# Subtotal diaphyseal replacement of the femur with modular mega-endoprosthesis following interprosthetic fracture. A case report

## TL;DR

A custom-made mega-endoprosthesis was successfully used to treat a rare interprosthetic femoral fracture, resulting in significant recovery and pain relief for the patient.

## Contribution

The paper presents a novel off-label use of a custom subtotal diaphyseal endoprosthesis for interprosthetic femoral fracture.

## Key findings

- The surgical procedure was completed in one hour and 40 minutes without complications.
- The patient achieved full weight bearing and reported no pain at one-year follow-up.
- Significant improvement was observed in the Harris Hip Score and WOMAC Index.

## Abstract

Mega-endoprostheses enable wide management options in the treatment of primary and periprosthetic fracture of the lower extremities. In this study, we report on the use of custom-made subtotal diaphyseal endoprosthetic replacement in treatment of interprosthetic femoral fracture. This procedure is off-label, but in this particular case, it was the safest and most stress-stable treatment option. The implant was delivered within three weeks. The surgical procedure for subtotal replacement of the femoral diaphysis was performed without any intra- or postoperative complication. The duration for the surgical intervention was one hour and 40 minutes. The patient was then mobilized with full weight bearing. At one-year follow-up, the patient did not complain of any pain. The Harris Hip Score HHS improved from 26 to 83 at one-year follow-up, the Western Ontario and McMaster Universities Osteoarthritis Index WOMAC improved from 88 to 16. Mega-endoprostheses enable a wide range of management options in the treatment of primary, peri- and interprosthetic fractures of the lower extremities. In many cases, an individual therapeutic plan is necessary ranging up to the use of custom-made implants.