# Acetabular Reconstruction in a Case of Chondrosarcoma

## TL;DR

This paper presents a cost-effective surgical technique using 3D-printed models to reconstruct the pelvis after removing a chondrosarcoma, offering an alternative to expensive customized implants.

## Contribution

The novel contribution is a cost-effective pelvic reconstruction technique using standard implants and 3D-printed models for tumor resection.

## Key findings

- The use of 3D-printed models allowed functional hip reconstruction after acetabular resection.
- The technique avoided customized implants, reducing costs while maintaining medium-term functionality.
- The method is suitable for resource-limited settings and can be adapted for complex pelvic resections.

## Abstract

Chondrosarcomas of the pelvis represent a challenge in clinical management because surgical resection is the only effective therapeutic option, given the resistance to radiotherapy and chemotherapy of malignant chondroid tumors. Reconstruction after resection involves critical structures, such as the acetabulum or hip joint, and is a demanding surgical procedure with high morbidity. Complications are frequent due to the complex anatomy of the pelvis, which on the one hand makes it difficult to obtain adequate surgical margins, and on the other hand, the various implants designed for reconstruction have shown a high rate of mechanical and infectious complications. In this report, we present an innovative technique for pelvic reconstruction after resection of the acetabular region (Enneking type II resection), whose planning included the use of a three-dimensional printed model (3D printing) of the patient's pelvis.

We describe a case of a 39-year-old patient with a grade 2 central chondrosarcoma. Surgical treatment included 3D model planning, followed by tumor resection and reconstruction of the acetabulum using conventional implants. The main mechanical support of the technique in this case was achieved using threaded Schanz wires as osteosynthetic fixation of the anterior and posterior columns, on which an acetabular basket was cemented. Although at six months, a fracture of the remaining iliac bone and slight elevation of the hemipelvis occurred, this did not mean pain or impairment of the ability to walk with a cane. This particular cost-effective technique allowed the functional reconstruction of the hip, at least in the medium term, so it can be considered as an alternative in resections in zone II of the pelvis. In comparison to customized 3D-printed implants, this approach represents a more cost-effective option, particularly in settings with limited resources. While personalized implants offer superior anatomic fit, they require specialized manufacturing and high costs, often limiting their accessibility. In contrast, this technique utilizes standard implants with planning aided by 3D models, allowing surgeons to tailor reconstructions without reliance on custom hardware. Given these advantages, the method may be adaptable to a broader range of complex pelvic resections where institutional resources are constrained.