title: Impaction grafting with a bone-graft substitute in a sheep model of revision hip replacement.
abstract: An experimental sheep model was used for impaction allografting of 12 hemiarthroplasty femoral components placed into two equal-sized groups. In group 1, a 50:50 mixture of ApaPore hydroxyapatite bone-graft substitute and allograft was used. In group 2, ApaPore and allograft were mixed in a 90:10 ratio. Both groups were killed at six months. Ground reaction force results demonstrated no significant differences (p > 0.05) between the two groups at 8, 16 and 24 weeks post-operatively, and all animals remained active. The mean bone turnover rates were significantly greater in group 1, at 0.00206 mm/day, compared to group 2 at 0.0013 mm/day (p < 0.05). The results for the area of new bone formation demonstrated no significant differences (p > 0.05) between the two groups. No significant differences were found between the two groups in thickness of the cement mantle (p > 0.05) and percentage ApaPore-bone contact (p > 0.05). The results of this animal study demonstrated that a mixture of ApaPore allograft in a 90:10 ratio was comparable to using a 50:50 mixture.
authors.affiliation: Centre for Biomedical Engineering, Institute of Orthopaedics and Musculoskeletal Science University College London, The Royal National Orthopaedic Hospital, Brockley Hill, Stanmore, Middlesex HA7 4LP, UK.
authors.forename: M
authors.initials: M
authors.lastname: Coathup
authors.forename: N
authors.initials: N
authors.lastname: Smith
authors.forename: C
authors.initials: C
authors.lastname: Kingsley
authors.forename: T
authors.initials: T
authors.lastname: Buckland
authors.forename: R
authors.initials: R
authors.lastname: Dattani
authors.forename: G P
authors.initials: GP
authors.lastname: Ascroft
authors.forename: G
authors.initials: G
authors.lastname: Blunn
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage; D019644:Arthroplasty, Replacement, Hip / Q000379:methods*; D015415:Biomarkers / Q000378:metabolism*; D001696:Biomechanical Phenomena; D018786:Bone Substitutes; D016025:Bone Transplantation / Q000379:methods*; D005260:Female; D005269:Femur / Q000503:physiopathology / Q000637:transplantation*; D008855:Microscopy, Electron, Scanning; D010012:Osteogenesis / Q000502:physiology*; D011474:Prosthesis Design / Q000592:standards; D012756:Sheep; D013752:Tetracycline / Q000008:administration & dosage
chemical_list: D000900:Anti-Bacterial Agents; D015415:Biomarkers; D018786:Bone Substitutes; D013752:Tetracycline