Key Role of Preoperative Recumbent Films in the Treatment of Severe Sagittal Malalignment

Abstract

Study DesignRetrospective cohort study. ObjectiveTo determine if severe sagittal malalignment (SM) patients without fixed deformities require a three-column osteotomy (3CO) to achieve favorable clinical and radiographic outcomes. Summary of Background Data3CO performed for severe SM has significantly increased in the last 15 years. Not all severe SM patients require a 3CO. MethodsSevere SM patients (sagittal vertical axis [SVA] >10 cm) who underwent deformity correction between 2002 and 2011. Patients with <33% change in their lumbar lordosis (LL) on a preoperative supine radiograph were classified as stiff deformities, whereas those with ≥33% change were categorized as flexible deformities. The clinical/radiographic outcomes were assessed at minimum two years postoperatively. ResultsSeventy patients met the inclusion criteria, 35 patients with flexible and 35 with stiff deformities. Eighteen flexible-deformity patients underwent a 3CO versus 22 stiff-deformity patients. The remaining patients in each group underwent spinal realignment without a 3CO. The flexible-deformity patients not undergoing a 3CO had overall improvement in all sagittal radiographic parameters. Preoperative LL (22°), LL–pelvic incidence (PI) mismatch (43), SVA (17 cm), and pelvic tilt (PT, 34°) improved to 46°, 18, 6 cm, and 26°, respectively, p < .05. Flexible-deformity patients who underwent a 3CO also had overall improvement in all radiographic parameters. Preoperative LL (8.5°), LL-PI mismatch (47), SVA (19 cm), and PT (37°) improved to 39°, 15, 7 cm, and 24°, respectively (p < .05). Stiff-deformity patients who underwent a 3CO had statistically significant improvement in all radiographic parameters. However, stiff-deformity patients who did not undergo a 3CO had suboptimal improvement in all radiographic parameters, except for SVA (14 cm-9 cm, p < .05). Flexible patients who did not undergo a 3CO had statistical improvement in the SRS domains of function and self-mage as well as in their ODI scores (p < .05). ConclusionSevere SM that is flexible can be corrected without a 3CO without compromising clinical and radiographic outcomes. Level of EvidenceLevel III.