Combination of Anatomical Locking Plate and Retrograde Intramedullary Nail in Distal Femoral Fractures: Comparison of Mechanical Stability

Objectives: This study aims is to investigate mechanical properties of intramedullary (IM) nailing and anatomical locking plate in a bone model based on the hypothesis that their combined usage increases safety of fixation stabilization.

Materials And Methods: Twenty-one left distal femoral fracture models were used in the study. Bones were divided into three equal groups. Group 1 specimens were fixed laterally by distal femoral anatomical locking plate. Group 2 specimens were fixed with retrograde distal femoral IM nail. Group 3 specimens were fixed with both distal femoral anatomical locking plate and retrograde distal femoral IM nail. In mechanical tests, alterations in axial loading, torsion angles, and load to failure values were measured and compared between groups.

Results: Compared to group 1, group 2 was relatively more resistant in axial load tests (p=0.225), and significantly more resistant in load to failure tests (p=0.048). Group 1 was relatively more resistant in torsional load tests (p=0.949) compared to group 2. Group 3 was significantly more resistant than group 1 in axial (p=0.001), torsional (p=0.012) load tests and load to failure tests (p=0.008). Group 3 was significantly more resistant compared to group 2 in axial (p=0.003), torsional (p=0.008) load tests, and relatively more resistant (p=0.059) in load to failure tests.

Conclusion: Thanks to its high mechanical strength and early mobilization capability, distal femoral anatomical locking plate and IM nail combination might be a choice of treatment in complicated osteoporotic or distal femoral fractures from high-energy trauma in young adults.