Objective To evaluate the efficacy of Yunpi Runtong Formula(composed of Haematitum,Atractylodis Macrocephalae Rhizoma,Paeoniae Radix Alba,Cinnamomi Ramulus,Ophiopogonis Radix,Angelicae Sinensis Radix,Cannabis Fructus,Aurantii Fructus Immaturus,Cimicifugae Rhizoma,Picrorhizae Rhizoma,etc.)in treating functional constipation(FC)of spleen deficiency type in children and to analyze its effects on gut microbiota,defecation patterns,and the serotonin(5-HT)signaling pathway.Methods A total of 160 children with FC of spleen deficiency type treated at Shanxi Institute of Traditional Chinese Medicine from August 2022 to August 2024 were enrolled and randomly divided into a control group and a study group,with 80 patients in each group.The control group received conventional western medicine(lactulose oral solution)treatment,while the study group received Yunpi Runtong Formula treatment in addition to the control group's treatment.Both groups underwent treatment for one month.Changes in traditional Chinese medicine(TCM)syndrome scores,defecation parameters[mean defecation time,spontaneous complete bowel movements(SCBM),Bristol Stool Form Scale(BSFS)],gastrointestinal function markers[substance P(SP),gastrin(GAS),motilin(MLT)],gut microbiota composition,and 5-HT signaling pathway components(serum 5-HT levels,5-HT3R and 5-HT4R protein expression)were analyzed.Clinical efficacy and safety were evaluated.Results(1)The intergroup comparison(by chi-square test)showed that the study group exhibited significantly higher total efficacy[95.00％(76/80)]than the control group[81.25％(65/80);P＜0.01].(2)Both groups exhibited reduced TCM syndrome scores(defecation duration,stool features,difficulty of defecation,interval of defecation,and secondary symptoms;all P＜0.05),with greater improvements in the study group(P＜0.01).(3)After treatment,both groups had shorter mean defecation time,increased SCBM,and higher BSFS scores(all P＜0.05),and the study group demonstrated superior improvements(P＜0.01).(4)Serum SP,GAS,and MLT levels increased in both groups(P＜0.05),with more pronounced elevations in the study group(P＜0.01).(5)Gut microbiota analysis revealed decreased levels of Enterococcus and Enterobacter(P＜0.05)and increased levels of Bifidobacterium and Lactobacillus(P＜0.05)in both groups,with the study group showing significantly greater modulation(P＜0.01).(6)The 5-HT pathway activation(serum 5-HT,5-HT3R/5-HT4R expression)was enhanced in both groups(P＜0.05),more markedly in the study group(P＜0.01).(7)No adverse events or abnormal liver/renal function were observed.Conclusion Yunpi Runtong Formula combined with lactulose effectively alleviates FC symptoms,improves defecation patterns,gastrointestinal function,and gut microbiota,likely via 5-HT pathway activation,with high safety.

ObjectiveTo dynamically observe the clinical symptoms and pathological changes in a rat model of vinorelbine-induced phlebitis via injection into the dorsalis pedis vein. MethodsTwenty-eight 11-week-old male SPF-grade SD rats were randomly divided into a model group (n=20) and a control group (n=8). The model group received a single injection of 0.1 mL vinorelbine solution (4 mg/mL) via the right hind limb dorsalis pedis vein, while the control group received an equal volume of normal saline via the same method. The occurrence and grading of phlebitis in both groups were observed and recorded daily. The volume of the injured limb was measured by the drainage method to calculate the swelling rate. The weight-bearing ratio of the injured limb was assessed using a bipedal balance pain meter, and the skin temperature of the injured limb was measured by infrared thermal imaging. These measurements were conducted for 9 consecutive days. Starting from day 1, three rats from the model group were euthanized every other day. A 1-cm segment of the vein extending proximally from the injection site was collected. Pathological changes in the vein tissue were examined by hematoxylin-eosin staining, and ultrastructural changes of the vascular endothelium were observed using scanning electron microscopy. ResultsCompared to the control group, the injected hindlimb of model rats showed redness and swelling on day 1, with the swelling rate peaking at (81.89±15.75) % on day 3 (P<0.001), then gradually alleviating and decreasing to (15.41±0.33) % by day 9 (P<0.01). Pain was observed in the affected limbs of model rats on day 1 and worsened markedly on day 3, with the weight-bearing ratio decreasing to (36.35±4.91)% (P<0.001). Meanwhile, the skin temperature of the lesion site increased, reaching (36.36±0.40) ℃ on day 5 (P<0.001). Both pain and fever returned to near normal levels by day 9. Phlebitis grading in the model group showed that 75.0% of rats were grade Ⅱ on day 1; grade Ⅲ and Ⅳ each accounted for 37.5% on day 3; from days 5 to 9, most rats exhibited cord-like veins, predominantly grade III. Venous tissue showed peripheral edema and inflammatory cell infiltration on day 1, which gradually progressed to intimal rupture, vessel wall thickening, and even lumen narrowing from day 3 to 9. The venous intima exhibited destruction of tight junctions between endothelial cells and adhesion of blood cells, progressing to roughened, wrinkled, and protruding intimal surfaces. ConclusionThe vinorelbine-induced phlebitis of dorsal foot vein in rat model is characterized by local redness, swelling, warmth, and pain from days 3 to 5, which largely resolve by day 9, although cord-like veins can still be observed. With disease progression, venous tissue develops edema, vessel wall thickening, and lumen narrowing. The venous intima shows rupture, roughening, and in some cases, complete loss.

ObjectiveTo dynamically observe the clinical symptoms and pathological changes in a rat model of vinorelbine-induced phlebitis via injection into the dorsalis pedis vein. MethodsTwenty-eight 11-week-old male SPF-grade SD rats were randomly divided into a model group (n=20) and a control group (n=8). The model group received a single injection of 0.1 mL vinorelbine solution (4 mg/mL) via the right hind limb dorsalis pedis vein, while the control group received an equal volume of normal saline via the same method. The occurrence and grading of phlebitis in both groups were observed and recorded daily. The volume of the injured limb was measured by the drainage method to calculate the swelling rate. The weight-bearing ratio of the injured limb was assessed using a bipedal balance pain meter, and the skin temperature of the injured limb was measured by infrared thermal imaging. These measurements were conducted for 9 consecutive days. Starting from day 1, three rats from the model group were euthanized every other day. A 1-cm segment of the vein extending proximally from the injection site was collected. Pathological changes in the vein tissue were examined by hematoxylin-eosin staining, and ultrastructural changes of the vascular endothelium were observed using scanning electron microscopy. ResultsCompared to the control group, the injected hindlimb of model rats showed redness and swelling on day 1, with the swelling rate peaking at (81.89±15.75) % on day 3 (P<0.001), then gradually alleviating and decreasing to (15.41±0.33) % by day 9 (P<0.01). Pain was observed in the affected limbs of model rats on day 1 and worsened markedly on day 3, with the weight-bearing ratio decreasing to (36.35±4.91)% (P<0.001). Meanwhile, the skin temperature of the lesion site increased, reaching (36.36±0.40) ℃ on day 5 (P<0.001). Both pain and fever returned to near normal levels by day 9. Phlebitis grading in the model group showed that 75.0% of rats were grade Ⅱ on day 1; grade Ⅲ and Ⅳ each accounted for 37.5% on day 3; from days 5 to 9, most rats exhibited cord-like veins, predominantly grade III. Venous tissue showed peripheral edema and inflammatory cell infiltration on day 1, which gradually progressed to intimal rupture, vessel wall thickening, and even lumen narrowing from day 3 to 9. The venous intima exhibited destruction of tight junctions between endothelial cells and adhesion of blood cells, progressing to roughened, wrinkled, and protruding intimal surfaces. ConclusionThe vinorelbine-induced phlebitis of dorsal foot vein in rat model is characterized by local redness, swelling, warmth, and pain from days 3 to 5, which largely resolve by day 9, although cord-like veins can still be observed. With disease progression, venous tissue develops edema, vessel wall thickening, and lumen narrowing. The venous intima shows rupture, roughening, and in some cases, complete loss.

Objective:To analyze the clinical efficacy of pasteurization-inactivated tumor bone replantation combined with intramedullary vascularized fibula for reconstructing bone defects after surgery for malignant bone tumors in children and adolescents.Methods:A retrospective analysis was performed on the data of 54 patients who underwent pasteurization-inactivated tumor bone replantation combined with intramedullary vascularized fibula reconstruction for bone defects after surgery for malignant bone tumors at the Bone and Soft Tissue Tumor Treatment Center of Peking University People's Hospital from September 2015 to September 2023. There were 39 males and 15 females, with an age of 12.4±5.6 years (range, 4 to 23 years). The tumor types included 33 cases of osteosarcoma, 19 cases of Ewing sarcoma, and 2 cases of soft tissue sarcoma. All cases were at Enneking stage IIB. The tumor locations were 30 cases in the femur, 19 cases in the tibia, 4 cases in the ilium, and 1 case in the humerus. The survival rate, bone healing time, tumor recurrence, and metastasis were observed. The limb function was evaluated using the Musculoskeletal Tumor Society (MSTS)-93 score.Results:All patients successfully completed the surgery and were followed up, with a follow-up time of 44.6±27.1 months (range, 12 to 96 months). The operation time was 527±132 min (range, 150 to 730 min), and the blood loss was 730±591 ml (range, 300 to 2,800 ml). The length of inactivated tumor bone was 16.5±4.5 cm (range, 9.1 to 24.0 cm), the defect length accounted for 43.4%±12.2% of the total length of the affected bone (range, 23.8% to 75.5%), the proximal osteotomy of the long bones in the extremities was 14.1±8.3 cm from the articular surface (range, 1.9 to 31.1 cm), the distal osteotomy was 9.4±6.2 cm from the articular surface (range, 1.7 to 22.9 cm), and the length of the harvested vascularized fibula was 18.0±4.0 cm (range, 11.0 to 26.4 cm). At the last follow-up, 51 patients were alive, including 47 with no evidence of tumor and 4 with tumor; 3 patients died of tumor progression. Local recurrence occurred in 5 patients, including 4 with soft tissue recurrence in the surgical area (3 underwent surgical resection and 1 received radiotherapy) and 1 with recurrence at the site of inactivated bone. Distant metastasis occurred in 11 patients, including 5 with lung metastasis only, 2 with bone metastasis only, and 4 with combined lung and bone metastasis. Among the 5 patients with lung metastasis only, lung metastases were resected, with 3 surviving with tumor, 2 surviving without tumor; the 2 patients with bone metastasis only underwent surgical resection of bone metastases, both surviving without tumor. Among the 4 patients with combined lung and bone metastasis, 3 died of tumor progression and 1 survived with tumor. The Kaplan-Meier curve showed a 5-year survival rate of 90.8%±6.2% and a 5-year recurrence-free and metastasis-free survival rate of 68.7%±7.9%. The osteotomy healing time at the diaphysis was 8.4±2.3 months (range, 4 to 13 months), the osteotomy healing time at the metaphysis was 5.9±1.7 months (range, 3 to 10 months), and the healing time between inactivated tumor bone and fibula was 6.4±2.0 months (range, 4 to 11 months). No nonunion occurred. The MSTS-93 score at the last follow-up was 94.4%±4.8% (range, 80% to 100%).Conclusion:Pasteurization-inactivated tumor bone replantation combined with intramedullary vascularized fibula reconstruction for bone defects after surgery for malignant bone tumors in children and adolescents has satisfactory clinical efficacy, high bone healing rate, and low rates of local recurrence and distant metastasis.

Objective:To evaluate the preliminary clinical efficacy of minimally invasive extendable prostheses in limb-salvage treatment for distal femoral osteosarcoma in children.Methods:A retrospective analysis was conducted on 36 children who underwent reconstruction of bone defects after distal femoral osteosarcoma resection with minimally invasive extendable prostheses at Peking University People's Hospital between December 2021 and December 2023. The cohort included 22 males and 14 females, with a mean age of 10.1±2.7 years (range: 4.3-14.3 years). Among them, 27 cases were primary tumor resections with post-resection bone defects of 17.4±3.2 cm (range: 13.5-25.0 cm), and 9 cases were revision surgeries. Preoperatively, femoral limb length discrepancy (LLD) was 29.6±14.3 mm (range: -1.2-55.0 mm), tibial LLD was 16.0±11.3 mm (range: -4.8-30.0 mm), and total lower limb LLD was 45.1±23.6 mm (range: -5.5-77.0 mm). The prosthesis was modular and compatible with existing tumor prosthesis components via taper connections. Lengthening was achieved by axial screw manual expansion through a 3-4 cm parapatellar arc incision, using a specialized wrench for adjustment. X-rays were performed pre-implantation, before and after each lengthening, and at the last follow-up to assess femoral, tibial, and total lower limb LLD, as well as extension length. At the final follow-up, limb function was assessed using the Musculoskeletal Tumor Society (MSTS)-93 score, and extension-related complications were analyzed.Results:All 36 children successfully underwent implantation and subsequent extension when indicated. The mean follow-up was 14.9±8.1 months (range: 6-31 months). Eleven patients underwent 16 lengthening procedures, with a mean of 1.5±0.8 per case (range: 1-3) and an average extension of 21.1±8.3 mm (range: 9.2-42.8 mm), achieving a total mean recovery of 31.0±16.1 mm (range: 10.4-61.7 mm). Two patients reached the maximum 5 cm extension capacity and underwent minor procedures to retract the extension device and secure the prosthesis. The remaining 25 patients did not require extension as their LLD was <2 cm. At the last follow-up, femoral, tibial, and total lower limb LLDs were 10.6±11.4 mm (range: -8.6-41.4 mm), 9.1±12.7 mm (range: -9.5-39.5 mm), and 20.1±21.0 mm (range: -10.4-72.5 mm), respectively. The mean MSTS-93 score for the 11 extended patients was 90.0%±12.7% (range: 80.0%-96.7%). Complications included two cases of aseptic loosening requiring revision, one transient peroneal nerve palsy after fixed-length filling, and three cases of prosthesis segment retraction due to excessive exercise. Retractions occurred at 9.1±3.3 months (range: 5.3-11.3 months) and were corrected during subsequent extensions without revision.Conclusions:Minimally invasive extendable prostheses allow individualized limb lengthening through small parapatellar incisions based on LLD and soft tissue tension. The extension mechanism is stable, and functional recovery is favorable.

Objective:To analyze the clinical efficacy of pasteurization-inactivated tumor bone replantation combined with intramedullary vascularized fibula for reconstructing bone defects after surgery for malignant bone tumors in children and adolescents.Methods:A retrospective analysis was performed on the data of 54 patients who underwent pasteurization-inactivated tumor bone replantation combined with intramedullary vascularized fibula reconstruction for bone defects after surgery for malignant bone tumors at the Bone and Soft Tissue Tumor Treatment Center of Peking University People's Hospital from September 2015 to September 2023. There were 39 males and 15 females, with an age of 12.4±5.6 years (range, 4 to 23 years). The tumor types included 33 cases of osteosarcoma, 19 cases of Ewing sarcoma, and 2 cases of soft tissue sarcoma. All cases were at Enneking stage IIB. The tumor locations were 30 cases in the femur, 19 cases in the tibia, 4 cases in the ilium, and 1 case in the humerus. The survival rate, bone healing time, tumor recurrence, and metastasis were observed. The limb function was evaluated using the Musculoskeletal Tumor Society (MSTS)-93 score.Results:All patients successfully completed the surgery and were followed up, with a follow-up time of 44.6±27.1 months (range, 12 to 96 months). The operation time was 527±132 min (range, 150 to 730 min), and the blood loss was 730±591 ml (range, 300 to 2,800 ml). The length of inactivated tumor bone was 16.5±4.5 cm (range, 9.1 to 24.0 cm), the defect length accounted for 43.4%±12.2% of the total length of the affected bone (range, 23.8% to 75.5%), the proximal osteotomy of the long bones in the extremities was 14.1±8.3 cm from the articular surface (range, 1.9 to 31.1 cm), the distal osteotomy was 9.4±6.2 cm from the articular surface (range, 1.7 to 22.9 cm), and the length of the harvested vascularized fibula was 18.0±4.0 cm (range, 11.0 to 26.4 cm). At the last follow-up, 51 patients were alive, including 47 with no evidence of tumor and 4 with tumor; 3 patients died of tumor progression. Local recurrence occurred in 5 patients, including 4 with soft tissue recurrence in the surgical area (3 underwent surgical resection and 1 received radiotherapy) and 1 with recurrence at the site of inactivated bone. Distant metastasis occurred in 11 patients, including 5 with lung metastasis only, 2 with bone metastasis only, and 4 with combined lung and bone metastasis. Among the 5 patients with lung metastasis only, lung metastases were resected, with 3 surviving with tumor, 2 surviving without tumor; the 2 patients with bone metastasis only underwent surgical resection of bone metastases, both surviving without tumor. Among the 4 patients with combined lung and bone metastasis, 3 died of tumor progression and 1 survived with tumor. The Kaplan-Meier curve showed a 5-year survival rate of 90.8%±6.2% and a 5-year recurrence-free and metastasis-free survival rate of 68.7%±7.9%. The osteotomy healing time at the diaphysis was 8.4±2.3 months (range, 4 to 13 months), the osteotomy healing time at the metaphysis was 5.9±1.7 months (range, 3 to 10 months), and the healing time between inactivated tumor bone and fibula was 6.4±2.0 months (range, 4 to 11 months). No nonunion occurred. The MSTS-93 score at the last follow-up was 94.4%±4.8% (range, 80% to 100%).Conclusion:Pasteurization-inactivated tumor bone replantation combined with intramedullary vascularized fibula reconstruction for bone defects after surgery for malignant bone tumors in children and adolescents has satisfactory clinical efficacy, high bone healing rate, and low rates of local recurrence and distant metastasis.

Objective:To evaluate the preliminary clinical efficacy of minimally invasive extendable prostheses in limb-salvage treatment for distal femoral osteosarcoma in children.Methods:A retrospective analysis was conducted on 36 children who underwent reconstruction of bone defects after distal femoral osteosarcoma resection with minimally invasive extendable prostheses at Peking University People's Hospital between December 2021 and December 2023. The cohort included 22 males and 14 females, with a mean age of 10.1±2.7 years (range: 4.3-14.3 years). Among them, 27 cases were primary tumor resections with post-resection bone defects of 17.4±3.2 cm (range: 13.5-25.0 cm), and 9 cases were revision surgeries. Preoperatively, femoral limb length discrepancy (LLD) was 29.6±14.3 mm (range: -1.2-55.0 mm), tibial LLD was 16.0±11.3 mm (range: -4.8-30.0 mm), and total lower limb LLD was 45.1±23.6 mm (range: -5.5-77.0 mm). The prosthesis was modular and compatible with existing tumor prosthesis components via taper connections. Lengthening was achieved by axial screw manual expansion through a 3-4 cm parapatellar arc incision, using a specialized wrench for adjustment. X-rays were performed pre-implantation, before and after each lengthening, and at the last follow-up to assess femoral, tibial, and total lower limb LLD, as well as extension length. At the final follow-up, limb function was assessed using the Musculoskeletal Tumor Society (MSTS)-93 score, and extension-related complications were analyzed.Results:All 36 children successfully underwent implantation and subsequent extension when indicated. The mean follow-up was 14.9±8.1 months (range: 6-31 months). Eleven patients underwent 16 lengthening procedures, with a mean of 1.5±0.8 per case (range: 1-3) and an average extension of 21.1±8.3 mm (range: 9.2-42.8 mm), achieving a total mean recovery of 31.0±16.1 mm (range: 10.4-61.7 mm). Two patients reached the maximum 5 cm extension capacity and underwent minor procedures to retract the extension device and secure the prosthesis. The remaining 25 patients did not require extension as their LLD was <2 cm. At the last follow-up, femoral, tibial, and total lower limb LLDs were 10.6±11.4 mm (range: -8.6-41.4 mm), 9.1±12.7 mm (range: -9.5-39.5 mm), and 20.1±21.0 mm (range: -10.4-72.5 mm), respectively. The mean MSTS-93 score for the 11 extended patients was 90.0%±12.7% (range: 80.0%-96.7%). Complications included two cases of aseptic loosening requiring revision, one transient peroneal nerve palsy after fixed-length filling, and three cases of prosthesis segment retraction due to excessive exercise. Retractions occurred at 9.1±3.3 months (range: 5.3-11.3 months) and were corrected during subsequent extensions without revision.Conclusions:Minimally invasive extendable prostheses allow individualized limb lengthening through small parapatellar incisions based on LLD and soft tissue tension. The extension mechanism is stable, and functional recovery is favorable.

This study was designed to investigate the potential protective effect of isopimpinelline against para-chlorophenylalanine(PCPA)-induced pineal gland damage in rats.Forty male Sprague-Dawley(SD)rats were divided into four groups(n=10 each):a normal group,a model group,a melatonin-treated group(10 mg/kg),and an isopimpinelline-treated group(1.5 mg/kg).All groups,except for the normal,received intraperitoneal injection of PCPA(450 mg/kg)to induce pineal gland damage.Subsequent treatments were administered orally for 7 days.Sleep latency and duration were evaluated on the sixth day using the pentobarbital sodium sleep synergy test.After the treatment period,serum melatonin levels and pineal gland inflammation markers were assessed alongside oxidative and antioxidative parameters.Histological examinations of the pineal gland were conducted,and the expression of proteins related to the Nrf2 and NF-κB signaling pathways were quantified.Data showed that isopimpinelline alleviates the structural damage in the pineal gland of model rats,significantly elevated serum melatonin levels,and markedly improved sleep latency and duration(P＜0.05).Isopimpinelline activated the Nrf2 signaling pathway by inhibiting Keap1 expression,which facilitated the nuclear translocation of Nrf2 and upregulated the antioxidant proteins NQO1 and HO-1,thereby mitigating oxidative stress in the pineal gland(P＜0.05).Furthermore,isopimpinelline significantly reduced the levels of pro-inflammatory cytokines IL-2,TNF-α and IL-6.Isopimpinelline also suppressed the NF-κB signaling pathway,reducing the expression of NF-κB p65,IKKβ,and p-IKKβ proteins,as well as the nuclear translocation of NF-κB p65(P＜0.05),thereby providing anti-inflammatory benefits.In conclusion,isopimpinelline could protect pineal gland from damage by activating the Nrf2 signaling pathway and inhibiting the NF-κB pathway.

AIM:To explore the molecular mechanism of Tiaopi Chengqi decoction (TpCqD) improving hyperthermia and high-protein food-induced hyperphagia mice based on transcriptomics. METHODS:C57 mice were randomly divided into a control group, model group, low-dose TpCqD group, high-dose TpCqD group, and domperidone group. The general condition of the experimental mice was observed and the average food intake was counted, and the rate of gastric emptying and intestinal propulsion was determined for each group of mice. H&E staining was used to observe pathological changes in gastric tissue. PAS staining was used to observe glycogen changes in gastric tissue. Pepsin activity was determined by colorimetry. pH value of gastric contents was measured by acid-base titration. Transcriptome sequencing was used to analyze the differential genes in gastric tissue, a volcano map and a cluster heat map were made for the differential genes, and KEGG was used to analyze the signal pathway enrichment of the differential genes. RT-qPCR verified the differential genes obtained by screening. RESULTS:After treatment with TpCqD, the body weight and average food intake of mice with food accumulation increased (P<0.05), and the intestinal propulsion rate and gastric emptying speed of mice with food accumulation accelerated (P<0.05). TpCqD could protect gastric tissue structure and glycogen degradation, increase pepsin activity (P<0.05), and reduce gastric content pH (P<0.05). Transcriptome results showed that TpCqD could regulate the expression of Acox2 and cilp2, regulate fat digestion and absorption, protein digestion and absorption, and pancreatic secretion signals. RT-qPCR showed that compare with model group, TpCqD up-regulated Acox2 (P<0.05) and down-regulated the mRNA level of cilp2 (P<0.05). CONCLUSION:TpCqD ameliorated digestive dysfunction in mice with high-calorie and high-protein diets leading to food accumulation involving the regulation of the fat and sugar metabolism genes Acox2 and cilp2, and pancreatic secretory signaling.

Objective:To describe the design, manufacture and use of three-dimensional (3D)-printed endoprosthesis for reconstruction after metaphysis-involved intercalary tumor resection and to evaluate its outcome.Methods:Forty-three patients who received metaphysis-involved intercalary tumor resection followed by 3D-printed endoprosthetic reconstruction in Musculoskeletal Tumor Center, Peking University People's Hospital between January 2018 and December 2021 were retrospectively reviewed. There were 25 males and 18 males with an average age of 20.1±15.2 years (range, 4-58 years). The pathological diagnosis included 24 cases of osteosarcomas, 6 cases of Ewing sarcomas, 5 cases of chondrosarcomas, 2 cases of pleomorphic undifferentiated sarcomas, 3 cases of soft-tissue sarcomas (liposarcoma, synovial sarcoma, malignant peripheral nerve sheath tumor for each) and 3 others (adamantinoma, recurrent aneurysmal bone cyst and recurrent osteofibrous dysplasia for each). The tumors located at femur in 25 patients (58%), including 14 lesions involving distal femoral metaphysis and 11 lesions involving both proximal and distal metaphysis; the tumors located at tibia in 11 patients (26%), including 4 lesions involving distal tibial metaphysis, 5 lesions involving proximal tibial metaphysis and 2 lesions involving both proximal and distal tibial metaphysis; the tumors located at humerus in 7 patients (16%), including 1 lesion involving distal humeral metaphysis, 3 lesions involving proximal humeral metaphysis and 3 lesions involving both proximal and distal humeral metaphysis. The endoprosthesis was designed in a semi-modular fashion and consisted of three parts: a diaphysis-fixing component, a semi-modular lap joint component, and a custom-made 3D-printed metaphysis-fixing component which was designed as two types with 3D-printed porous bone-contacting surfaces according to the osteotomy plane (Type I on meta-diaphyseal region, Type II on meta-epiphyseal region). The functional outcome was assessed using Musculoskeletal Tumor Society (MSTS) 93 system.Results:All surgeries were accomplished sucessfully. The median resection length and the distance from osteotomy plane to adjacent joint was 16.0 (13.0, 22.0) cm and 4.5 (3.5, 6.0) cm, respectively. 59 metaphysis-fixing components were installed in 43 patients. Type I components were used in single and dual ends of endoprosthesis in 12 and 6 cases respectively. Type II components were used in single and dual ends in 15 and 5 cases respectively. Hybrid endoprosthesis with Type I and II components were used in 5 cases. The mean follow-up time was 26.0 (17, 37) months (range, 12-54 months). The mean MSTS 93 score was 29.0 (28.0, 30.0) points (range, 21-30 points). Implant failures were found in 5 patients, including 2 cases of aseptic loosening (loosening was observed in the cementing diaphysis-fixing stems while no evidence of loosening in metaphysis-fixing components) and 3 cases of local tumor progression. The 2-year implant survival rate was 90.3% (95% CI: 0.81, 0.99). Conclusion:Using 3D-printed intercalary endoprosthesis for reconstruction after intercalary resection of metaphysis-involved bone tumor shows satisfactory functional outcome and implant survival. Moreover, by assembling endoprosthetic components according to the different osteotomy plane, the semi-modularized endoprosthesis also provids a comprehensive and individualized reconstruction for patients with metaphysis-involved intercalary tumor.