Abstract Introduction In computer-assisted bone tumor resection, surgeons manually plan cut planes with a safe margin before surgery and follow them using navigation during osteotomy. However, manual planning is prone to error and often fails to ensure adequate margins. To address this, we propose an efficient method to rapidly and accurately generate a 3D safe-margin volume that uniformly extends the tumor by a safe margin. Methods The study was conducted on 20 patients (9 males, 11 females) between May 2018 and October 2023. The average age was 41.75 ± 14.72 years (14–66) and the tumor types were chondrosarcoma in 5 cases, giant cell tumor in 5 cases, osteosarcoma in 2 cases, chordoma in 2 cases, Ewing sarcoma in 2 cases, spindle cell sarcoma in 1 case, osteochondroma in 1 case, chondromyxoid fibroma in 1 case and peripheral nerve sheath tumor in 1 case. The quality of the generated safe-margin volumes were assessed by visual comparison outcomes, geometric errors and maximum absolute geometric errors, time costs and clinical outcomes. Results All 20 patients were successfully followed up, with a mean follow-up duration of 42.30 ± 18.75 months (range: 3–86 months). The generated 3D safe-margin volumes were visually closer to the ground truth compared to those from the 3D morphological dilation and anisotropic distance transform methods. The method achieved a mean geometric error of approximately 0.10 mm, significantly lower than the dilation method (up to 10.00 mm) and the anisotropic method (about 1.00 mm). The average maximum absolute geometric error was 0.1818 mm, and statistical tests confirmed significant improvements (P-value < 0.01). The method also exhibited favorable computational efficiency, with an average runtime of 26.82 s, substantially faster than our previous point-based method (6.29 min) and acceptable for preoperative planning. Conclusion In this study, we developed a fast and accurate safe-margin volume generation method by combining 3D image resampling with anisotropic distance transform. This method shows strong potential in clinical practice.

Neoadjuvant radiotherapy is crucial in the treatment of soft tissue sarcoma, yet it faces multiple challenges. This study assessed the knowledge, attitudes, and practices (KAP) of Chinese orthopedic and soft tissue sarcoma specialists regarding neoadjuvant therapy. This multicenter cross-sectional study was conducted at multiple hospitals in Beijing between November and December 2023 and enrolled orthopedic and soft tissue sarcoma specialists through purposive sampling. The baseline characteristics, KAP regarding neoadjuvant therapy, and doctor-patient relationship were collected using an investigator-designed self-administered questionnaire. The analysis included 467 participants with non-problematic questionnaires. They were 42.20 years old, and the mean doctor-patient relationship scores were 22.61 ± 5.62. The mean KAP scores were 15.52 ± 2.68 (possible range: 0–18), 34.01 ± 2.87 (possible range: 8–40), and 26.19 ± 2.99 (possible range: 8–30), respectively. Significant differences in KAP were observed across demographic factors, including department affiliation and patient consultation frequency (P < 0.05). Positive correlations were observed between KAP, indicating that higher knowledge was associated with better attitudes and practices (P < 0.001). The structural equation modeling analysis revealed that knowledge had a direct positive effect on attitude (β = 0.526, P = 0.007) and that attitude had a direct positive effect on practice (β = 0.516, P = 0.005), while knowledge had no statistically significant direct effect on practice but had an indirect effect (β = 0.271, P = 0.002). Orthopedic and soft-tissue sarcoma specialists exhibited good knowledge, positive attitudes, and proactive practices regarding neoadjuvant radiotherapy for soft-tissue sarcoma. These findings underscore the need to optimize policies and healthcare services to improve the practice of soft tissue sarcoma management. Not applicable.

Background: Achieving adequate margins in pelvic bone tumor resection remains difficult, as conventional navigation provides no direct three-dimensional margin feedback. We proposed an innovative dangerous region generation method based on 3D image resampling and anisotropic distance transform, integrated with computer-assisted navigation, to enhance surgical margin accuracy. This study aimed to evaluate its oncological safety, functional outcomes, and perioperative efficacy in pelvic tumor surgery. Methods: The study was conducted on 19 patients (8 males, 11 females) with primary pelvic bone tumors between May 2018 and June 2024. The age range was 19 to 66 years (mean age: 62.67 years). Histological diagnoses included chondrosarcoma (n = 6), giant cell tumor (n = 4), osteosarcoma (n = 1), chordoma (n = 2), Ewing sarcoma (n = 3), spindle cell sarcoma (n = 1), chondromyxoid fibroma (n = 1), and peripheral nerve sheath tumor (n = 1). The feasibility of the dangerous region generation method for computer-assisted pelvic tumor resection surgery was assessed by general results, oncological and functional results. Results: All patients successfully underwent surgery with a mean operative time of 252 min and average intraoperative blood loss of 1358 mL. The mean hospital stay was 22 days, and all patients completed follow-up (mean, 37 months). Two patients developed postoperative wound complications, which resolved after debridement. Adequate surgical margins were achieved in all cases. The 5-year overall survival rate was 75.6%, increasing to 80.0% among patients with wide-margin resections. At the final follow-up, the mean MSTS score among 16 limb-salvage patients was 26.6, corresponding to an average functional recovery of 88.5%. Most patients exhibited a normal gait and were able to ambulate without assistive devices. Conclusions: This dangerous region generation method, when combined with computer-assisted techniques for pelvic bone tumor resection, is feasible and can achieve favorable clinical outcomes.

Aims:The aim of this study was to evaluate the long-term outcomes of computer navigation-assisted resection for primary pelvic bone tumours. Methods:Using our prospectively collected oncology database, a retrospective case control study was conducted on 63 patients who underwent computer navigation-assisted resection and 145 patients who underwent non-navigated resection for primary pelvic sarcomas between January 2000 and December 2018. The rates of local recurrence and mortality were calculated using the Kaplan-Meier method. The function and complications were recorded in the follow-up. Results:The local recurrence rates were 9.5% (6/63) in the navigation group and 19.3% (31/145) in the non-navigation group, respectively (p = 0.040). The two-, five-, and ten-year local recurrence-free survival (LRFS) rates were significantly higher in the navigation compared with non-navigation group (two-year 95% (95% CI 85 to 98) vs 86% (95% CI 79 to 91); p = 0.041; five-year and ten-year 89% (95% CI 77 to 95) vs 75% (95% CI 66 to 82); p = 0.025). Meanwhile, the two-, five-, and ten-year disease-specific survival (DSS) rates were statistically higher in the navigation compared with the non-navigation group (two-year 89% (95% CI 78 to 95) vs 76% (95% CI 68 to 82); p = 0.032; five-year 85% (95% CI 74 to 92) vs 63% (95% CI 54 to 71); p < 0.001; ten-year 85% (95% CI 74 to 92) vs 59% (95% CI 50 to 67); p < 0.001). The multivariate Cox regression showed that the use of navigation was associated with better LRFS and DSS. The mean Musculoskeletal Tumor Society (MSTS) scores were not found to be superior in the navigation group (85% (SD 10) in the navigation group vs 84% (SD 13) in the non-navigation group; p = 0.742). Conclusion:This study shows that computer navigation-assisted surgery improves the ability to achieve negative bone margins for primary pelvic sarcomas and has better DSS at long-term follow-up. Obtaining adequate soft-tissue margins remains a challenge, and our results show navigation assistance did not result in significant soft-tissue margin improvement. No function improvement was found, and further research is warranted to focus on precise resection and the important preservation of normal structures.

The purpose of this study was to investigate the clinical outcomes of joint-preserving endoprosthesis reconstruction for primary sarcomas about the knee. A retrospective cohort study was conducted on 45 patients (21 males, 24 females) who underwent joint-preserving endoprosthesis reconstruction (JPER) for bone tumours about the knee between January 2009 and January 2023. The average age was 23.9 ± 15.1 years (range, 7–66 years) and the most common pathological type was osteosarcoma (34), followed by Ewing’s sarcoma (5), adamantinoma (3), spindle cell sarcoma (2), and undifferentiated pleomorphic sarcoma (UPS, 1). There were 35 cases of tumors located in the femur and 10 cases located in the tibia. The oncological outcomes included local control, metastasis, progression-free survival, and overall survival. The functional outcomes were evaluated by the Musculoskeletal Tumour Society Score (MSTS-93). 45 patients were included in this retrospective study, and no patient were lost in the follow-up. The mean follow-up time was 105.3 ± 44.6 months (range, 15–183 months). Five patients (11.1

BACKGROUND:Proximal tibial resection and reconstruction with a hinged knee megaprostheses may result in severe limb length discrepancy (LLD) in very young children because of the removal of the distal femoral and proximal physis. An alternative reconstruction using a proximal tibial hemiarthroplasty reconstruction has been proposed and reduces the degree of LLD because the distal femoral physis is preserved. However, there are very few reports on the results from this reconstruction, and it is not certain that the disadvantages of a more unstable knee are outweighed by the possibility of reducing limb length inequality. QUESTIONS/PURPOSES:(1) What was the survivorship at 5 and 10 years after proximal tibial hemiarthroplasty reconstruction in children with malignant tumors, using amputation, endoprosthesis removal, and revision surgery as the main endpoints of interest? (2) What was the Musculoskeletal Tumor Society Score-93 (MSTS-93) after reconstruction at a minimum of 2 years after the procedure? (3) What percentage of patients experienced a major complication (resulting in unplanned reoperation), and what percentage of patients experienced minor complications (resulting in nonoperative treatment)? (4) What factors were associated with knee subluxation, and what factors were associated with an LLD measuring ≥ 4 cm? METHODS:This was a retrospective study performed by four consultant surgeons at a tertiary tumor referral center (Beijing Jishuitan Hospital, National Center for Orthopaedics, PR China) between 2005 and 2022. During that time, we generally recommended a tibial hemiarthroplasty to children with primary malignant tumors of the proximal tibia (Enneking stages IA, IB, and IIA and chemotherapy-responsive Stage IIB and IIIB tumors), as well as some metastatic tumors and some soft tissue sarcomas involving and surrounding the proximal tibia in children. We considered the ideal age range to be 9 to 13 years for males and 9 to 12 years for females, and we generally did not offer this procedure unless the surgeon believed that the neurovascular bundle was either uninvolved or could be separated during surgery. During that time, we considered 883 patients with primary malignant bone tumors to be potentially eligible. Of those, 781 were excluded because they underwent joint-preserving endoprosthetic reconstruction, recycled autografts, or extraarticular resection, leaving 110 who met the inclusion criteria for this study. Of those, 15% (16) of patients were lost to follow-up before the minimum follow-up of 2 years, leaving 85% (94) for analysis in this article at a mean ± SD follow-up time of 7 ± 4 years. The most common diagnoses were osteosarcoma (97% [91 of 94]) and Ewing sarcoma (3% [3 of 94]). The mean ± SD age was 11 ± 2 years; 57% (54 of 94) were male. At the last follow-up, 72% (68 of 94) of the patients had no evidence of disease, 9% (8) were alive with disease, 18% (17) had died of disease, and 1% (1) had died of other causes. Survivorship was estimated using the competing risk estimator, and data were presented at 5 and 10 years; outcome scores were derived from a longitudinally maintained institutional database. We reported on patients who developed major complications and underwent unplanned reoperation and minor complications that did not involve further surgery. Cox regression was used to evaluate the factors associated with knee subluxation and severe LLD (≥ 4 cm). RESULTS:Five-year and 10-year survival of the surgically treated limb free of amputation for all patients was 96% (95% confidence interval [CI] 91% to 99%) and 90% (95% CI 81% to 96%), respectively. The 5-year endoprosthesis removal-free survival rate for all patients was 94% (95% CI 89% to 99%), and the 10-year survival rate was 85% (95% CI 75% to 94%). The 5-year endoprosthetic survivorship free from any revision surgery for all patients was 86% (95% CI 77% to 92%), and the 10-year endoprosthetic survivorship was 68% (95% CI 57% to 79%). The mean ± SD MSTS-93 score was 83% ± 7%. Twenty-eight percent (26 of 94) of patients underwent a total of 28 reoperations. Three percent (3 of 94) of patients underwent revision for knee subluxation (n = 1) and aseptic loosening (n = 2), and 11% (10 of 94) of patients underwent endoprosthesis revision surgery or amputation for local progression (n = 7) and infection (n = 3). No patient had an epiphysiodesis. After controlling for confounding variables such as gender, endoprosthetic type, and mesh reconstruction, multivariate analysis showed that previous surgery at the same site (cause-specific HR 10 [95% CI 5.2 to 59.0]; p < 0.001) and not using medial gastrocnemius flaps (cause-specific HR 7.1 [95% CI 1.4 to 33.0]; p = 0.02) were associated with the increased risk of knee subluxation, whereas age at operation ≤ 9 years was associated with the increased risk of severe LLD (≥ 4 cm) (cause-specific HR 7.3 [95% CI 3.7 to 25.0]; p = 0.002). CONCLUSION:For skeletally immature patients with proximal tibial sarcomas, proximal tibial hemiarthroplasty appears to be a reasonable alternative to the standard rotating-hinge megaprosthesis, especially for pediatric patients age 10 years and older. This reconstruction can preserve the distal femoral epiphyseal growth capacity and thus potentially reduces final LLD. Moreover, patient age, skeletal maturity, implant availability, technical expertise, and surgeon preference should be considered when choosing a reconstructive approach after proximal tibial resection in children with osteosarcoma. This study did not compare pediatric patients treated with extendable prostheses. Future studies should consider direct comparisons between the two types of prosthetic reconstruction. LEVEL OF EVIDENCE:Level IV, therapeutic study.

Background:The ketogenic diet, characterized by high fat, moderate protein, and extremely low carbohydrate intake, has been widely used as a medical treatment for various conditions and has gained increasing attention in recent years due to its health benefits. Objectives:This study aims to investigate the effectiveness of a ketogenic diet on outcomes in cancer patients compared to conventional non-ketogenic diets. Materials and methods:Studies that assigned cancer patients to either a ketogenic diet or a standard diet control group were included. Two reviewers independently extracted and analyzed the data. Results:This meta-analysis revealed that the ketogenic diet significantly reduced fat mass, visceral fat, insulin levels, blood glucose, fatigue, and insomnia compared to a non-ketogenic diet while improving low-density lipoprotein (LDL) cholesterol, total cholesterol, thyroid-stimulating hormone (TSH) levels, protein uptake, ketosis events, emotional function, and social function. Furthermore, the ketogenic diet induced ketosis by increasing β-hydroxybutyrate levels. Conclusion:The ketogenic diet was found to improve cancer patients' outcomes more effectively than non-ketogenic diets. Notably, C-reactive protein levels showed greater improvement when the intervention lasted more than 12 weeks, with a diet composition of 2-4% carbohydrates, 16-18% protein, and 80-85% fat. Systematic review registration:(https://www.crd.york.ac.uk/PROSPERO/view/CRD42024553878) PROSPERO CRD4202455387.

This study was to evaluate the efficacy of soft tissue reconstruction using synthetic mesh and a medial gastrocnemius flap in patients who underwent proximal tibial hemiarthroplasty after resection of proximal tibial bone sarcomas. A retrospective cohort study was conducted on 102 skeletally immature children (58 males, 44 females) who underwent proximal tibial Hemiarthroplasty between January 2005 and December 2023. The most common diagnoses were osteosarcoma (95

BACKGROUND:The reconstruction options for Enneking II/II+III pelvic tumors-defined as periacetabular tumor with or without involving the pubis or ischium-remain controversial. Short-term outcomes of ipsilateral femoral head autograft for the reconstruction of acetabular defects have been reported in limited case series studies. However, the long-term stability and complications of this method remain unknown. QUESTIONS/PURPOSES:At a minimum of 5 years of follow-up: (1) What was the graft survival rate in patients who underwent pelvic Enneking II/II+III tumor resections using an ipsilateral autologous femoral head graft for reconstruction? (2) What were the radiologic outcomes? (3) What were the functional outcomes, and what factors were independently associated with poor functional outcomes (Musculoskeletal Tumor Society Score [MSTS]-93 scores < 80%)? (4) What percentage of patients experienced complications, and what were they? METHODS:Between January 2007 and June 2020, we surgically treated 583 patients with Enneking II/II+III pelvic tumors. Ten percent (61 of 583) of patients underwent amputation, 57% (335 of 583) underwent curettage, and the remaining 32% (187 of 583) underwent en bloc resection. During the period in question, we generally used en bloc resection in patients with primary pelvic tumors, invasive benign pelvic tumors, and metastatic pelvic tumors. Patients who underwent en bloc resection were considered potentially eligible for inclusion. This study only included patients who underwent Enneking II/II+III pelvic tumor resections with partial preservation of the acetabulum and ipsilateral femoral head autograft reconstruction and who had 5 years or more of follow-up. Twenty-one percent (120 of 583) of patients were excluded because they received other reconstruction methods. Although 2% (10 of 583) of patients had < 5 years of follow-up or were lost to follow-up, some patients may have experienced failure or complications prior to 5 years or at the time of loss to follow-up. Consequently, these patients should still be included, leaving 10% (57 of 583) of patients for analysis. The mean ± SD age at diagnosis was 41 ± 13 years, and the mean follow-up time was 11 ± 3 years. Fifty-one percent (29 of 57) of patients were men. The most common pathologic diagnoses were giant cell tumor of bone (42% [24 of 57]) and chondrosarcoma (35% [20 of 57]). At the last follow-up, 84% (48 of 57) of patients had no evidence of disease, 9% (5 of 57) were alive with disease, and 7% (4 of 57) died of disease. The graft cumulative removal rate and revision rate were estimated using the competing risk estimator. We used preoperative and postoperative thin-section CT scans to assess the displacement of the hip rotation center. We classified complications into major and minor complications according to whether patients underwent unplanned reoperation. The MSTS-93 score was used to assess functional outcomes. Preoperative and postoperative CT scans were used to assess the displacement distance of the hip rotation center and the femoral neck. Cox regression analysis was used to evaluate risk factors associated with poor postoperative functional scores (MSTS-93 < 80%). RESULTS:The cumulative implant removal rates at 2 years and 5 years were 2% (95% confidence interval [CI] 0.3% to 8%) and 5% (95% CI 1% to 13%), respectively. The revision rates at 2 years and 5 years were 10% (95% CI 4% to 18%) and 15% (95% CI 7% to 25%), respectively. The median (range) MSTS-93 score was 90% (57% to 100%). Sixteen percent (9 of 57) of patients developed a total of 11 complications, including five major complications and six minor complications. The most common complications were infection (5% [3 of 57]), delayed wound healing (5% [3 of 57]), and hip dislocation (4% [2 of 57]). After controlling for potential confounding variables such as gender, age, and previous surgery, we found that abductor muscle resection (cause-specific HR 2.9 [95% CI 1.3 to 6.1]; p = 0.012) was an independent risk factor associated with poor function. CONCLUSION:Among patients with Enneking II/II+III pelvic tumors with partial preservation of the acetabulum, ipsilateral autologous femoral head autografting combined with hip arthroplasty is a viable reconstructive approach. For patients who cannot undergo tumor prosthesis or allograft reconstruction because of difficulties in obtaining grafts, costs, or social and/or religious reasons, this reconstruction technique may be considered. Additionally, we do not recommend this surgery for patients with complete acetabular resection, as autologous femoral head transplantation is insufficient to completely compensate for bone defects. Future studies with larger sample sizes should compare the advantages and disadvantages of this reconstruction technique with prosthetic or biological reconstruction and focus on clarifying the patient indications for existing reconstruction techniques. LEVEL OF EVIDENCE:Level IV, therapeutic study.

Background:The aim of this study was to investigate the clinical outcomes and complications of vascularized fibular epiphyseal transfer (VFET) and clavicle pro humero (CPH) for proximal humeral reconstruction after primary sarcoma resection in skeletally immature patients. Patients and Methods:This retrospective case-control study included 29 skeletally immature patients (18 male patients, 11 female patients) with primary bone sarcomas who were treated between January 2009 and June 2023 at Beijing Jishuitan Hospital. The average age was 9.4 ± 2.8 years (range, 5-14), and the pathological type included osteosarcoma (25) and Ewing sarcoma (4). We compared the graft survival, function, and complication rate between the VFET group and the CPH group. Results:The 2-year and 5-year overall survival rates for the VFET group and CPH group were 94%, 75%, 86%, and 55%, respectively. The 2-year and 5-year revision-free survival for the VFET group and CPH group were 77%, 61%, 75%, and 37%, respectively. At the final follow-up, the mean MSTS-93 score in the VFET group was 82% (67%-97%), while the mean MSTS-93 score in the CPH group was 79% (73%-96%, p > 0.05). The incidence of mechanical complications was significantly higher in the CPH group (88%, 7/8) than that in the VFET group (52%, 11/21) (p = 0.036). The mean difference in upper limb length in the VFET group was 5.0 ± 2.9 cm and 10.2 ± 4.2 cm in the CPH group (p = 0.003). Conclusions:We suggest that vascularized fibular epiphyseal transfer may be considered as a promising biological reconstruction option for pediatric patients with proximal humeral osteosarcoma who have a longer life expectancy. For institutions lacking the necessary microsurgical techniques, clavicle pro humero reconstruction remains a relatively simple and feasible alternative reconstruction option. Level of Evidence:Level III Case-control study. See Instructions for Authors for a complete description of levels of evidence.

Background: Total humeral replacement (THR) is one of the few options for reconstruction when the humerus is extensively involved or with skip lesions. However, there are few studies focusing on the long-term outcomes of THR for primary sarcomas, and the function and endoprosthesis survival remains uncertain. Questions/purposes: The purposes of this study were to answer the following questions: (1) What are the oncological and functional outcomes of THR? (2) What are the overall survival (OS) and revision-free survival rates of THR? (3) What are the failure mechanisms of THR? Methods: A retrospective cohort study was conducted on 34 patients (22 males, 12 females) between January 1997 and December 2021. The average age was 30.1 +/- 20.1 years (7-72) and the pathological type included osteosarcoma (24), chondrosarcoma (6), Ewing's sarcoma (2), and undifferentiated pleomorphic sarcoma (2). The oncological outcomes included local recurrence, metastasis, and OS. The functional outcomes were assessed by the Musculoskeletal Tumor Society Score-93 (MSTS), the Toronto Extremity Salvage Score, the American Shoulder and Elbow Surgeons score, and the range of motion of the shoulder. All modes of failure were recorded in the follow-up. The significance level was adjusted to 0.025 after Bonferroni correction. Results: The mean follow-up of all patients was 78.5 +/- 72.6 months (range, 9-292 months) and 103 +/- 71.6 months (range, 32-292 months) in all survivors. Fourteen patients (41. 7%) died in the last follow-up. The 5-, 10-, and 15-year OS rate of the endoprosthesis was 94% (95% confidence interval 66.6%-99.1%). The average Musculoskeletal Tumor Society Score-93 score was 78% (range, 53%-86%), the average Toronto Extremity Salvage Score was 80% (60%-90%), and the average American Shoulder and Elbow Surgeons was 79% (63%-93%), respectively. The most common failure mechanisms were tumor progression (type 5, 17.6%, 6/34), followed by soft tissue failure (type 1, 14.7%, 5/34), and structural failure Conclusions: THR is a long-term reconstructive option for patients with massive tumors requiring complete resection of the humerus. The most common failure mechanisms were tumor progression (type 5) and soft tissue failure (type 1). Overall functional outcomes were acceptable with good hand and elbow function, but shoulder function was limited.

Abstract Objectives The aim of this study was to to investigate the outcomes of geographic resections with computer navigation for treatment of bone tumors in lower extremities. Methods A retrospective cohort analysis was conducted on 51 patients who underwent computer-navigation assisted (25 cases) and free-hand (26 cases) geographic resections of bone tumors in lower extremities between September 2010 and Feburary 2022. All patients’ bone defects were reconstructed by allograft bones. The oncological outcomes, functional outcomes, resection accuracy and complications were compared between these two groups in this study.The oncological outcomes comparasion included the local control,metastasis and 3-year and 5-year overall survival differences between the navigation-assisted (NA) group and the free-hand (FH) group. The oncological outcomes were evaluated by Musculoskeletal Tumor Society (MSTS) scores. The resection accuracy was evaluated by indicators such as the major-axis length,the minor-axis length and maximal gap. The resection error (RE) was defined as the resected specimen length minus the planned resection length and were compared between the two groups. The maximal gap error (MGE) was defined as the length between the margin of allograft bones and the host bones at the bone cutting sites. Results 51 consecutive patients was included in this retrosepective cohort and there were no patients lost in the follow-up period. The mean follow-up time was 93.76+38.49 (22-179) months. No navigation-related surgical complications were observed. The resection errors between the postoperative specimen length and the preoperative planned length were compared to evaluate the resection accuracy after surgery. In the navigation group, the resected errors of the long axis, short axis and depth were 1.760±1.109 (-3.9 to 3.8) mm, 1.32±0.571 (-2.3 to 2.3) mm and 1.58±0.360 (-2.1 to 2.3) mm in the navigation group and 3.67±1.829 (-4.2 to 3.4) mm, 4.61±2.488 (-9.4 to 10.4) mm and 4.21±1.902 (-7.1 to 9.5) mm in the free-hand group, respectively(p<0.001). While the comparasion of oncological, functional outcomes and complications between the groups didn’t show statistical difference (p>0.05). Conclusions These resection accuracy of computer-navigation assisted surgery is better than free-hand group for bone tumors in lower extremities, and does not affect the oncological outcomes, functional outcomes and complications compared to the control group. Level of evidence: level III Therapeutic.

This study aimed to analyse the clinical outcomes of preoperative adjuvant denosumab therapy (PADT) combined with resection and arthrodesis for recurrent grade 3 giant cell tumor of bone (GCTB) in the distal radius. A retrospective study was conducted on twenty-three patients (8 males, 15 females) who were treated with the adjuvant denosumab combined with en bloc resection (EBR) and arthrodesis for biopsy confirmed recurrent Campanacci III giant cell tumor of bone in the distal radius between January 2015 and December 2022. All 23 patients were treated with wrist arthrodesis reconstruction using autogenous free iliac crest bone graft (ICBG), bridging plate and screws. The local control, metastasis and overall survival were evaluated during the follow-up period. Functional outcomes were evaluated using the Disabilities of the Arm, Shoulder and Hand (DASH) score, Musculoskeletal Tumor Society Score (MSTS-87 and MSTS-93), and grip strength in the follow-up period. Additionally, all surgical or denosumab-related complications that occurred were recorded in this study. Twenty-three patients were included in this retrospective study and no patients were lost in the follow-up period. The average patient age was 32.5 ± 10.2 years (range, 19–53 years) and the mean follow-up time was 35.5 ± 18.4 months (range, 13–72 months). The average tumor length was 71.7 ± 8.7 mm (range, 50 to 85 mm) and bone reconstruction length was 78.5 ± 8.5 mm (range, 60 to 90 mm). Four patients (17.4

Correction of leg length discrepancy (LLD) in skeletally mature patients with osteosarcoma was rarely reported and quite challenging. This study aimed to propose a treatment strategy of staged lengthening and reconstruction with a standard static prosthesis to address LLD and restore limb function. It also evaluated the effectiveness of the strategy in terms of leg lengthening, functional outcomes, and complications. The strategy for lengthening included three stages. In stage 1, the previous prosthesis was removed and an external fixator with a temporary rod-cement spacer was placed. In this stage, the external fixator was used to lengthen the limb to the appropriate length. In stage 2, the external fixator was removed and the old rod-cement spacer was replaced with a new one. In stage 3, the rod-cement spacer was removed and the standard static prosthesis was planted. Nine skeletally mature distal femoral osteosarcoma patients with unacceptable LLD were treated in our institution from 2019 to 2021. We performed a chart review on nine patients for the clinical and radiographic assessment of functional outcomes, LLD, and complications. The mean (range) leg lengthening was 7.3 cm (3.6–15.6). The mean (range) LLD of the lower limbs decreased from 7.6 cm (4.1–14.2) before the lengthening to 0.3 cm (− 0.3 to 2.1) at the final follow-up with statistical significance (P = 0.000). The mean (range) Musculoskeletal Tumor Society score improved from 30.3% (16.7%–53.3%) before the lengthening to 96.3% (86.7%–100%) at the final follow-up with statistical significance (P = 0.000). Three patients (33.3%) had a minor complication; none needed additional surgical intervention. In the short term, the current staged lengthening and reconstruction with standard static prosthesis provided satisfactory functional outcomes and LLD correction with few complications. The long-term effects of this method need further exploration.

e23573 Background: Generally sarcomas are categorized as soft tissue and bone sarcomas and represent heterogenous group of malignancies with more than 70 distinct histologic subtypes. Due to their rarity and heterogeneity, sarcomas present particular challenges for accurate diagnosis, prognosis, and treatment. The presence and persistence of circulating tumor cells (CTCs) in the peripheral blood are believed to be associated with poor prognosis and distant metastases. A blood-based CTCs test is thus greatly needed for monitoring disease progression and predicting clinical outcomes. Methods: In this study, we developed a CTCs test for the detection and surveillance of sarcoma patients’ CTCs, and subsequently explored its clinical value. 123 patients with sarcomas were enrolled as the cohort for serial CTCs tests. Dynamic CTCs counting, in combination with therapy evaluation and post-treatment follow-up, was used to explore predicting pre- and post-chemotherapy evaluation and prognosis. Results: Quantification of CTCs demonstrated a significant increase in sarcoma patients compared to healthy individuals. Furthermore, patients in stage III-IV had a higher CTC count than those in stage I-II (p<0.01), suggesting a correlation between CTCs and disease development. Remarkably, there was variation in the quantity of CTCs among different types of sarcomas. The highest number of CTCs was observed in undifferentiated small round cell sarcoma, followed by soft tissue tumor, while bone tumors had the lowest number. In addition, the number of CTCs in patients with positive PD-L1 expression was considerably greater than in those with negative expression (p<0.01). The count of CTCs shown a substantial decrease following neoadjuvant chemotherapy treatment. There was a decline in the number of CTCs both before and after postoperative adjuvant chemotherapy treatment, however, there was no significant statistical discrepancy. The number of CTCs at the baseline was shown to be considerably larger in the group of patients with progressive disease or stable disease (PD+SD) compared to the group with partial response or complete response (PR+CR) (p<0.05). This difference was particularly pronounced for interstitial-type CTCs (p<0.01). Conclusions: The rate of presence of CTCs in the peripheral blood of sarcoma patients is high, and patients with an increased percentage of CTCs after treatment have a poor treatment effect. The dynamic monitoring of changes in CTCs counts after treatment has clinical significance for the timely detection of recurrence or metastasis. CTCs also showed a clinical value in prediction of therapy efficiency or prognosis, and may be clinically valuable for the whole course management of patients.

This was a multicenter, single-arm, open-label, phase Ib/II study (NCT04255576), aimed to evaluate the efficacy and safety of JMT103 in patients with unresectable or surgically-challenging giant cell tumor of bone (GCTB). JMT103 (2 mg/kg) was administered subcutaneously every four weeks, with loading doses on days 8 and 15. The primary endpoint was the objective tumor response rate (OTR) based on best response, defined as the proportion of patients who achieved elimination of at least 90% of the giant cells or radiologic complete or partial response per the modified Inverse Choi density/size (mICDS) or modified European Organization for Research and Treatment of Cancer (mEORTC) within 12 weeks. Secondary endpoints included objective response rate (ORR) per mICDS and mEORTC, and safety. A total of 139 patients were enrolled, and 135 were analyzed for efficacy. OTR, determined by the independent review committee (IRC) was 93.3% (95% CI 87.7-96.9). Treatment-related adverse events occurred in 90 (64.7%) patients, with hypophosphatemia and hypocalcemia being the most common. No serious treatment-related adverse events were observed. Thus, JMT103 demonstrates potential as a therapeutic option for GCTB. Giant cell tumor of bone (GCTB) is a rare primary osteolytic bone tumor with high local recurrence rate after surgical resection. Here the authors conduct a phase Ib/II trial, evaluating the efficacy and safety of JMT103 (RANK-RANKL inhibitor) in patients with unresectable or surgically-challenging GCTB.

The proximal humeral reconstruction is challenging. This study aims to investigate the survival, function and complications of clavicla pro humero (CPH) for pediatric proximal humeral reconstruction. A retrospective cohort study was conducted on eight patients (4 males, and 4 females) who underwent clavicla pro humero reconstruction between January 2009 and December 2020 in our institution. The average age was 10.4 ± 2.7 years (range, 6 to 14 years). The functional outcomes were assessed by the Musculoskeletal Tumor Society Score (MSTS-93), the Toronto Extremity Salvage Score (TESS), the American Shoulder and Elbow Surgeons (ASES) score and the range of motion (ROM) of the shoulder. The complications and overall survivorship of clavicla pro humero were recorded in the follow-up. The mean follow-up of all patients was 54.6 ± 23.9 months (range, 24 to 84 months) and 73.3 ± 8.5 months (range, 72 to 84 months) in all survivors. All patients had a bone union at an average of 3.8 months after the initial procedure. Only one patient had no complications in the follow-up. The most common complications were clavicle fracture (87.5

This study was to analyze the clinical outcomes and prognostic factors of dedifferentiated central chondrosarcomas (DCCS) in extremities. A retrospective study was conducted on 49 patients (27 males, 22 females) who underwent surgical treatment between January 2001 and March 2023 in our institution. All patients were diagnosed with dedifferentiated central chondrosarcomas by needle biopsy or postoperative histopathological examination. The general characters, treatment and clinical outcomes were recorded in the follow-up and all surgical-related complications that occurred were recorded in this study. Overall, these data were used to analyse the prognostic factors of DCCS. 49 patients were included in this retrospective study and there were no patients lost in the follow-up period. The median diagnosis age of all patients was 57 years old (ranging from 17 to 87) and the median follow-up time was 34 months (range, 1-289). The average tumor size was 9.6 ± 2.4 cm (3.0-15.5). Median overall survival (OS) and progression-free survival (PFS) were 34 and 23 months, respectively. The 1-year, 2-year, 5-year, and 10-year OS were 87.8

Abstract Purpose This study aims to compare the clinical outcomes of intercalary frozen autograft and allograft reconstruction for primary malignant bone tumors. Methods A retrospective study was conducted on 144 patients who underwent intercalary biological reconstruction for primary malignant bone tumors at a single institution between January 2012 and July 2023. Seventy-two patients underwent intercalary liquid nitrogen-frozen autograft reconstruction, and 72 patients underwent intercalary allograft reconstruction in this study. A modified International Society of Limb Salvage classification system was used to evaluate the complications. Results The mean follow-up time was 60.2 ± 32.1 (range, 12–149) months. The mean union time was 9.6 months in the frozen autograft group and 15.9 months in the allograft group (p < 0.001). The 5-year overall survivorship was 86.8% in the frozen autograft group and 73.2% in the allograft group (p = 0.017). The average MSTS-93 score was comparable between the two groups (89.7% by autograft versus 87.6% by allograft, p > 0.05). Of the patients, 48.6% (70/144) had at least one complication. The most common complications were bone nonunion (20.8%, 30/144), followed by structural failure (17.4%, 25/144), tumor progression (10.4%, 15/144), infection (10.4%, 15/144), and soft tissue failures (5.6%, 8/144). Higher rates of bone nonunion (type 4B; p = 0.002) and structural failure (type 3B; p = 0.004) were obtained in the allograft group than in the frozen autograft group. Conclusions The intercalary frozen autografts had shorter union time and lower complication rates than allograft reconstruction. Therefore, we recommend that frozen autograft reconstruction be considered when the tumor bone has not suffered severe osteolytic injury or pathological fracture. Level of evidence: level III, case–control study.

Abstract Purpose The aim of this study was to analyze the long-term clinical outcomes of intercalary allograft reconstruction for primary malignant bone tumors in lower extremities. Methods A retrospective study was conducted on 29 patients (16 males, 13females) who underwent intercalary allograft reconstruction for primary malignant bone tumors in lower extremities between September 2007 and December 2012. The average age were 23.4 ± 15.1 years (range, 9–64) and the most common pathological type was osteosarcoma (17) followed by Ewing’s sarcoma (4), adamantinoma (4), chondrosaroma in 2, angiosarcoma of bone in 1 and undifferentiated pleomorphic sarcoma in 1. The tumor locations were in the femur in 13 and the tibius in 16. All complications and allograft failures occuered were recorded in this study. The oncological outcomes included local control, metastasis, progression-free survival and overall survival. The functional outcomes were evaluated by Musculoskeletal Tumor Society Score (MSTS-93). Results 29 patients was included in this retrosepective study and there were no patients lost in the follow-up period. The mean follow-up time was 149.8 ± 42.1 months (43–194). Three patients (10.3%) deceased in the last follow-up due to distant metastasis. The average diaphyseal bone resection length was 172.7 ± 29.2 mm (range, 130 to 240mm). The average allograft survival time was 134.4 ± 53.7 months (range, 6 to 194 months). The mean union time was 16.3 (6–29) months and overall survivorship of the allograft was 82.7% (24/29) at an average 12.5 years follow-up. The average MSTS-93 score was 86% (range, 70–100%). Ninteen patients (66.5%) had at least one complication in the follow-up time. The common unoncological complications were bone non-union (8), fracture (3), infection (2) and leg length discrepancy (LLD, 2). Conclusions The intercalary allograft reconstruction is a reliable technique to resolve the massive bone defects after primary diaphyseal bone tumor resection in lower extremities with acceptable long-term function and satisfaction. Level of evidence: level IV Therapeutic.