The Cervical Spine Injury Severity Score (CSISS) is one of several different ways to classify the severity of cervical spine injuries in order to predict who might need surgery to stabilize the spine. The CSISS is favored by some surgeons because it’s easy to use by the surgeon and proven to be reliable and valid (accurate in predicting who needs surgery). The CSISS is for patients with neck injuries involving the lower cervical spine (C3 to C7).
Other classification models for the lower cervical spine focus on how the injury occurred (called the mechanism of injury). But the CSISS uses X-rays and CT scans to take a look at four anatomical features of the cervical spine and scores them based on injury present (e.g., fracture, dislocation).
The scoring system of the CSISS takes into account the location of the injury, severity (nondisplaced vs. displaced fracture), and neurologic damage. Four columns of the cervical spine are evaluated separately: the two facet (spinal) joints, the vertebral body, and the posterior area of the spinous process. You can feel the spinous processes of your spine by rubbing your fingers up and down the back of your neck. As you probably know, the largest bump near the top of your spine is the spinous process of C2. At the base of the neck where the cervical and thoracic spines join together, you’ll feel another large spinous process. That’s C7.
These bony knobs are the place where the two lamina bones join together at the back of the spine. There is a bony ring that attaches to the back of the vertebral body. The ring forms an opening for the spinal cord to travel from the brain down to the end of the spine. This ring has two parts. Two pedicle bones form a short column of bone that connects directly to the back of the vertebral body. Two lamina bones join the pedicles to complete the outer rim of the ring.
The surgeon uses a CT scan of the injury and scores the four columns based on where the fracture(s) occurred and how many fractures there are. Each of the four areas (right and left facet joints, vertebral body, posterior ring with spinous process) is scored from zero to five. Each column is scored independently and then the scores are added up for all four columns. Zero indicates no fracture or dislocation is present. A score of one is given for a mild (one to three millimeter) nondisplaced fracture. A score of two means there is a one to three millimeter displaced fracture. Three is for a three to five millimeter displacement. And anything more than five millimeters is scored as a five.
The total score reflects not only the amount of displacement (the higher the score, the more severe the injury), but also gives the surgeon an idea of how stable/unstable the fracture site is. A CSISS score of seven or more is a sure sign that surgery is needed to stabilize the spine. A score of three suggests there is one fracture that is moderately displaced. It’s also possible to obtain a score of three with three nondisplaced fractures or even one nondisplaced fracture and one moderately displaced columns.
With this information, if you are still unclear about the injury, you may want to go back and take a second look at the X-rays or CT scans. It’s not uncommon for patients and/or family members to need additional information — especially when a child of any age is involved.