Abstract
INTRODUCTION AND IMPORTANCE: Pelvis reconstruction after tumor resection poses a challenge, especially in younger patients where preserving the patient's function and mobility is paramount. CASE PRESENTATION: A 16 years old female presented in March 2019 with vague right iliac area pain, diagnosed as pelvic Ewing's sarcoma after imaging studies (MRI and MSCT scan) and obtaining an incisional biopsy. After initial chemotherapy cycles, the tumor decreased in size, and surgical intervention in two stages was performed. The first stage was in October 2019 and consisted of pelvic resection type I and II according to Enneking and Dunham classification, proximal femur upshifting to compensate for the pelvic bone defect, and a cement spacer to fill the space of the resected proximal femur. The second stage was performed after two months and consisted of implanting a total hip arthroplasty using Megaprostheses and a cementless dual mobility acetabular cup. No local recurrence or distant metastases were detected during follow-ups. At the final follow up after 36 months, the patient showed acceptable functional outcomes (HHS score 83, and MSTS score 23 (76.7 %) points), and the radiographs showed proper implant positioning and stability. CLINICAL DISCUSSION: Treating pelvic Ewing's sarcoma requires a multidisciplinary team. After surgical resection, the pelvic reconstruction options include using allografts or autografts, femur upshifting, and hemipelvis prostheses, which should be chosen considering patients and tumor characteristics as well as surgical team efficiency. CONCLUSION: Reconstructing the pelvic defect after bone tumor resection by proximal femoral upshifting is a valid biological option with acceptable outcomes.