Sleeve (2) comprising a longitudinal axis (14), a right portion (22), a left portion(23), an outer wall (15), an interior wall (16) and a lumen (7), said sleeve (2)being implantable across the opposed cortices (4) of a long bone (5) and said lumen(7) being adapted for receiving a pin (3) connectable to an external supportingstructure (9) of an external skeletal fixator (8), wherein said lumen (7) comprisesat least one contraction (6) in said right portion (22) and at least one contraction(6) in said left portion (23), said at least two contractions (6) having a formto serve as supports for said pin (3) for avoiding contact between said pin (3)and said interior wall (16) except at said contractions (6). Transfixation device(1) for an external skeletal fixator (8) comprising such a sleeve (2) and one ormore pins (3).
