An IM nail is positioned within a medullary canal and secured in position by bone screws. The nail includes bores which engage insert assemblies and engage the screws. Each insert assembly is in two parts. Part includes a head and a narrower neck and similarly, part includes a head and a narrower neck. A bore extends through the assembly from one side to the other. Part of the assembly is engaged with a nail by insertion into the nail via mouth and part is engaged with the nail by insertion into the nail via mouth. When in position the parts abut one another and define bore which can receive screws. The nail is made from a polyetheretherketone (PEEK)/carbon fibre composite. Parts of the insert assemblies are produced separately from the nail. They may be produced by injection moulding a polymeric composition comprising PEEK and barium sulphate.
