Supplemental medial small fragment fixation adds stability to distal femur fixation: A biomechanical study

Medial augmentation of distal femur fractures using the contralateral distal femur locking plate: A technical note

Introduction

Lateral locking plates are commonly employed for the fixation of distal femur fractures. However, scenarios involving medial comminution, extremely distal fractures, periprosthetic fractures, or nonunion could necessitate medial augmentation. This study explores the possibility of using lateral distal femoral locking plate systems for medial fixation by employing the contralateral plate.

Methods

This study presents a technical note on the application of lateral distal femur locking systems for medial augmentation in patients as indicated by current literature findings. Postoperative imaging modalities, including radiography and computed tomography (CT), were used to assess the plates' fit to the distal femur. Three cases following the specified technical note are presented.

Results

The various plate systems, all comprising distal femur locking systems, demonstrated adaptability to the medial femur anatomy as confirmed by intraoperative visualization and postoperative radiographs, including two-dimensional and three-dimensional CT scans. It has also been possible to achieve at least 3 independent fixation points regardless of the size of the medial condyle.

Conclusions

Locking distal femoral plates can be a viable option for medial augmentation in indicated cases, achieving anatomical adaptation to the distal femur. This provides robust augmentation without the need for additional instruments beyond those used for the lateral cortex.

Does the type of medial plate fixation matter for supplemental fixation of distal femur fractures manage with a lateral pre-contoured locked plate? A Biomechanical study

INTRODUCTION

Fixation of distal femur fractures with a lateral pre-contoured locking plate provides stable fixation and is the standard treatment in most cases, allowing early range of motion with a high rate of union. However, in situations, the stability achieved with the lateral plate alone may be insufficient, predisposing to fixation failure. The objective of the study was to compare, in synthetic bone models, the biomechanical behaviour of the fixation with a distal femur lateral pre-contoured locking plate solely and associated with a 3.5 mm proximal humeral locking plate applied upside down or a 4.5 mm helical locking compression plate on the medial side.

MATERIAL AND METHODS

A total of 15 solid synthetic left femur samples were used. A metaphysical defect at the level of the medial cortex was simulated. The samples were randomly distributed into three groups equally. All groups received a 4.5/5.0 mm single lateral 9-hole distal femur lateral pre-contoured locking plate. Group 1 had no supplementary plate. Group 2 received a supplementary 6-hole 3.5 mm proximal humeral locking plate and Group 3 received a supplementary 4.5/5.0 mm helical 14-hole narrow locking compression plate.

RESULTS

Both supplementary plate types used in groups 2 and 3 contributed to increase the apparent stiffness of the construct, but pairwise comparison showed statically significant difference only between group 1 and 3. No significant difference was observed between groups 2 and 3.

CONCLUSION

Both supplementary plates might be considered for improving the fixation in distal femur fracture in selected cases.

Maintaining the Neutral Axis in the Treatment of Distal Femur Fractures Via Dual Plate or Nail Plate Combination Technique: When and How?

SUMMARY

Distal femur fractures in the elderly have been historically treated with locked plating or retrograde intramedullary nailing with good, reliable results. However, in certain more complex fracture patterns (native or periprosthetic), increased density of fixation via dual-plate or nail plate combination can help achieve immediate weight-bearing. It can also potentially increase rates of union by shifting and maintaining the neutral axis, distributing forces more evenly across the fracture site. Here, we discuss the indications, pros and cons of both dual-plate and nail plate combination techniques in a concise case-based format.