well not exactly. the lung doesn't "rupture " exactly. it can collapse though. this is called " pneumothorax. " a broken rib can indeed puncture your lung. in fact it's not all that uncommon. if you watch any of those real-life trauma shows on television you will see emergency room personnel placing chest tubes in patients due to collapsed lungs and you can bet some of those collapses occurred due to fractured ribs. but if by "cracked" you mean "not completely fractured or displaced " then the answer probably is "no. " when a rub breaks and the two sides pull away from each other then one of them can puncture the lung. if a rib is "cracked" but the ends never comes apart then it's unlikely to penetrate the tissue surrounding the lung. on the other hand if you took a forceful blow to the chest that alone could cause a collapsed (not "ruptured") lung. so if you experienced chest trauma sufficient to crack a rib you certainly could experience a pneumothorax. surprisingly you can experience a collapsed lung without any known cause whatsoever. wishing you well!
can your lungs be ruptured if you cracked a rib?