Disc herniation: Whenever the displacement of disc material beyond the limits of the intervertebral disc space is called as a disc herniation. A herniated disc may or may not be covered by annulus fibroses. Herniation can be focal or bulging. When herniation is less than 180 0 disc circumference it is called a focal disc herniation and when it is 180 0 to 360 0 beyond the edges of the ring apophyses it is called disc buldge [Table/Fig-12]. If herniation & buldge was present, it was marked with a Y .