Impact of Spinopelvic sagittal alignment on the surgical outcomes of dropped head syndrome: a multi-center study

Abstract

Background Most of the previous studies about the surgical treatment of dropped head syndrome (DHS) are small case series, and their primary outcome measures were cervical alignment parameters. Therefore, little is known about the associations between pre- and postoperative global sagittal alignment in the whole spine and the clinical outcomes of the surgical treatment of DHS. In this study, we investigated the surgical outcomes of DHS, including correction of cervical and global spinal sagittal alignment. Methods This study was a retrospective observational study. Fifteen patients with DHS who had undergone correction surgery were enrolled. Surgical outcomes, including complications and implant failures, were investigated. We assessed cervical alignment parameters as well as spinopelvic global alignment parameters, including pelvic incidence (PI), lumbar lordosis (LL), and C7-sacral sagittal vertical axis (SVA). We examined the changes in these parameters using pre- and posoperative whole spine lateral radiographs. The parameters were compared between the failure and nonfailure groups. Results Recurrence of sagittal imbalance and horizontal gaze difficulty was observed in 6 cases (40%). In all, 3 cases (20%) exhibited a distal junctional failure and required multiple surgeries with extension of fusion. Of all the radiographic parameters compared between the failure and nonfailure groups, significant differences were only observed in pre and postoperative SVA and PI-LL. Conclusions Our results suggest that the global sagittal alignment parameters, including PI-LL and SVA, were different between the patients with failure and non failure, and these parameters might have notable impacts on surgical outcomes. Surgeons should consider PI-LL and SVA while determining the surgical course for patients with DHS.

Cervical sagittal alignment in patients with dropped head syndrome

“…4 Regarding surgery for DHS, Kudo et al reported that pre-and postoperative SVA and PI (pelvic incidence)-LL (lumbar lordosis) were associated with surgical outcomes of patients with DHS. 14 The present study could not analyze operative results because of the inclusion of many non-operative cases. However, our results showed that P-DHS represented low C2-C7A and T1 due to loss of thoraco-lumbar compensation, and also that there was a difference between P-and N-DHS concerning the sagittal spinal compensation mechanism.…”

“…8 In a recent study, Kudo et al analyzed the poor surgical outcome of DHS and proposed consideration of the global spinopelvic sagittal alignment parameters. 14 The purpose of the present study was to analyze the cervical sagittal alignment of DHS from the point of view of global sagittal spinal alignment.…”

“…8 In a recent study, Kudo et al analyzed the poor surgical outcome of DHS and proposed consideration of the global spinopelvic sagittal alignment parameters. 14…”

Management of two patients with dropped head syndrome utilizing anterior-posterior cervical surgery

“…DHS can be classified into three groups based on preoperative radiological parameters; Type 1 (SVA ≤0 mm and PI-LL ≤10°), Type 2 (SVA > 0 mm and PI-LL ≤10°), and Type 3 (PI-LL >10°). [ 5 ] Several surgical strategies for DHS have been reported including; posterior multiple-level fixation or combined anterior and posterior cervical fixation [ Table 2 ]. [ 1 , 2 , 4 , 7 - 9 ] In our two cases of DHS, we chose first to perform posterior cervical facetectomies with pedicle screw application, followed by multilevel ACDF with posterior rod/pedicle/screw fusion.…”

Radiological features of cervical spine in dropped head syndrome: a matched case–control study

“…Hashimoto et al reported that DHS could be classified into two distinct types based on the sagittal vertical axis (SVA) in global alignment: SVA + and SVA− [11]. Other reports suggested that global spine alignment parameters in patients with DHS are related to surgical treatment outcomes [14]. Nonetheless, most previous studies have focused on alignment factors, and few studies have assessed other radiological characteristics in DHS.…”