Background: Three-dimensional (3D)-printed customized implants can be fabricated and utilized for all bones with massive bone defects. The main safety issues with 3D-printed implants made of Ti6Al4V alloy are related to the release of metal debris and residual powder. In this study, we investigated the perioperative titanium concentrations in whole blood and peri-implant fluid samples of patients who underwent limb salvage surgery with a 3D-printed Ti6Al4V implant. Methods: Nineteen patients who underwent limb salvage surgery with 3D-printed Ti6Al4V implants were divided into two groups:the serial samples group and the follow-up group. To observe metal distribution and clearance in the body, serial samples of blood and peri-implant fluid from the surgical drain were prospectively collected for five patients in the serial samples group. For the remaining 14 patients who were followed up for more than a year, blood samples were collected only once. Results: In the serial samples group, the mean baseline titanium concentration was 0.78 μg/L (range, 0.1–2.2 μg/L): 3 patients showed peak concentration before the third postoperative month, while 2 patients still showed an increasing pattern at this point.Total titanium mass in the surgical drain showed a wash-out phenomenon in a week, with a significant uniform decrease (p = 0.04).In 14 patients in the follow-up group, the mean titanium concentration in the whole blood was 10.8 μg/L (range, 0.3–36.6 μg/L). For the 14 patients with a long-term follow-up, the aluminum and vanadium concentrations were all negligible. Conclusions Whole blood titanium concentrations were higher after surgery using 3D-printed implants than after that using conventional orthopedic implants, but markedly lower than in patients with implant failure. None of the patients developed serious clinical adverse effects during follow-up.

Purpose: Due to low incidence, epidemiologic data of Ewing sarcoma in the Asian population are scarce. We aimed to examine the incidence pattern and outcome of patients with Ewing sarcoma in the Republic of Korea. Materials and Methods: Data of patients with Ewing sarcoma diagnosed between 1999 and 2017 were obtained from the Korea Central Cancer Registry (KCCR). Incidence, clinical characteristics, and survival rates were analyzed and compared between different age groups. Results: There were 788 cases (459 males, 329 females), with a median age at diagnosis of 20 years. The age-standardized rate of Ewing sarcoma was 1.01. The number of cases and incidence rates in each age group were as follows: children, 1.6; adolescents and young adults (AYA), 0.93; adults, 0.44; and elderly, 0.53. There were more male cases in children and the AYA group (p < 0.001). Extraskeletal tumors (p < 0.001), primary sites other than extremity (p=0.007), and presence of metastasis at diagnosis (p=0.031) were more frequent in the adults and elderly group. With a median survival time of 78 months, the 5-year overall survival (OS) rate of the entire cohort was 52%. Children fared best (5-year OS, 75%), and the 5-year OS of AYA patients (51%) approximated the OS of the entire cohort. A two-fold difference of 5-year OS was observed between adults and elderly patients (42% vs. 19%). On univariate and multivariate analyses, age ≥ 15 years and presence of metastasis were adverse prognostic factors. Conclusion This was the first epidemiologic study of Ewing sarcoma using the KCCR data. With a similar incidence to other Asian countries, the survival rate was slightly lower than that of Euro-American cases. Collaborative clinical studies are necessary to improve the outcome of Ewing sarcoma in low-incidence populations.

Purpose: No standard salvage regimen is available for relapsed or refractory sarcoma. We investigated the efficacy and toxicity of the vincristine, irinotecan, and temozolomide combination (VIT) for relapsed or refractory sarcomas of variable histology in children and young adults. Materials and Methods: We retrospectively reviewed data from the relapsed or refractory sarcoma patients who were treated with VIT. The VIT protocol was given every 3 weeks as follows: vincristine, 1.5 mg/m2 intravenously on day 1, irinotecan, 50 mg/m2/day intravenously on days 1-5, and temozolomide, 100 mg/m2/day orally on days 1-5. Results: A total of 26 patients (12 males) with various sarcoma histology were included in the study. Most common diagnosis was rhabdomyosarcoma (n=8) followed by osteosarcoma (n=7). Median age at the start of VIT was 18.5 years (range, 2.0 to 39.9). VIT was delivered as 2nd to 7th line of treatment, with 4th line most common (9/26, 34.6%). Median number of VIT courses given was 3 (range, 1 to 18). Of the 25 evaluable patients, there was two partial response (PR) and 11 stable disease (SD) with an overall control rate (complete remission+PR+SD) of 52%. PR was seen in one (50%) of the two evaluable patients with Ewing sarcoma and one (14.3%) of the seven patients with osteosarcoma. Overall survival and progression-free survival rates were 79.3% and 33.9% at 1 year, and 45.5% and 25.4% at 2 years, respectively. There was no treatment-related mortality. Conclusion The VIT regimen was effective and relatively safe in our cohort of sarcoma patients.

Background: A minimally invasive procedure for symptomatic pelvic bone metastasis is a feasible option for advanced cancer patients, and bone cement injection plays an essential role. Pulmonary embolism caused by thrombus, fat, or tumor emboli is a major complication related to bone cement injection, and increasing intraosseous pressure is a predisposing factor. This study aimed to quantify the degree of pressure change in the pelvic bone during percutaneous bone cement injection and investigate whether there is a significant decrease in intraosseous pressure when a decompressive route is additionally established. Methods: Bone cement injection into the acetabulum of swine pelvises by simulating the actual surgical procedure in terms of the injection method, bone cement, and surgical instruments was performed while recording the intraosseous pressure. Twenty swine pelvises were used and grouped into a decompression group and a non-decompression group. Bone cement injection and pressure measurement were conducted in the same way in both groups, but an additional decompressive route was established for each pelvis in the decompression group. Continuous variables were compared using the Mann-Whitney test. Results: The mean amount of injected bone cement was 19.8 mL and 20.3 mL and the mean speed of bone cement injection was 0.14 mL/sec and 0.12 mL/sec in the decompression group and the non-decompression group, respectively. The mean peak intraosseous pressures was 10.5 kPa with decompression and 37.8 kPa without decompression, and the difference was statistically significant (p < 0.01). Conclusions Intraosseous pressure during bone cement injection into swine pelvises was similar to that during vertebroplasty or kyphoplasty. When the additional decompression route was established, the intraosseous pressure decreased to one third the level.

Orthopaedics is an area where 3-dimensional (3D) printing technology is most likely to be utilized because it has been used to treat a range of diseases of the whole body. For arthritis, spinal diseases, trauma, deformities, and tumors, 3D printing can be used in the form of anatomical models, surgical guides, metal implants, bio-ceramic body reconstruction, and orthosis. In particular, in orthopaedic oncology, patients have a wide variety of tumor locations, but limited options for the limb salvage surgery have resulted in many complications. Currently, 3D printing personalized implants can be fabricated easily in a short time, and it is anticipated that all bone tumors in various surgical sites will be reconstructed properly. An improvement of 3D printing technology in the healthcare field requires close cooperation with many professionals in the design, printing, and validation processes. The government, which has determined that it can promote the development of 3D printing-related industries in other fields by leading the use of 3D printing in the medical field, is also actively supporting with an emphasis on promotion rather than regulation. In this review, the experience of using 3D printing technology for bone tumor surgery was shared, expecting orthopaedic surgeons to lead 3D printing in the medical field.
Congenital Abnormalities ; Delivery of Health Care ; Humans ; Limb Salvage ; Models, Anatomic ; Orthotic Devices ; Printing, Three-Dimensional* ; Spondylarthritis ; Surgeons

BACKGROUND: We aimed to describe the clinical characteristics and outcomes of unplanned excisions of synovial sarcomas. METHODS: In total, 90 patients with synovial sarcomas in the extremities were retrospectively reviewed. Patients were divided into unplanned excision (n = 38) and planned excision (n = 52) groups. The average follow-up period was 6 years. The clinicopathological characteristics and oncologic outcomes were compared. RESULTS: The unplanned excision group showed longer duration of symptoms before diagnosis (p = 0.023), smaller lesion dimensions (p = 0.001), superficial location (p = 0.049), and predilection in the upper extremities (p = 0.037). Synovial sarcomas were most commonly misdiagnosed as neurogenic tumors (56%) in the upper extremities or as cystic masses (47%) in the lower extremities. Oncological outcomes, including disease-specific survival, metastasis-free survival, or local recurrence were not significantly different between the 2 groups (p = 0.159, p = 0.444, and p = 0.335, respectively). Repeated unplanned excision (p = 0.012) and delayed re-excision (p = 0.038) were significant risk factors for local recurrence in the unplanned excision group. CONCLUSIONS: Synovial sarcomas treated with unplanned excision had distinct characteristics. These findings are important for developing diagnostic and therapeutic strategies for synovial sarcoma.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Child ; Child, Preschool ; Female ; Humans ; Male ; Middle Aged ; Retrospective Studies ; Sarcoma, Synovial/*diagnosis/*surgery ; Soft Tissue Neoplasms/*diagnosis/*surgery ; Treatment Outcome ; Young Adult

Soft tissue tumors are classified into benign and malignant on the basis of the patient's age, medical history, physical examination, pathological and radiologic examination. We have to caution against misdiagnosis of malignant tumor which can delay the treatment time. Lipoma, schwannoma, hemangioma, and ganglion cysts are common benign tumors, usually of small size and are often located in the superficial layer. Although it may be suspected as a benign tumor, performing contrast-enhanced magnetic resonance maging is preferably advantageous. Liposarcoma and undifferentiated pleomorphic sarcoma, the most common malignant soft tissue tumors, usually occur after middle age; rhabdomyosarcoma is usually presented in children and synovial sarcoma often occurs at a younger age. The magnetic resonance (MR) signal intensity of lipoma shows uniformity with subcutaneous fat, sarcoma should be suspected if it has a contrast-enhanced and non-fat-suppressed part. The MR signals of ganglion cysts show homogeneous and same signal intensity with joint fluid and urine, while the liquid containing sarcoma, like synovial sarcoma, is characterized by heterogeneous signal intensity and contrast enhancement. If surgery is performed, an incision should be made in the longitudinal direction of the limb and the excised tumor should be sent for pathology analysis. When the macroscopic finding of the tumor during surgery is different from the expected diagnosis, the operation should cease with biopsy only or the small superficial tumor can be excised widely if possible. The transfer should be considered unless you can be sure of a benign tumor in hands and feet of children. When diagnosed as malignant tumors, patients should be provided with sufficient information that can lead them to a musculoskeletal tumor specialist.
Biopsy ; Child ; Diagnosis* ; Diagnostic Errors ; Extremities ; Foot ; Ganglion Cysts ; Hand ; Hemangioma ; Humans ; Joints ; Lipoma ; Liposarcoma ; Middle Aged ; Neurilemmoma ; Pathology ; Physical Examination ; Rhabdomyosarcoma ; Sarcoma ; Sarcoma, Synovial ; Specialization ; Subcutaneous Fat

A femoral bone tumor causing a valgus deformity by affecting the growth plate was found. Long intramedullary diaphyseal tumor was separated by septum at the metapysis. Low grade chondrosarcoma was confirmed diagnosed by pathologists. Progressive limb deformity can be a sign of bone tumor in growing period.
Chondrosarcoma* ; Congenital Abnormalities* ; Extremities* ; Growth Plate

Limb salvage should be considered after complete remission in young and physically active patients with osteosarcoma. Herein we described a patient who was treated with whole knee allograft reconstruction for the clinical implications of biological reconstruction which can avoid the problems with several consecutive sessions of mega-prosthesis revision. The mid-term result of this whole knee joint allograft reconstruction showed that it provided optimal joint congruence with durable joint stability, well balanced mechanical axis without joint space narrowing, and satisfactory gait pattern.
Allografts* ; Axis, Cervical Vertebra ; Gait ; Humans ; Joints ; Knee ; Knee Joint* ; Limb Salvage* ; Osteosarcoma*

PURPOSE: We aimed to assess the treatment outcomes and factors affecting bone union of intercalary allograft reconstruction after primary malignant bone tumor resection around the knee. MATERIALS AND METHODS: Twenty-one patients who underwent intercalary allograft reconstruction after resection of a malignant tumor of femur or tibia were retrospectively reviewed. The average follow-up period was 46.4 months. Location of the tumor was as follows: femur in 12 cases and tibia in 9. Osteosarcoma was the most common tumor (12 cases). Intercalary allograft was internally fixed with an intramedullary (IM) nail in 3 cases, with a plate in 12 cases and with an IM nail combined with a plate in 6 cases. The survival of the grafts and functional outcomes were evaluated. Factors affecting bone union and complications were assessed. RESULTS: All allografts survived without removal. The average Musculoskeletal Tumor Society functional score was 27. The mean length of the allograft was 16.7 cm and bony union took 10.9 months, in average. Nonunion occurred in 6 cases: at the diaphyseal side in 3, and the remaining 3 at the metaphyseal side. The graft length was shorter than average in all the diaphyseal side nonunion cases and longer than average in all the metaphyseal side nonunion cases. All cases of nonunion obtained bone union after additional operations (autologous bone graft alone: 1, bone graft with hardware change: 5). CONCLUSION: Survival and functional outcomes of intercalary allograft were satisfactory. Long allograft showed a tendency of fracture or nonunion at the metaphyseal side. Nonunion could be managed with additional operation without allograft removal.
Femur ; Follow-Up Studies ; Humans ; Knee ; Nails ; Osteosarcoma ; Retrospective Studies ; Tibia ; Transplantation, Homologous ; Transplants