Explanation:The correct option is 'b'. A Neer Type II distal clavicle fracture is highly unstable. The fracture occurs medial to the coracoclavicular (CC) ligaments. The CC ligaments remain attached to the small distal fragment, holding it down, while the trapezius and sternocleidomastoid muscles pull the proximal fragment superiorly and posteriorly. This high degree of displacement leads to a nonunion rate of up to 30% if treated non-operatively.
Reference: Neer CS 2nd. Fractures of the distal third of the clavicle. Clin Orthop Relat Res. 1968;58:43-50.