Case Report: Winkelmann hip rotationplasty as a last-resort solution.

Background: Rotationplasty, an invasive surgery, serves as an alternative to amputation in pediatric orthopedic oncology. It is currently applied in broader cases (e.g., infection, trauma, or malignant tumors). Winkelmann Type BII rotationplasty is a rare procedure with limited literature. Furthermore, no description of rotationplasties where the femur is attached to the sacroiliac joint has been published to date. Methods: Between September 2022 and March 2023, three patients underwent Type BII rotationplasty. We used the Clavien-Dindo classification to describe postoperative complications and the musculoskeletal tumor society score (MSTS) for functional result assessments. Results: One patient suffered from multiple complications during the first 6 months postoperatively, one presented a single complication, and one had no complications after 4 and 3 months postoperatively, respectively. Two patients could walk pain-free with the help of crutches. One patient developed a crack on the femur, which did not require surgical revision. They all achieved satisfactory joint amplitudes of at least 50° in passive hip flexion. Unfortunately, one of the patients suffered from lung metastases. Conclusions: Winkelmann's Type BII rotationplasty is a reliable alternative to hindquarter amputation. Furthermore, we demonstrated that complete resection of the iliac wing and femur fixation through the sacroiliac joint is feasible.