Transforaminal Anterior Release for the Treatment of Fixed Sagittal Imbalance and Segmental Kyphosis, Minimum 2-Year Follow-Up Study

Abstract

Study DesignRetrospective review of prospectively accrued patient cohort. ObjectiveTo report minimum 2 years' follow-up after a single-surgeon series of 47 consecutive patients in whom fixed sagittal imbalance or segmental kyphosis was treated with a novel unilateral transforaminal annular release. Summary of Background DataFixed sagittal imbalance has been treated most recently with pedicle subtraction osteotomy with great success but is associated with significant blood loss and neurologic risk. MethodForty-seven consecutive patients with fixed sagittal imbalance (n = 29) or segmental kyphosis (n = 18) were treated by a single surgeon with a single-level transforaminal anterior release (TFAR) to effect an opening wedge correction. Sagittal and coronal correction was performed with in situ rod contouring. An interbody cage was captured in the disc space with rod compression. Radiographic and clinical outcome analysis was performed with a minimum 2-year follow-up (range 2–7.8 years). ResultsThe average increase in lordosis was 36° (range 24°–56°) in the fixed sagittal deformity group. Coronal corrections averaged 34° (range 18°–48°). The average improvement in plumb line was 13.6 cm. There were four pseudarthroses, one at the TFAR. Average blood loss was 578 mL (range 200–1,200). One patient had a transient grade 4/5 anterior tibialis weakness. There were no vascular injuries or permanent neurologic deficits. There were significant improvements in the Oswestry Disability Index (p < .001) and Scoliosis Research Society Questionnaire scores (p = .003). Eighty-four percent of patients reported improvement in pain, self-image, and satisfaction with the procedure. ConclusionTFAR is a useful procedure for correcting segmental kyphosis and fixed sagittal imbalance with relatively low blood loss and was found to be neurologically safe in this single-surgeon series. Level of EvidenceTherapeutic study, Level IV (case series, no control group).