Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Achilles tendon healing in rats is improved by intermittent mechanical loading during the inflammatory phase
Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine. Linköping University, Faculty of Health Sciences.
Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine. Linköping University, Faculty of Health Sciences.
Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Surgery, Orthopaedics and Cancer Treatment, Department of Orthopaedics in Linköping.
2012 (English)In: Journal of Orthopaedic Research, ISSN 0736-0266, E-ISSN 1554-527X, Vol. 30, no 2, 274-279 p.Article in journal (Refereed) Published
Abstract [en]

Tendons adapt to changes in mechanical loading, and numerous animal studiesshow that immobilization of a healing tendon is detrimental to the healingprocess. The present study addresses whether the effects of a few episodes ofmechanical loading are different during different phases of healing. Fifty femalerats underwent Achilles tendon transection, and their hind limbs were unloadedby tail suspension on the day after surgery. One group of 10 rats was taken downfrom suspension to walk on a treadmill for 30 minutes per day, on days 2-5 aftertransection. They were euthanized on day 8. Another group underwent similartreadmill running on days 8-11 and was euthanized on day 14. Completelyunloaded groups were euthanized on day 8 and 14. Tendon specimens were thenevaluated mechanically. The results showed that just 4 loading episodesincreased the strength of the healing tendon. This was evident irrespective of thetime-point when loading was applied (early or late). The positive effect on earlyhealing was unexpected, considering that the mechanical stimulation was appliedduring the inflammatory phase, when the calluses were small and fragile. Ahistological study of additional groups with early loading also showed someincreased bleeding in the loaded calluses. Our results indicate that a smallamount of early loading may improve the outcome of tendon healing. This couldbe of interest to clinical practice.

Place, publisher, year, edition, pages
Wiley Online Library , 2012. Vol. 30, no 2, 274-279 p.
Keyword [en]
Early loading, tail-suspension, unloading, mechanical testing, cell differentiation
National Category
Medical and Health Sciences
Identifiers
URN: urn:nbn:se:liu:diva-70772DOI: 10.1002/jor.21511ISI: 000298581200016OAI: oai:DiVA.org:liu-70772DiVA: diva2:441499
Note

funding agencies|Swedish National Centre for Research in Sports||Swedish Research Council| VR 2009-6725 |Ostergotland County Council||

Available from: 2011-09-16 Created: 2011-09-16 Last updated: 2017-12-08Bibliographically approved
In thesis
1. Response to mechanical loading in healing tendons
Open this publication in new window or tab >>Response to mechanical loading in healing tendons
2011 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Ruptured tendons heal faster if they are exposed to mechanical loading. Loading creates deformation of the extracellular matrix and cells, which give rise to intracellular signalling, increased gene expression and protein synthesis. The effects of loading have been extensively studied in vitro, and in intact tendons in vivo. However, the response to loading in healing tendons is less known.

The general aim of this thesis was to understand more about the response to mechanical loading during tendon healing. The specific aims were to find out how short daily loading episodes could influence tendon healing, and to understand more about genes involved in tendon healing.

The studies were performed using rat models. Unloading of healing tendons resulted in a weaker callus tissue. This could be reversed to some extent by short daily loading episodes. Loading induced more matrix production, making the tendons thicker and stronger, but there was no improvement in the material properties of the matrix. Lengthening is one potential adversity with early loading, during tendon healing in patients. This was also seen with continuous loading in the rat models. However, short loading episodes did not result in any lengthening, not even when loading was applied during the inflammatory phase of healing. It also appeared as loading once daily was enough to make healing tendons stronger, while loading twice daily with 8 hours interval did not give any additional effect. The strongest gene expression response to one loading episode was seen after 3 hours. The gene expression changes persisted 12 hours after the loading episode but had disappeared by 24 hours. Loading appeared to regulate genes involved in inflammation, wound healing and coagulation, angiogenesis, and production of reactive oxygen species. Inflammation-associated genes were regulated both by continuous loading and by one short loading episode. Inflammation is an important part of the healing response, but too much can be harmful. Loading might therefore have a role in fine-tuning the inflammatory response during healing.

In conclusion, these studies show that short daily loading episodes during early tendon healing could potentially be beneficial for rehabilitation. Loading might have a role in regulating the inflammatory response during healing.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2011. 86 p.
Series
Linköping University Medical Dissertations, ISSN 0345-0082 ; 1247
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-70774 (URN)978-91-7393-166-3 (ISBN)
Public defence
2011-09-09, Nils-Holger salen, Hälsouniversitetet, Campus US, Linköpings universitet, Linköping, 13:00 (English)
Opponent
Supervisors
Available from: 2011-09-16 Created: 2011-09-16 Last updated: 2012-03-27Bibliographically approved

Open Access in DiVA

fulltext(570 kB)566 downloads
File information
File name FULLTEXT01.pdfFile size 570 kBChecksum SHA-512
8e1ca0e051ea72f35962ae3ea3cba18bb7ef13862a95526e5ab188b92f244dd3be192857c9d2b9a1259f343e711d466b391e7812db8ae44efcfd7ae3899bdd82
Type fulltextMimetype application/pdf

Other links

Publisher's full text

Search in DiVA

By author/editor
Andersson, ThereseEliasson, PernillaAspenberg, Per
By organisation
Orthopaedics and Sports MedicineFaculty of Health SciencesDepartment of Orthopaedics in Linköping
In the same journal
Journal of Orthopaedic Research
Medical and Health Sciences

Search outside of DiVA

GoogleGoogle Scholar
Total: 566 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 371 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf