Topping-off technique prevents aggravation of degeneration of adjacent segment fusion revealed by retrospective and finite element biomechanical analysis

Abstract

AimThe aim of this study was to evaluate the effect of the Topping-off technique in preventing the aggravation of degeneration caused by adjacent segment fusion.MethodsClinical parameters of patients who underwent L5-S1 posterior lumbar interbody fusion + interspinous process at L4-L5 (PLIF + ISP) with the Wallis system (Topping-off group) were compared retrospectively with those of patients who underwent solely PLIF. Pre- and post-operative x-ray measurements, visual analogue scale (VAS) scores, and Japanese Orthopaedic Association (JOA) scores were assessed in all subjects. Normal L1-S1 lumbosacral finite element models were established in accordance with the two types of surgery in our study, respectively. Virtual loading was added to assess the motility, disc pressure, and facet joint stress of L4-L5.ResultsThere were 22 and 23 valid cases included in the Topping-off and PLIF groups. No degeneration was observed in either group. Both VAS and JOA scores improved significantly post-operatively (P < 0.01). The intervertebral angle and lumbar lordosis of L4-L5 were both significantly increased (t = −2.89 and −2.68, P < 0.05 in the Topping-off group and t = −2.25 and −2.15, P < 0.05 in the PLIF group). In the Topping-off group, x-ray in dynamic position showed no significant difference in the angulation or distance of the anterior movement of the L4-L5 segment. The angle of hyper-extension and distance of the posterior movement of L4 were significantly decreased. In the PLIF group, both hyper-flexion and hyper-extension and posterior movement were increased significantly. In finite element analysis, displacement of the L4 vertebral body, pressure of the annulus fibrosus and nucleus pulposus, and stress of the bilateral facet joint were less in the Topping-off group under loads of anterior flexion and posterior extension. Facet joint stress on the left side of the L4-L5 segment was also less in the Topping-off group under left flexion loads.ConclusionShort-term efficacy and safety between Topping-off and PLIF were similar, whilst the Topping-off technique could restrict the hyper-extension movement of adjacent segments, prevent back and forth movement of proximal vertebrae, and decrease loads of intervertebral disc and facet joints.

Could the Topping-Off Technique Be the Preventive Strategy against Adjacent Segment Disease after Pedicle Screw-Based Fusion in Lumbar Degenerative Diseases? A Systematic Review

“…The “topping-off” technique provides a transitional zone between caudal rigid fused segment and cephalad mobile unfused spines, which may decrease the incidence of ASD [10, 11]. Based on posterior dynamic stabilization system reported by Khoueir et al [12], the Dynesys construct belongs to hybrid stabilization device; Wallis and DIAM belong to posterior interspinous device.…”

Topping-Off Technology versus Posterior Lumbar Interbody Fusion in the Treatment of Lumbar Disc Herniation: A Meta-Analysis

“…After exclusion of duplicate or irrelevant references, 393 articles were retrieved. Ultimately, 16 studies [11,14,16,18,[21][22][23][24][25][26][27][28][29][30][31][32], including 1372 cases, were selected for analysis after two authors reviewed the full text according to the inclusion and exclusion criteria ( Figure 1). Table 1 shows the characteristics of the included studies.…”

“…Postoperative GLL was evaluated in 5 studies [11,14,23,25,28]. e fixed effect model was applied considering that there is no significant heterogeneity between the two groups (I 2 � 0%).…”

“…At the present study, there have been various flexible systems in spinal motion preservation technology. e topping-off technique is a newly developed surgical technique, which combines rigid fusion with an interspinous process device in the adjacent segment to prevent ASD [14]. However, the comparison between topping-off technique and fusion therapy in postoperative outcomes is controversial due to the lack of clear clinical evidences [13,15,16].…”

Clinical Factors, Disease Parameters, and Molecular Therapies Affecting Osseointegration of Orthopedic Implants

“…Clinical evidence strongly supports bisphosphonate effects on both the intermediate (i.e., periprosthetic bone loss and implant migration) and clinical outcomes. Systemic, long-term use of bisphosphonates significantly reduces the risk of revision in arthroplasty patients 87–97 . For example, in a meta-analysis of 4 studies, THA and TKA patients who used bisphosphonates for a long period had a 50% reduction in their risk of implant revision 94 .…”