Abstract
Objective The aim of this study was to document the effects of positive-profile threaded external
skeletal fixation (ESF) pin insertion without predrilling on heat generation, structural
damage and pullout strength in avian bone than that with predrilling.
Study design This study was an ex vivo study.
Materials and Methods Twenty paired tibiotarsi and 40 paired humeri from 20 Mallard duck cadavers were
used. Specimens were randomized to have positive-profile threaded ESF pins placed
with or without predrilling insertion sites. Heat generation (maximum—baseline temperature)
was measured during drilling and pin insertion with infrared thermography. Structural
damage (gross trans-cortical damage and thread quality) was evaluated and scored using
a visual analog scale (VAS). Mechanical testing was performed to evaluate pullout
strength of inserted pins.
Results VAS scores for trans-cortical surfaces were significantly higher than for cis-cortical
surfaces; however, no difference was noted between predrilled and non-predrilled specimens.
No significant difference in heat generation or pullout strength was noted between
pins placed with and without predrilling.
Conclusion Pin insertion without predrilling in avian humeri and tibiotarsi does not cause significantly
more structural damage or heat generation, or reduced pullout strength, compared with
predrilling. Overall, our results indicate that predrilling prior to ESF pin placement
provides no obvious advantage in avian bone.
Keywords external skeletal fixation pins - avian - bone - infrared thermography - pin pullout