Does the Addition of a Dynamic Pedicle Screw to a Fusion Segment Prevent Adjacent Segment Pathology in the Lumbar Spine?

Abstract

Study DesignRetrospective clinical cohort study.Purpose To investigate whether the combined use of dynamic pedicle screws and polyaxial pedicle screws was effective on adjacent segment pathology (ASP).Overview of LiteratureVarious screw and rod models have been recently developed for preventing adjacent segment disease, and hybrid systems have been described along with posterior instrumentation in the fusion segment. In the literature, although the success of dynamic systems has been demonstrated in non-fusion posterior instrumentation, it remains unclear whether the addition of a screw-based dynamic system to a fusion segment would successfully prevent ASP in the long term.MethodsThe study included 101 patients who underwent surgery for degenerative spine diseases between 2007 and 2014 with lumbar stabilization that used either polyaxial pedicle screws alone or polyaxial pedicle screws plus dynamic stabilization screws (with hinged screw heads). These two patient groups were compared using retrospectively obtained postoperative new clinical findings, Oswestry disability index (ODI) scores, visual analog scale (VAS) scores, and radiological data.ResultsThe proportion of patients with ASP who were radiologically assessed was low (p <0.01) in the group that underwent lumbar stabilization along with dynamic screws. Treatment outcomes were clinically successful in both groups according to ODI and VAS scores, and no significant difference was determined between the groups in terms of clinical ASP (p >0.05).ConclusionsAlthough the combined use of dynamic screws and the static system was radiologically found to be effective for preventing ASP in patients who underwent lumbar fusion with posterior instrumentation, it did not completely eliminate ASP or result in a significant improvement in clinical ASP.

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

“…Eight studies discussed reoperation rates [16,20,22,24,26,30,32,33]. ere was no signi cant heterogeneity in this analysis (I 2 0%).…”

“…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.…”

“…Five studies [22,27,[29][30][31] evaluated postoperative ODI within 3 years ( Figure 7). Because there was a significant heterogeneity in this analysis (I 2 � 83%), random effect model was used in this analysis.…”

“…No betweengroup difference could be found in this analysis (SMD − 0.34; 95% CI − 2.09, 1.40; I 2 � 76%; P � 0.70). [18,22,25,28,[30][31][32]. Random effect model was used in this analysis, because a significant heterogeneity could be found (I 2 � 95%).…”

“…No signi cant betweengroup di erence could be found in the results (OR 1.34; 95% BioMed Research International CI 0.80, 2.26; I 2 1%; P 0.27) ( Figure 11). Dural tear rates were reported in ve studies [22,23,28,29,31]. Fixed e ect model was used in this evaluation [26,30].…”