fig1 schematically shows the knee joint with a tibia t and femur f , between which a cruciate ligament ( tendon ) transplant tt is arranged . the tendon transplant tt extends with its femoral end fi into a bone channel 2 in the femur and with its tibial end ti into a bone channel 4 in the tibia t . the bone channels 2 and 4 each extend from the joint sides 6 and 8 of the femur and tibia , respectively , to the respective rear sides of the bone . this means that they are designed as through - channels or through - holes . in the shown embodiment , the fastening of the tendon transplant tt in the bone channel 2 in the femur is effected with the help of a fixation anchor 10 , which is inserted into the inside of the bone channel 2 . in this manner , the tendon transplant tt at its femoral end fi does not need to extend through the complete bone channel , but has a necessary length lf in the bone channel 2 , which is shorter than the bone channel 2 . fig2 and 3 show the fixation anchor in detail . the fixation anchor 10 is designed as a cone with two flattened , diametrically oppositely lying peripheral surface sections 12 . these peripheral surface sections 12 , as second peripheral surface sections , lie between the two peripheral surface sections 14 which are arranged in a diametrically opposite manner . the first peripheral surface sections 14 form sections of the outer peripheral surface of a cone and are curved about the longitudinal axis x of the fixation anchor 10 . the diameter or radius of curvature reduces in the insertion direction e , which runs in the direction of the longitudinal axis x of the fixation anchor 10 . the fixation anchor 10 comprises a first through - hole 16 extending normally to the longitudinal axis x between the second peripheral surface sections 12 . the through - hole 16 is designed for receiving the transplant tt and has a diameter which is selected so large that the tendon transplant tt can extend through the through - hole 16 . the first through - hole 16 has a maximal diameter which is slightly smaller than the maximum distance of the first peripheral surface sections 14 in the diametric direction . preferably , the diameter of the through - hole 16 is larger than the minimal distance of the first peripheral surface sections 14 in the diametric direction , i . e . larger than the smallest diameter of the fixation anchor 10 between the two first peripheral surface sections 14 at the tapered end of the cone . thus , the diameter of the through - hole 16 can be just as large or larger than the smallest diameter of the bone channel 2 . the diameter of the bone channel 2 can also be designed such that it is adapted to the thickness of the tendon bundle or tendon transplant tt which is to be received , i . e . the bone channel 2 only needs to be designed insignificantly larger than the thickness of the tendon transplant tt , so that it does not lead to a weakening of the bone . a second through - hole 18 extends between the second peripheral surface sections 12 , in a manner parallel to the first through - hole 16 and spaced from it in the insertion direction e . this second through - hole serves for receiving a suture for the fixation of the tendon transplant tt on the fixation anchor 10 . fig4 shows that the end 20 of the fixation anchor 10 , which is at the rear in the insertion direction e , is designed in a curved manner , wherein the curved surface of the rear end 20 extends essentially concentrically to the middle axis of the first through - hole 16 . as is to be seen in fig4 , the bone channel 2 in the femur is designed in the manner of a bottle neck . this means that the bone channel 2 has a first section 22 with a larger diameter and a second section 24 with a smaller diameter , wherein the second section 24 is adjacent the joint side 6 of the femur f . the second section 24 with the smaller diameter thus forms a cross - sectional reduction with a bearing - contact shoulder 26 . the second section 24 in the extension direction of the bone channel 2 is designed in a very short manner compared to the first section 22 , so that it merely forms a web which projects radially inwardly form the peripheral wall of the bone channel 2 and is adjacent the joint side 6 , i . e . on the end of the bone channel 2 which faces the joint . the inner cross section or the inner diameter of the section 24 is smaller than the smallest diameter of the fixation anchor 10 between the first peripheral surface sections 14 defining the cone surfaces . the greatest distance or diameter of the fixation anchor 10 between the first peripheral surface sections 14 , as is to be seen in fig4 , corresponds essentially to the inner diameter of the first section 22 of the bone channel 2 . before inserting the fixation anchor 10 into the bone channel 2 , the tendon transplant tt is led in the manner of a loop through the first through - hole 16 of the fixation anchor 10 , so that the tendon transplant tt bears on the two second peripheral surface sections 12 of the fixation anchor 10 . there , the tendon transplant tt is fixed with the help of a suture 28 which is led through the second through - hole 18 of the fixation anchor 10 and around its side 30 which is at the front in the insertion direction . subsequently , the tendon is pulled in the insertion direction e through the bone channel 2 and thus moves the end of the tendon transplant tt with the fixation anchor 10 from the side which is away from the joint , into the bone channel 2 , until the fixation anchor 10 comes to bear in a clamping manner on the bearing - contact shoulder 26 , which is defined by the section 24 which is smaller in diameter . then the tendon transplant tt is also clamped between the fixation anchor 10 and the inner wall of the bone channel 2 , in this region , so that a secure fixation is achieved here . it will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof . it is understood , therefore , that this invention is not limited to the particular embodiments disclosed , but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims .
a tendon fixation anchor is designed for being received in a bone channel and includes at least one first through - hole which extends transversely to an insertion direction of the anchor . the tendon fixation anchor can be inserted into a bone channel . a transplant tendon to be fastened can be led through the at least one first through - hole .