370 - Global Cervical Sagittal Alignment, Balance and Segmental Contribution...

#370 Global Cervical Sagittal Alignment, Balance and Segmental Contribution: Radiographic Outcomes of One and Two Level Disc Replacement with NuNec and Prestige LP Implants

Oral Posters: Cervical Arthroplasty

Presented by: A. Berg

Author(s):

R.P. Jeavons (1)
A.J. Berg (1)
C.D. Jensen (1)
G. Reddy (1)
T. Friesem (1)

(1) University Hospital of North Tees, Spinal Unit, Stockton on Tees, United Kingdom

Abstract

Introduction: Cervical disc replacement provides an alternative to fusion; maintaining motion, restoring alignment and relieving stenosis related symptoms. We present radiographic outcome data collected following the use of different systems.

Aims: Assess the ability of different disc replacements to improve global sagittal alignment and balance in the cervical spine and assess the segmental contribution of individual replaced levels.

Methods: Review of radiographs regarding NuNec (Pioneer Surgical Technology. USA) and Prestige LP (Medtronic Ltd. UK) cervical disc replacements over 5 years.

189 patients included in the study.

One level: NuNec (n=41); Prestige (n=29);

Two level: NuNec (n=61); Prestige (n=58);

Lateral neutral, flexion and extension radiographs analysed (pre-operative, initial post-operative, recent follow up) for:

Global Cervical Sagittal Alignment

- Cobb angle from inferior end plates of C2 - C7 on lateral neutral radiographs

Global Cervical Sagittal Balance.

- Difference between Cobb angle from inferior end plates of C2 - C7 in flexion and extension.

Segmental Contribution

- Posterior vertebral body angle of replaced segments.

Results: At current follow up.

Mean time since surgery:

1 level NuNec = 28.8 months; 2 level NuNec = 28.8 months.

1 level Prestige =50 months; 2 level Prestige = 47.8 months.

Conclusions: Both implants maintain global sagittal alignment but lose global sagittal balance in 1 and 2 level procedures. Prestige shows a greater loss in global sagittal balance than NuNec in the 2 level series. Individual contribution of each segment does not account for the loss of global sagittal balance in the 1 level series but does mirror the greater motion loss in the 2 level Prestige group.

Table 1

Table 2