Cervical scoliosis in the Klippel-Feil patient

Abstract

Summary: A multicenter database was used to compare patients undergoing primary surgery for AIS to those having revision surgery. The incidence of complications and were comparable between groups. Those with revision surgery had had similar SRS scores to the primary patients at two year follow-up despite more frequent spinal cord monitoring changes intraoperatively and less correction of the main curve. Introduction: The incidence of revision surgery for adolescent idiopathic scoliosis (AIS) has been recently reported from several institutions with some variability. There are no published studies which have analyzed the radiographic and clinical outcomes following revision AIS surgery. Methods: A prospective multi-institution prospective database was reviewed. A group of AIS patients who had primary surgery were compared to those who underwent revision surgery. Radiographic, surgical and functional scores were compared for the two groups. Results: There were 3317 patients in the primary group and 115 in the revision group. The most common reasons for revision were curve progression (23.2%), symptomatic instrumentation (20.5%), pseudoarthrosis (12.5%) and implant failure (7.1%). There were no differences in gender or BMI. The primary patients were younger (14.8 vs 16.4 years, p<0.05), had larger preoperative major curves (57.4° vs 45.5°, p<0.05), greater trunk shift (19.9 vs 15.3 mm, p<0.05) and had greater curve correction (62.6% vs 45.3%, p<0.05) at two years. The primary group had less preoperative thoracic kyphosis (22.2°vs 30.9°, p<0.05) but the revision group improved such that the thoracic kyphosis at two years (22.1° vs 22.9 °) was similar between the two groups. There were no differences in baseline SSEP or MEP, but there was a trend toward a higher incidence of critical changes in SSEP (1.2% vs 3.4%, p=0.07) and MEP (3.0% vs 5.9%, p=0.09) for the revision group. Preoperatively, the revision patients had lower SRS-30 Pain (4.07 vs 3.65, p<0.05) and Activity (4.09 vs 3.85, p<0.05) domain scores and a lower Total score (3.82 vs 3.66, p<0.05). At two years, the revision patients improved, such that their SRS scores were similar to the primary group. Conclusion: Patients undergoing revision surgery for AIS improve their thoracic sagittal deformity, but have greater incidence of critical changes in SSEP and MEP. Despite worse preoperative pain and activity scores, patients undergoing revision AIS surgery demonstrate similar scores in these domains and total SRS-scores at two years.