title: Calcium homeostasis influences radiological fracture healing in postmenopausal women.
abstract: BACKGROUND
  Recent studies suggest that calcium and 25-[OH]-cholecalciferol represent substantial co-factors in fracture healing. However, there still seems to be no sustainable consensus regarding the influence on fracture healing patterns. In this study, the influence of calcium and vitamin D levels on fracture callus formation was prospectively analysed using pQCT scan.
  
  
  METHODS
  94 postmenopausal females with distal radius fractures and consecutive surgery were included. Calcium, 25-[OH]-cholecalciferol, parathyroid hormone and bone-specific alkaline phosphatase levels were obtained prior surgical treatment and after 6 weeks. A pQCT scan was performed on both sites. Bone mineral density and fracture callus area were determined after detecting the outer border contour at a threshold of 280 mg/ccm. Patients received daily supplements of 1000 mg calcium and 880 IU 25-[OH]-cholecalciferol.
  
  
  RESULTS
  Mean 25-[OH]-cholecalciferol level was 19.61 ± 21.87 ng/ml, mean parathyroid hormone level was 52.6 ± 58.9 ng/l and mean Ca level was 2.23 ± 0.35 mmol/l. After 6 weeks of supplementation a significant increase of calcium (p < 0.001) and 25-[OH]-cholecalciferol (p < 0.001), and a significant decrease of parathyroid hormone (p < 0.001) levels were observed. Sixth week follow-up fracture callus area correlated significantly with postoperative normal range calcium levels on the fractured site (p = 0.006). Bone mineral density correlated with age (p < 0.001), but not with calcium and 25-[OH]-cholecalciferol levels after 6 weeks. All fractures presented timely adequate callus formation.
  
  
  CONCLUSIONS
  Calcium and parathyroid hormone serum levels influence fracture callus area interpreted as fracture callus formation patterns. Calcium levels within physiological range accounted for highest fracture callus area. Therefore, a balanced calcium homeostasis is required for appropriate callus formation.
authors.affiliation: Department of Trauma, Hand and Reconstructive Surgery, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany. janphilippkolb@me.com
authors.forename: J P
authors.initials: JP
authors.lastname: Kolb
authors.forename: A F
authors.initials: AF
authors.lastname: Schilling
authors.forename: J
authors.initials: J
authors.lastname: Bischoff
authors.forename: A
authors.initials: A
authors.lastname: Novo de Oliveira
authors.forename: A
authors.initials: A
authors.lastname: Spiro
authors.forename: M
authors.initials: M
authors.lastname: Hoffmann
authors.forename: M
authors.initials: M
authors.lastname: Amling
authors.forename: J M
authors.initials: JM
authors.lastname: Rueger
authors.forename: W
authors.initials: W
authors.lastname: Lehmann
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000469:Alkaline Phosphatase / Q000097:blood; D015519:Bone Density; D002146:Bony Callus / Q000503:physiopathology; D002112:Calcifediol / Q000097:blood* / Q000627:therapeutic use; D002118:Calcium / Q000097:blood* / Q000627:therapeutic use; D019587:Dietary Supplements; D005260:Female; D017102:Fracture Healing / Q000502:physiology*; D006706:Homeostasis; D006801:Humans; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood*; D017698:Postmenopause; D011885:Radius Fractures / Q000097:blood* / Q000503:physiopathology* / Q000601:surgery; D014057:Tomography, X-Ray Computed
chemical_list: D010281:Parathyroid Hormone; D000469:Alkaline Phosphatase; D002112:Calcifediol; D002118:Calcium