Custom-made, three-dimensionally-printed (3D) bone prostheses gain increasing importance in the reconstruction of bone defects after musculoskeletal tumor resections. They may allow preservation of little remaining bone stock and ensure joint or limb salvage. However, we believe that by constructing anatomy-imitating implants with highly cancellous titanium alloy (TiAl₆V₄) surfaces using 3D printing technology, further benefits such as functional enhancement and reduction of complications may be achieved. We present a case series of four patients reconstructed using custom-made, 3D-printed intercalary monobloc tibia prostheses treated between 2016 and 2020. The mean patient age at operation was 30 years. Tumor resections were performed for Ewing sarcoma (n = 2), high-grade undifferentiated pleomorphic bone sarcoma (n = 1) and adamantinoma (n = 1). Mean resection length was 17.5 cm and mean operation time 147 min. All patients achieved full weight-bearing and limb salvage at a mean follow-up of 21.25 months. One patient developed a non-union at the proximal bone-implant interface. Alteration of implant design prevented non-union in later patients. Mean MSTS and TESS scores were 23.5 and 88. 3D-printed, custom-made intercalary tibia prostheses achieved joint and limb salvage in this case series despite high, published complication rates for biological and endoprosthetic reconstructions of the diaphyseal and distal tibia. Ingrowth of soft tissues into the highly cancellous implant surface structure reduces dead space, enhances function, and appears promising in reducing complication rates.

This study aimed to retrospectively analyze the follow-up results of cases in which the adjacent joint was preserved using a custom-made uncemented short-stem design (hollow stem) with optional external flanches in tumor endoprosthetic replacement due to bone sarcomas in 13 patients (with an average age of 9.6 years) between 2017 and 2023. Reconstructions were proximal femur (n = 6), intercalary femur (n = 4), intercalary tibia (n = 2), and proximal humerus (n = 1) tumor prostheses. The hollow body was used distally in 10 of the megaprotheses, proximally in 1, and both proximally and distally in 2 of them. The average distance from the joints was 6 cm in stems with flanches and 11.8 cm in stems without flanches. No aseptic loosening or deep infection was observed during an average follow-up of 34 months. Except for one case with a tibial intercalary prosthesis that needed a revision, all cases were well osteointegrated and all lower extremity cases could bear full weight without pain. In cases where the remaining bone stock after bone resection is insufficient for a standard stem implantation, reconstruction with a patient-specific short hollow-stem design appears to be a good alternative to protect healthy joints with high prosthesis survival and low revision rates in the short-term follow-up.

Joint Diseases and Related Surgery (JDRS), the official journal of the Turkish Joint Diseases Foundation, is an international, peer-reviewed, immediate open access journal. All published articles in JDRS has been free for everyone, without embargo, since 1990.

Background: Soft tissue sarcomas (STS) in children, adolescents, and young adults are rare and biologically heterogeneous, and prognostic factors for local recurrence, metastasis, and survival remain incompletely defined. This study aimed to characterize oncological outcomes and to explore clinical, surgical, and treatment-related factors associated with these endpoints at a tertiary sarcoma center. Methods: This retrospective single-center cohort study included 42 consecutive patients aged ≤25 years with histologically confirmed STS who underwent definitive surgery between June 2018 and November 2025. Local recurrence-free (LRFS), metastasis-free (MFS), event-free (EFS), and overall survival (OS) were estimated by the Kaplan–Meier method with competing-risks sensitivity analyses. Given the limited number of events, pre-specified univariable comparisons (log-rank, Fisher exact, Mann–Whitney U) were performed and regarded as exploratory. Results: The median age was 16.7 years and 26 patients (61.9%) were female. A microscopically complete (R0) resection was achieved in 35 of 41 patients with assessable margins (85.4%), and limb preservation in 38 (90.5%). Over a median follow-up of 23.1 months, the 24- and 60-month estimates were LRFS 85.7% and 79.6%, MFS 93.3% and 84.8%, EFS 82.3% and 64.7%, and OS 96.0% and 81.5%, respectively. Metastatic disease at diagnosis was the only variable associated with metastatic status at last follow-up (p = 0.035). No factor was robustly associated with local recurrence; anatomical site (p = 0.68), resection-margin status (p = 0.23), and tumor volume (p = 0.97) were not significant, and an apparent association with a sub-millimeter margin rested on a single event (complete separation). Conclusions: Metastatic disease at diagnosis emerged as the most important prognostic factor for MFS in our cohort. Despite the complexity of treatment in this young patient population, high rates of complete resection and limb preservation were achieved, highlighting the value of multidisciplinary management in specialized sarcoma centers. While the limited cohort size did not allow the identification of further statistically significant prognostic factors for local recurrence, such associations may become detectable in larger multicenter studies.