Compression forces of internal and external ankle fixation devices with simulated bone resorption.

Journal Article (Journal Article)


Internal and external fixation techniques have been developed to provide rigidity and stability to a fusion site such as in tibiotalocalcaneal (TTC) arthrodesis. Compression of the fusion site plays an integral role in primary bone healing, though little work has been done to quantify the compressive force values of ankle fixation devices.

Materials and methods

Using synthetic and cadaveric bone models, a Newdeal/Integra PantaNail and DePuy VersaNail were tested as compressive intramedullary (IM) nails while an Encore True/Lok and an Ace-Fischer frame were tested as external fixators.


The PantaNail experienced maximum compressive loads of 1898 and 1255 N in synthetic and cadaveric constructs, respectively. The VersaNail experienced max compressive loads 388 N during installation. All IM nails tested experienced decreased compressive loads after removal of the external guide and instrumentation. The external fixators were loaded to approximately 1200 N in both synthetic and cadaveric constructs. The decrease in compressive load was recorded as a function of simulated fusion site bone resorption for all devices. The IM nails experienced a 90% reduction in load with less than 1 mm of resorption, while the external fixators held 50% load for over 4 mm of resorption. These data were verified using a simple constitutive model of IM nails and external fixators.


Intramedullary nails are capable of generating compression, however, are unable to provide sustained compression for any considerable amount of resorption. External fixators are inherently capable of applying and sustaining greater amounts of compression.

Clinical relevance

Surgeons who perform TTC arthrodesis procedures should be aware of a device's ability to generate and sustain compression with respect to bone resorption.

Full Text

Duke Authors

Cited Authors

  • Yakacki, CM; Khalil, HF; Dixon, SA; Gall, K; Pacaccio, DJ

Published Date

  • January 2010

Published In

Volume / Issue

  • 31 / 1

Start / End Page

  • 76 - 85

PubMed ID

  • 20067727

Electronic International Standard Serial Number (EISSN)

  • 1944-7876

International Standard Serial Number (ISSN)

  • 1071-1007

Digital Object Identifier (DOI)

  • 10.3113/fai.2010.0076


  • eng