With the development of imaging technology, advancements in surgical techniques, application of multidrug chemotherapy, and collaboration in postoperative rehabilitation, the local recurrence rate and survival of patients with osteosarcoma after limb-sparing surgery are comparable to those of patients after amputation. The area around the knee joint, including the distal portion of the femur and the proximal portion of the tibia, is a typical site of involvement for osteosarcoma. Metal prosthetic replacement is the most common method to reconstruct bone defect after tumor resection, which provides rapid recovery of limb function after surgery. This article mainly discusses the clinical challenge of limb-saving technology for pediatric osteosarcoma. It also describes how to optimally preserve the growth potential of children’s affected limbs to reduce the future limb length discrepancy. Limb-sparing technology is one of the most cutting-edge precision medical technologies in the industry. Sacrificing or preserving the knee joint according to the distance between the tumor of distal femur and the epiphyseal growth plate, retaining the potential for limb growth, 3D-printed reconstructed prostheses are becoming increasingly popular. This article summarizes the progress and future development in the surgical treatment of pediatric osteosarcoma around the knee to offer insights for orthopedic treatment of this disease.

Objective:To explore the role and value of indocyanine green (ICG) fluorescence imaging in the surgery of bone and soft tissue tumors.Methods:A total of 38 patients with bone and soft tissue tumors, including 17 males and 21 females, aged 36±21 years (range 5-75 years), who underwent resection with application of ICG-based NIR imaging were retrospectively analyzed. ICG was intravenously administrated at a dose of 2 mg/kg on the day before surgery. Intraoperative NIR imaging was performed to confirm the tumor fluorescence and to detect residual tumor after tumor resection. The NIR imaging was post hoc analyzed to explore the influence factor of tumor stain rate and SBR value.Results:Tumor staining with ICG was successful in 34 of the 38 patients, with an overall staining rate of 90%. The ICG tumor stain rate was not influenced by different pathology types, malignant or benign pathology, the reception of neoadjuvant chemotherapies or not, and the length of time between drug administration and surgery ( P>0.05). The median SBR of 34 patients with successful tumor staining was 2.9 (2.3, 5.7). Different pathological types, malignant or benign pathology, whether to receive neoadjuvant chemotherapy, preoperative ICG administration time, preoperative dose of denosumab administration in giant cell tumor of bone patients and tumor response to neoadjuvant chemotherapy had no significant effects on SBR ( P>0.05). After tumor resection, a total of 57 pieces of tissue with residual fluorescence signals were detected and resected under the fluorescence guidance, 30 of which were pathologically confirmed to contain residual tumor lesions, with an overall accuracy of 53%. The accuracy of intralesional resection was significantly higher than that of en bloc resection (71% vs. 16%, χ 2=15.51, P=0.000). Conclusion:A high percentage of bone and soft tissue tumors can be stained with ICG. The tumor stain of ICG was stable and not easily influenced by external factors. This technique was useful to detect residual tumors, especially after piecemeal resection.

Objective:To evaluate the clinical outcome of a special physeal sparing knee prosthesis for pediatric distal femoral osteosarcoma regarding the functional outcome, retention of the growth potential of the proximal tibia, and postoperative complications.Methods:A retrospective study was conducted to review 37 pediatric patients with osteosarcoma of distal femur who were treated in a single musculuskeletal tumor center between August 2015 and January 2019. Among them, 21 were boys and 16 were girls, aged from 5 to 12 years at the time of operation, with an average age of 9.1±2.1 years and the height of 115 to 160 cm, with an average of 140±10 cm. Tumor resection of distal femur was performed and the bone defect was reconstructed by a special hinged knee prosthesis which can preserve the proximal tibial epiphyseal plate. Demographic data was recorded. Overall leg length and tibial length was assessed by full-length standing anteroposterior radiographs of bilateral lower extremity with the patella pointing anteriorly preoperativelly and postoperativelly at each follow up. And the growth potential of the affected proximal tibia was calculated by comparing with the preoperative length of tibia. Meanwhile, the functional outcome was assessed by using the Musculoskeletal Tumor Society (MSTS) system, and the postoperative complications were analysed.Results:All patients underwent the tumor resection and reconstruction operation successfully. The average operation duration was 143±41 minutes, ranging 90 to 250 minutes. The average intraoperative blood loss was 314±397 ml, ranging 30 to 2 200 ml. The patients were followed up for 24 to 64 months, averaging 42.3±12.1 months. The postoperative knee range of motion was 100-130 degrees, with an average of 115.6±7.2 degrees. The postoperative MSTS score was 23-30, with an average of 26.7±1.6. To the last follow-up, the limb length discrepancy of the lower limb was 1.3 to 10 cm, and the length of the tibia was shortened from 0 to 3.8 cm compared with the opposite side, with an average of 1.3±1.0 cm. The growth percentage of the proximal tibial epiphysis on the affected side was 30% to 100%, with an average of 70%±17%. Totally, 13 patients suffered postoperative complication, the overall incidence of complications was 35% (13/37), and prosthesis-related complications were 16% (6/37). Three patients with wound dehiscence were managed by debridement and antibiotics. Radiographs revealed femoral stem loosening in a single patient 3 years after the initial operation and then the prosthesis was converted to an adult tumor knee endoprosthesis. Two cases experienced breakage of the femoral stem at 30 and 33 months, respectively, due to an accidental injury. They received revision surgery, and a new femoral prosthesis component was replaced. One patient developed femoral stem breakage at 10 months after surgery due to fatigue fracture, which treated with revision surgery. Tumor recurrence occurred in 6 patients. Among them, tumor recurrence in soft tissue occurred in 4 patients, and treated with regional resection without further recurrence. The other 2 patients experienced tumor recurrence at the distal femoral site, and treated with resection and prosthetic revision.Conclusion:The physeal sparing pediatric knee prosthesis can preserve the growth potential of the proximal tibial epiphyseal plate with good postoperative function and low incidence of prosthesis complications. Therefore, it can be an alternativeespecially for skeletally immature patients with distal femur osteosarcoma.

Obiective:To investigate the design, the key points of surgery and the outcome of short-term follow-up of hemi-elbow-arthroplastic bionic total humeral prosthesis by using 3D-print.Methods:The clinical data of 8 patients with humerus malignant tumor who underwent total humerus resection and a 3D-printed auxiliary hemi-elbow-arthroplastic total humeral prosthesis replacement from March 2018 to March 2020 at Peking University People's Hospital were retrospectively analyzed. The operative data, oncological outcome, complication profiles of prosthesis and functional status of all 8 patients were also analyzed. There were 3 males and 5 females with a mean age of 5-37 years. Histological diagnosis included 5 cases of osteosarcoma, 2 cases of Ewing's sarcoma and 1 case of chondrosarcoma.Results:The time for production of the prosthesis was (9.8±2.7) d, the operation time was (209±23) min and intraoperative hemorrhage was (569±173) ml. All the prostheses were implanted successfully and no patients experienced intraoperative complications. While 2 patients had postoperative complications, 1 case of temporary palsy of radial nerve and 1 case of local recurrence. LARS artificial ligament or hernia patch was used to reconstruct joint capsule and tendon-ligament attached around the elbow and shoulder joint. The flexion and extension of the elbow was (118±15)° (100-140°) and (11±9)° (0-25°), and the abduction and anteflexion of the shoulder was (28±12)° (15-50°) and (26±9)° (15-40°), respectively. The postoperative Musculoskeletal Tumor Society (MSTS)-93 scale score was (24.1±1.5) scores. The median follow-up time was 17 months (12-32 months), 7 patients had disease-free survival and 1 patient survived with tumor.Conclusions:The novel 3D-printed total humeral prosthesis with hemi-elbow-arthroplasty has a good perioperative safety, which is effective in restoring the function of elbow joint, solving the problem of stress concentration of ulnar marrow lever of total elbow joint prosthesis and lowering long-term wear rate and loosening rate of prosthesis.

Objective:We designed and applied a novel, bionic megaprosthesis for distal femur, which substituted the hinged articulation with an artificial ligament and a constrained tibial insert in order to maintain articular stability and reduce stress and the risks of wearing, loosening and breakage.Methods:We reviewed the cases of distal femoral osteosarcoma in children population who were initially treated in our center during 2019. Twelve cases of bionic distal femoral prosthesis (bionic group) and 21 cases of fixed-hinge distal femoral prosthesis (control group) were included. In the bionic group, there were six female and six male with the mean age as 8.8±2.6 y. One patient had pathological fracture. Staging according to Enneking system included 1 case of stage IIA, 10 cases of stage IIB and 1 case of stage III. In the control group, there were seven female and fourteen male with the mean age as 8.6±2.2 y. Pathological fracture was seen in three cases. Staging included 15 cases of stage IIB and 6 cases of stage III.We investigated the peri-operative safety, oncological outcome, complication profiles and post-operative functional status of the bionic prosthesis by comparing the baseline data, operative data, and oncological and prosthetic outcomes between the two groups.Results:The two groups were comparable in terms of baseline data including gender, age, height, weight and onset duration, and operative data including duration of operation (126.7±27.9 min vs 143.3±38.9 min, P=0.203), intra-operative hemorrhage (162.5±212.3 ml vs 247.6±175.6 ml, P=0.224) and duration of wound drainage (6.3±2.4 d vs 6.4±3.4 d, P=0.908). The mean follow-up duration of bionic group was 16.0±4.7 months, during which time three patients had systemic progression and one of them died of disease. Another patient had local recurrence and subluxation of the prosthesis that was treated by amputation. Subluxation might be related to the huge tumor mass and excessive resection of the quadriceps femoris. As for the control group, the mean follow-up duration was 12.7±4.5 months. Three patients had systemic progression and all patients were still alive by last follow-up. Local recurrence was seen in two patients and was treated by excision. No prosthetic complications were seen in the control group. The averaged range of motion (ROM) was greater in the bionic group than that in the control group (120.6°±13.6° vs 92.0°±7.7°, P<0.05), but the MSTS 93 scores were similar between groups (29.1±0.9 vs 29.5±0.6, P=0.337). Conclusion:Compared with the fixed-hinge distal femoral prosthesis, the bionic prosthesis had good peri-operative safety, did not increase the risks of prosthetic complications, and could achieve a better range of motion and a similar functional status based on the results of short-term follow-up.

Surgical treatment for bone and soft tumors of pelvis and sacrum presents a big challenge, because of the complex anatomy of sacropelvic region, large tumor volume at presentation, rich blood supply to the tumor and visceral involvemen, et al. Therefore, surgical excision and reconstruction are technically difficult for sacropelvic tumors. Extensive intraoperative haemorrhage could be life-threatening, and this issue remains a major concern. How to effectively control bleeding during surgery is critical for successful operation and patient's favorable prognosis. Some previous attempts, such as interventional selective internal iliac artery embolization or manual ligation through an additional anterior approach, were tested to be ineffective. Inspired by the success of resuscitative endovascular balloon occlusion of the aorta (REBOA) which resemble an endovascular tourniquet for traumatic hemorrhagic shock, some researchers have applied this techinique to control surgical bleeding during pelvic or sacral tumor resection.The authors have performed REBOA for more than 1 500 sacropelvic tumr surgeries since 2003 in Peking University People's Hospital. The patient age, the diameter of femoral artery and aorta, atherosclerosis, as well as tumor location, volume and expansion and blood suppy, have to be thoroughly evaluated prior to REBOA administration. Admittedly, the application of REBOA do reduce intraoperative bleeding, shorten the operation duration, improve the safety of surgery, yet some complications were observed including local hematoma at the puncture site, acute arterial thrombosis, femoral artery pseudoaneurysm or occlusio, et al. The purpose of this study is to review the literature on REBOA administration in pelvic and sacral tumors excision, with the focus on its indications, performing procedure, the safety and efficacy, and complications. Moreover, in order to popularize the clinical application of aortic balloon occlusion in the future, we summarize our experience of abdominal aortic balloon occlusion over 10 years.

Objective:To investigate the causes,prevention and treatment of femoral artery puncture related complications caused by the application of resuscitative endovascular balloon occlusion of the aorta (REBOA) in the resection of pelvic and sacral tumors.Methods:Clinical data of 23 patients with femoral artery puncture related complications who received REBOA in the resection of pelvic and sacral tumors from August 2010 to August 2018 at the Musculoskeletal Tumor Center,Peking University People′s Hospital were retrospectively analyzed.There were 8 males and 15 females,with the age of (37.0±16.2) years (range:15 to 65 years).Arterial access via the Seldinger technique for REBOA was obtained in the right common femoral artery of 18 cases,and in the left of 6 cases.An arterial sheath with a diameter of 11 to 12 F(1 F≈0.33 mm) was used for the patient.The occurrence and treatment of postoperative complications were analyzed.Results:Acute femoral arterial thrombosis occurred in 18 patients,which was managed by open repair 48 hours postoperatively.Among the 349 patients admitted before 2015 who received hemostasis by compression after femoral artery sheath removal,12 patients (3.4%) developed acute femoral artery thrombosis.While the 476 patients admitted after 2015 who used a percutaneous suture device to close the femoral artery wound,6 patients (1.3%) developed acute femoral artery thrombosis.One case of retroperitoneal hematoma and 1 case of femoral pseudoaneurysm were found and surgically fixed.Postoperative follow-up was (40±18) months (range:13 to 108 months).Three cases with chronic lower extremity ischemia were confirmed by Doppler ultrasonography during 1 to 5 years follow-up.Two of them had minimal symptoms and denied further treatment,while the other one received femoral-femoral artery bypass surgery to restore distal flow for pain and numbness relief.Conclusions:Acute femoral arterial thrombosis is the most common femoral artery puncture.Technique refinement of REBOA,the use of percutaneous suture device and close follow-up can reduce the approach-specific complications,and help to detect and treat the complications timely,which may popularize the clinical application of REBOA.

Objective:To investigate the causes,prevention and treatment of femoral artery puncture related complications caused by the application of resuscitative endovascular balloon occlusion of the aorta (REBOA) in the resection of pelvic and sacral tumors.Methods:Clinical data of 23 patients with femoral artery puncture related complications who received REBOA in the resection of pelvic and sacral tumors from August 2010 to August 2018 at the Musculoskeletal Tumor Center,Peking University People′s Hospital were retrospectively analyzed.There were 8 males and 15 females,with the age of (37.0±16.2) years (range:15 to 65 years).Arterial access via the Seldinger technique for REBOA was obtained in the right common femoral artery of 18 cases,and in the left of 6 cases.An arterial sheath with a diameter of 11 to 12 F(1 F≈0.33 mm) was used for the patient.The occurrence and treatment of postoperative complications were analyzed.Results:Acute femoral arterial thrombosis occurred in 18 patients,which was managed by open repair 48 hours postoperatively.Among the 349 patients admitted before 2015 who received hemostasis by compression after femoral artery sheath removal,12 patients (3.4%) developed acute femoral artery thrombosis.While the 476 patients admitted after 2015 who used a percutaneous suture device to close the femoral artery wound,6 patients (1.3%) developed acute femoral artery thrombosis.One case of retroperitoneal hematoma and 1 case of femoral pseudoaneurysm were found and surgically fixed.Postoperative follow-up was (40±18) months (range:13 to 108 months).Three cases with chronic lower extremity ischemia were confirmed by Doppler ultrasonography during 1 to 5 years follow-up.Two of them had minimal symptoms and denied further treatment,while the other one received femoral-femoral artery bypass surgery to restore distal flow for pain and numbness relief.Conclusions:Acute femoral arterial thrombosis is the most common femoral artery puncture.Technique refinement of REBOA,the use of percutaneous suture device and close follow-up can reduce the approach-specific complications,and help to detect and treat the complications timely,which may popularize the clinical application of REBOA.

Objective:To investigate the clinicopathological, immunohistochemical and molecular features of small round cell sarcoma (SRCS) of the bone and soft tissue, and to compare the diagnostic value of different techniques.Methods:Seventy-two cases of SRCS of the bone and soft tissue diagnosed at People′s Hospital, Peking University from January 2016 to March 2020 were recruited and retrospectively analyzed for pathological morphology, immunophenotype and fluorescence in situ hybridization (FISH) data. Next generation sequencing (NGS) was performed on 13 difficult cases.Results:In the study cohort, the patients ranged in age from 4-55 years, with a male predominance. The most Ewing′s sarcomas and osteosarcomas occurred in the bone, while CIC-rearranged sarcomas, BCOR-rearranged sarcoma, synovial sarcoma, extraskeletal myxoid chondrosarcoma and FUS-NFATc2 rearranged sarcoma occurred in soft tissue. Histologically, all cases were composed predominantly of small round cells. Most cases were positive for vimentin and CD99, and showed a variable reactivity for neurogenic markers. Muscle marker and epithelial marker were negative for most cases. Combined with clinical features, histopathologic findings, immunophenotype, FISH and NGS, we diagnosed 46 Ewing sarcomas, 14 osteosarcomas, 3 CIC-rearranged sarcomas, 1 BCOR-rearranged sarcoma, 1 synovial sarcoma, 1 clear cell soft tissue sarcoma, 1 extraskeletal myxoid chondrosarcoma, 1 FUS-NFATc2 rearranged sarcoma, and 4 undifferentiated small round cell sarcomas.Conclusions:SRCS of bone and soft tissue is a group of malignant mesenchymal tumors based on morphological features. Most cases can be diagnosed with a combination of clinical characteristics, morphological features and immunohistochemical phenotype, while some cases require such further tests as FISH and NGS technologies, and NGS can be useful in diagnosing and categorizing SRCS.

Objective The purpose of this study was to investigate the preliminary clinical outcomes of total elbow arthroplasty (TEA) in the treatment of elbow deformity caused by tumor-like lesions.Methods Between September 2009 and June 2017,the technique of triceps facial tongue exposure was adopted for all 11 patients who underwent total elbow arthroplasty.There were 5 females and 6 males with the mean age of 56.7±14.7 years.There were 6patients with synovial chondromatosis and 5 with pathologic hypertrophy of synovium.Seven of 11 patients were performed by posterior approach only,while the other 4by combined posterior-anterior approach.A semi-constrained Coonrad-Morrey prosthesis which provides 7° varas/valgus laxity was used in 7 patients,and custom-made total constrained prosthesis which only allow flexion and extension on a single plane was used in 4 cases.Preoperative average flexion range of elbow was 50.5°±14.0° (range,20°-70°).The ulnar nerve compression and claw hand deformity was identified in 2patients preoperatively and the nerve was transposed during operation.According to Mayo elbow function score (MEPS score),the average preoperative MEPS score was 42.1±12.7 points (range,15-60).Results Perioperative complications were not found.None of patients lost in thefollow-up and all the patients were alive.There was no pain in the joints,no triceps fracture or weakening of muscle strength,and no recurrence of the lesions.All 11 patients were followed up for 7 to 63 months with an average of 36.3±19.5 months.The mean MEPS score was improved to 89±7.2 point after surgery (t=-11.993,P=0.000).The average flextion-extension arc improved from preoperative 50.5° to 105.9° postoperatively (t=-8.697,P=0.000).The average pronation-supination arc improvement from preoperative 105°-123.2° postoperatively (t=-6.901,P=0.000).For the two patients with ulnar nerve deficit before surgery,one patient recovered 6 months after operation,however,the other patient did not 2 years later.One Coonrad-Morrey prosthesis with deep infection was treated by removing the implant.Three of 4 custom-made total constrained prostheses experienced implant failure due to loosening or periprosthetic fracture.The incidence of complications of semi-constrained prosthesis was lower than that of total constrained prosthesis (14％ vs.75％),however,it did not reach a significant difference.Conclusion This study reveals an acceptable outcome with triceps facial tongue exposure for TEA in the treatment of tumor-like lesions of elbow.TEA is a viable good alternative treatment for selected patients with large mass around the elbow or with severe deformation.However,the failure rate of fully constrained prosthesis tends to be higher than semi-constrained one,possible due to its design flaw.