge of a cast, fluent movement at the PIPJ and DIPJ is lost and a stiff hand is usually the result.