Impairment of early fracture healing by skeletal muscle trauma is restored by FK506

Brady J. Hurtgen, Beth E.P. Henderson, Catherine L. Ward, Stephen M. Goldman, Koyal Garg, Todd O. McKinley, Sarah M. Greising, Joseph C. Wenke, Benjamin T. Corona

Research output: Contribution to journalArticlepeer-review

31 Scopus citations

Abstract

Background: Heightened local inflammation due to muscle trauma or disease is associated with impaired bone regeneration. Methods: We hypothesized that FK506, an FDA approved immunomodulatory compound with neurotrophic and osteogenic effects, will rescue the early phase of fracture healing which is impaired by concomitant muscle trauma in male (~4 months old) Lewis rats. FK506 (1 mg/kg; i.p.) or saline was administered systemically for 14 days after an endogenously healing tibia osteotomy was created and fixed with an intermedullary pin, and the overlying tibialis anterior (TA) muscle was either left uninjured or incurred volumetric muscle loss injury (6 mm full thickness biopsy from middle third of the muscle). Results: The salient observations of this study were that 1) concomitant TA muscle trauma impaired recovery of tibia mechanical properties 28 days post-injury, 2) FK506 administration rescued the recovery of tibia mechanical properties in the presence of concomitant TA muscle trauma but did not augment mechanical recovery of an isolated osteotomy (no muscle trauma), 3) T lymphocytes and macrophage presence within the traumatized musculature were heightened by trauma and attenuated by FK506 3 days post-injury, and 4) T lymphocyte but not macrophage presence within the fracture callus were attenuated by FK506 at 14 days post-injury. FK506 did not improve TA muscle isometric torque production Conclusion: Collectively, these findings support the administration of FK506 to ameliorate healing of fractures with severe muscle trauma comorbidity. The results suggest one potential mechanism of action is a reduction in local T lymphocytes within the injured musculoskeletal tissue, though other mechanisms to include direct osteogenic effects of FK506 require further investigation.

Original languageEnglish (US)
Article number253
JournalBMC Musculoskeletal Disorders
Volume18
Issue number1
DOIs
StatePublished - Jun 12 2017
Externally publishedYes

Keywords

  • Adaptive immune response
  • Composite injury
  • Immunomodulation
  • Inflammation
  • Musculoskeletal
  • Open fracture
  • Orthopaedic trauma
  • Skeletal muscle injury
  • Tacrolimus
  • Volumetric muscle loss

ASJC Scopus subject areas

  • Rheumatology
  • Orthopedics and Sports Medicine

Fingerprint

Dive into the research topics of 'Impairment of early fracture healing by skeletal muscle trauma is restored by FK506'. Together they form a unique fingerprint.

Cite this