49 - The Comparison of Sagittal Cervical Alignment among Arthroplasty and H...

#49 The Comparison of Sagittal Cervical Alignment among Arthroplasty and Hybrid Construct and Cage Alone in Two-level Cervical Disc Disease

Cervical ADR

Poster Presented by: H.S. Oh

Author(s):

H.S. Oh (1)
B.-W. Hwang (1)
S.-J. Park (1)
S.-J. Lee (1)

(1) Busan Wooridul Spine Hospital, Busan, Korea, Republic of

Abstract

Background: The maintenance and/or improvement of sagittal balance are essential in preserving functionality after reconstructive spinal procedures. We wanted to know that which construct has more benefits in the respect of cervical lordosis and dynamic motion. The purpose of this study is to evaluate the radiological outcomes among these five groups.

Methods: Between December 2006 and May 2012, we focused the patients who underwent 2-level cervical surgery using two arthroplastys (2A), hybrid construct as one arthroplasty and one cage (1A1C), hybrid construct with zero-profile cage (1A1Z), two single cages (2C), and two zero-profile cages (2Z). There were 13 patients in 2A, 15 in 1A1C, 12 in 1A1Z, 11 in 2C and 11 in 2Z. The all group, except 1A1Z, had radiologically followed up more than 2 years. The data was investigated retrospectively and consecutively. ProDisc-C and Prestige was used for arthroplasty in 2A and 1A1C, Baguera C was used in 1A1Z, and the PEEK cage was used for fusion construct in 1A1C and 2C. Cervical lordosis at the device level, cranial and caudal adjacent level, total cervical lordosis (C2-C7), and sagittal rotatory angle (SRA) were measured for radiologic outcome. All patients underwent 3D-reconstructed computed tomography(CT) scan at postop 2 years. Heterotropic ossification was investigated during follow-up period and radiologically correlated segmental height and device insertion angle, artificial disc replacement(ADR) rotator angle was also investigated.

Results: Among the five groups, there was no statistical significance regarding the whole lordosis (p=0.716) and segmental lordosis (p=0.557). But the involving artificial disc replacement groups (2A, 1A1C, 1A1Z) had more lordotic results than fusion groups (2C, 2Z). In the results of whole SRA, there was statistically difference between 2A and 2C groups (p=0.003). In segmental SRA, there was statistically difference among 2A, 1A1C and 1A1Z groups at post-op 1 year (p=0.004). But there was no statistically difference between 2A and 1A1C group at 2 years (p=0.316). In ADR group, intraoperative ADR condition as the change of segmental height and device angle was statistically correlated with device function (ADR rotatory angle) and HO grade. When compared between 1A1C and 1A1Z, high correction of segemtal lordosis may affect adversely to the adjacent ADR function.

Conclusions: We concluded that there was the no statistically difference in restoration of sagittal cervical alignment among all groups, although the involving ADR group (2A, 1A1C, 1A1Z) has better and sustained lordosis. In SRA, the involving ADR group, especially 2A, has the difference in the restoration and maintenance of SRA.