Disclosed is a sleeve for a transfixation device for an external skeletal fixator having a longitudinal axis, a right portion, a left portion, an outer wall, an interior wall and a lumen. The sleeve is implantable across the opposed cortices of a long bone. The lumen is adapted to receive a pin that is connectable to an external supporting structure of the external skeletal fixator. The lumen includes at least one contraction in the right portion and at least one contraction in the left portion. The at least two contractions serve as supports for the pin for avoiding contact between the pin and the interior wall, except at the contractions. Also disclosed is a transfixation device for an external skeletal fixator including a sleeve such as described and one or more pins.