Nonunions and malunions are conditions that can occur after a bone is fractured (broken). Nonunion is the term that we use to describe a bone that hasn’t healed (the bone has not united). Malunion is the term that we use to describe the condition when the bone heals in a crocked (angulated or less ideal) position. When either happens, it can cause either pain or limited function and often both, in the affected extremity. This can happen, and often does, despite everything being done correctly with the first surgery. It can often be suspected or even diagnosed with just plain x-rays. It is common for the hardware (plates, screws, nails, pins etc.) to have loosened or broken when a nonunion (the bone does not heal) has occurred. Although broken or loose hardware is much less common with a malunion (the bone heals but heals in the wrong position), it can occur. On occasion, we may note that a plate or nail may bend prior to the bone healing and then the bone goes on to healing but now is in a malunited position.


Tim Weber 2012