What constitutes a "significant or substantial physical injury" in a motor vehicle accident?

"It is well settled that the determination of great bodily injury is essentially a question of fact, not of law. '"Whether the harm resulting to the victim . . . constitutes great bodily injury is a question of fact for the jury. [Citation.] If there is sufficient evidence to sustain the jury's finding of great bodily injury, we are bound to accept it, even though the circumstances might reasonably be reconciled with a contrary finding."' [Citations.]" (People v. Escobar (1992) 3 Cal.4th 740, 750, fn omitted.) A bone fracture may qualify as a "'significant or substantial physical injury.'" (People v. Johnson (1980) 104 Cal.App.3d 598, 608 [fractured jaw held to qualify as great bodily injury].)