Spontaneous correction of angular fracture deformity in the rat

Li, Jian; Ahmed, Mahmood; Samnegård, Eva; Ahmad, Tashfeen; Stark, André; Kreicbergs, Andris

doi:10.1080/17453670510041358

Cited by 7 publications

(3 citation statements)

References 17 publications

(27 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…4B), where predominantly resorption took place contributing to correction of the angular deformity (Figs. 1A and 4A) 23, 28. Although this seems to contradict the assumed stimulatory role of SP in bone formation, SP under certain circumstances might promote bone resorption.…”

Section: Discussionmentioning

confidence: 95%

Occurrence of substance P in bone repair under different load comparison of straight and angulated fracture in rat tibia

Ahmed

Bergström

et al. 2010

Journal Orthopaedic Research

Self Cite

View full text Add to dashboard Cite

Substance P (SP) has been shown in vitro to stimulate both formation and resorption of bone. This seemingly contradictory observation could be explained by in vivo variations in skeletal loading and rate of bone turnover, features which may be explored during different phases of fracture healing. In 50 SD rats, the right tibia was fractured and fixed with an intramedullary pin in straight alignment and in anterior angulation resulting in a convex and concave side under different load. Fracture repair was assessed by radiography, histology, and semi-quantitative immunohistochemistry of SP nerve fiber occurrence at days 7, 21, 35, 56, and 84 post-fracture. During regeneration, days 7-35, abundant SP-nerve ingrowth was observed in the fracture callus reaching a side-symmetrical peak at day 21 in straight fractures. In angulated fractures, the SP peak was also observed at day 21 on the concave loaded side, but not until day 35 on the convex unloaded side. Each SP-peak coincided with cortical bridging. During remodeling, days 35-84, a side-symmetrical disappearance of SP-positive fibers was seen in straight fractures. The same pattern was seen on the concave loaded side of angulated fractures. However, on the convex unloaded side, where resorption now took place, SP-fibers remained until the end of the experiment. Our study suggests that neuronal SP during bone regeneration has a stimulatory role on bone formation, while during remodeling increased SP fiber density in unloaded areas may be related to bone resorption. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J. Orthop. Res. 28: 1643Res. 28: -1650Res. 28: , 2010 Keywords: fracture healing; mechanical load; bone remodeling; neuropeptide; substance P Mechanical load promotes bone formation as illustrated by the trabecular pattern of the proximal femur and by increased bone mass in the active arm of tennis players. Load also enhances fracture healing. However, whether these observations reflect a direct effect of load on the cytoskeleton of bone cells via for example canalicular flow, 1 or an indirect effect via other mediators is unknown. The latter would imply a system sensitive and responsive to load and capable of regulating local bone turnover. Plausible candidates are various signaling pathways of the nervous system. Evidence suggests that neuronal mediators are involved in skeletal development and local bone turnover. 2−8 Patients and animals with hemiparesis or systemic neuropathies exhibit decreased bone density and impaired fracture healing characterized by excessive callus formation, decreased mechanical strength, and nonunion. 9−12 Over the last decade a number of neuropeptides, 3,5,6,13,14 have been implicated in the regulation of local bone turnover in addition to nociception, inflammation, angiogenesis, and cellular proliferation. Notably, the sensory neuropeptide substance P (SP) was identified in the most active areas of osteogenesis, such as growth plate, periosteum, and bone marrow. 14−16 Moreover, the SP r...

show abstract

Section: Discussionmentioning

confidence: 95%

Occurrence of substance P in bone repair under different load comparison of straight and angulated fracture in rat tibia

Ahmed

Bergström

et al. 2010

Journal Orthopaedic Research

Self Cite

View full text Add to dashboard Cite

show abstract

“…Recently, we reported on an angulated tibial fracture model in the rat, which elicited intense new bone formation on the concave side and bone resorption on the convex side of deformity within the first 5 weeks postfracture. 13,14 Such angulated fracture model can be utilized to assess the expression of different factors involved in local bone turnover on the two opposing sides during fracture healing and remodeling. In the present study, we analyzed the temporal and sitespecific expression of CGRP-positive fibers at the fracture site of both straight and angulated tibia by morphologic and semi-quantitative analysis using immunohistochemistry.…”

Section: Introductionmentioning

confidence: 99%

Site‐specific CGRP innervation coincides with bone formation during fracture healing and modeling: A study in rat angulated tibia

Kreicbergs

Bergström

et al. 2007

Journal Orthopaedic Research

Self Cite

View full text Add to dashboard Cite

Sensory neuropeptide involved in local bone turnover is known, but poorly understood. In the present study, we analyze the occurrence of neuronal CGRP during healing and modeling of straight and angular tibial fractures in 74 rats. Bone healing and modeling was assessed by radiography and reinnervation by semi-quantitative immunohistochemistry method at fracture site between 1-12 weeks postfracture. The regenerating nerve fibers containing CGRP were observed in fracture callus as well as in close proximity to chondrocytes, with woven bone in both fractures already at week 1. Notably, it located predominantly on the concave side of angulated fracture in the manner of sprouting into bone from weeks 3 to 5 postfracture. In both fractures, fracture calluses peaked radiographically at week 3 postfracture. In angulated fracture, a reduction of 11% in callus thickness on convex side and an increase of 365% on concave side were noted from weeks 3 to 12. A 27-fold increase in total neuronal CGRP in straight fracture and 38-fold increases in angular fracture compared to intact bone was observed at week 3. In both types of fracture, neuronal CGRP was greater on the concave side than the convex; this difference was more pronounced in the angulated fracture. CGRP immunoreactivity clearly coincides with amount of new bone formation especially on the concave side of angulated fracture. The combined results suggest that fracture evokes an intense, localized in-growth of new nerve fibers containing CGRP, which may prove to be a prerequisite of fracture healing and modeling. ß

show abstract

“…This could be one of the limitations of this present fracture model. Li et al [48]; Auregan et al [15] reported that 85.8 % and 88% of the femoral closed fractures produced were transverse with little deviation from the targeted mid shaft location.…”

Section: Discussionmentioning

confidence: 99%

Generation of Open Metatarsal Fracture in Rats: A Model for Secondary Fracture Healing

et al. 2020

View full text Add to dashboard Cite

A fracture model in rats for the study of secondary bone healing was described. Standard open midshaft transverse metatarsal fracture was produced with bone cutting forceps in 28 rats. The commonly open and close fracture models utilized for bone and mineral researches are associated with varying degree of complications ranging from a high degree of fracture comminution to severe associated soft tissue injury which interferes with the healing process. We hypothesized that fracture model in rat third metatarsal bone could be associated with low -post-surgical complications and could be a reproducible model. To test this, open mid-shaft transverse fractures were created on the metatarsals of 28 rats. The objectives of the study were to evaluate the fracture complications, to determine the nature of fracture produced, evaluate the fracture consolidation during healing periods, and to assess the histological and radiographic healing of the fracture. The fracture produced in the mid metatarsal shaft of all rats was 100% transverse, 73% located at the midshaft. Minimal fracture angulations were recorded (0.48 ± 0.09o; 0.78 ± 0.17o) for anterior-posterior and lateral views respectively. Minimal soft tissue injury was recorded immediately post-surgery, but no infection and the delayed union was observed. Varying degrees of weight-bearing lameness was also recorded but seized at day six onward post-operative. Callus index observed was peaked at week 2 and 3 (2.02 ± 0.1, 1.99 ± 0.13) respectively but declined to 1.10 ± 0.04 at week 7 during the consolidation period. The fracture line disappeared completely at week 7. The histological and radiographic healing scores were (3.5 ± 0.13 and 3.75 ± 0.25) respectively (out of the maximum healing score of 4) at week 7 post-operative. There was a positive correlation between the histological and radiographic healing scores. The metatarsal fracture model is considered to be a suitable model for in vivo study of secondary fracture healing. Doi: 10.28991/SciMedJ-2020-0204-2 Full Text: PDF

show abstract

Spontaneous correction of angular fracture deformity in the rat

Cited by 7 publications

References 17 publications

Occurrence of substance P in bone repair under different load comparison of straight and angulated fracture in rat tibia

Occurrence of substance P in bone repair under different load comparison of straight and angulated fracture in rat tibia

Site‐specific CGRP innervation coincides with bone formation during fracture healing and modeling: A study in rat angulated tibia

Generation of Open Metatarsal Fracture in Rats: A Model for Secondary Fracture Healing

Contact Info

Product

Resources

About