# Does Pressurized Carbon Dioxide Lavage Improve Bone Cleaning in Cemented Arthroplasty?
## 4 Discussion
Since we saw similar results for single use carbon dioxide lavage (Group B) compared to single use of pulsatile lavage (Group A) it has to be considered, that using carbon dioxide lavage only, might be faster, less wet and more controlled to saline lavage. Studies showed that using high-pressure lavage to clean contaminated wounds can cause irreversible insult to tissue, resulting in mynecrosis and dystrophic calcification [43; 44]. Even bacteria can be propagated into soft tissue or significant damage to the architecture of the bone can occur [45; 46]. Therefore, lower impact pressure as shown in our investigation can hold advantages. Despite these potential advantages case reports are published showing gas embolisms occurred during femoral intramedullary usage of carbon dioxide lavage [33; 34]. Further investigation focusing on in vivo impact can help revealing, if a specific range of pressure orchestrates all benefits while avoiding complications. In this experimental in vitro study where we compared high-pressure saline lavage to carbon dioxide lavage and its combination, we detected significant lower impact pressure and a deeper cleaning effect with carbon dioxide lavage used additionally to high-pressure pulsatile saline lavage in standardized carbon foam specimens representing cancellous bone. However, these effects were statistically not significant. We found no evidence that using carbon dioxide lavage reduces the effect of saline lavage. Using carbon dioxide lavage only had similar outcomes compared to high-pressure pulsatile lavage. Since aseptic loosening still is the main reason for implant failure due to poor cementing, better cleaning of cancellous bone prior to cementing will have a positive effect on implant durability. In conclusion, using a combination of high-pressure saline lavage followed by carbon dioxide lavage showed a clear tendency of resulting in improved cleaning effects prior to cementing and therefore seems to have a positive effect on stability of endoprosthesis. Further investigation in human bone and larger clinical trials will determine, if using additional carbon dioxide lavage will confirm its positive effect on bone cement interface and therefore on success of endoprosthesis implantation itself. Conceptualization, K.K. and S.J. ; Data curation, K.K., M.S., C.S. and S.J. ; Formal analysis, K.K., S.J. and C.S. ; Methodology, K.K. and S.J. ; Project administration, K.K., S.J. and M.I. ; Writing--original draft, K.K. and S.J. ; Writing--review & editing, K.K., C.S., M.I., M.S., T.G., T.R. and S.J. All authors have read and agreed to the published version of the manuscript. This research received no external funding. Not applicable. The authors declare no pertinent conflict of interest. S.J. reports grants from B Braun Aescalup, Johnson & Johnson Deputy Synthes, Heraeus Medical, Waldemar Link, Peter Brehm and Zimmer Biomet that are not related to the current study. T.G. reports personal fees paid to T.G. during the conduct of the study from Zimmer Biomet, Europe and from Deputy Synthes Orthopadie GmbH, Peter Brehm GmbH, ImplanTec GmbH outside the submitted work. Research grants paid to the institution during the conduct of the study from Zimmer Biomet, Europe, Mathys AG Switzerland, Anika Therapeutics outside the submitted work that are not related to the current study. TR reports research funding/travel expenses and/or paid speaking engagements by the German Federal Ministry of Education and Research (BMBF), The German Federal Ministry for Economic Cooperation and Development (BMZ), Otto Bock Foundation, Stiftung Oskar-Helene-Hein Berlin, DePuy Int, Zimmer, Aescalup/B. Braun, the Vielberth Foundation, German Society of Orthopaedics and Traumatology (DGOU) and the German Association of Orthopaedics and Orthopaedic Surgery (DGOOC). [PERSON] is associate editor of \"Der Orthopadie\" and \"Der Unfallchirurg\" (Springer Heidelberg, Berlin, New York) and member of the International Advisory Board of the Journal of the American Academy of Orthopaedic Surgeons (AAOS).