Is 3D-printed self-stabilizing endoprosthesis reconstruction without supplemental fixation following total sacrectomy a viable approach for sacral tumours?

PURPOSE: The spinopelvic reconstruction poses significant challenges following total sacrectomy in patients with malignant or aggressive benign bone tumours encompassing the entire sacrum. In this study, we aim to assess the functional outcomes and complications of an integrated 3D-printed sacral endoprostheses featuring a self-stabilizing design, eliminating the requirement for supplemental fixation. METHODS: We retrospectively analyzed patients with sacral tumours who underwent total sacrectomy followed by reconstruction with 3D-printed self-stabilizing endoprosthesis. Clinically, we evaluated functional outcomes using the 1993 version of the musculoskeletal tumour society (MSTS-93) score. Perioperative and postoperative complications were also documented. RESULTS: 10 patients met final inclusion criteria. The median age was 49 years (range, 31-64 years). The median follow-up time was 26.5 months (range, 15-47 months). Median postoperative functional MSTS-93 was 22.5 (range, 13-25). The median operation time was 399.5 min (305-576 min), and the median intraoperative blood loss was and 3200 ml (2400-7800 ml). Complications include wound dehiscence in one patient, bowel, bladder, and sexual dysfunction in four patients, cerebrospinal fluid leak in one patient, and tumour recurrence in one patient. There were no mechanical complications related to the endoprosthesis at the last follow-up. CONCLUSION: The utilization of 3D-printed self-stabilizing endoprosthesis proved to be a viable approach, yielding satisfactory short-term outcomes in patients undergoing total sacral reconstruction without supplemental fixation.

Reconstruction of the proximal radius with 3D-printed personalized prosthesis after tumor resection: case series.

BACKGROUND: Giant cell tumor of bone (GCTB) (Campanacci III) or malignant tumors extend to the epiphyseal region of the proximal radius, and intra-articular resection of the proximal radius is often needed. In the present study, we present the patients who underwent reconstruction of the proximal radius with 3D-printed personalized prosthesis after tumor resection, aiming to describe the prosthesis design and surgical technique and evaluate the clinical outcomes of this method. METHODS: Between November 2018 and January 2021, 9 patients received radial hemiarthroplasty with 3D-printed personalized prostheses after tumor resection. The pathologic diagnosis was GCTB (Campanacci III) in 7 patients, osteosarcoma (IIB) in 1 patient, and synovial sarcoma (IIB) in 1 patient. The range of motion (ROM) and strength in terms of elbow flexion/extension and forearm supination/pronation were evaluated. Pain was assessed by the visual analog scale (VAS) preoperatively and at each follow-up visit. To evaluate the functional outcome, the Mayo Elbow Performance Score (MEPS) system and the Musculoskeletal Tumor Society (MSTS) scoring system were administered at each follow-up visit. Complications and oncological outcomes were recorded. RESULTS: The patients were followed from 24 to 51 months, with a median follow-up of 35 months. No patients were lost to follow-up. During the follow-up, local recurrence and metastasis were not observed. The VAS score improved from a median of 5 points (range 4-7) preoperatively to 1 point (range 0-2) at the last follow-up visit. The mean MEPS score was 88.5% (83-93), and the mean MSTS score was 25.3 (24-27) at the last follow-up visit. No complications such as infection and aseptic loosening were detected. CONCLUSIONS: The implantation of a 3D-printed personalized prosthesis after proximal radial resection showed excellent oncologic outcomes and postoperative function at short-term follow-up and is a viable alternative method for reconstruction of the proximal radius bone defect after tumor resection.

Advancements in Photothermal Therapy Using Near-Infrared Light for Bone Tumors.

Bone tumors, particularly osteosarcoma, are prevalent among children and adolescents. This ailment has emerged as the second most frequent cause of cancer-related mortality in adolescents. Conventional treatment methods comprise extensive surgical resection, radiotherapy, and chemotherapy. Consequently, the management of bone tumors and bone regeneration poses significant clinical challenges. Photothermal tumor therapy has attracted considerable attention owing to its minimal invasiveness and high selectivity. However, key challenges have limited its widespread clinical use. Enhancing the tumor specificity of photosensitizers through targeting or localized activation holds potential for better outcomes with fewer adverse effects. Combinations with chemotherapies or immunotherapies also present avenues for improvement. In this review, we provide an overview of the most recent strategies aimed at overcoming the limitations of photothermal therapy (PTT), along with current research directions in the context of bone tumors, including (1) target strategies, (2) photothermal therapy combined with multiple therapies (immunotherapies, chemotherapies, and chemodynamic therapies, magnetic, and photodynamic therapies), and (3) bifunctional scaffolds for photothermal therapy and bone regeneration. We delve into the pros and cons of these combination methods and explore current research focal points. Lastly, we address the challenges and prospects of photothermal combination therapy.

The optimal strategy for 3D-printed uncemented endoprosthesis for the bone defect reconstruction of the distal radius, based on biomechanical analysis and retrospective cohort study.

INTRODUCTION: Prosthetic reconstruction after resecting giant cell tumor of bone (GCTB) of the distal radius has been proposed. However, this is generally associated with various complications. To improve the functional outcomes, we designed a three-dimensional (3D)-printed uncemented endoprosthesis. Meanwhile, using finite-element analysis and clinical observation, an optimization strategy was explored. MATERIALS AND METHODS: We retrospectively analyzed patients with Campanacci III or recurrent GCTB of the distal radius who underwent 3D-printed uncemented endoprosthesis reconstruction. Clinically, according to the different palmar tilts of the endoprosthesis, patients were divided into the biological angle (BA) group and the zero-degree (ZD) group. We recorded and evaluated the differences in functional outcomes and complications between the two groups. Biomechanically, four 3D finite-element models (normal and customized endoprostheses with three different implemented palmar tilts) were developed. RESULTS: We analyzed 22 patients (12 males and 10 females). The median follow-up period was 60 (range, 19-82) months. Of the 22 patients, 11 patients were included in the BA group and the remaining 11 patients were in the ZD group. Both groups showed no significant differences in the range of motion, Mayo score, and disabilities of the arm, shoulder, and hand scores postoperatively. The subluxation rate was significantly lower in the ZD group than in the BA group. The biomechanical results showed similar stress and displacement distribution patterns in the normal and prosthetic reconstruction models. Additionally, the endoprosthesis with 0° palmar tilt showed better biomechanical performance. CONCLUSION: 3D-printed uncemented endoprosthesis provides acceptable midterm outcomes in patients undergoing distal radius reconstruction. Optimizing the design by decreasing the palmar tilt may be beneficial for decreasing the risk of wrist joint subluxation.

Is three-dimension-printed mesh scaffold an alternative to reconstruct cavity bone defects near joints?

PURPOSE: Reconstruction of cavity bone defects after curettage of benign bone tumours around the joint remains challenging. We designed a novel 3D-printed mesh scaffold as a substitute for bone cement, aiming to support the articular surface, protect the subchondral bone, and reduce complication rates. METHODS: We retrospectively analyzed seven patients who received curettage and reconstruction using a 3D-printed mesh scaffold between January 2020 and June 2021. Pain and function were evaluated using the 10-cm Visual Analogue Scale (VAS) score and the 1993 version of the Musculoskeletal Tumor Society (MSTS-93) score. Radiographs were used to evaluate articular surface supporting, subchondral bone protection, and complications. RESULTS: The median functional MSTS-93 and VAS scores were both improved after surgery, and the median 3D-printed mesh scaffold volume was smaller than the median defect volume. Articular surface supporting, subchondral bone preservation, and osteogenesis were observed post-operatively. No related complications were observed during the last follow-up. CONCLUSIONS: The 3D-printed mesh scaffold provided sufficient mechanical support for the articular surface and protected the subchondral bone. We recommended the 3D-printed mesh structure as an alternative to repair cavity bone defects around joints.

Role of crosstalk between STAT3 and mTOR signaling in driving sensitivity to chemotherapy in osteosarcoma cell lines.

Osteosarcoma (OS) is a malignant bone neoplasm, mostly occurring in pediatric patients. OS is characterized by a highly aggressive and metastatically active tumor. Chemotherapy followed by surgical excision is the treatment of choice but is often associated with both chemoresistance and relapse. Hence, it is important to develop further understanding of OS pathogenesis and identify potential therapeutic targets. Both the signal transducer and activator of transcription 3 (STAT3) and mammalian target of rapamycin (mTOR) have been implicated in OS pathogenesis. Crosstalk between mTOR and STAT3 signaling has been shown to regulate hypoxia-induced angiogenesis in other diseases. In this study, we determined using OS cell lines if there is a crosstalk between these two pathways and how that impacts sensitivity to treatment with Rapamycin. OS cell lines exhibited differential sensitivity to mTOR inhibitor Rapamycin. Evaluation of phosphorylated STAT3 showed that in Rapamycin-sensitive 143B cells, the inhibitor decreased phosphorylation of STAT3 at Y705, but not at S727 whereas, in Rapamycin-resistant U2OS cells, the inhibitor decreased S727 phosphorylation but not Y705. However, knockdown of STAT3 in U2OS cells made them sensitive to Rapamycin. Immunofluorescence (IF) analysis showed that mTOR is constitutively activated in the 143B cells but is suppressed in the U2OS cells, indicating that this might be their reason for being resistant to Rapamycin. Both cell lines were sensitive to treatment with the STAT3 inhibitor Napabucasin (NP). Treatment with NP inhibited STAT3 activation at Y705 and additionally inhibited mTOR activation, indicating crosstalk between STAT3 and mTOR signaling pathways. Rapamycin could effectively prevent lung metastasis in an orthotropic OS mice model using 143B cells. However, Rapamycin could not inhibit lung metastasis in mice injected with U2OS cells. The STAT3 inhibitor NP attenuated lung metastasis with the U2OS cells. Our results thus established yet undefined crosstalk of STAT3 and mTOR signaling pathways in OS and highlight the possibility of using mTOR inhibitors for treatment in patients with OS.

Revision for Solid-Body Breakage of the 3D-Printed Implant Following Joint-Sparing Surgery: A Technical Note.

BACKGROUND: The advent of three-dimensional (3D)-printed custom-made implants has revolutionized orthopaedic surgery, particularly in limb- and joint-sparing surgeries. However, clinical experience in the revision for 3D-printed implant breakage is lacking, and the revision surgery remains challenging. This study reported the revision of proximal tibial prosthetic reconstruction necessitated by solid-body breakage of a 3D-printed implant, aiming to detail the surgical techniques and evaluate postoperative outcomes. CASE PRESENTATION: A patient diagnosed with osteosarcoma underwent joint-sparing surgery with a 3D-printed implant, but implant breakage occurred during subsequent follow-up. The initial implant was broken into two parts: the proximal implant breakage part (IBP) integrated with the host bone and the distal IBP left in the prosthetic component. Four revision protocols were devised, each based on one of the four hypothesis results of taking out the initial implant. A new custom-made implant and a series of assistance devices ("positioning devices," "drill devices," "tap devices," and "separator devices") were specifically prepared for revision surgery. The proximal IBP was taken out from the host bone, but the distal IBP was not taken out from the initial prosthetic component. The patient received the new custom-made implant for reconstruction, with the knee joint preserved. The patient recovered uneventfully after revision surgery and achieved satisfactory function. The Musculoskeletal Tumor Society was 28 at the last follow-up. No complications were detected during the follow-up period. CONCLUSION: Comprehensive preoperative planning and preparation, enabling the surgeon to effectively address intraoperative challenges, are crucial for the successful revision of 3D-printed implant breakage. It is feasible to re-implant a 3D-printed custom-made implant, demonstrating satisfactory clinical and functional results.

Survivorship, complications, and functional outcomes of uncemented distal femoral endoprosthesis with short, curved stem for patients with bone tumours.

Aims: Endoprosthetic reconstruction following distal femur tumour resection has been widely advocated. In this paper, we present the design of an uncemented endoprosthesis system featuring a short, curved stem, with the goal of enhancing long-term survivorship and functional outcomes. Methods: This study involved patients who underwent implantation of an uncemented distal femoral endoprosthesis with a short and curved stem between 2014 and 2019. Functional outcomes were assessed using the 1993 version of the Musculoskeletal Tumour Society (MSTS-93) score. Additionally, we quantified five types of complications and assessed osseointegration radiologically. The survivorship of the endoprosthesis was evaluated according to two endpoints. A total of 134 patients with a median age of 26 years (IQR 16 to 41) were included in our study. The median follow-up time was 61 months (IQR 56 to 76), and the median functional MSTS-93 was 83% (IQR 73 to 91) postoperatively. Results: Overall, 21 patients (16%) encountered complications, and the rate of aseptic loosening was 7% (9/134). The survival rate up to 8.5 years was 93% for aseptic loosening as the endpoint, and 88% for any reason as the endpoint, retrospectively. Conclusion: The use of an uncemented distal femoral endoprosthesis with a short, curved stem demonstrated a low incidence of aseptic loosening and achieved long-term survivorship of up to nine years. Meanwhile, aseptic loosening typically occurs in the early stage postoperatively.

Short-to-Mid-Term Outcomes of Ipsilateral Femoral Head Autograft Combined with Uncemented Total Hip Replacement for Partial Periacetabular Defects Following Tumor Resection.

OBJECTIVE: Periacetabular tumors, especially in young to middle-aged patients with invasive benign tumors or low-grade malignant tumors involving type II or II + III, present significant challenges due to their rarity and the complexity of the anatomical and biomechanical structures involved. The primary difficulty lies in balancing the need to avoid unfavorable oncological outcomes while maintaining postoperative hip joint function during surgical resection. This study aimed to evaluate the effectiveness and reliability of a surgical method involving partial weight-bearing acetabular preservation combined with the use of an uncontaminated femoral head autograft to reconstruct the segmental bone defect after intra-articular resection of the tumorous joint, providing a solution that ensures both oncological safety and functional preservation of the hip joint in these patients. METHODS: We conducted a retrospective study with a follow-up period of at least 36 months. From January 2010 to October 2020, we reviewed 20 cases of patients under 60 year of age with periacetabular invasive benign tumors or primary low-grade malignant tumors. All patients underwent reconstruction of the tumorous joint using autologous femoral head grafts. Data collected included patient age, gender, tumor type, preoperative and postoperative visual analog scale (VAS) scores, Musculoskeletal Tumor Society (MSTS) scores, Harris Hip Scores (HHS), patient survival rates, postoperative tumor recurrence, and surgical complications. To analyze the data, we utilized various statistical methods, including descriptive statistics to summarize patient demographics and clinical characteristics, and paired sample t-tests to compare preoperative and postoperative scores. RESULTS: The study included 20 patients, and a total median follow-up was 83 months. Their pathologic diagnoses comprised 13 giant cell tumors (GCTs), 5 chondrosarcomas, one chondroblastoma, and 1 leiomyosarcoma. Postoperatively, the median differences in vertical and horizontal center of rotation (COR) were 3.8 and 4.0 mm. Median limb length discrepancy (LLD) postoperatively was 5.7 mm (range, 2.3-17.8 mm). Two patients (10%) experienced delayed wound healing, resolved with antibiotics and early surgical debridement. One patient experienced dislocation 3 months postoperatively, which was promptly addressed under general anesthesia without further dislocation. CONCLUSION: Through multiplanar osteotomy with limited margins, femoral head autograft, and uncemented total hip replacement for pelvic segmental bone defects in selected patients in type II or II + III appears to be an encouraging limb-sparing surgery worthy of consideration for carefully selected patients.

The application of lung immune prognostic index in predicting the prognosis of 302 STS patients.

Background: Soft tissue sarcoma (STS) are heterogeneous and rare tumors, and few studies have explored predicting the prognosis of patients with STS. The Lung Immune Prognostic Index (LIPI), calculated based on baseline serum lactate dehydrogenase (LDH) and the derived neutrophils/(leukocytes minus neutrophils) ratio (dNLR), was considered effective in predicting the prognosis of patients with pulmonary cancer and other malignancies. However, the efficacy of the LIPI in predicting the prognosis of patients with STS remains unclear. Methods: This study retrospectively reviewed patients with STS admitted to our center from January 2016 to January 2021. Their hematological and clinical characteristics were collected and analyzed to construct the LIPI specific to STS. The correlations between various predictive factors and overall survival (OS) were examined using Kaplan-Meier and Cox regression analyses. Independent risk factors for OS were identified using univariate and multivariate analyses. Finally, a LIPI nomogram model for STS was established. Results: This study enrolled 302 patients with STS, of which 87 (28.9%), 162 (53.6%), and 53 (17.5%) were classified into three LIPI-based categories: good, moderate, and poor, respectively (P < 0.0001). The time-dependent operator curve showed that the LIPI had better prognostic predictive ability than other hematological and clinical characteristics. Univariate and multivariate analyses identified the Fédération Nationale des Centres de Lutte Contre le Cancer grade (FNCLCC/G), tumor size, and LIPI as independent risk factors. Finally, a nomogram was constructed by integrating the significant prognostic factors. Its C-index was 0.72, and the calibration curve indicated that it could accurately predict the three- and five-year OS of patients with STS. The decision and clinical impact curves also indicated that implementing this LIPI-nomogram could significantly benefit patients with STS. Conclusion: This study explored the efficacy of the LIPI in predicting the prognosis of 302 patients with STS, classifying them into three categories to evaluate the prognosis. It also reconstructed a LIPI-based nomogram to assist clinicians in predicting the three- and five-year OS of patients with STS, potentially enabling timely intervention and customized management.

Three-dimensional printed custom-made modular talus prosthesis in patients with talus malignant tumor resection.

BACKGROUND: Talar malignant tumor is extremely rare. Currently, there are several alternative management options for talus malignant tumor including below-knee amputation, tibio-calcaneal arthrodesis, and homogenous bone transplant while their shortcomings limited the clinical application. Three-dimensional (3D) printed total talus prosthesis in talus lesion was reported as a useful method to reconstruct talus, however, most researches are case reports and its clinical effect remains unclear. Therefore, the current study was to explore the application of 3D printed custom-made modular prosthesis in talus malignant tumor. METHODS: We retrospectively analyzed the patients who received the 3D printed custom-made modular prosthesis treatment due to talus malignant tumor in our hospital from February 2016 to December 2021. The patient's clinical data such as oncology outcome, operation time, and volume of blood loss were recorded. The limb function was evaluated with the Musculoskeletal Tumor Society 93 (MSTS-93) score, The American Orthopedic Foot and Ankle Society (AOFAS) score; the ankle joint ranges of motion as well as the leg length discrepancy were evaluated. Plain radiography and Tomosynthesis-Shimadzu Metal Artefact Reduction Technology (T-SMART) were used to evaluate the position of prosthesis and the osseointegration. Postoperative complications were recorded. RESULTS: The average patients' age and the follow-up period were respectively 31.5 ± 13.1 years; and 54.8 months (range 26-72). The medium operation time was 2.4 ± 0.5 h; the intraoperative blood loss was 131.7 ± 121.4 ml. The mean MSTS-93 and AOFAS score was 26.8 and 88.5 respectively. The average plantar flexion, dorsiflexion, varus, and valgus were 32.5, 9.2, 10.8, and 5.8 degree respectively. One patient had delayed postoperative wound healing. There was no leg length discrepancy observed in any patient and good osseointegration was observed on the interface between the bone and talus prosthesis in all subjects. CONCLUSION: The modular structure of the prosthesis developed in this study seems to be convenient for prosthesis implantation and screws distribution. And the combination of solid and porous structure improves the initial stability and promotes bone integration. Therefore, 3D printed custom-made modular talus prosthesis could be an alternative option for talus reconstruction in talus malignant tumor patients.

Intercalary Prosthetic Reconstruction with Three-Dimensional-Printed Custom-Made Porous Component for Defects of Long Bones with Short Residual Bone Segments After Tumor Resection.

BACKGROUND: Intercalary reconstruction for patients with short residual bone segments remains challenging. Three-dimensional (3D)-printed custom-made porous implants are a promising technique for short-segment fixation in these patients. This study aims to evaluate the efficiency of 3D-printed custom-made porous components (3DCPCs) for short-segment fixation, focusing on prosthesis survivorship, radiographic results, and potential complications. METHODS: This retrospective study involved 39 patients who underwent intercalary prosthetic reconstruction with 3DCPCs after tumor resection of the femur, tibia, or humerus from June 2015 to October 2020. Segment bone loss involved the femur (n = 15), tibia (n = 16), and humerus (n = 8), leaving 78 residual bone segments. There were 46 short segments requiring 46 3DCPCs and 32 segments with the ability to accommodate 32 off-the-shelf standard uncemented stems for prosthesis fixation. Clinical and functional outcomes were evaluated. Prosthesis-overall survivorship and prosthesis-specific survivorship were analyzed using Kaplan-Meier survival analysis. Radiographic results and modes of failure of using this technique were also examined. RESULTS: The mean follow-up was 41 months. The prosthesis-overall survivorship was 87.2% and 84.6% at 2 and 5 years, respectively. The prosthesis-specific survivorship was 92.1% and 89.5% at 2 and 5 years, respectively. There was not a substantial difference in prosthesis survivorship among the femur, tibia, and humerus. The average MSTS score was 26.2, ranging from 22 to 28. The radiographic evaluation results revealed excellent or good interface (38/46) in most of the 46 porous components. A total of 38 of 46 bone segments' remolding demonstrated no change. In total, seven patients (16.3%) had complications requiring further surgery. CONCLUSION: The prosthesis survivorship of using 3DCPCs for short-segment fixation is similar or better compared to other studies involving intercalary prosthetic reconstruction with short-segment fixation. Radiographic evaluation revealed good osteointegration and avoidance of stress shielding. Overall, intercalary prosthetic reconstruction with 3DCPC is a feasible modality for patients with short residual bone segments after tumor resection.

Biomimetic design and clinical application of Ti-6Al-4V lattice hemipelvis prosthesis for pelvic reconstruction.

OBJECTIVE: This study aims to biomimetic design a new 3D-printed lattice hemipelvis prosthesis and evaluate its clinical efficiency for pelvic reconstruction following tumor resection, focusing on feasibility, osseointegration, and patient outcomes. METHODS: From May 2020 to October 2021, twelve patients with pelvic tumors underwent tumor resection and subsequently received 3D-printed lattice hemipelvis prostheses for pelvic reconstruction. The prosthesis was strategically incorporated with lattice structures and solid to optimize mechanical performance and osseointegration. The pore size and porosity were analyzed. Patient outcomes were assessed through a combination of clinical and radiological evaluations. RESULTS: Multiple pore sizes were observed in irregular porous structures, with a wide distribution range (approximately 300-900 µm). The average follow-up of 34.7 months, ranging 26 from to 43 months. One patient with Ewing sarcoma died of pulmonary metastasis 33 months after surgery while others were alive at the last follow-up. Postoperative radiographs showed that the prosthesis's position was consistent with the preoperative planning. T-SMART images showed that the host bone was in close and tight contact with the prosthesis with no gaps at the interface. The average MSTS score was 21 at the last follow-up, ranging from 18 to 24. There was no complication requiring revision surgery or removal of the 3D-printed hemipelvis prosthesis, such as infection, screw breakage, and prosthesis loosening. CONCLUSION: The newly designed 3D-printed lattice hemipelvis prosthesis created multiple pore sizes with a wide distribution range and resulted in good osteointegration and favorable limb function.

3D-Printed Personalized Lattice Implant as an Innovative Strategy to Reconstruct Geographic Defects in Load-Bearing Bones.

OBJECTIVE: Geographic defect reconstruction in load-bearing bones presents formidable challenges for orthopaedic surgeon. The use of 3D-printed personalized implants presents a compelling opportunity to address this issue. This study aims to design, manufacture, and evaluate 3D-printed personalized implants with irregular lattice porous structures for geographic defect reconstruction in load-bearing bones, focusing on feasibility, osseointegration, and patient outcomes. METHODS: This retrospective study involved seven patients who received 3D-printed personalized lattice implants for the reconstruction of geographic defects in load-bearing bones. Personalized implants were customized for each patient. Randomized dodecahedron unit cells were incorporated within the implants to create the porous structure. The pore size and porosity were analyzed. Patient outcomes were assessed through a combination of clinical and radiological evaluations. Tomosynthesis-Shimadzu metal artifact reduction technology (T-SMART) was utilized to evaluate osseointegration. Functional outcomes were assessed according to the Musculoskeletal Tumor Society (MSTS) 93 score. RESULTS: Multiple pore sizes were observed in porous structures of the implant, with a wide distribution range (approximately 300-900 um). The porosity analysis results showed that the average porosity of irregular porous structures was around 75.03%. The average follow-up time was 38.4 months, ranging from 25 to 50 months. Postoperative X-rays showed that the implants matched the geographic bone defect well. Osseointegration assessments according to T-SMART images indicated a high degree of bone-to-implant contact, along with favorable bone density around the implants. Patient outcomes assessments revealed significant improvements in functional outcomes, with the average MSTS score of 27.3 (range, 26-29). There was no implant-related complication, such as aseptic loosening or structure failure. CONCLUSION: 3D-printed personalized lattice implants offer an innovative and promising strategy for geographic defect reconstruction in load-bearing bones. This approach has the potential to match the unique contours and geometry of the geographic bone defect and facilitate osteointegration.

3D-printed Personalized Porous Acetabular Component to Reconstruct Extensive Acetabular Bone Defects in Primary Hip Arthroplasty.

OBJECTIVE: Management of extensive acetabular bone defects in total hip arthroplasty (THA) remains challenging. This study aims to investigate the feasibility and preliminary outcomes of 3D-printed personalized porous acetabular components for the reconstruction of acetabular defects in primary THA. METHODS: This retrospective study involved seven patients who received 3D-printed acetabular components in primary THA between July 2018 and March 2021. Preoperatively, acetabular bone defects were evaluated by referencing the Paprosky classification. There were two "Paprosky type IIIA" defects and five "Paprosky type IIIB" defects. The acetabular components were custom-made for each patient to reconstruct the extensive acetabular defects. The hip function was assessed according to the Harris hip score (HHS). Clinical and radiographic outcomes were assessed. RESULTS: The average follow-up period was 40 months, ranging from 26 to 57 months. There were no patients lost to follow-up. The HHS improved from 44 (range: 33-53) before the operation to 88 (range: 79-93) at the final follow-up. Postoperative X-rays showed that the 3D-printed personalized components were properly fitted with the acetabulum. The average center of rotation (COR) discrepancy was 2.3 mm horizontally and 2.1 mm vertically, respectively. Tomosynthesis-Shimadzu metal artifact reduction technology images showed that the implant was in close contact with the host bone. Moreover, no complications were observed during the follow-up period, including loosening, dislocation, or component protrusion. CONCLUSION: The implantation of 3D-printed personalized acetabular components showed accurate reconstruction, stable mechanical support, and favorable function at short-term follow-up. This may be a viable alternative method for reconstructing extensive acetabular defects in THA.

Case report: Individualized 3D-printed uncemented distal fibular prosthesis preserving the lateral malleolus for repair of distal fibular defects.

Background: Involvement of the distal fibula by alveolar soft-part sarcoma is rare. Extensive resection or amputation may be needed; however, distal fibula resection can disrupt foot and ankle biomechanics, leading to ankle joint instability. Reports on joint preservation for maintaining optimal ankle joint function are scarce. Computer-aided design and individualized three-dimensional (3D)-printed uncemented implants represent an evolving solution for reconstructing the distal fibula. Case presentation: A 34-year-old woman was diagnosed with alveolar soft-part sarcoma in the right lower leg involving the cortical bone of the fibula. After anlotinib treatment, the tumor size decreased, and the tumor response rate was a partial response (PR); however, the patient continued to experience adverse reactions. With multiple disciplinary team discussions, surgical resection was deemed appropriate. Due to the extensive defect and ankle joint instability after resection, a custom-made 3D-printed prosthesis was designed and fabricated to reconstruct the defect, preserving the lateral malleolus. During the follow-up, the patient achieved favorable ankle function, and no prosthesis-related complications were observed. Conclusion: 3D-printed personalized uncemented implants constitute a novel approach and method for addressing the reconstruction issues of the distal fibula and ankle joint. Through the personalized design of 3D-printed prostheses, the lateral malleolus can be preserved, ensuring the normal anatomical structure of the ankle joint. They achieve a well-integrated interface between the prosthesis and bone, ensuring satisfactory postoperative function. Additionally, they offer valuable insights for reconstructing distal bone defects near joints in the extremities. However, confirming these findings requires extensive cohort studies.

Efficacy and safety of anlotinib in patients with desmoid fibromatosis: a retrospective analysis.

Introduction: Desmoid fibromatosis is an aggressive fibroblastic neoplasm with a high propensity for local recurrence. Targeted therapy for Desmoid fibromatosis represents a novel avenue in systemic treatment. Anlotinib, a novel multitargeted angiogenesis inhibitor, represents a novel approach for targeted therapy. Therefore, this study aims to assess the efficacy and safety of anlotinib in patients with Desmoid fibromatosis. Methods: We retrospectively gathered the clinical medical records of Desmoid fibromatosis patients who underwent anlotinib treatment between June 2019 and November 2023 at our center. Anlotinib was initiated at a daily dose of 12 mg and adjusted based on drug-related toxicity. Tumor response was evaluated using the Response Evaluation Criteria in Solid Tumors 1.1 criteria. Progression-free survival served as the primary endpoint and was analyzed utilizing the Kaplan-Meier method. Results: In total, sixty-six consecutive patients were enrolled. No patients achieved a complete response; however, fourteen patients (21.21%) exhibited a partial response, while forty-six patients (70%) experienced disease stability. Progressive disease was observed in 6 patients (9.10%), and the progression-free survival rates at 12 and 36months were 89.71% and 82.81%, respectively. The disease control rate was 90.91%, while the objective response rate was 21.21%. Conclusion: Anlotinib proves effective in managing recurrent and symptomatic patients with Desmoid fibromatosis. However, the toxicity profile of anlotinib presents a higher risk of Hand-Foot Skin Reaction and hypertension. Therefore, given that 41.67% of patients were subjected to dose adjustments associated with the initial dose of 12 mg, implementing dosage reductions may help balance efficacy with side effects.

Nanosilicate-reinforced GelMA-PEGDA hydrogel promotes angiogenesis for bone regeneration.

Bone tissue engineering has emerged as a pivotal field addressing the critical clinical needs of bone fractures. This study focused on developing multi-composite hydrogels by synergizing biocompatible GelMA macromolecules with synthetic PEGDA and reinforcing them with nanosilicates (SN). The incorporation of SN introduces crucial trace elements such as silicon, magnesium, and lithium, promoting both angiogenesis and osteogenesis. Characterizations revealed that PEGDA significantly reinforced the composite hydrogels' stability, while SN further enhanced the mechanical integrity of the GelMA-PEGDA-SN (GPS) hydrogels. Cell studies designated that GPS improved cell proliferation and migration, angiogenic VEGF/eNOS expression and osteogenic differentiation. In vivo experiments showed that GPS hydrogels effectively enhanced calvarial bone healing, with the GPS-2 formulation (2 % SN) displaying superior bone coverage and increased vascular formation. Assessments of osteogenic formation and the angiogenic marker CD31 validated the comprehensive bone regeneration potential of GPS hydrogels. These findings highlight the significant promise of GPS hydrogels in fostering bone healing with promoted angiogenesis.

Reconstruction of a 3D-printed endoprosthesis after joint-preserving surgery with intraoperative physeal distraction for childhood malignancies of the distal femur.

BACKGROUND: Joint-salvage surgery has been proposed in children with metaphysis malignancy of the distal femur. However, there is still some drawbacks regarding to the surgical technique and endoprosthetic design. In this study, we evaluated the efficacy of a joint-sparing surgical technique for the distal femur in pediatric patients using intraoperative physeal distraction and reconstruction of a 3D-printed endoprosthesis. METHODS: We retrospectively analyzed pediatric patients with distal femoral malignancy who underwent intraoperative physeal distraction and 3D-printed endoprosthetic reconstruction. Clinically, we evaluated functional outcomes using the 1993 version of the Musculoskeletal Tumor Society (MSTS-93) score pre- and post-operation. Complications were also recorded. RESULTS: Seven children with a median age of 11 years (range 8-15 years) were finally included in our study. The median follow-up time was 30 months (range 27-59 months). The median postoperative functional MSTS-93 score was increased compared with the preoperative scores. The bone-implant interface showed good osseointegration. One patient developed deep infection and another had lung metastasis after surgery. Endoprosthetic complications were not observed. CONCLUSION: We recommended that joint-preserving surgery with intraoperative physeal distraction and a 3D-printed endoprosthesis for reconstruction as an option for malignancies of the distal femur in selected pediatric patients.

3D-printed custom-made short stem with porous structure for fixation of massive endoprosthesis in joint-preserving reconstruction after tumor resection.

BACKGROUND: Large malignant bone tumors and revision limb salvage procedures often result in massive bone loss, leaving a short residual bone segment that cannot accommodate a standard stem for endoprosthesis fixation. Three-dimensional-printed (3DP) short stem with porous structure seems to be an alternative for short-segment fixation. This retrospective study aims to evaluate surgical outcomes, radiographical results, limb functions, and complications of using 3DP porous short stems in massive endoprosthesis replacement. METHODS: Between July 2018 to February 2021, 12 patients with massive bone loss undergoing reconstruction with custom-made, short-stemmed massive endoprostheses were identified. Endoprosthesis replacement involved the proximal femur (n = 4), distal femur (n = 1), proximal humerus (n = 4), distal humerus (n = 1), and proximal radius (n = 2). RESULTS: The mean percentage of resected bone was 72.4% of the whole length of the bone, ranging from 58.4 to 88.5%. The mean length of 3DP porous short stems was 6.3 cm. The median follow-up was 38 months (range, 22-58 months). The mean MSTS score was 89%, ranging from 77% to 93%. Radiographical assessment results showed bone in-growth to the porous structure in 11 patients, and the implants were well osseointegrated. Breakage of the 3DP porous short stem occurred in one patient intraoperatively. The patient developed aseptic loosening (Type 2) four-month after surgery and underwent revision with a plate applied to assist fixation. The implant survivorship was 91.7% at 2 years. No other complications were detected, such as soft-tissue failures, structural failures, infection, or tumor progression. CONCLUSIONS: 3DP custom-made short stem with porous structure is a viable method for fixation of the massive endoprosthesis in the short segment after tumor resection, with satisfactory limb function, great endoprosthetic stability, and low complication rates.