Induced membrane technique for aseptic recalcitrant nonunion of the femur and tibia: Bone union and deformity correction outcomes.

INTRODUCTION

Aseptic recalcitrant nonunion (ARNU) of the femur and tibia is an entity in which the absence of bony union, misalignment, and limb length discrepancies (LLD) coexist. Currently, the management of these cases lacks consensus. This study aimed to describe the bone union rate and deformity correction outcomes in patients with ARNU of the femur or tibia treated with the Induced Membrane Technique (IMT).

METHODS

We retrospectively review ten consecutive patients with ARNU (eight femoral and two tibial) treated with IMT in two stages, between January 2021 and May 2023, at a single center. The median age was 47.6 years (range 28-67), with an average of 2.76 previous surgeries (range 2-5). Six were atrophic, and four were eutrophic nonunions. All had LLD ranging from 11 to 35 mm (median 23.9), with coronal or sagittal plane misalignment between 10 and 15° (median 11.8) in six cases and rotational misalignments between 10 and 30° (median 17.5) in six cases, assessed by lower limb scanograph and rotations by computed tomography (CT) scan.

RESULTS

The median bone defect length was 43 mm (range 30-60). Treatment involved a traction table in five cases, manual traction in three, and a femoral distractor in two. Fixation in the first stage included eight intramedullary nails and two locked plates. In the second stage, we filled the defect with autograft in eight cases and mixed (auto-allograft) in two (1:1 ratio). At the end of the follow-up, 9/10 patients showed bone union (seven without additional surgeries). There was one failure due to graft resorption. LLD was wholly corrected in four cases; the remaining six had a median discrepancy of 8.16 mm (range 2-15). No patients had axial or rotational misalignment exceeding 5°.

CONCLUSION

The results of this study suggest that IMT is viable for complex cases such as ARNU. Manipulating the defect allowed us to achieve an acceptable bone union rate, correcting length discrepancies up to 35 mm, axial misalignment up to 15°, and rotational misalignment up to 30°.