Patent ID: 6843791

Claim:
A locking cap assembly for locking a spinal fixation element to a spinal fixation element receiving body, comprising: an outer locking element having opposed proximal and distal ends and inner and outer surfaces, the outer locking element having a proximal mating element; and an inner locking element having proximal and distal ends, the inner locking element having a proximal mating element on its proximal end rotatably mated to the outer locking element proximal mating element so that the inner locking element is rotatably mounted within the outer locking element; a first one of the inner and outer locking elements having an engagement element formed thereon for engaging a spinal fixation element receiving body so as to close the spinal fixation element to the spinal fixation element receiving body upon tightening of the engagement element; and a second one of the inner and outer locking elements having a deformable spinal fixation element contacting ring disposed on its distal end; wherein tightening the spinal fixation locking cap assembly to the spinal fixation element receiving body to lock the spinal fixation element therein causes the deformable spinal fixation element contacting ring to contact the spinal fixation element and to deform the deformable spinal fixation element contacting ring to provide secure locking of the spinal fixation element within the spinal fixation element receiving body.