# 3D‐Printed Cut Guides and Custom Prostheses for Pelvic Reconstruction in Bone Sarcoma Patients: Complications, Survival Rates, and Functional Outcomes

## TL;DR

This study examines the use of 3D-printed tools in pelvic surgery for bone cancer patients, finding good functional results but notable complications.

## Contribution

The study introduces a detailed evaluation of 3D-printed cutting guides and prostheses in pelvic sarcoma reconstructions.

## Key findings

- A 46% reoperation rate was observed, mainly due to infection and mechanical issues.
- The average MSTS score was 83.7%, showing strong functional recovery.
- Local recurrence occurred in 21% of patients at a median of 5 months post-surgery.

## Abstract

Pelvic reconstruction following bone sarcoma resection presents significant challenges. This study evaluates the outcomes of using 3D‐printed custom‐made prostheses and cutting guides to improve surgical precision and functional results in periacetabular reconstructions. Therefore, in this study, we asked: (1) What is the cumulative incidence of reoperation for any reason following pelvic resection and reconstruction with a custom‐made 3D‐printed prosthesis involving the acetabulum in patients with primary bone sarcoma, and what factors contribute to an increased risk of reconstruction failure? (2) Does the use of 3D custom‐made cutting guides, combined with a 3D custom‐made hemipelvis prosthesis, ensure the attainment of safe resection margins and allow for anatomical reconstruction with optimal fit at the bone‐prosthesis interface? (3) What were the observed outcome scores as measured by the Musculoskeletal Tumor Society (MSTS) Score? Additionally, how do the type of resection and the volume of the primary bone sarcoma affect the outcomes in relation to the type of reconstruction?

We conducted a retrospective review of 24 patients treated for primary bone sarcomas at our institution from January 2013 to December 2023. Each patient received a 3D‐printed cutting guide and a 3D‐printed custom‐made prosthesis tailored to their specific anatomical needs, based on high‐resolution imaging and computer‐aided design.

The use of custom‐made 3D prostheses resulted in a reoperation rate of 46%, primarily due to complications such as infection and mechanical failures. Specific complications included an 8% rate of deep infections and mechanical issues like aseptic loosening. Local recurrence was observed in 5 patients (21%) at a median time of 5 months post‐surgery. Despite these challenges, the average MSTS score was 83.7%, indicating a high level of functional recovery post‐surgery.

The integration of 3D printing in pelvic reconstructions for bone sarcomas significantly enhances anatomical and functional outcomes. However, the technology demands further refinement to reduce complication rates. Continued advancements in 3D‐printing materials and techniques are crucial to maximizing the benefits of this innovative approach in orthopedic oncology.

A 60‐year‐old male patient with Grade 2 chondrosarcoma. High‐intensity signals were observed in the coronal (A) and transverse (B) MRI images (T1‐fat suppression with contrast) in the left hemi‐pelvis, involving the periacetabular area but without infiltration into the hip joint. 3D computer renderings for the frontal (C) and lateral (D) views of the left hemi‐pelvis show the planned P1–P2–P3 resection highlighted [in red] and the planned 3D‐printed custom‐made cutting guide positioning and fixation [in white]. (E) 3D computer renderings post‐tumor resection depict the insertion of the 3D‐printed prosthesis and its fixation points. The actual cutting points were confirmed using a 3D‐printed bone model. The fixation points for the cancellous screws and stems were also determined, allowing for the calculation of the appropriate lengths for drilling and the sizes of the planned screws or stems. (E) Postoperative CT 3D reconstruction after the tumor resection and prosthetic reconstruction. It should be noted that the screw on the ischial branch is not included in the figure, as resection was extended intraoperatively and fixation omitted in that region, following soft tissue disease progression observed during chemotherapy.