When managing a ‘Boxer’s fracture’ (a fracture of the 5th metacarpal neck), what is the generally accepted maximum degree of volar angulation that can be treated conservatively with immobilization without causing significant functional impairment?

Explanation:
The correct option is c. The carpometacarpal (CMC) joints of the hand have varying degrees of mobility. The 2nd and 3rd CMC joints are rigid, so fractures there require near-anatomic reduction. However, the 5th CMC joint is highly mobile, allowing for roughly 20 to 30 degrees of compensatory motion. Because of this massive compensatory mobility, the 5th metacarpal neck can tolerate massive volar angulation—up to 40 to 70 degrees depending on the literature—without causing a functionally limiting loss of extension or a painful 'pseudo-clawing' grip. Reference: Ali A et al. Fifth metacarpal neck fractures: current concepts. J Am Acad Orthop Surg.