3 point symmetry is not disturbed in which fracture-: (A) Fracture ulna only, (B) Fracture radius only, (C) Fracture of radius & ulna both bones of forearm, (D) Weak posterior capsule
Answer is B. Actually, no option is correct (see previous two explanations). But I will have to find out the answer for you : -
If ulna fracture involves olecranon than the three-point bony relationship can be disturbed. This can occur either in isolated ulna fracture (option a) or ulna fracture with radium (option c).


The weak posterior capsule can cause dislocation of the elbow in which three bony point relationship is disturbed.
Isolated radius fracture will not alter three bony point relationship.