Clinical and Radiological Outcomes of Anchored Stand-Alone Cage Compared to Conventional Plating in Multilevel Anterior Cervical Discectomy and Fusion: A Systematic Review

Abstract

Multilevel cervical degenerative disc disease (cDDD) is typically treated through anterior cervical discectomy and fusion (ACDF). Traditionally, the plate-cage construct (PCC) has been utilized, though alternatives such as the locking stand-alone cage (LSC) have become popular. This systematic review aims to assess differences in clinical and radiological outcomes between LSC and PCC methods in the ACDF management of multilevel cDDD by aggregating existing literature. A comprehensive search of five electronic databases (PubMed, Medline, Ovid, Embase, and Cochrane) was conducted from 2015 to 2022 following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The comparative studies were assessed using the Methodological Index for Non-randomized Studies (MINORS) criteria and the two randomized controlled trials (RCTs) were assessed using the Jadad scale for RCT. Eight studies met the inclusion criteria, comprising a total cohort of 516 contiguous multilevel cDDD cases treated via ACDF, with 254 (49%) managed with PCC and 262 (51%) treated with LSC. The comparative outcomes assessed included the rate of subsidence and the rate of postoperative dysphagia. The LSC approach exhibited a higher incidence of cage subsidence compared to PCC. Conversely, dysphagia was observed more frequently in patients receiving PCC compared to those treated with LSC. Clinical outcomes and functional scores did not reveal significant differences. Clinical measures such as the Japanese Orthopaedic Association (JOA) score, Neck Disability Index (NDI), visual analog scale (VAS), and Odom's and Robinson's criteria revealed no significant differences between treatment groups in seven of the studies. However, one of the included studies reported a statistically significant improvement in the LSC group for VAS and Odom's criteria. The incidence of cage subsidence in ACDF surgery varies depending on the cage type employed. Among the reviewed studies, the LSC group exhibited a higher incidence of subsidence compared to the PCC group, with the exception of one study that reported no cases of subsidence. Variability in subsidence rates across studies may be attributed to differences in surgical techniques, patient demographics, and follow-up periods. Further research is necessary to investigate associated risk factors and to develop strategies aimed at minimizing this complication in ACDF procedures.

Keywords: anchored; anterior; anterior plate construct; arthrodesis; cervical discectomy; fusion; plate; stand-alone.

Figure 1. Flow diagram of search strategy results conducted per Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

PRISMA [18].

Figure 2. Incidence of postoperative dysphagia.

LSC: locking stand-alone cage; PCC: plate-cage construct. References: Shi et al. (2015) [13]; Y Chen et al. (2016) [14]; Perrini et al. (2017) [15]; Yun et al. (2017) [6]; He et al. (2018) [12]; Zhu et al. (2019) [16]; Scholz et al. (2020) [11]; Z Chen et al. (2021) [17].

Figure 3. Percentage of cage subsidence.

LSC: locking stand-alone cage; PCC: plate-cage construct. References: Shi et al. (2015) [13]; Y Chen et al. (2016) [14]; Perrini et al. (2017) [15]; Yun et al. (2017) [6]; He et al. (2018) [12]; Zhu et al. (2019) [16]; Scholz et al. (2020) [11]; Z Chen et al. (2021) [17].