A method and apparatus for fixing a ligament in a bone tunnel by cross-pinning the ligament in the bone tunnel. A cross-pin guide assembly (5) for placement of at least one cross pin in a bone tunnel, such as the tibial tunnel of a knee joint. The cross pin guide assembly (5) having an L-shaped member (10) having a base portion (15) and an arm portion (20). The arm portion (20) extends transversely to base portion (15).La présente invention concerne un procédé et un appareil qui permettent de fixer un ligament dans un tunnel osseux au moyen de linstallation, dans le tunnel osseux, dun croisillon pour le ligament.