Moderate soft tissue trauma delays new bone formation only in the early phase of fracture healing

Abstract

The aim of this study was to investigate the effect of a moderate soft tissue trauma to the course of fracture healing in a standardized animal model. Thirty‐eight Wistar rats were randomly divided into a fracture group (F, n = 19) and a group with a fracture and a soft tissue trauma (F + STT, n = 19). The fracture and the soft tissue trauma were created using an impact device with a standardized energy. All fractures were stabilized by two Kirschner wires. Three rats were measured for blood flow and sacrificed at days 1, 3, 7, and 14, and seven rats at day 28, from both groups. A three‐point bending test was performed on the healed tibia after 28 days. During the first 24 h there was a reduction in blood flow, which was more pronounced in the F + STT group than in the F group. From histological sections, the shape of the callus formation, as well as the tissue distribution of newly formed bone, fibrous cartilage and fibrous connective tissue were determined. Distinctly more periosteal new bone formed and a larger callus formed at days 3 and 7 in group F compared to group F + STT. However, by days 14 and 28, the ossification and overall callus size no longer showed differences between the two groups. A fast recovery of blood flow and callus formation took place in the F + STT group, which led to similar histological and biomechanical results in fracture healing observed after 28 days between the two groups. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 24:1178–1185, 2006

Temporal Variation in Fixation Stiffness Affects Healing by Differential Cartilage Formation in a Rat Osteotomy Model

“…As the individual callus areas varied, points on the grid covering empty area outside the boundaries of a particular callus were excluded from analysis. The grid-measuring method was performed in a blinded fashion and has repeatability of better than 90% [8,9]. The number of animals achieving bony bridging of the osteotomy gap in the periosteal (medial and lateral), intracortical (medial and lateral), and endosteal zones was quantified (Table 2).…”

Temporary distraction and compression of a diaphyseal osteotomy accelerates bone healing

“…In the control group the periosteal callus contained more fibrous cartilage (14.1%), which is characteristic for a flexibly fixed fracture with cyclical interfragmentary movements. 17 In contrast, the TD group showed somewhat less fibrous cartilage (7.2%), comparable to values seen in callus distraction (approximately 5% 12 ). The bone formation rate (Table 3) at days 20 and 30 showed that temporary distraction, which was finished at day 19, stimulated the peripheral callus formation on days 20 and 30.…”

External fixation of tibial pilon fractures and fracture healing

“…Some aspects of fracture care, such as motion at the fracture site (Sarmiento et al 1977), surgical delay (Smith et al 1974, Coutts et al 1982, type of fixation (Claes et al 2006) and periosteal stripping during open reduction (Hayda et al 1998), have been shown to affect fracture union.…”