rod 30 and two axially spaced screw retainers 34 c and 34 d are connected to the rod 32 the screw retainers 34 a 34 b 34 c and 34 d retain pedicle screws 38 a 38 b 38 c and 38 d respectively each of which extends through and is supported by its corresponding retainer the screws 38 a and 38 c extend into the pedicles of the vertebrae v 4 and the screws 38 b and 38 d extend into the pedicles of the vertebrae v 5 it is understood that the rods 30 and 32 the retainers 34 a 34 d and the screws 38 a 38 d are installed in connection with the procedure to be described or that they could have been previously installed in connection with another procedure as shown in fig5 and 6 a spacer 40 is provided that is fabricated from a relatively flexible soft material and is substantially rectangular in shape with the exception that two curved notches or saddles 40 a and 40 b are formed at its respective end portions the notch 40 a extends around the spinous process 22 of the vertebrae v 3 and since the spinous process of the vertebrae v 4 has been removed an adapter 44.