A
The fracture line exits lateral to the trochlear groove (Salter-Harris IV).
B
The fracture line exits through the apex of the trochlear groove (Salter-Harris IV).
C
The fracture line is purely epiphyseal without metaphyseal involvement (Salter-Harris III).
D
The fracture involves the medial epicondyle and transits laterally.
Explanation:The correct option is 'b'. The Milch classification categorizes lateral condyle fractures based on the exit point of the fracture line. A Milch Type II fracture line extends medially and exits through the apex of the trochlear groove, destabilizing the radiocapitellar joint and making the elbow unstable. A Milch Type I fracture exits lateral to the trochlear groove (capitellotrochlear sulcus) and leaves the trochlear ridge intact, keeping the joint relatively stable.
Reference: Milch H. Fractures and fracture dislocations of the humeral condyles. J Trauma. 1964;4:592-607.