Though I can't help but wonder what the point of that broken bone even was. It was just brushed off with seemingly no consequence in the long run. Sanji is running, jumping and kicking as lively as ever. And Vergo's toughness could have been demonstrated in other ways.
Unless Oda plans to turn the wound into a complication later on, which results in Sanji losing a leg or some shit.
Losing a limb isn't that unlijely, but in Sanji's case maybe it'll be a spur for him to develop an attack that doesn't break his bones. Many are expecting him to develop sone kind of tempest kick.