Background: The distal femur is a common site of bone tumors. After surgical resection, prosthetic replacement is a major reconstruction method. We aimed to elucidate the long-term outcomes of the Kyocera Modular Limb Salvage (KMLS) systems after resection of tumors in the distal part of the femur. Methods: Between 1998 and 2014, 125 patients were treated at 14 institutions. There were 59 males and 66 females, with a mean age of 35 years. The mean follow-up period was 132 months. Results: There had been 65 additional surgeries, including 56 revisions and 9 amputations: 15 for aseptic loosening, 14 for stem breakage, 13 for deep infection, 13 for rotator-hinge bushing failure, 5 for local recurrence, and 5 for others. Implant survival rates at 10 and 15 years were 58.5% and 39.4%. The cumulative incidence of 15-year revision for femoral stem breakage was 31.7% in patients with cementless fixation. The 15-year cumulative incidence of revision for aseptic loosening was 19.8% in patients with cement fixation. Conclusions: KMLS systems represent a reliable system with long-term results. Stem breakage should be considered in patients with cementless and/or smaller femoral stem sizes. Aseptic loosening should be considered in patients with cement systems after 10 years.

Bone‑modifying agents (BMAs), including bisphosphonate and anti‑receptor activator of NF‑κB ligand (RANKL) antibodies, are effective in treating bone metastases. The present study is a case report on the efficacy and side effects of long‑term treatment with zoledronic acid, a BMA, in a 57‑year‑old woman. The patient was diagnosed with concurrent stage IV triple‑negative breast cancer and stage II colon cancer. The patient experienced complete remission of both these cancers following chemotherapy, zoledronic acid treatment and irradiation for breast cancer and surgery for colon cancer. The patient received long‑term zoledronic acid treatment and has survived >7 years after her initial diagnosis. The patient subsequently reported bilateral hip pain that was diagnosed as osteonecrosis of the femoral head, after the presence of bone metastases was ruled out using magnetic resonance imaging. The patient underwent bilateral artificial hip joint replacements. After orthopedic surgery, the multiple distant metastases, including a brain metastasis, remained in complete remission. It is well established that BMAs, such as zoledronic acid, increase the risk of osteonecrosis of the jaw, but it is not well understood if they can increase this risk in other anatomical locations. The findings of the present case study suggested that while long‑term use of BMAs may be effective in managing bone metastases, it may increase the risk of osteonecrosis in anatomical locations other than the jaw.

Aim: Patients with skeletal metastasis from prediagnosed primary malignancy sometimes have concurrent oncologic emergency (OE) during the first visit. This study aims to investigate the types of OEs and treatment outcome in such patients.Methods: We have experienced 359 patients with skeletal metastasis from unknown primary malignancy. Among them, 130 patients required immediate admission for OE treatment (OE group), 229 patients had no OE and did not required immediate admission (non‐OE group).Results: The recognized types of OE were spinal cord compression in 60 patients, cancer pain in 30, hypercalcemia in 19, delirium in 16, deep vein thrombosis in 13, acute renal failure in 6, respiratory failure in 3, gastrointestinal hemorrhage in 3, and disseminated intravascular coagulation in 1. The overall 5‐year survival rates were 28% and 37% in the OE and non‐OE groups, respectively (P < 0.001). The multivariate analysis revealed that delirium (hazard ratio 4.2; 95% confidence interval, 1.6–12.5; P < 0.005) and respiratory failure (hazard ratio 22.6; 95% confidence interval, 4.5–92.8; P < 0.001) were significant prognostic factors in patients with OEs, whereas other OEs did not confer a significant risk for patient outcomes.Conclusion: In this study, OE was observed in as many as 36% of patients with skeletal metastasis from unknown primary malignancy. Delirium and respiratory failure were only two significant prognostic risk factors, which suggest that many of the OEs in untreated advanced cancer patients have probable chance to resolve. Early detection followed by appropriate treatment of such OEs is recommended.

This study aimed to retrospectively analyze the clinical outcomes of patients with pelvic and retroperitoneal bone and soft tissue sarcoma (BSTS). Overall, 187 patients with BSTS in the pelvis and retroperitoneal region treated at 19 specialized sarcoma centers in Japan were included. The prognostic factors related to overall survival (OS), local control (LC), and progression-free survival (PFS) were evaluated. The 3-year OS and LC rates in the 187 patients were 71.7% and 79.1%, respectively. The 3-year PFS in 166 patients without any distant metastases at the time of primary tumor diagnosis was 48.6%. Osteosarcoma showed significantly worse OS and PFS than other sarcomas of the pelvis and retroperitoneum. In the univariate analyses, larger primary tumor size, soft tissue tumor, distant metastasis at the time of primary tumor diagnosis, P2 location, chemotherapy, and osteosarcoma were poor prognostic factors correlated with OS. Larger primary tumor size, higher age, soft tissue tumor, chemotherapy, and osteosarcoma were poor prognostic factors correlated with PFS in patients without any metastasis at the initial presentation. Larger primary tumor size was the only poor prognostic factor correlation with LC. This study has clarified the epidemiology and prognosis of patients with pelvic and retroperitoneal BSTS in Japan.

Objectives Delirium, a neurocognitive disorder, typically occurs in older patients and those with advanced cancer. Although there have been numerous reports on delirium in patients with cancer in various conditions, there are no reports that specifically focus on patients with musculoskeletal tumours. This prospective study aimed to investigate the incidence, risk factors and prognostic implications of delirium in patients with musculoskeletal tumours. Methods In this single institutional study, 148 patients with musculoskeletal oncology were enrolled. The estimated risk factors included age, sex, alcohol abuse, performance status (PS), dietary status, admission route, tumour malignancy, oncological stage and blood test results. The significance of delirium in survival was also examined. Results Only 18 patients with malignant tumours had delirium (12.2%). Based on univariate analysis, older age, poor PS, dietary status, admission from another hospital, malignant tumour, carcinoma rather than sarcoma, anaemia and some laboratory abnormalities were found to be significant risk factors for delirium. Multivariate analysis showed that poor PS was significantly correlated with delirium. Additionally, delirium was significantly correlated with poor survival. Conclusions The incidence of delirium among patients with musculoskeletal tumours was 12.2% and was observed only in patients with malignant tumours. PS is a significant risk factor for delirium. Delirium is correlated with poor prognosis.