Impact of Postoperative Infection on Lower Limb Function After Surgery for Malignant Bone and Soft Tissue Tumors: Data from a Nationwide Registry in Japan.

Background: Due to the scarcity of cases, adjustments for confounding factors in analyses of the effects of postoperative infections on limb function after surgery for malignant bone and soft tissue tumors were insufficient in previous studies. One solution is to use big data from a nationwide registry.

Methods: Data from the Bone and Soft Tissue Tumor Registry in Japan were used to examine the impact of postoperative infections on limb function after surgery for malignant bone and soft tissue tumors in the lower extremities.

How Musculoskeletal Tumor Management Changed During the COVID-19 Pandemic: Data from a Nationwide Questionnaire Survey of Hospitals Specializing in Musculoskeletal Tumors in Japan.

Background: While changes in clinical practice during the COVID-19 pandemic in Japan have been widely studied, data specific to bone and soft tissue tumor care remain limited.

Methods: A nationwide web-based survey was conducted among hospitals specializing in musculoskeletal tumors. It assessed the occurrence of COVID-19-related events (patient infections, outbreak clusters, and staff infections), delays in referral and diagnosis, postponement or cancellation of specific treatments, and changes in institutional management strategies.

Methotrexate, Doxorubicin, and Cisplatin Versus Methotrexate, Doxorubicin, and Cisplatin + Ifosfamide in Poor Responders to Preoperative Chemotherapy for Newly Diagnosed High-Grade Osteosarcoma (JCOG0905): A Multicenter, Open-Label, Randomized Trial.

Purpose: Our previous NECO phase II studies on high-grade osteosarcoma suggested that administering ifosfamide (IF; 16 g/m [4g/m once on day 1, then 2g/m once on days 2-7] × six) to patients showing a poor response (PrRsp) to preoperative chemotherapy with methotrexate, doxorubicin, and cisplatin (MAP) improves their prognoses. In this Japan Clinical Oncology Group (JCOG) study, JCOG0905, we aimed to investigate the efficacy and safety of IF in patients with PrRsp.

Methods: JCOG0905 is a multicenter, open-label, multi-institutional, randomized trial.

Comparative surgical invasiveness of internal fixation for pathological fractures in metastatic bone disease versus traumatic fractures: a quantitative analysis of operative time and blood loss.

Objective: The primary aim of this study was to compare the surgical invasiveness of internal fixation for pathological fractures caused by metastatic bone tumors with that for traumatic fractures. The secondary aim was to identify factors contributing to the complexity of surgeries for metastatic bone disease and provide insights for improving surgical strategies by analyzing operative time and blood loss.

Methods: Patients undergoing internal fixation for femoral fractures at 10 institutions between January 2021 and December 2023 were included.

Predictive variables for intraoperative blood loss and surgical time in resection of malignant soft tissue tumors without reconstruction.

Background: Procedural techniques such as dissection and separation of blood vessels or nerves from the tumor for preserving limbs and functions involves high surgical difficulty. We hypothesized the relation of vessel and/or nerve preservation to surgical time and blood loss, accurately reflecting surgical difficulty. In this study, we elucidated the variables affecting surgical time and intraoperative bleeding in patients with malignant soft tissue tumors who did not undergo any reconstruction after tumor resection.

Clinical characteristics and outcomes of patients with chondroblastoma undergoing surgery with various adjuvant procedures: a retrospective study of 59 cases.

Background: Chondroblastoma is classified as a benign bone tumor. However, postoperative local recurrence remains a concern. We analyzed the factors contributing to chondroblastoma local recurrence and the clinical challenges associated with treating these patients.

Development of an Artificial Intelligence System for Distinguishing Malignant from Benign Soft-Tissue Tumors Using Contrast-Enhanced MR Images.

Introduction: The integration of artificial intelligence (AI) into orthopedics has enhanced the diagnosis of various conditions; however, its use in diagnosing soft-tissue tumors remains limited owing to its complexity. This study aimed to develop and assess an AI-driven diagnostic support system for magnetic resonance imaging (MRI)-based soft-tissue tumor diagnosis, potentially improving accuracy and aiding radiologists and orthopedic surgeons.

Methods: An experienced orthopedic oncologist and radiologist annotated 720 images from 77 cases (41 benign and 36 malignant soft-tissue tumors).

Japanese orthopaedic association (JOA) clinical practice guideline on the management of primary malignant bone tumors - Secondary publication.

Background: In Japan, there are currently no general guidelines for the treatment of primary malignant bone tumors. Therefore, the Japanese Orthopaedic Association established a committee to develop guidelines for the appropriate diagnosis and treatment of primary malignant bone tumors for medical professionals in clinical practice.

Methods: The guidelines were developed in accordance with "Minds Clinical Practice Guideline Development Handbook 2014″ and "Minds Clinical Practice Guideline Development Manual 2017".

Infection of surgery for bone and soft tissue sarcoma with biological reconstruction: Data from the Japanese nationwide bone tumor registry.

Background: Although biological reconstruction (such as recycled autograft, vascularized autograft, allograft, or bone transport) is possible for bone defects after malignant bone or soft tissue tumor resection, a high incidence of postoperative complications, including infection, poses a problem. The difficulty in accumulating cases has resulted in a lack of reliable etiological information, such as the incidence and risk factors of postoperative infections.

Methods: We conducted a retrospective study on the nationwide registry data.

Incidence and risk of infection in malignant soft tissue tumor resection: Data from the nationwide soft tissue tumor registry.

Background: Postoperative infection is a devastating complication in limb salvage surgery for malignant soft tissue tumors. The low absolute case numbers of these rare cancers represent a bottleneck for data collection and analysis. The administration of nationwide registry data is a practical option for the accumulation of cases.

Incidence and risk of surgical site infection/periprosthetic joint infection in tumor endoprosthesis-data from the nationwide bone tumor registry in Japan.

Background: Surgical site infection (SSI)/periprosthetic joint infection (PJI) is a devastating complication in limb salvage surgery with endoprosthesis reconstruction for malignant bone tumors. The main bottleneck for data collection and analysis for the status of SSI/PJI in tumor endoprosthesis is the low absolute case numbers of this rare cancer. The accumulation of many cases is possible by administrating nationwide registry data.

Clinical Outcome of Low-Grade Myofibroblastic Sarcoma in Japan: A Multicenter Study from the Japanese Musculoskeletal Oncology Group.

This retrospective multicenter study aimed to analyze the clinical features and prognosis of 24 patients diagnosed with LGMS between 2002 and 2019 in the Japanese sarcoma network. Twenty-two cases were surgically treated and two cases were treated with radical radiotherapy (RT). The pathological margin was R0 in 14 cases, R1 in 7 cases, and R2 in 1 case.

Relationship between the 25-question Geriatric Locomotive Function Scale and physical function in the elderly people.

Introduction: Locomotive syndrome (LS) is a condition of reduced mobility. The LS stage can be determined by the stand-up test, two-step test, and 25-question geriatric locomotive function scale (GLFS-25). This study aimed to establish whether the LS stage can be reliably determined using the GLFS-25, and to clarify the correlation between the GLFS-25's six subcategories and physical functions.

Dedifferentiated liposarcoma in the extremity and trunk wall: A multi-institutional study of 132 cases by the Japanese Musculoskeletal Oncology Group (JMOG).

Background: Dedifferentiated liposarcoma occurs predominantly in the retroperitoneum. Given the paucity of cases, information on the clinical characteristics of this entity in the extremities and trunk wall is quite limited. In particular, the significance of preoperative evaluation and principles of intraoperative management of the different components, i.

Optimal timing for intermittent administration of parathyroid hormone (1-34) for distraction osteogenesis in rabbits.

Background: To date, the usefulness of parathyroid hormone [PTH (1-34)] in distraction osteogenesis has been reported in several studies. We aimed to determine the optimal timing of PTH (1-34) administration in a rabbit distraction osteogenesis model.

Methods: The lower hind leg of a Japanese white rabbit was externally fixed, and tibial osteotomy was performed.

Complications of surgery for giant cell tumor of bone in the extremities: Incidence, risk factors, management modality, and impact on functional and oncological outcomes.

Background: Due to the wide variations in location, size, local invasiveness, and treatment options, the complications associated with surgery for giant cell tumor of bone have been sporadically reported. For quality assessment, fundamental data based on large-scale surveys of complications under a universal evaluation system is needed. The Dindo-Clavien classification is an evaluation system for complications based on severity and required intervention type and is suitable for the evaluation of surgery in a heterogeneous cohort.

Identification of a Novel MAN1A1-ROS1 Fusion Gene Through mRNA-based Screening for Tyrosine Kinase Gene Aberrations in a Patient with Leiomyosarcoma.

Background: Soft tissue sarcomas are a heterogeneous group of rare malignant tumors. Advanced soft tissue sarcomas have a poor prognosis, and effective systemic therapies have not been established. Tyrosine kinases are increasingly being used as therapeutic targets for a variety of cancers and soft tissue sarcomas.

Clinical Outcomes of Patients with Metastatic Solitary Fibrous Tumors: A Japanese Musculoskeletal Oncology Group (JMOG) Multiinstitutional Study.

Background: Although the unpredictable malignant behavior of solitary fibrous tumors (SFTs) has been recognized, the clinical features and prognosis of metastatic SFTs have not been well documented due to the extreme rarity of these cases. The aim of this study is to investigate the clinical features, prognostic factors, and optimal management of patients with metastatic SFTs.

Patients And Methods: Sixty patients with metastatic SFT were retrospectively reviewed.