Percutaneous balloon calcaneoplasty versus open reduction and internal fixation (ORIF) for intraarticular SANDERS 2B calcaneal fracture: Comparison of primary stability using a finite element method
Résumé
Fractures of the calcaneus are common, with 65% being intra-articular, which can lead to a
major impairment of the patient’s quality of life. Open reduction and internal fixation with locking plates
can be considered as gold-standard technique but has a high rate of post-operative complications. Min-
imally invasive calcaneoplasty combined with minimally invasive screw osteosynthesis is largely drawn
from the management of depressed lumbar or tibial plateau fractures. The hypothesis of this study is that
calcaneoplasty associated with minimally invasive percutaneous screw osteosynthesis presents biome-
chanical characteristics comparable with conventional osteosynthesis.
Materials and methods: Eight hind feet were collected. A SANDERS 2B fracture was reproduced on each
specimen, while four calcanei were reduced by a balloon calcaneoplasty method and fixed with a lateral
screw, four others were manually reduced and fixed with conventional osteosynthesis. Each calcaneus
was then segmented for 3D finite element modeling. A vertical load was applied to the joint surface in
order to measure the displacement fields and the stress distribution according to the type of osteosyn-
thesis.
Results: Analyses of the intra-articular displacement fields showed lower overall displacements in cal-
caneal joints treated with calcaneoplasty and lateral screw fixation. Better stress distribution was found
in the calcaneoplasty group with lower equivalent joint stresses. These results could be explained by the
role of the PMMA cement as a strut, enabling better load transfer.
Conclusion: Balloon Calcaneoplasty combined with lateral screw osteosynthesis has biomechanical char-
acteristics at least comparable to locking plate fixation in the treatment of SANDERS 2B calcaneal joint
fractures in terms of displacement fields and stress distribution under the premise of anatomical reduc-
tion