# Pedicled medial femoral condyle corticoperiosteal flap for achieving union in patients with nonunion of the distal half of the femur (A short case series of three patients)

## TL;DR

A new surgical technique using a flap from the femur helps heal difficult-to-treat bone fractures in the lower part of the femur, with promising results in three patients.

## Contribution

Introduces the pedicled medial femoral condyle corticoperiosteal flap as a novel surgical approach for treating nonunion fractures in the distal femur.

## Key findings

- All three patients achieved bony union with an average time to union of 6.7 months.
- No mechanical failures occurred, though complications like nerve injury and hernia were observed.
- The technique showed a 100% union rate in recalcitrant nonunion cases of the distal femur.

## Abstract

Recalcitrant bone nonunion is characterized by impaired biological potential at the fracture site due to diminished vascularity and loss of osteogenic cells, reducing the success rate of nonvascularized bone grafts. In cases of ununited fractures of the tibia and femur with minimal gapping, the medial femoral condyle (MFC) corticoperiosteal flap offers a promising solution. This study aims to evaluate the effectiveness of the pedicled MFC corticoperiosteal flap in achieving union in recalcitrant nonunion of the distal half of the femur. The secondary objective is to report complications associated with this technique.

Three male patients with recalcitrant nonunion of the distal half of the femur were included. The transposition ratio was calculated by dividing the distance between the medial femoral epicondyle and the nonunion site (DMEB) by the distance from the medial femoral epicondyle to the apex of the lesser trochanter (DMELT). Patients with a ratio greater than 0.5 were excluded. Each patient underwent adequate rigid fixation, followed by harvesting a pedicled MFC corticoperiosteal flap from the medial distal femur. The flap was rotated to cover the nonunion site and augmented with an iliac crest bone graft to fill residual gaps. Bony union was monitored through monthly X-rays and CT scans.

All three patients (average age 36.7 years) had recalcitrant nonunion, two cases being aseptic atrophic and one septic. Union was achieved in all patients (100% union rate), with an average time to union of 6.7 months. No mechanical failures were observed. Complications included saphenous nerve injury and seroma in one patient, and an incisional hernia at the iliac crest graft donor site in another.

The pedicled MFC-CP flap appears to be a feasible option for treating recalcitrant distal femur nonunion, with minimal donor site morbidity. However, larger studies are needed to confirm its efficacy.