Search Results (62)

This is a retrospective, single-center cohort study comparing the long-term radiographic osseointegration and aseptic loosening between a 3D-printed EPORE^® collar and a prior generation HA-coated collar in endoprosthetic reconstructions. Achieving stable bone integration in endoprosthetic reconstructions remains challenging, with hydroxyapatite (HA)-coated collars being the only option available in the past. Earlier studies from our center have shown reliable and accelerated osseointegration at the bone–collar interface using a novel highly porous 3D-printed EPORE^® collar system compared to a previously used HA-coated collar. Methods: Twenty-eight patients who underwent an implantation of endoprostheses utilizing the novel 3D-printed EPORE^® collar system were case-matched to 24 patients who had previously undergone surgeries using a HA-coated collar. The mean age at surgery was 65.2 years (range: 17–95 years). Patients in the HA-coated collar group had a mean age of 63.8 years (range: 17–86 years), while those in the 3D-printed collar group had a mean age of 66.7 years (range: 32–95 years), with no statistically significant difference between groups (p = 0.876). A minimum radiological and clinical follow-up of 2 years was available in all included cases. Osseointegration was evaluated using postoperative plain radiographs in two planes based on a previously validated semi-quantitative score. Results: When aseptic loosening was used as the primary endpoint, no failures occurred in the 3D-printed EPORE^® group during the study period. The overall rate of stem loosening (including both aseptic and septic causes) was 7% (2/28) in the 3D-printed group and 16% (4/24) in the HA-coated group. All cases of loosening in the 3D-printed cohort were related to septic failure. This translates into a 2-year aseptic-loosening-free survival of 100% in the 3D-printed group. When the radiographic osseointegration was analyzed as the endpoint, the rate of successful osseointegration was significantly higher in the 3D-printed group (92.9%, 26/28; 95% CI 76.5–99.1%) compared with the HA-coated group (70.8%, 17/24; 95% CI 48.9–87.4%; p = 0.04). The distribution of ongrowth scores also differed significantly between groups. The highest ongrowth score (grade 4) was achieved in 82.14% of 3D-printed implants (23/28; 95% CI 63.1–93.9%), compared with 37.5% of HA-coated implants (9/24; p = 0.0002). The time to achieve grade 4 ongrowth was significantly shorter in the 3D-printed cohort, with a median of 470 days (IQR 360–610), compared with 1482 days (IQR 1020–1860) in the HA-coated group (p < 0.0001). In addition, patients in the 3D-printed implant group had a significantly higher mean body mass index compared with the HA-coated group (32.51 vs. 28.36, p = 0.01). Conclusions: These results show that the novel highly porous 3D-printed EPORE^® collars reduce aseptic loosening and accelerate extracortical bridging in endoprosthetic replacements. This benefit persisted even in higher BMI or revision contexts when compared to the previously used HA-coated collars. Full article

The number of patients who require endoprosthetic treatment related to osteoporosis has increased in recent years. Vitamin D3 supplementation has long been standard practice in osteoporosis treatment, while vitamin K2 has gained importance. Using our in vitro model, we compared the osteogenic behaviour of primary healthy human osteoblasts (hOBs) and primary osteoporotic human osteoblasts (hopOBs) under unchanged conditions, with vitamin K2, vitamin D3 and the combined addition. Fluorescence microscopy examinations on a plastic surface and a rough titanium surface structure revealed morphological differences. A quantitative analysis of mineralisation and differentiation was performed using an alizarin red S assay and analysis of alkaline phosphatase activity. It was shown that the hopOBs behave differently morphologically on the titanium surface, while hopOBs are particularly noticeable due to the higher number of cell–cell interactions with vitamin K2. The rough surface led to more pronounced mineralisation of the hopOBs. This effect was pronounced under vitamin K2. Vitamin D3 had an effect in the initial phase of hopOB differentiation. Overall, vitamin K2 had a greater influence on the mineralisation of hopOBs than expected. It must be assumed that vitamin K2 plays a significantly greater role in the metabolism of hopOBs than previously assumed. Full article

(1) Background: The reconstruction of periacetabular defects after tumor resection remains one of the most challenging procedures in orthopaedic oncology. The modular LUMiC^® system was designed to improve fixation stability and reduce implant-related complications compared with earlier hemipelvic prostheses. We investigated patient and implant survival after LUMiC^® reconstruction, complication types and functional outcomes. (2) Methods: Eighteen patients (8 men, 10 women; mean age 58.9 years) underwent LUMiC^® endoprosthetic reconstruction between 2011 and 2025. Kaplan–Meier analysis was used to estimate patient and implant survival. Complications were categorized according to Henderson. Functional results were evaluated at follow-up using MSTS and TESS. (3) Results: Mean follow-up was 35.52 months (SD 36.89). Overall implant survival was 72.2%. Instability (27.8%) and infection (16.7%) were the leading complications. Two-thirds of patients required at least one revision (mean 3.1 revisions per case). Metastatic disease reduced patient survival (p = 0.012) but did not affect implant longevity (p = 0.31). Functional outcomes were available for only 3 of 18 patients and should therefore be regarded as exploratory. Mean MSTS was 58.9% (SD 21.43) and mean TESS was 73.4% (SD 6.836). (4) Conclusions: Despite high revision rates, the LUMiC^® prosthesis provides durable fixation. Early revision does not appear to compromise implant survival. However, the small and heterogeneous cohort represents a limiting factor of this study. Full article

The long-term success of orthopedic implants is fundamentally dependent on the synergy between mechanical performance and biological integration. Thus, a comprehensive investigation of both mechanical characteristics and microstructural parameters is essential for the development of reliable implant systems in hip arthroplasty, both in human medicine and veterinary practice. The present study provides a detailed analysis of the mechanical properties, microstructure, and chemical composition of a Ti-6Al-4V-based femoral implant using nanoindentation, scanning electron and optical microscopy, and energy-dispersive X-ray spectroscopy. Then, using finite element analysis, the influence of Young’s modulus on the stress–strain state of the endoprosthesis was evaluated. Dynamic loading conditions were considered by analyzing an impact on a cantilever beam, simulating an animal’s jump onto a supporting limb. For reliable numerical simulation, the model geometry was constructed utilizing computed X-ray microtomography. The numerical simulations were performed for three material cases: reference Ti-6Al-4V, experimentally characterized Ti-6Al-4V (with properties determined by nanoindentation), and CoCrMo alloy, which is also widely used in endoprosthetic applications. The influence of the founded mechanical characteristics on the stress–strain state of the prostheses was assessed. In particular, the results indicate that under dynamic loading conditions, the load-bearing capacity of CoCrMo is lower by approximately 30% and 21% compared to the reference and experimentally characterized Ti-6Al-4V, respectively. Full article

Background and Objectives: Total femoral replacement (TFR) was originally developed for limb salvage following the resection of malignant tumors. Over time, its indications have expanded, now serving as a reconstructive option for failed endoprosthetic replacements and severe trauma cases. Despite its advantages, TFR is a highly complex surgical procedure associated with significant complication rates. This study aims to analyze the management of complications and propose strategies to mitigate associated risks. Materials and Methods: This is a retrospective study conducted on patients from two independent hospitals who underwent TFR for different reasons. Results: Nineteen patients were included: eight underwent TFR for oncological indications, while 11 had the procedure as a revision following failed endoprosthetic arthroplasty or trauma. Postoperative complications were observed in 10 patients (53%), including hip dislocation (21%), mechanical implant failure (11%), infection (21%), wound healing complications (26%), and metal allergy symptoms (5%). Revision surgery was required in six patients (32%), but no cases necessitated amputation. Conclusions: TFR is associated with a high risk of complications, with infection and wound healing issues being the most prevalent. In our experience effective complication management strategies should include early intervention, considering TFR at an earlier stage in non-oncological patients to minimize multiple revision surgeries; allergy screening, assessing for potential metal hypersensitivity preoperatively; dislocation prevention, implementing dual mobility bearings to reduce instability; infection control, utilizing intraoperative local antibiotic therapy in revision cases; and wound management, applying vacuum-assisted closure (VAC) therapy postoperatively to enhance wound healing. Implementing these strategies may improve patient outcomes and reduce the burden of complications associated with TFR. Full article

Background: Limb-salvage surgery using extendable distal femoral endoprostheses has become the standard reconstruction following tumor resection in skeletally immature patients, allowing continued growth and improved function. However, mechanical complications, particularly tibial pain, remain challenging and poorly understood. This study aimed to identify radiographic predictors of tibial pain and evaluate their potential utility in early risk detection. Methods: A retrospective cohort study was conducted of 29 skeletally immature patients (mean age 10.4 years) who underwent expandable distal femoral endoprosthetic replacement between 2008 and 2018 at a tertiary orthopedic oncology center. Standardized radiographs were analyzed at 6 months and final follow-up (mean 75 months) to assess cortical thickness, stem-to-cortex distances, stem migration, stress shielding, pedestal formation, and periosteal reaction. Associations between radiographic parameters and tibial pain were assessed using multivariable logistic regression, t-tests, and chi-square analyses. Results: Seventeen patients (58.6%) developed activity-limiting tibial pain requiring analgesics, as documented during follow-up. Mean medial and lateral cortical thickness increased from 3.0 mm and 3.4 mm to 4.1 mm and 5.1 mm, respectively. The logistic regression model demonstrated strong explanatory power (Pseudo R² = 0.57, p = 0.004). Medial cortical thickness at last follow-up was the only significant independent predictor of tibial pain (p = 0.042), and was significantly associated with tibial pain. Patients with tibial pain exhibited greater medial cortical thickening (p < 0.001). Stem migration (φ = 0.421, p = 0.065), stress shielding (φ = 0.476, p = 0.044), pedestal formation (φ = 0.608, p = 0.004), and periosteal reaction (φ = 0.569, p = 0.008) were also associated with pain. Conclusions: Medial cortical hypertrophy emerged as a potential radiographic biomarker for tibial pain. after expandable distal femoral endoprosthesis in growing patients. The findings suggest that cortical remodeling, stress shielding, and pedestal formation collectively reflect stem micromotion and bone adaptation. Early radiographic surveillance of these parameters warrants further investigation in prospective studies to determine their clinical utility. Larger multicenter studies are warranted to validate these predictors and refine postoperative monitoring protocols. Full article

(1) Background: Pelvic osteosarcoma accounts for a small proportion of osteosarcoma cases but is associated with significantly poorer outcomes than extremity tumors. This study evaluates contemporary survival outcomes and prognostic factors in a single-center cohort. (2) Methods: We retrospectively analyzed 56 patients with primary pelvic osteosarcoma treated between 2006 and 2019. Demographic characteristics, surgical margins, adjuvant therapies, local recurrence, metastasis, survival outcomes and the Musculoskeletal Tumor Society (MSTS) Score were assessed. Kaplan–Meier analysis was performed for overall survival (OS), including subgroup analyses by age and Enneking classification. (3) Results: Median age at surgery was 24 years. R0 margins were achieved in 96.4% of cases. OS at 1, 3, and 5 years was 69%, 54%, and 48%, respectively. Younger patients (≤25 years) showed significantly improved 5-year OS (68%) compared with older groups. Enneking classification showed limited prognostic discrimination. Metastatic disease at any time strongly predicted inferior survival (5-year OS 30% vs. 66%). The mean MSTS score one year after operation was 14.1 points. Functional outcome showed marked variability and was strongly influenced by patient age, extent of resection, reconstruction strategy, and postoperative complications. Younger patients and those undergoing limited or non-acetabular reconstructions achieved superior functional results, whereas complex endoprosthetic reconstructions and revision-requiring complications were associated with reduced MSTS scores. (4) Conclusions: Pelvic osteosarcoma continues to be associated with substantial morbidity and mortality. Younger age and absence of metastatic disease are strong predictors of improved survival. Functional outcomes are typically moderate; further advances are needed to improve results. Full article

Objective: To compare the clinical prognosis of metal endoprosthetic reconstruction versus biological reconstruction in the treatment of limb osteosarcoma and to analyze associated prognostic factors. Methods: From October 2014 to October 2021, a retrospective study was carried out of patients with high-grade extremity osteosarcoma. Patients were categorized into two groups based on the type of reconstruction: endoprosthetic reconstruction and biological reconstruction. Demographic data and prognosis were systematically compared between the two groups. Furthermore, a Cox proportional hazards model was employed to evaluate the risk factors associated with recurrence and survival outcomes. Results: A total of 133 patients were enrolled in the study, comprising 88 patients in the endoprosthetic reconstruction group and 45 patients in the biological reconstruction group. The 5-year overall survival (OS) and disease-free survival (DFS) rates for the endoprosthetic reconstruction group were 76.2% and 70.5%, respectively, which were higher than those observed in the biological reconstruction group (64.3% and 60%). Additionally, the local recurrence rate was significantly higher in the biological reconstruction group compared to the endoprosthetic reconstruction group (17.8% vs. 2.3%, p = 0.004). Cox regression analysis revealed that pathological fracture (p = 0.034) and the biological reconstruction (p = 0.007) were independent risk factors for local recurrence. Conclusions: Endoprosthetic reconstruction may be preferable for patients requiring early functional recovery or presenting with pathological fractures. Biological reconstruction may be considered for younger patients with diaphyseal defects and demanding long-term functional requirements, albeit with elevated local recurrence risk. Individualized decision-making incorporating tumor location, patient age, and functional goals is essential. Full article

Background/Objectives: Osteosarcoma and Ewing sarcoma are the predominant malignant bone tumors of the lower limbs in children. With 5-year survival rates of 70–77% for localized disease, limb salvage with growth-compatible reconstruction has replaced amputation as the standard. This review aimed to synthesize current reconstruction strategies, propose an age-and defect-based decision algorithm, and highlight growth-preserving innovations for skeletally immature patients. Methods: This narrative review of surgical techniques—including rotationplasty, biological reconstruction (vascularized/non-vascularized fibula, allograft, recycled autograft, “hot dog” composite), bone transport, and endoprosthetic replacement (modular, extendable, 3D-printed)—was conducted, with a literature search covering January 1990 to October 2025 and emphasized pediatric studies published after 2020, emphasizing pediatric outcomes, complication profiles, and functional scores. Results: Across pediatric and mixed-age cohorts (typically n ≈ 10–30 per technique; median follow-up 3–10 years), rotationplasty demonstrated high durability with Musculoskeletal Tumor Society (MSTS) scores of 21–28/30, especially in children < 6 years. Biological reconstruction achieved >80% union in defects < 6 cm, while vascularized fibula grafts yielded 82–95% union for 6–15 cm defects. Bone transport produced reliable union for 3–15 cm defects but required prolonged fixation (40–60 days/cm) and had high pin-tract infection rates (50–60%). Extendable endoprostheses demonstrated 5-year prosthesis survival of 54–87%, while early joint-preserving 3D-printed implants improved MSTS scores from 17 to 28 points in a pediatric series (n = 7, mean follow-up 30 months). Conclusions: Personalized reconstruction guided by a child-centered algorithm optimizes oncologic control, skeletal growth, and long-term function. Emerging 3D-printed joint-preserving implants and noninvasive lengthening technologies promise further reduction in revisions and complications in pediatric limb salvage. Full article

Given the higher incidence of bone tumors in younger populations, achieving post-operative biomechanical stability is critical to maintaining long-term mobility. The objective of this study was to evaluate the biomechanical impact of endoprosthetic reconstruction in patients with distal femur and proximal tibia bone tumors in comparison with a control group. The Embase, Scopus, PubMed, and Cochrane databases were systematically searched until January 2025, according to PRISMA guidelines. Heterogeneity was assessed via Cochran’s Q statistic and quantified using the I² statistic. A total of 23 studies with 692 participants were included, providing data on gait, knee muscle strength, energy expenditure during walking, physical activity level, balance, and joint position sense. Patients demonstrated significant reductions in gait velocity, cadence, and stride length relative to healthy controls, with abnormalities also observed in ground reaction forces, joint internal moments, and joint power. Additionally, both knee flexion strength and extension strength decreased markedly. This study highlights that endoprosthetic reconstruction substantially altered the biomechanical characteristics of the lower limb in patients with distal femur and proximal tibia tumors. These findings have shown the need for further refinement of surgical techniques, rehabilitation strategies, and follow-up programming. Full article

The number of endoprosthetic implants is constantly increasing. Successful osseointegration of the inserted material into the bone is essential for a prosthesis to remain in the bone as long as possible. In the clinical setting, a roughened titanium surface of implants is used as standard to enable the best possible osseointegration. Vitamin K2 and vitamin D3 play a decisive role in dynamic bone metabolism and therefore also influence osseointegration. For the first time, we carried out in vitro investigations with clinically relevant cells, primary healthy human osteoblasts (hOBs). We qualitatively compared the adhesion behaviour of hOBs on a plastic surface, a smooth, regular titanium surface structure and a roughened, irregular titanium surface structure by scanning electron microscopy and fluorescence microscopy. The osteogenic behaviour and the osteogenic differentiation capacity were quantitatively investigated by analysing the activity of alkaline phosphatase and the alizarin red S assay under the influence of vitamin K2, vitamin D3 and the combination of both vitamins. It was shown that more adhesion points formed between the cells and the titanium on the rough surface structure. In addition, a solid cell network developed more quickly on this side, with cell runners forming in three-dimensional space, which means the interactions between the cells across different cell layers. On the other hand, a structured cell network also appeared on the regular smooth surface structure, which means that the network seems to be formed and built up along a defined structure. The addition of vitamins further increased the osteogenic differentiation capacity on the rough titanium surface structure. In particular, the isolated addition of vitamin K2 showed an improved osteogenic differentiation in the long-term observation, whereas the combined addition of both vitamins promoted the initial osteogenic differentiation. Vitamin K2, therefore, plays a greater role in osseointegration than previously assumed. This opens up new possibilities for the use of vitamin K2 during and after the surgical insertion of an implant. The use of vitamin K2 should be reconsidered for clinical applications in implant care and further investigated clinically. Full article

Background/Objective: Endoprosthetic proximal femoral replacement is a reconstructive procedure for preserving ambulatory function following tumor resection. Different prosthetic systems for endoprosthetic proximal femoral replacement may result in different stem placement techniques, especially regarding the anteversion angle of the stem. The aim of this study was to evaluate femoral rotation and stem anteversion following endoprosthetic proximal femoral replacement using two different prosthetic systems, and to investigate their influence on postoperative quality of life. Methods: We retrospectively reviewed 30 patients who underwent endoprosthetic proximal femoral replacement at our institution between 2008 and 2022. The evaluated parameters included patient demographics, anatomical and functional stem anteversion, femoral rotation, femoral resection length, implant type, and Musculoskeletal Tumor Society score. Results: The cohort comprised 16 males and 14 females with a mean age of 65.2 ± 13.5 years. Twenty patients received the Global Modular Replacement System implants and 10 received the Kyocera Modular Limb Salvage System implants. The mean anatomical stem anteversion was 17.0 ± 17.7°, and the mean femoral rotation was 14.4 ± 22.6°. The Global Modular Replacement System implants demonstrated less variability in anatomical stem anteversion (11.7 ± 15.2°) compared to the Kyocera Modular Limb Salvage System (27.6 ± 18.4°, p = 0.02). A significant negative correlation was found between anatomical stem anteversion and femoral rotation (r = −0.78, p < 0.01), and a positive correlation between femoral rotation and functional stem anteversion (r = 0.62, p < 0.01). Musculoskeletal Tumor Society scores were available in 14 patients and correlated significantly with functional stem anteversion (r = −0.62, p = 0.02) and femoral resection length (r = −0.61, p = 0.02), but not with anatomical stem anteversion or femoral rotation alone. Conclusions: This study demonstrated that stem placement angles differ between prosthetic systems. These differences are attributable to variations in surgical implantation techniques and prosthesis design philosophies. In particular, the Global Modular Replacement System incorporates built-in anteversion, and when using such prostheses, referencing the linea aspera enables more stable restoration of the anatomical stem anteversion. Excessive reduction in anatomical stem anteversion is not recommended to avoid excessive external femoral rotation. Full article

Background: Megaprosthetic replacement is widely used following tumour resection but remains challenged by periprosthetic joint infection (PJI) and variable functional outcomes. This narrative review aims to summarise current evidence on infection rates, prevention strategies, and functional outcomes following proximal humerus megaprosthetic reconstruction. We hypothesise that antibacterial coatings and improved soft-tissue techniques reduce infection rates and enhance functional recovery. Methods: A comprehensive narrative review of PubMed, Web of Science, and the Cochrane Library was performed using the terms proximal humerus, shoulder, bone tumor, sarcoma, neoplasm, infection, megaprosthesis, and endoprosthetic replacement. Reference lists were screened manually. Case reports and series with fewer than five patients were excluded. Twenty-seven clinical studies (more than 1100 patients; mainly osteosarcoma, chondrosarcoma, and metastatic lesions) were included and qualitatively analyzed. Results: The reported infection rates ranged from 4% to 20%, with higher risk in patients receiving adjuvant therapy. Silver-coated implants reduced PJI compared with uncoated designs (e.g., 11.2% → 9.2% in primary implants; 29.2% → 13.7% in revisions) without systemic toxicity. Alternative antibacterial coatings (e.g., silver- or copper-enriched hydroxyapatite) showed promising early results but remain supported by limited clinical data. Soft-tissue stabilization with Trevira tube or synthetic mesh improved joint stability and did not increase infection risk. Functional outcomes, usually assessed by MSTS or TESS, were moderate to good (≈60–80%) overall, with better scores when the deltoid and axillary nerve were preserved or when reverse total shoulder arthroplasty was possible. Conclusions: Proximal humerus megaprosthetic reconstruction benefits from meticulous soft-tissue handling, selective use of antibacterial technologies, and multidisciplinary management. The current literature is mainly retrospective, heterogeneous, and non-comparative. Prospective multicenter studies are needed to clarify the long-term effectiveness of silver or alternative coatings, soft-tissue reconstruction techniques, and emerging custom-made 3D-printed prostheses. Full article

Background: The reconstruction of diaphyseal bone defects following tumor resection offers various biological and endoprosthetic treatment options. The present study analyzes the impact of the fixation method (cemented; uncemented; with locking screw; without locking screw) of the diaphyseal implant on clinical outcomes. Factors such as patient age and weight as well as tumor type and location are also considered. Methods: This study included 39 patients who underwent intercalary endoprosthetic reconstruction of the humerus (n = 4); femur (n = 29); and tibia (n = 6) between 1998 and 2020. Prosthetic complications, fixation methods and the MSTS score for functional outcome were statistically analyzed using SPSS and R. Results: The event-free probability in the competing risk model was 61% (95% CI 43–74%) after one year and 11% (95% CI 3–28%) after five years. The complication rate in the patient cohort was 54%. Cementless prosthesis fixation was associated with a statistically significant better functional outcome. Additionally, higher body weight and older patient age were associated with lower MSTS scores. Conclusions: Patients requiring rapid remobilization or adjuvant radiation therapy may benefit more from diaphyseal implants compared to biological reconstructions. However, the complication and revision rates of diaphyseal implants are elevated. The chosen fixation method shows a statistically significant influence on functional outcome. Full article

Objectives: The indications for femoral endoprosthesis replacement (EPR) use in limb reconstruction have broadened over the last decade. Despite its success, loosening remains the most common reason for failure. No previous system has classified loosening based on the anatomical site in relation to the prosthesis. The aim of this study is to propose a simple reproducible classification system for EPR loosening. Methods: Adult patients that underwent a revision EPR for loosening from 1 January 2023–1 May 2025 were included. Radiographs and computed tomography (CT) images were retrospectively reviewed. The grading was developed on radiographs to classify loosening around EPRs as normal (grade 1), loosening at the shoulder (grade 2), loosening around the shaft of the peg (grade 3), loosening below the tip of the prosthesis (grade 4), associated penetration of prosthesis through the cortex (grade 5), and associated fracture (grade 6). Results: A total of 28 patients were included. The majority of patients were male (n = 17; 61%) with a mean age of 50.6 years (SD 16.1). The average time from the index surgery to diagnosis of loosening was 10.1 years (SD 7.6). The most common pattern of loosening was grade 3 (N = 16; 57.1%). Conclusions: Our classification system proposes an easily adopted way to describe all patterns of loosening around EPRs, potentially guiding revision surgical strategies. Standardizing the approach in evaluating loosening will aid in producing national guidelines for managing this complex complication and may help improve future EPR design. Full article