A 77-year-old woman reported a spiral right humeral shaft fracture, which was treated by closed reduction and fixation with elastic bundle retrograde intramedullary nail. Despite a proper closed reduction and a minimally invasive surgery obtained, nonunion arose. The patient refused the advised second surgical treatment. At 12 months, the patient was admitted to our department as a consequence of persistent pain and unnatural humeral shaft mobility. New X-ray imaging highlighted intramedullary nail rupture due to excessive implant mobility at the nonunion site. Consequently, nail removal was performed, and plate and screws were then fixed, and a bone allograft was placed to allow fracture healing and proper stabilization. The literature reports optimal outcomes with elastic bundle intramedullary nailing. It is strongly suggested to obtain a closed reduction and minimally invasive dynamic fixation. Nonetheless, it may lead to several complications such as nonunion, for which surgical treatment is technically demanding and highly invasive.