A bone nail for the medical care of spoke bone (i.e., radius) fractures comprises a hollow shaft (10) curved in a plane, which shaft is to be distally and posteriorly inserted into a spoke bone medullary canal and which includes a proximal end portion which is slotted so as to be able to be spread apart by a spreading body. A straddling member (36) having an outer threaded portion (44) cooperates with an inner threaded portion (18) in the slotted portion (12) of the shaft (10) of the nail so as to radially expand the proximal nail end when the straddling body (36) is rotated. A cross bore (22) at the distal end of the shaft (10) receives a bone screw extending approximately vertical to the plane of the curvature.