Evidence map›Paper›PMID 41371947›Full record

ArticleInternational journal of spine surgery2026

Biomechanical Effect of a Lumbar Interfacet Cage (FFX) Device When Combined With Pedicle Screw Constructs: A Finite Element Study.

Rachid Saddiki, Alexandre Dhenin, Ludovic Montron, Thierry Dufour, Lionel Simon, Romain Buttin, Robin Srour

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Article in International journal of spine surgery, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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4 · The record

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5 · Who and what money

Authors and funding

7 authors.

Rachid SaddikiOrthopedic Surgery, Clinique d'Occitanie, Muret, France.
Alexandre DheninOrthopedic Surgery, Clinique Saint Jean - Sud de France, Montpellier, France.
Ludovic MontronOrthopedic Surgery, Clinique Belharra, Bayonne, France.
Thierry DufourNeurosurgery, Hôpital Privé Geoffroy Saint-Hilaire, Paris, France.
Lionel SimonEngineering, LS Conseil & Formation, Lyon, France.
Romain ButtinEngineering, LS Conseil & Formation, Lyon, France.
Robin SrourNeurosurgery, Hôpitaux Civils de Colmar, Colmar, France robin.srour@ch-colmar.fr.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundExcessive stress on the pedicle screws or inadequate load-sharing with surrounding spinal components increases the mechanical demand and the risk of loosening or breakage. The lumbar interfacet cage (FFX device) is designed to prevent spinal instability and facet motion, enhancing facet joint fusion.

objectiveThe present study aimed to compare the biomechanical performance of a lumbar interfacet cage when associated with a pedicle screw construct, compared with pedicle screws alone and pedicle screws associated with lumbar interbody cages, using the FE method.The authors hypothesized that implanting additional lumbar interfacet cages would reduce mechanical stress on pedicle screw constructs. STUDY

designComparative biomechanical study by finite element (FE) method.

methodsA validated FE model for the lumbar spine was used to assess stress variations on pedicle screw constructs and discs in the prefusion stage following surgery. Modeled scenarios included (1) a short pedicle screw construct (L4/L5), with and without bilateral lumbar interfacet cage device placement and with or without interbody fusion cages, and (2) a long pedicle screw construct (L2-S1), with and without lumbar interfacet cage placement at all levels.

resultsBoth facet and interbody cage placement in conjunction with short L4/L5 pedicle screw constructs significantly reduced mechanical loading on pedicle screws and rods compared with the pedicle screw construct alone. The placement of lumbar interfacet cages used in combination with pedicle screw constructs in long L2 to S1 constructs also significantly reduced stress loading on pedicle screws and rods, especially at the lower extremity of the construct.

conclusionsThe placement of facet cages in conjunction with pedicle screws can improve the load distribution of the construct, enhancing its stability and durability. This approach may help reduce the rate of pedicle screw loosening and breakage, which are complications commonly associated with long pedicle screw constructs. CLINICAL RELEVANCE: Pedicle screw loosening and breakage remain frequent complications in lumbar fusion, especially in long constructs. This finite element analysis demonstrates that adding lumbar interfacet cages to pedicle screw constructs significantly reduces mechanical stress on screws and rods. By improving load distribution in both short and long constructs, the technique may decrease the risk of screw loosening and implant failure before fusion, potentially improving construct durability and reducing reoperation rates. LEVEL OF EVIDENCE: 5:

Indexed as

biomechanicsFFXfinite element analysislumbar facet jointlumbar spinepedicle screw breakagepedicle screw looseningPLIFTLIF

Identifiers

PMID41371947
PMCPMC13036454

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.