Apparatus for securing a first bone fragment to a second bone fragment, said apparatus comprising: a fusion device, said fusion device comprising: a shaft having a first end and a second end; a first bone-engaging feature formed on said shaft at a first location, said first bone-engaging feature comprising at least one barb which, in its unbiased condition, flares outwardly from the longitudinal axis of said shaft and which is capable of being elastically constrained to a position substantially parallel to the longitudinal axis of said shaft, such that said first end of said shaft may be advanced into a hole in the first bone fragment when said at least one barb is elastically constrained to a position substantially parallel to the longitudinal axis of said shaft but is prevented from being withdrawn from the hole in the first bone fragment when said at least one barb is in its unbiased condition; and a second bone-engaging feature formed on said shaft at a second location, said second bone-engaging feature comprising at least one barb which, in its unbiased condition, flares outwardly from the longitudinal axis of said shaft and which is capable of being elastically constrained to a position substantially parallel to the longitudinal axis of said shaft, such that said second end of said shaft may be advanced into a hole in the second bone fragment when said at least one barb is elastically constrained to a position substantially parallel to the longitudinal axis of said shaft, but is prevented from being withdrawn from the hole in the second bone fragment when said at least one barb is in its unbiased condition.