Patent ID: 8403938

Claim:
A method for producing an anchorage in a load bearing tissue, the anchorage having a load bearing capability and being created with the aid of mechanical vibration and a thermoplastic material which is liquefiable by the mechanical vibration, the method comprising the steps of: providing a vibrating element with a distal end and a proximal end, wherein the proximal end is rigidly attached to a vibration source and the vibrating element is capable of transmitting vibration of the vibration source to the distal end and wherein the distal end comprises a first contact face; providing a counter element with a contact end and an opposite end, wherein the contact end comprises a second contact face being adapted to the first contact face to be able to be positioned against the first contact face; providing a first liquefiable thermoplastic portion on at least one of the first and second contact faces; positioning the vibrating element and the counter element relative to said tissue, while holding the elements against each other with first and second contact faces in contact with each other, and with one of a pair of opposite holding forces being applied to each one of said elements, such that a tissue surface extends across outer edges of the contact faces; vibrating the vibrating element while holding the elements against each other and thereby liquefying the liquefiable thermoplastic material between the contact faces; maintaining the vibration and the holding forces and thereby moving the elements against each other and letting the liquefied material flow out from between the contact faces for a period of time sufficient for the liquefied material to contact the tissue surface and, on re-solidification, to form a positive fit connection between at least one of the elements and said tissue surface; wherein the vibrating element comprises a first axis extending between the distal end and the proximal end and the first contact face extending around the first axis and non-parallel thereto, wherein the counter element comprises a second axis extending between the contact end and the opposite end, and the second contact face extending around the second axis and non-parallel thereto, and wherein in the step of positioning, the first and second axes are aligned and the holding forces or components thereof are directed parallel to the first and second axes; wherein the contact face of the vibrating element faces towards the proximal end of the vibrating element and the counter element is positioned between the proximal and the distal end of the vibrating element, the vibrating element reaching past or through the counter element; wherein the vibrating element comprises a stem of a smaller cross section and an end piece of a larger cross section and being located at a distal end of the stem and the counter element comprises a through opening or groove adapted to the stem, and wherein the step of positioning comprises positioning the stem through the through opening or into the groove.