title: Effect of osteoporosis on bone mineral density and fracture repair in a rat femoral fracture model.
abstract: Osteoporosis (OP) is one of the most prevalent bone diseases worldwide with bone fracture the major clinical consequence. The effect of OP on fracture repair is disputed and although it might be expected for fracture repair to be delayed in osteoporotic individuals, a definitive answer to this question still eludes us. The aim of this study was to clarify the effect of osteoporosis in a rodent fracture model. OP was induced in 3-month-old rats (n = 53) by ovariectomy (OVX) followed by an externally fixated, mid-diaphyseal femoral osteotomy at 6 months (OVX group). A further 40 animals underwent a fracture at 6 months (control group). Animals were sacrificed at 1, 2, 4, 6, and 8 weeks postfracture with outcome measures of histology, biomechanical strength testing, pQCT, relative BMD, and motion detection. OVX animals had significantly lower BMD, slower fracture repair (histologically), reduced stiffness in the fractured femora (8 weeks) and strength in the contralateral femora (6 and 8 weeks), increased body weight, and decreased motion. This study has demonstrated that OVX is associated with decrease in BMD (particularly in trabecular bone) and a reduction in the mechanical properties of intact bone and healing fractures. The histological, biomechanical, and radiological measures of union suggest that OVX delayed fracture healing.
authors.affiliation: Queen's University Belfast, Division of Surgery and Perioperative Care, Department of Orthopaedic Surgery, Musgrave Park Hospital, Stockman's Lane, Belfast, Ulster BT9 7JB, United Kingdom. r.mccann@qub.ac.uk
authors.forename: Roseleen M
authors.initials: RM
authors.lastname: McCann
authors.forename: Gary
authors.initials: G
authors.lastname: Colleary
authors.forename: Carolyn
authors.initials: C
authors.lastname: Geddis
authors.forename: Susan A
authors.initials: SA
authors.lastname: Clarke
authors.forename: Grant R
authors.initials: GR
authors.lastname: Jordan
authors.forename: Glenn R
authors.initials: GR
authors.lastname: Dickson
authors.forename: David
authors.initials: D
authors.lastname: Marsh
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D001835:Body Weight; D015519:Bone Density; D005260:Female; D005264:Femoral Fractures / Q000150:complications* / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D017102:Fracture Healing; D007091:Image Processing, Computer-Assisted; D009068:Movement; D010024:Osteoporosis / Q000150:complications* / Q000209:etiology / Q000473:pathology / Q000503:physiopathology*; D010052:Ovariectomy; D051381:Rats; D017207:Rats, Sprague-Dawley; D013718:Tensile Strength; D014057:Tomography, X-Ray Computed