ORIGINAL RESEARCH article

Front. Physiol.

Sec. Skeletal Physiology

Volume 16 - 2025 | doi: 10.3389/fphys.2025.1630268

Metamizole does not affect fracture healing in a murine ischemia model

Provisionally accepted
Christian  SchönbeckChristian Schönbeck1Janine  StutzJanine Stutz1Sebastian  T SchreiberSebastian T Schreiber1Lukas  KellerLukas Keller1Chiara  SiepChiara Siep1Wolfgang  MetzgerWolfgang Metzger1Mario  GiorgiMario Giorgi2Irene  SartiniIrene Sartini2Tobias  FritzTobias Fritz1Tim  PohlemannTim Pohlemann1Michael  D MengerMichael D Menger3Emmanouil  LiodakisEmmanouil Liodakis1Matthias  W. LaschkeMatthias W. Laschke3Marcel  OrthMarcel Orth1*
  • 1Department of Trauma, Hand and Reconstructive Surgery, Saarland University, Homburg, Germany
  • 2Department of Veterinary Sciences, University of Pisa, San Piero a Grado, Italy
  • 3Institute for Clinical and Experimental Surgery, Saarland University, PharmaScienceHub (PSH), Homburg, Germany

The final, formatted version of the article will be published soon.

Metamizole is a commonly used analgesic drug in clinical fracture management, which does not affect the healing process under physiological conditions. However, many fracture patients suffer from co-morbidities resulting in ischemic conditions with impaired bone healing. The effect of metamizole on fracture healing under ischemic conditions has not been analyzed so far. Accordingly, in this study 44 CD-1 mice underwent ligation of the deep femoral artery to induce mild ischemia in the right hind limb. The femur was then fractured and stabilized with an intramedullary lag screw and the animals were daily treated per os with 50 mg/kg metamizole (n = 23) or vehicle (control; n = 21). Serum concentrations of the active metamizole metabolites, 4-methyl-amino-antipyrine (4-MAA) and 4-amino-antipyrine (4-AA), were determined 30, 60 and 90 minutes after administration. Bone healing was analyzed by biomechanical, radiological, histomorphometrical and Western blot analysis at 2 and 5 weeks postoperatively. The plasma level of 4-MAA was high at all time points, whereas 4-AA peaked at 90 minutes after administration. Biomechanical, radiological and histomorphometrical analyses revealed no differences between metamizole-treated and control mice, while both groups showed a delayed fracture healing. Of interest, Western blot analyses of callus tissue showed an increased expression of the pro-angiogenic factor Cyr61 and the osteoanabolic runt-related transcription factor 2 (RUNX2) as well as the osteocatabolic receptor activator of NF-κB ligand (RANKL) in metamizole-treated animals when compared to controls. Taken together, these findings indicate that the application of metamizole does not affect fracture healing under ischemic conditions. Therefore, treatment with this analgesic drug may be also recommended in fracture patients suffering from co-morbidities resulting in tissue ischemia.

Keywords: metamizole, Ischemia, Fracture Healing, bone turnover, Angiogenesis, Mouse

Received: 17 May 2025; Accepted: 30 Jun 2025.

Copyright: © 2025 Schönbeck, Stutz, Schreiber, Keller, Siep, Metzger, Giorgi, Sartini, Fritz, Pohlemann, Menger, Liodakis, Laschke and Orth. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Marcel Orth, Department of Trauma, Hand and Reconstructive Surgery, Saarland University, Homburg, Germany

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