Cervical sagittal alignment in patients with dropped head syndrome

Acute Progressive Pediatric Post-Traumatic Kyphotic Deformity

Cervical kyphosis is a rare entity with challenging management due to the limitations of pediatric age, along with a growing spine. The pathogenesis is made up of a large group of congenital, syndromic and acquired deformities after posterior element deterioration or as a result of previous trauma or surgery. In rare progressive cases, kyphotic deformities may result in severe "chin-on-chest" deformities with severe limitations. The pathogenesis of progression to severe kyphotic deformity after minor hyperflexion trauma is not clear without an obvious MR pathology; it is most likely multifactorial. The authors present the case of a six-month progression of a pediatric cervical kyphotic deformity caused by a cervical spine hyperflexion injury, and an MR evaluation without the pathology of disc or major ligaments. Surgical therapy with a posterior fixation and fusion, together with the preservation of the anterior growing zones of the cervical spine, are potentially beneficial strategies to achieve an excellent curve correction and an optimal long-term clinical outcome in this age group.

Cervical sagittal balance after consecutive three-level hybrid surgery versus anterior cervical discectomy and fusion: radiological results from a single-center experience

INTRODUCTION

According to the different numbers and relative locations of cervical disc replacement (CDR) and anterior cervical discectomy and fusion (ACDF), three-level hybrid surgery (HS) has many constructs. The purpose of this retrospective study was to compare the sagittal alignment parameters of HS and ACDF for cervical degenerative disc disease (CDDD) and the association of the respective parameters.

METHODS

This study involved patients with three-level CDDD who underwent ACDF or HS at our institution between June 2012 and August 2021. This follow-up included one-level CDR and two-level ACDF (type I group), two-level CDR and one-level ACDF (type II group) and three-level ACDF. Cervical sagittal alignment parameters included cervical lordosis (CL), segment alignment (SA), T1 slope (T1S), C2-C7 sagittal vertical axis (SVA), T1S-CL, C2 slope (C2S), occipital to C2 angle (O-C2A) and segment range of motion (ROM). Postoperative complications included adjacent segment degeneration, imbalance, prosthetic subsidence and heterotopic ossification.

RESULTS

The three groups with a total of 106 patients were better matched in terms of demographics. Patients who underwent HS had significantly higher CL than those who underwent ACDF at 1 week, 6 months, 12 months and the final follow-up after surgery, as well as significantly better SA at 12 months and the final follow-up. There was no significant difference in T1S, SVA, T1S-CL, C2S, O-C2A or segment ROM among the three groups after surgery. The T1S-CL was significantly associated with C2S in the type I and type II groups at the preoperative and final follow-up. There was no significant difference in postoperative complications among the three groups.

CONCLUSIONS

Most improvements in cervical sagittal alignment (CL, SA, T1S, SVA, T1S-CL, C2S, O-C2A, and segmental ROM) were observed in all three groups postoperatively. HS was more advantageous than ACDF in the maintenance of postoperative CL and SA. Thus, three-level HS may be better for maintaining cervical curvature. The number of replacement segments differed in those who underwent HS but did not affect the correlation between T1S-CL and C2S, both of which are well balanced.

Global Sagittal Spinal Compensation for Dropped Head Alignment

STUDY DESIGN

This is a retrospective radiographic study of a consecutive series of cases in patients with dropped head syndrome (DHS) at a single tertiary referral center.

OBJECTIVE

The aim was to clarify the compensation among parameters of spinal sagittal alignment in patients with DHS.

SUMMARY OF BACKGROUND DATA

The treatment strategy for DHS should vary according to the types of global sagittal spinal alignment. However, theoretical evidence in consideration of spinal sagittal compensation against the dropped head condition is lacking.

MATERIALS AND METHODS

One hundred sixteen patients diagnosed with isolated neck extensor myopathy were enrolled. Radiographic measurements were made, including parameters of spinal sagittal alignment. The patients were divided into three groups according to sagittal spinal balance: C7SVA (sagittal vertical axis) ≥ +50 mm (P-DHS; positive imbalanced DHS), -50 mm ≤C7SVA <+50 mm (B-DHS; balanced DHS), and C7SVA <-50 mm (N-DHS; negative imbalanced DHS). Correlations among the various spinal parameters were analyzed.

RESULTS

Among all types of DHS, there was no correlation between C2-C7 angle (C2-C7A) and T1 slope. In B-DHS, other correlations among the adjacent spinal segments were maintained. In N-DHS, there was no correlation between C2-C7A and TK, and in P-DHS, there was also no correlation between TK and lumbar lordosis.

CONCLUSIONS

The loss of compensation at the cervicothoracic junction was observed in all DHS types. B-DHS showed decompensation only at the cervicothoracic junction. N-DHS presented additional decompensation of the thoracic spine, and P-DHS showed decompensation between the thoracic and lumbar spine. Evaluation of global sagittal spinal balance is important for determining global spinal compensation associated with DHS and when considering treatment strategy.