P65. Total disc replacement as a part of adult scoliosis surgical treatment of 205 patients with minimum of two years of follow-up

Abstract

BACKGROUND CONTEXT Surgical scoliosis treatment in adults must face beyond the curve correction, degeneration disc disease, dislocations, spondylolisthesis with sagittal and frontal unbalance and lumbar kyphosis. Two technical components of the surgery have been used to resolve those difficult problems: the fixation through the pelvis, with a complete loss of lumbar mobility and its consequences. The higher rate of pseudarthrosis, despite complex contracts, on one hand, and the necessity of posterior lumbar osteotomies to restore an acceptable lordosis with severe risk of complications on the other hand. PURPOSE To explore the capacity to maintain or restore part of mobility and lumbar lordosis, using total disc replacement TDR), by anterior approach (with or without ALIF) in association with the posterior reduction, fixation. STUDY DESIGN/SETTING Retrospective clinical study. PATIENT SAMPLE A total of 205 patients, 40M, 165F, 18-82 years old (average age 57 yo). Of them, 112 idiopathic scoliosis never operated before, 43 degenerative scoliosis in adults never operated on, and 50 cases already operated on by posterior approach (below prior surgery). Of them, 286 TDR Prodisc implanted (129 - 1 level, 71 - 2 levels, 5 – 3 levels). OUTCOME MEASURES The patients’ analysis includes the perioperative, preop and postop VAS and ODI (3, 6, 12, 24, late follow-up), mobility of the disc replacement and the evolution of the curve (Cobb, sagittal parameters), radiographic analysis. METHODS Between 2000 and 2018, 123 patients with scoliosis and lumbar disc degeneration have received one or more TDR and eventually ALIF, before or after their posterior fixation reduction. The posterior device associated classically hooks, screws and the rods. The choice of the TDR is one of the key points as with the deformity, there is a need for semi-constrained (fixed center) prosthesis, to neutralize the shear forces and compensate the deficit of anterior and posterior longitudinal ligaments. RESULTS ODI preop was 24/50 and declined to 10 in 24 months, VAS lumbar 7.2, radicular 5.7 prep went to 2.6 and 2.1 at 24 months and stabilized at latest follow-up. The mobility measurement at 24 months showed: 151 of 205 patients had a ROM at the TDR level more than 10° in flexion-extension at 24 months. The lordosis capacity of the implants eventually associated to and ALIF with appropriated angulation, allowed the sagittal balance restoration, with T1 axe correction and pelvic tilt reduction. There were no major complications, 4 anterior hematomas (2 drainages, 2 surgical treatments), 2 partial neurological deficits (1 L4, 1 L5). We had no implant TDR complications, no displacements, no explanation required. Two cases of screw revised, 6 posterior device removal (2 total, 4 partial), 2 complementary laminectomies, and 2 extension of posterior instrumentation. CONCLUSIONS The choice of TDR, with a semi–constrained prosthesis and loss restoration of motion and sagittal balance in adult scoliosis. It shows interest in the results, as a clinical and mobility point of view that is maintained in long term follow-up. That allows to avoid the pelvic fixation in majority of cases, escaping for the clinical bad results and complications of the lawn posterior constructions extend it to the pelvis and also illuminates the risks of posterior transpedicular osteotomies. In elderly people, there is a need for osteodensitometry measurement and eventually cementopalsty of the vertebra that receive the prosthesis. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.