THE ONE STEP FORWARD LATERAL SPINAL X-RAY: MEASUREMENT OF SAGITTAL AND SPINOPELVIC PARAMETERS IN A FUNCTIONAL POSITION

Özet

Objective: Previous studies demonstrated an association between health related quality of life and sagittal balance for the adult spinal deformity (ASD) population, rendering an accurate evaluation of sagittal balance very important. Patients develop compensatory extension of hips, retroversion of pelvis and flexion of knees, identification and elimination of which may be useful. One step forward (OSF) is a lateral X-ray taken with the patient in the “starting to walk” position, taking the first step forward. To compare the sagittal balance and spinopelvic parameters between regular lateral and OSF X-rays in an ASD population and in those with increased pelvic retroversion [pelvic tilt (PT) >25]. Materials and Methods: Forty seven patients with ASD enrolled had their standing lateral X-rays in regular and OSF positions. OSF was defined as that with the patient taking one full step forward with the self-preferred side. Sagittal spinal and spinopelvic parameters were measured. Comparisons were made for the entire population and for patients with PT >25 degrees. Results: Of 47 patients, 17 had PT >25 degrees. OSF did not create any effect in the general population but did so in PT >25 patients for spinopelvic angle, spinosacral angle and global tilt and for sacral slope, PT and pelvic incidence. Conclusion: As evidenced by a decrease in the PT values, OSF eliminates the compensatory pelvic retroversion. It would be reasonable to accept the measurements in OSF as the more “functional” measurements. It is also probable that using OSF in surgical planning may decrease the possibility of imbalance.