The fracture gap size influences the local vascularization and tissue differentiation in callus healing
- 410 Downloads
Revascularization of a fracture depends on fracture stability and fracture gap conditions. The aim of the study was to determine quantitatively the revascularization and tissue differentiation in an animal model with different fracture gaps and controlled biomechanical conditions.
Materials and method
The study was performed on ten sheep with an osteotomy on the right metatarsal. The fracture was stabilized by an external fixator that allowed adjustable axial interfragmentary movement. Two groups of five sheep each were adjusted to a medium sized gap (M, 2.1 mm) and a large gap (L, 5.7 mm) under comparable interfragmentary strain (30–32%). The animals were killed after 9 weeks, and the metatarsals were prepared for undecalcified histology and analysis of tissue differentiation and vessel distribution.
Group M showed significantly more revascularization (M=1.62, L=0.85 vessels/mm2), more bone formation (M=37.2%, L=13.9%) and less fibrocartilage tissue (M=18.1%, L=39.1%) than group L. Larger vessels (>40 μm) were found mainly in the medullary channel, and smaller vessels (<20 μm) mainly in the peripheral callus. Histologically, group M showed partial bony bridging of the osteotomy gap, and the group L had delayed healing.
A good reduction of a fracture with small interfragmentary gaps is important for its revascularization and healing.
KeywordsBone healing Fracture gap Revascularization
This study was kindly supported by the German Research Council (DFG-Cl 77/2).
- 6.Eitel F (1996) Revaskularisierung langer Röhrenknochen nach Fraktur und Osteosynthese. In: Kuner EH (ed) Stabile Osteosynthese. Thieme, Stuttgart New YorkGoogle Scholar
- 9.Claes LE, Heigele CA, Neidlinger-Wilke C, Kaspar D, Seidl W, Margevicius KJ, Augat P (1998) Effects of mechanical factors on the fracture healing process. Clin Orthop 355S:132–147Google Scholar
- 13.Carter DR, Beaupré GS, Giori NJ, Helms DDS (1998) Mechanobiology of skeletal regeneration. Clin Orthop 355S:41–55Google Scholar