positioned in the bone of a bone flap 1 in retracted position with spring 34 compressed the bone flap and device are positioned to allow entry of the second movable shank into a hole 38 drilled in the skull 2 on allowing the retractable shank 32 to be urged outward by spring 34 the respective shanks 32 and 30 positioned in bone flap 1 and skull 2 respectively stably maintain an abutting relationship between the skull and bone flap as shown in fig3 d note that the absence of a collar allows close abutment of the skull and bone flap although the hollow shank portion is illustrated as positioned in the bone flap reverse positioning is also possible the hollow shank positioned in the skull bone a view of skulls with bone flaps in place are shown in fig4 a and 4 b in fig4 a a circular bone flap having pins 40 radially distributed is shown while in fig4 b a rectangular flap is shown note that the pins do not have to be parallel as shown in fig4 a and that opposed pins may be used as shown in fig4 b which then does not require the use of wires or screw type fasteners as necessitated by prior art devices as illustrated in fig2 b alternative embodiments are shown in fig5 a 5 d in fig5 a a device with blunt ends 50 and 51 rather than pointed ends is shown in fig5 b a device having a compressible elastomer 52 e g a cellular or microcellular elastomer rather than a spring elastic member is shown in fig5 c a device having an optional and less preferred flange 54 is shown in fig5 d a device having a retaining means in the hollow shank portion is shown in.