An Uncommon Case Report: Pathologic Fracture in a Proximal Femur Aneurysmal Bone Cyst in a Child

Abstract

Introduction: Aneurysmal bone cysts (ABCs) are a group of benign, expansile, locally aggressive lesion characterized by fluid-filled cysts usually in the metaphyseal end of long bones. They usually affect children and young adults, with an atypical etiology and uncommon presentation. Treatment modalities include en bloc resection and curettage with or without bone graft or bone substitute augmentation with instrumentation, sclerosing agents, arterial embolization, and adjuvant radiotherapy.

Case report: We report a rare case of ABC with pathological fracture in the proximal femur of a 13-year-old male patient, who presented to the emergency department with severe pain in the right hip and inability to walk following trivial fall while playing. Curettage with open biopsy was performed followed by implantation with modified hydroxyapatite granules and internal fixation for the subtrochanteric fracture with pediatric dynamic hip screw and four hole plate, with a favorable outcome.

Conclusion: There is a lack of a standard guideline for the management on account of uniqueness of these cases; curettage with bone graft or bone substitutes in conjunction with internal fixation of associated pathologic fracture yields bony union with adequate clinical results.

Keywords: Aneurysmal bone cyst; pathological fracture; proximal femur.

Figure 1

Pre-operative anteroposterior view radiograph of affected right hip.

Figure 2

Pre-operative lateral view radiograph of the affected right hip.

Figure 3

5-year follow-up post-operative anteroposterior radiograph.

Figure 4

5-year follow-up post-operative lateral radiograph.

Figure 5

Clinical photograph showing good clinical outcome at 5-year follow-up.