PEEK cages versus PMMA spacers in anterior cervical discectomy: comparison of fusion, subsidence, sagittal alignment, and clinical outcome with a minimum 1-year follow-up.

Jan-Helge Klingler,Evangelos Kogias,Ronen Sircar,Christian Scheiwe,Ulrich Hubbe,Florian Volz,Marie T Krüger,Christoph Scholz

doi:10.1155/2014/398396

Abstract

Purpose. To compare radiographic and clinical outcomes after anterior cervical discectomy in patients with cervical degenerative disc disease using PEEK cages or PMMA spacers with a minimum 1-year follow-up. Methods. Anterior cervical discectomy was performed in 107 patients in one or two levels using empty PEEK cages (51 levels), Sulcem PMMA spacers (49 levels) or Palacos PMMA spacers (41 levels) between January, 2005 and February, 2009. Bony fusion, subsidence, and sagittal alignment were retrospectively assessed in CT scans and radiographs at follow-up. Clinical outcome was measured using the VAS, NDI, and SF-36. Results. Bony fusion was assessed in 65% (PEEK cage), 57% (Sulcem), and 46% (Palacos) after a mean follow-up of 2.5 years. Mean subsidence was 2.3–2.6 mm without significant differences between the groups. The most pronounced loss of lordosis was found in PEEK cages (−4.1°). VAS was 3.1 (PEEK cage), 3.6 (Sulcem), and 2.7 (Palacos) without significant differences. Functional outcome in the PEEK cage and Palacos group was superior to the Sulcem group. Conclusions. The substitute groups showed differing fusion rates. Clinical outcome, however, appears to be generally not correlated with fusion status or subsidence. We could not specify a superior disc substitute for anterior cervical discectomy. This trial is registered with DRKS00003591.

Highlights

Cervical degenerative disc disease includes disc herniation and spinal canal stenosis and is a common cause of neck pain with radicular and myelopathic symptoms
We retrospectively identified 225 patients in our database of a single center who underwent anterior cervical discectomy (ACD) without anterior plating for cervical degenerative disc disease with or without posterior osteophytes between January 2005 and February 2009
Radicular symptoms were present in 87 patients (81.3%) and myelopathic symptoms were present in 25 patients (23.4%). 73 patients were operated on in one level and 34 patients in two levels leading to a total of 141 operated levels

Summary

Introduction

Cervical degenerative disc disease includes disc herniation and spinal canal stenosis and is a common cause of neck pain with radicular and myelopathic symptoms. If cervical degenerative disc disease is limited to one or two levels, an anterior cervical discectomy (ACD) is usually performed including decompression of neural structures and implantation of a disc substitute. No disc substitute or an iliac crest autograft was used. Iliac crest autograft was found to provide higher fusion rates than other substitutes and led to relevant donor site morbidity [1]. As part of further development, bone cement was implanted into the intervertebral disc space in order to restore segmental height and to avoid donor site morbidity [2,3,4,5,6,7,8]. The implantation of an artificial disc is a further surgical option; a clear superiority over ACD and fusion, has not been specified [28]

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