Patella preparation system/device comprising: a fixing device being adapted to, especially fixedly, hold a patella, a guiding device which is linked to the fixing device to be moveable relative thereto by translatory and tilting movements/motions, and an operation device (14, 17) for manually moving the guiding device relative to the fixing device individually and separately in a translatory and a tilting manner, characterized in that the guiding device is adapted to guide a cutting instrument used to perform a resection on the patella, the fixing device comprises an upper fixing portion configured to contact the front surface of the patella and a lower fixing portion configured to contact the lower surface of the patella, the upper and the lower fixing portion (10, 11), which are especially parallel to each other, being each connected to a central connecting portion, while the guiding device is movable in a direction parallel to the length axis of the connecting portion and is inclinable relatively to the upper and lower fixing portions (10, 11), wherein the operation device (14, 17) comprises - a cutting height adjustment device which is configured to position the guiding device in a height with respect to the patella such that the cutting instrument can perform the resection on the patella with a preferred cutting height, and comprises - a cutting angle adjustment device for adjusting the angle of the guiding device with respect to at least the upper fixing portion of the fixing device and hence to the patella separately to the cutting height adjustment device such that the cutting instrument can perform the resection on the patella in a preferred angle. a fixing device being adapted to, especially fixedly, hold a patella, a guiding device which is linked to the fixing device to be moveable relative thereto by translatory and tilting movements/motions, and an operation device (14, 17) for manually moving the guiding device relative to the fixing device individually and separately in a translatory and a tilting manner, characterized in that the guiding device is adapted to guide a cutting instrument used to perform a resection on the patella, the fixing device comprises an upper fixing portion configured to contact the front surface of the patella and a lower fixing portion configured to contact the lower surface of the patella, the upper and the lower fixing portion (10, 11), which are especially parallel to each other, being each connected to a central connecting portion, while the guiding device is movable in a direction parallel to the length axis of the connecting portion and is inclinable relatively to the upper and lower fixing portions (10, 11), wherein the operation device (14, 17) comprises - a cutting height adjustment device which is configured to position the guiding device in a height with respect to the patella such that the cutting instrument can perform the resection on the patella with a preferred cutting height, and comprises - a cutting angle adjustment device for adjusting the angle of the guiding device with respect to at least the upper fixing portion of the fixing device and hence to the patella separately to the cutting height adjustment device such that the cutting instrument can perform the resection on the patella in a preferred angle. - a cutting height adjustment device which is configured to position the guiding device in a height with respect to the patella such that the cutting instrument can perform the resection on the patella with a preferred cutting height, and comprises - a cutting angle adjustment device for adjusting the angle of the guiding device with respect to at least the upper fixing portion of the fixing device and hence to the patella separately to the cutting height adjustment device such that the cutting instrument can perform the resection on the patella in a preferred angle.