Aseptic loosening of the option stemmed tibial tray in the Zimmer NexGen LPS total knee arthroplasty system

Rohan M Bhalekar; Stephen R Wells; Matthew Matthew Nargol; Shahrzad Shariatpanahi; Antoni V F Nargol; Susan Waller; Linda Wildberg; Simon Tilley; David J Langton

doi:10.1016/j.knee.2023.12.004

Aseptic loosening of the option stemmed tibial tray in the Zimmer NexGen LPS total knee arthroplasty system

Knee. 2024 Jan 2:47:1-12. doi: 10.1016/j.knee.2023.12.004. Online ahead of print.

Authors

Rohan M Bhalekar¹, Stephen R Wells², Matthew Matthew Nargol³, Shahrzad Shariatpanahi⁴, Antoni V F Nargol⁵, Susan Waller⁶, Linda Wildberg⁷, Simon Tilley⁸, David J Langton⁹

Affiliations

¹ ExplantLab, The Biosphere, Newcastle Helix, Newcastle Upon Tyne NE4 5BX, UK. Electronic address: rohan.bhalekar@gmail.com.
² ExplantLab, The Biosphere, Newcastle Helix, Newcastle Upon Tyne NE4 5BX, UK. Electronic address: stephen.r.wells1989@gmail.com.
³ ExplantLab, The Biosphere, Newcastle Helix, Newcastle Upon Tyne NE4 5BX, UK. Electronic address: nargol@live.co.uk.
⁴ ExplantLab, The Biosphere, Newcastle Helix, Newcastle Upon Tyne NE4 5BX, UK. Electronic address: shahrzadshariat@engineer.com.
⁵ University Hospital of North Tees, Hardwick Rd, Stockton-on-Tees TS19 8PE, UK.
⁶ University Hospital of North Tees, Hardwick Rd, Stockton-on-Tees TS19 8PE, UK. Electronic address: s.waller2@nhs.net.
⁷ University Hospital of North Tees, Hardwick Rd, Stockton-on-Tees TS19 8PE, UK. Electronic address: linda.wildberg@nhs.net.
⁸ University Hospital Southampton NHS Foundation Trust, Tremona Road, Southampton, Hampshire SO16 6YD, UK. Electronic address: Simon.Tilley@uhs.nhs.uk.
⁹ ExplantLab, The Biosphere, Newcastle Helix, Newcastle Upon Tyne NE4 5BX, UK. Electronic address: djlangton22@doctors.org.uk.

PMID: 38171206
DOI: 10.1016/j.knee.2023.12.004

Abstract

Background: We investigated the relationship between the backside deformation of polyethylene (PE) tibial inserts and aseptic loosening of the Option stemmed tibial tray used with Zimmer NexGen posterior-stabilised (PS) devices. We hypothesized that explanted inserts used in PS designs would exhibit greater extents of PE backside deformation than those used in equivalent cruciate retaining (CR) designs and that PE inserts retrieved from total knee arthroplasties (TKAs) revised for aseptic tibial tray loosening would exhibit greater extents of backside deformation than TKAs revised for other reasons.

Methods: A total of 73 explanted fixed-bearing TKAs (42 CR and 31 PS) were examined. PE components underwent geometric examination with a coordinate measuring machine using validated techniques. Multiple regression modelling was used to identify variables associated with revision secondary to aseptic loosing and to determine factors associated with increased PE backside deformation.

Results: PE inserts retrieved from TKAs with aseptic loosening had significantly greater backside deformation than those retrieved from TKAs revised for other reasons (p < 0.001). Greater PE backside deformation was significantly associated with larger tray/insert clearance heights (p < 0.001), thinner inserts (p < 0.001) and PS TKAs (p = 0.001).

Conclusion: PE backside deformation was significantly greater in the PS TKAs. This may provide one explanation for the increased rate of aseptic loosening reported with the Option tibial tray used with the Legacy Posterior Stabilised (LPS) system.

Keywords: Deformation; Knee arthroplasty; Polyethylene; Retrieval analysis; Tibial tray loosening.