Does hybrid fixation prevent junctional disease after posterior fusion for degenerative lumbar disorders? A minimum 5-year follow-up study

Abstract

Purpose Medium-to long-term retrospective evaluation of clinical and radiographic outcome in the treatment of degenerative lumbar diseases with hybrid posterior fixation. Methods Thirty patients were included with the mean age of 47.8 years (range 35 to 60 years). All patients underwent posterior lumbar instrumentation using hybrid fixation for lumbar stenosis with instability (13 cases), degenerative spondylolisthesis Meyerding grade I (6 cases), degenerative disc disease of one or more adjacent levels in six cases and mild lumbar degenerative scoliosis in five patients. Clinical outcomes were evaluated using Oswestry disability index (ODI), Roland and Morris disability questionnaire (RMDQ), and the visual analog scale (VAS) pain scores. All patients were assessed by preoperative, postoperative and follow-up standing plain radiographs and lateral X-rays with flexion and extension. Adjacent disc degeneration was also evaluated by magnetic resonance imaging (MRI) at follow-up.Results At a mean follow-up of 6.1 years, we observed on X-rays and/or MRI 3 cases of adjacent segment disease (10.0 %): two of them (6.6 %) presented symptoms and recurred a new surgery. The last patient (3.3 %) developed asymptomatic retrolisthesis of L3 not requiring revision surgery. The mean preoperative ODI score was 67.6, RMDQ score was 15

Evaluation of a Hybrid Dynamic Stabilization and Fusion System in the Lumbar Spine: A 10 Year Experience

“…DTO implantation is a good alternative to rigid fixation in the carefully selected patient, being ideal for those patients with critical spinal instability and adjacent level pathology of lesser severity that requires decompression but not necessarily rigid fixation. Overall, data regarding this hybrid system is limited, but some small retrospective reviews indicate that DTO implants can alleviate back pain with ASD reported in 10.0% and 12.5% of patients at five-year and mean eight-month follow-ups, respectively [ 13 - 14 ]. Lee, et al recently compared ASD development between rigid fixation and hybrid fusion to dynamic stabilization at two-year follow-up and found that hybrid systems delayed, but did not prevent, ASD [ 24 ].…”

“…Of the implants, two required conversion to formal arthrodesis, one became infected, one required the implantation of an intrathecal pump, and two exhibited signs of screw loosening [ 12 ]. More recently, Baioni, et al reported no cases of implant breakage or screw loosening in five-year follow-up with a 30 patient cohort of DTO implants [ 14 ]. In our previous analysis, we reported treatment failure in 12.5% of patients implanted with DTO [ 13 ].…”

“…Dynesys screws (6.25 mm in diameter and 45 to 55 mm in length) were placed under real-time fluoroscopy in a lateral-to-medial trajectory at the base of the transverse process as to avoid facet damage [ 14 ]. Longer screws were utilized when possible, depending on the patient’s vertebral anatomy.…”

“…Instrumented fusion was performed by placing screws bilaterally into the pedicles with a bony autograft between segments. Optima screws (6.0 to 7.0 mm in diameter and 45 to 55 mm in length) were attached posteriorly with a standard 6 mm titanium rod [ 14 ]. The Dynesys dynamic stabilization system and Optima rigid fixation system were separated by a transition pedicle screw.…”

Biomechanical effects of hybrid stabilization on the risk of proximal adjacent-segment degeneration following lumbar spinal fusion using an interspinous device or a pedicle screw–based dynamic fixator

“…27,28 Based on this evidence for ASD, the concept of hybrid stabilization comprising rigid fixation and dynamic stabilization has emerged. 2 Hybrid stabilization is generally classified into interspinous device (ISD)-based hybrid stabilization (IH; interspinous process stabilizer with conventional fusion) and pedicle screw-rod-based hybrid stabilization (PH; pedicle screw-rod construct with flexible rod at the adjacent upper segment). Several retrospective clinical studies 1,20,25 have demonstrated the effectiveness of IH and PH in preventing ASD.…”