Fragility fracture of the fourth rib in a patient with a cardiac pacemaker: an uncommon case.

Pacemaker implantation might have caused shoulder dysfunction and pectoral tightness resulting in reduced flexibility of the trunk. Consequently, a reaching motion of the arm with a trunk rotation might have directed rotational force vectors towards the osteopenic left 4th rib causing a fragility fracture. In elderly with a pacemaker, osteopenia and concomitant sarcopenia may create a predisposition to this atypical complication.