A surgical method of operating on the spinal column includes the steps of making a slit in the back of a patient proximate to the spinal column, such to divide a first muscle portion around the spinal column into a pair of separate side muscle portions, and detaching at least one of the separate side muscle portions from the spinal column by force-fitting an elongate gauze member into the slit and compressing the gauze member between the spinal column and the at least one of the side muscle portion, such to controllably detach an additional separate muscle portion of the side muscle portions from the spinal column.