SLR - November 2023 - Cohen
Title: The Modified Lapidus Fusion: A Systematic Review of Biomechanical StudiesReference: Riegger M, Habib N, Testa EA, Müller J, Guidi M, Candrian C. The modified Lapidus fusion: a systematic review of biomechanical studies. EFORT Open Rev. 2023 Apr 25;8(4):162-174. doi: 10.1530/EOR-22-0069. PMID: 37097047; PMCID: PMC10155126.
Level of Evidence: Level 1 – Systematic Review
Scientific Literature Review
Reviewed By: David Cohen
Residency Program: East Liverpool City Hospital
Podiatric Relevance: This article should be interesting to the podiatric surgeon because it compares many different fixation methods for the modified Lapidus procedure to assess which method has the greatest biomechanical stability.
Methods: A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis. After a comprehensive literature search was done using PubMed/Medline, Embase, Google Scholar and the Cochrane Library, 17 articles were included that met inclusion criteria,a biomechanical study comparing different types of MTC joint arthrodesis using cadaveric studies or sawbone studies. No specific type of fixation was excluded. Only studies were excluded if they were not done on cadaveric studies or sawbones or if they were comparing the Lapidus technique to the modified Lapidus technique. All these fixation techniques were compared to see which ones had better outcomes and better biomechanical stability based on Load to failure, stiffness and compressive forces. The search was updated until September 2021.
Results: Of the 17 included articles, 10 were cadaveric studies (56.3%) and 7 were polyurethane foam type IV sawbone studies (43.7%). The studies were compared in different ways. Studies that compared crossing screws vs a plate showed that crossing screws were a better biomechanical construct than a plate on its own, but if you throw a compression screw outside the plate, that constructs has better biomechanical stability than the crossing screws. Different plating methods were compared showing that a plantar or medial plate showed better biomechanical stability and again that a compression screw outside the plate was superior. Staple fixation was also compared with results showing that 2 staples is better than 1 staple and better than a plate construct, but no compression screw was used in the plating constructs. Interosseous fixation methods were also compared with results showing that they are inferior to crossed screws and plating constructs.
Conclusions: The 2 crossed screws construct is still a fixation option, but the authors conclude that there is strong evidence that a plate construct with compression screw provides superior stability and biomechanical advantage. The authors also conclude that there is strong evidence that plantar plates seem to be advantageous compared to dorsal and dorsomedial plating. Based on the results of this study I would agree that a plate construct with compression screw is superior, but this study has some limitations. This study used studies that used cadaveric models and sawbone models. These 2 models are different from “in vivo” bone. Another limitation was that plates of many different sizes and amounts of holes were used in comparison with crossed screws, staples or internal fixation. These different plates were not compared with each other to see if there is a plate construct that is better than the rest. This study does help you make a better choice on fixation for your patients.