title: Are OPG and RANKL involved in human fracture healing?
abstract: Human fracture healing is a complex interaction of several cytokines that regulate osteoblast and osteoclast activity. By monitoring OPG (osteoprotegerin) and sRANKL we aimed to possibly predict normal or impaired fracture healing. In 64 patients with a fracture of a long bone serum level of sRANKL and OPG were evaluated with respect to bony union (n=57) or pseudarthrosis (n=7). Measurements were carried out at admission and at 1, 2, 4, 6, 8, 12, 24, and 48 weeks after the injury. Patients' serum levels were compared to 33 healthy controls. Fracture hematoma contained significantly higher sRANKL and OPG concentrations compared to patients serum (p=0.005, p=0.028). OPG level in fracture hematoma was higher compared to the unions serum level (p=0.028). sRANKL was decreased in unions during the observation period. In non-unions sRANKL and OPG levels showed a variable course, with no statistical significance. This is the first study to document the course of OPG and sRANKL in normal and delayed human fracture healing emphasizing its local and systemic involvement. We provide evidence of strongly enhanced OPG levels in patients with a long bone fracture compared to healthy controls. Further, levels of free sRANKL were decreased during regular fracture repair.
authors.affiliation: Medical University Vienna, University Clinic for Trauma Surgery, Währinger Gürtel 18-20, 1090, Vienna, Austria.
authors.forename: Julia
authors.initials: J
authors.lastname: Köttstorfer
authors.forename: Anita
authors.initials: A
authors.lastname: Thomas
authors.forename: Markus
authors.initials: M
authors.lastname: Gregori
authors.forename: Mathias
authors.initials: M
authors.lastname: Kecht
authors.forename: Georg
authors.initials: G
authors.lastname: Kaiser
authors.forename: Stefan
authors.initials: S
authors.lastname: Eipeldauer
authors.forename: Kambiz
authors.initials: K
authors.lastname: Sarahrudi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D017102:Fracture Healing / Q000502:physiology*; D006406:Hematoma / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010010:Osteoclasts / Q000378:metabolism; D053244:Osteoprotegerin / Q000097:blood / Q000502:physiology*; D053245:RANK Ligand / Q000097:blood / Q000502:physiology*
chemical_list: D053244:Osteoprotegerin; D053245:RANK Ligand; C505688:TNFSF11 protein, human
keywords: OPG; RANKL; fracture healing