Comparative Study between a Curved and a Wedge PEEK Cage for Single-level Anterior Cervical Discectomy and Interbody Fusion

Abstract

ObjectiveThis study evaluated the efficiency of a curved polyetheretherketone (PEEK) cage in comparison with a wedge PEEK cage according to radiologic and clinical outcomes in patients with cervical degenerative disease.MethodsA total of 37 patients who suffering from cervical disc disease with radiculopathy or myelopathy were reviewed retrospectively. Seventeen patients were underwent anterior cervical discectomy and interbody fusion with a curved shape PEEK cage (curved cage group), and twenty patients with wedge shape PEEK cage (wedge cage group). Clinical assessment was graded using Odom's criteria, NDI score and VAS score. For radiologic analysis, disc height (DH), segmental angle (SA), subsidence were measured at the preoperative and last follow up.ResultsA comparison of the preoperative and postoperative results revealed improvements after the surgery in the DH and SA in both cage groups. The change of postoperative DH between the preoperative and the last follow-up in wedge cage group and curved cage group was 6.85% and 25.5%, respectively. The change of postoperative SA was 1.75° and 0.95°, respectively. There was no statistically significant difference in the DH and SA between the 2 groups. The subsidence rate in the wedge cage group and curved cage group was 20% and 6%, respectively.ConclusionThe 2 different cage groups showed significant improvements in the disc height, segmental angle and clinical outcomes. However, the shape of PEEK Cage influences the tendency for subsidence. Increasing contact surface area and fitting into two adjacent vertebral body prevent significant subsidence.

The Mismatch Between Bony Endplates and Grafted Bone Increases Screw Loosening Risk for OLIF Patients With ALSR Fixation Biomechanically

“…Clinical studies have shown that the mismatch between BEP and GB triggers complications, including nonunion and cage subsidence (Kim et al, 2012;Hu et al, 2021), and the mechanism of this phenomenon has been well explained. Specifically, biomechanical studies proved that the mismatch between BEP and GB changes the local load transmission pattern, and stress concentration can be observed on both the cranial and caudal sides of BEP and sub-BEP cancellous bone (Agarwal et al, 2013;Zhang et al, 2016).…”

A Systematic Review and Meta-Analysis of Silicon Nitride and Biomaterial Modulus as it Relates to Subsidence Risk in Spinal Fusion Surgery

“…2012 studied curved and wedged shaped PEEK cages and suggested that implant shape was an important risk factor. [35] Similarly, Le et al. 2012 found that wider cages significantly mitigated the risk of subsidence while length was not significant.…”

The improved bioactive n-HA/PA66 cage versus the PEEK cage in anterior cervical fusion: results from a 6-year follow-up and a case-matched study

“…To overcome these drawbacks, a novel porous n-HA/PA66 composite has been developed in recent years [24][25][26][27]. More effort Cage subsidence in ACDF can be influenced by many factors, including end plate preparation, postoperative cervical motion, cage design and material properties, implantation of the anterior cervical plate, and bone mineral density or age [28][29][30][31]. This case-matched study was performed to reduce the confounding factors as much as logically and reasonably possible to examine the impact of the subsidence of material characteristics, and the two groups were well matched.…”