# 3D-Planned, Patient-Specific Distal Radius Reconstruction with a Vascularized Double-Barrel Free Fibular Graft After Secondary Aneurysmal Bone Cyst

## TL;DR

A 67-year-old woman with a rare secondary aneurysmal bone cyst in her wrist was successfully treated with a custom 3D-printed bone graft, leading to good recovery.

## Contribution

A successful case of treating a rare secondary aneurysmal bone cyst in an elderly patient using patient-specific 3D-printed osteotomy templates and a vascularized fibular graft.

## Key findings

- The patient showed excellent bone union and functional recovery after treatment.
- No donor site morbidity or limitations in daily life were reported.
- The use of patient-specific 3D-printed templates contributed to successful reconstruction.

## Abstract

Background/Objectives: An Aneurysmal Bone Cyst (ABC) is a rare benign osteolytic bone lesion with locally destroying growth. It occurs mostly in the first two decades of life, rarely in older patients, and commonly affects the metaphysis. Clinical presentation includes pain and pathologic fractures. While most ABCs occur as primary lesions, there is an entity of secondary (reactive) ABC following osseous lesions such as fractures. We report a rare case of a secondary aneurysmal bone cyst of the distal radius following a distal radius fracture 4 years prior, with subsequent treatment and reconstruction. Methods: A 67-year-old female patient presented with a pathologic distal forearm fracture with radiologically expansive lytic bone lesion of the metaphysis of the distal radius, suspicious of an ABC. A biopsy and primary fracture management with an external fixator were performed due to the unclear dignity of the lesion. The diagnosis of an ABC was confirmed in the biopsy. The tumor resection and reconstruction were performed with a vascularized free fibula graft (ipsilateral, double barrel), using patient-specific 3D-printed osteotomy templates. Results: Follow-up radiographs showed excellent bone union with progressive remodeling. The functional outcome was very good with almost the same range of motion and grip strength as the contralateral side. No limitation in everyday life and no donor site morbidity was reported. Conclusions: ABC is a rare benign bone tumor the treatment of which consists of complete resection and reconstruction. Reconstruction of the distal radius can be achieved with a fibula graft. In our case, an excellent result was achieved with patient-specific osteotomy templates. Only a few cases of ABC in the distal radius and at this age have been reported; nevertheless, it should be considered as a differential diagnosis for osteolytic bone lesions