Biomechanical Stability of Intramedullary Nailing vs Plate Fixation in Displaced Intra-articular Calcaneal Fractures...

From a biomechanical perspective, intramedullary fixation offers potential benefits, including a central load-sharing axis that may better withstand axial and bending forces, while preserving the periosteal blood supply and reducing soft tissue damage. This review aimed to determine whether intramedullary nailing in displaced intra-articular fractures provides comparable or superior biomechanical stability to plate fixation.

A literature search identified studies comparing the biomechanical stability of intramedullary fixation with plate fixation, screw-only fixation, or combined constructs in calcaneal fractures. Eligible studies used human cadaveric specimens or computational models, examined biomechanical outcomes such as stiffness, load to failure, displacement, or stress distribution, and employed laboratory, cadaveric (n = 3), or finite element analyses (n = 4).

Experimental and numerical studies showed that intramedullary fixation consistently provides greater or comparable construct stiffness and load to failure than locking plates, with no implant failures observed. Plates produced higher stress concentrations at screw junctions, whereas intramedullary nails yielded a more uniform stress distribution in most models; however, 1 finite element analysis study reported higher calcaneal bone stress with intramedullary nail fixation.

Intramedullary calcaneal fixation provides comparable or superior biomechanical stability to plate fixation, especially under cyclic axial loading. Construct durability appears more dependent on axial load sharing than on implant category alone. Whether these biomechanical findings translate to improved clinical outcomes remains to be demonstrated.