Subtotal proximal resection and tibial reconstruction with a modular endoprosthesis complemented with custom-made short distal stem (a case report)

Introduction Malignant tumors are frequently localized in the long bones. Radical resection and reconstruction with megaprostheses is the gold standard of surgery in this group of patients. Unfortunately, the use of standard modular components is not possible in subtotal resection or is associated with a high risk of instability. Development of personalized shortened components of endoprostheses based on 3D computer modeling expands the possibilities of limb salvage surgical treatment. Materials and methods We describe a case of surgical treatment of a patient with extensive tibial fibrosarcoma. Pre-operative diagnosis based on CT, MRI, PET-CT and biopsy was low-grade fibrosarcoma, post-operative diagnosis was the same. Radical subtotal proximal resection of the tibia was performed, and modular knee megaprosthesis based on 3D-modelling custom-made distal short tibial component of hybrid fixation was used for reconstruction. Rehabilitation after surgery included wearing knee and ankle orthoses. Results No tumor recurrence or metastases were revealed one year after surgery, functional and radiological results were excellent. Patient walked without support, her gate was correct, and MSTS score was 83 %. Discussion In recent years, custom-made short components of oncological endoprostheses using 3D computer modeling have been developed. The short custom-made tibial component used by us in the report is a combination of a short cemented stem locked with two extraosseous plates with a rough surface. It simultaneously ensures the strength of the implant and increases the contact with the distal tibia. Excellent radiological and functional results obtained one year after the operation allow us to hope for a positive outcome in the medium term and to delay extirpation of the tibia. Conclusion Radical bone resections and megaprosthetic reconstruction in malignant tumors provide the best functional results. Implementation of based on 3D-modelling custom-made prosthetic components in extensive resections is a perspective trend in limb-salvage surgery.