# Aneurysmal Bone Cyst of the Distal Femoral Metaphysis in a Three-Year-Old Male Patient Presenting With a Pathologic Fracture: A Case Report

## TL;DR

A three-year-old boy with a bone cyst suffered a fracture and deformity after surgery, highlighting the need for careful treatment choices in pediatric cases.

## Contribution

The paper presents a case emphasizing the risks of physeal damage in pediatric aneurysmal bone cyst treatment and suggests alternative approaches.

## Key findings

- En bloc resection followed by the Masquelet technique caused valgus deformity and limb length discrepancy.
- Physeal damage from resection, not reconstruction, likely caused complications.
- Physeal-sparing approaches may improve outcomes in pediatric ABC cases.

## Abstract

This case report discusses the management of a three-year-old male presenting with a pathological fracture of the distal femur due to an aneurysmal bone cyst (ABC). Due to diagnostic uncertainty and limited resources, the treatment involved an en bloc resection followed by the Masquelet technique with a fibular and cancellous graft. While this approach successfully reconstructed the bone defect, the patient developed a progressive valgus deformity and limb length discrepancy, likely due to physeal damage from the resection rather than the reconstruction technique itself. This case highlights the challenges of balancing recurrence risk, functional outcomes, and resource limitations in pediatric ABC treatment. A more physeal-sparing approach, such as curettage with bone grafting, might have mitigated complications while preserving long-term limb function.