Anterior and lateral lumbar interbody fusion supplemented with posterior pedicle screws is a common construct for the operative management of many degenerative lumbar diseases. While standalone interbody cages can promote fusion, posterior stabilization provides additional biomechanical stability. Supplementing interbody fusion with posterior fixation has been shown to reduce range of motion, improve sagittal alignment, and provide higher fusion rates compared to interbody cages alone, typically with low complication rates [
1,
2]. However, pedicle screw construct loosening and breakage may occur and are common causes for revision procedures [
3]. These failures are often secondary to pseudarthrosis resulting from non-union, as continual stresses on a non-fused segment may lead to construct complications over time. The incidence of pedicle screw loosening in the literature varies considerably, generally ranging from 6 to 15% [
4,
5]. The clinical course of patients with screw loosening is generally favorable. However, revision rates ranging from 1 to 5% are typical, with some studies reporting up to 16%, mainly due to screw-related chronic pain [
5,
6]. These associated risks are higher in patients with low bone density [
7]. Numerous attempts have been made to reduce these failure modes, such as the use of high-performance biomaterials, optimized design parameters, and augmentation of the screw-bone interface using allograft, cement, expandable features, and hydroxyapatite coating. However, these attempts have not translated into improved clinical outcomes [
10,
11]. There is a continued need for fixation options that provide the immediate stability of pedicle screw constructs without the associated failure modes.
There has been growing interest in using computational methods such as finite element analysis (FEA) to enhance the understanding of the biomechanical characteristics of spinal implants [
12‐
14]. Unlike clinical studies that rely on patient outcomes and postoperative observations, FEA allows researchers to simulate and analyze the stress, strain, and displacement patterns within the spine and implant components. By precisely controlling the simulation parameters, FEA enables investigations into the potential causes of implant failure, loosening, and complications that may be difficult to explore in a clinical study. Furthermore, FEA facilitates comparative analyses to directly compare the biomechanical effects between different implant designs, implant locations, or surgical approaches [
15].
The current FEA study evaluated an FDA-cleared polyetheretherketone (PEEK) strap that provides circumferential cortical fixation by utilizing the strongest elements of the posterior lumbar spine (lamina, superior articular process, and inferior articular process), which are anchored to the pedicle. Using a traditional open or minimally invasive approach, the cortico-pedicular posterior fixation (CPPF) device is implanted through two intersecting bone tunnels in the posterior column, providing immediate stability during lumbar fusion procedures. A hypothetical advantage of this device is the potential for anterior load transfer, which may enhance fusion rates by promoting bone growth and facilitating the incorporation of interbody devices [
16]. This study aimed to compare the biomechanical characteristics of stability and load-sharing between the CPPF device and a conventional pedicle screw system (PSS) in different instrumentation scenarios using FEA.