title: Stabilization of an inserted tricalcium phosphate spacer enhances the healing of a segmental tibial defect in sheep.
abstract: The effect of inserting a tricalcium phosphate (TCP) spacer stabilized by a rigid or non-rigid fixation technique on the healing of segmental tibial defects of critical size was established. The osteotomized tibiae, 11 with and 8 without TCP spacers, were fixed by an external circular device in 11 mature sheep and by plates in 8 mature sheep, respectively. Healing was evaluated roentgenographically 16 weeks after the operation. Compared with the defects without TCP spacers, enhanced stability and healing were observed in the defects with TCP spacers under an identical external fixation. Furthermore, a significantly higher incidence of healing was obtained with plate fixation than with external device fixation in the TCP-implanted defects (P < 0.04). An abundant bridging callus was roentgenograpically demonstrated in most of the healed defects, but none in the unhealed defects. The TCP spacer with its mechanical integrity enhances the stability of external fixation, and the stable immobilization provided by rigid fixation is essential for osteoconduction of an inserted TCP spacer in the healing of segmental diaphyseal defects in sheep.
authors.affiliation: Institute of Medical Technology, University of Tampere, Finland.
authors.forename: T J
authors.initials: TJ
authors.lastname: Gao
authors.forename: T S
authors.initials: TS
authors.lastname: Lindholm
authors.forename: B
authors.initials: B
authors.lastname: Kommonen
authors.forename: P
authors.initials: P
authors.lastname: Ragni
authors.forename: A
authors.initials: A
authors.lastname: Paronzini
authors.forename: T C
authors.initials: TC
authors.lastname: Lindholm
mesh_terms: D000818:Animals; D001860:Bone Plates; D002130:Calcium Phosphates; D016267:External Fixators; D016348:Osseointegration; D010027:Osteotomy; D019736:Prostheses and Implants; D012756:Sheep; D013977:Tibia / Q000293:injuries* / Q000503:physiopathology / Q000601:surgery; D014945:Wound Healing / Q000502:physiology
chemical_list: D002130:Calcium Phosphates; C485828:alpha-tricalcium phosphate; C485830:tetracalcium phosphate; C485838:calcium phosphate, monobasic, anhydrous; C020243:calcium phosphate; C485829:calcium phosphate, dibasic, anhydrous