Aims

The aim of this study was to report the patterns of symptoms and insufficiency fractures in patients with tumour-induced osteomalacia (TIO) to allow the early diagnosis of this rare condition.

We studied the bone mineral density (BMD) of 48 long-term survivors of highly malignant osteosarcoma who had been treated according to the chemotherapy protocols of the German- Swiss-Austrian Co-operative Osteosarcoma Study Group which include high-dose methotrexate. The mean age of the patients was 31 ± 4.2 years and the mean follow-up 16 ± 2.2 years. The BMD of the lumbar spine and of the proximal femur of the non-operated side was measured by dual- energy x-ray absorptiometry. A questionnaire was given to determine life-style factors, medical history and medication. Ten patients were osteoporotic, 21 osteopenic and 17 normal according to the WHO definition. Eighteen patients suffered fractures after receiving chemotherapy and all had significantly lower levels of BMD for all the sites measured

The rising incidence of atraumatic fractures in patients either with Ewing's sarcoma or osteosarcoma years after chemotherapy revealed a growing population of childhood cancer survivors with a decreased bone mineral density (BMD) possibly due to a long-term effect of the chemotherapy. Therefore we started to screen our patients below 50y of age who were treated for bone malignancies between 1994 and 2009. The first series of measurements included 15 patients – eight Ewing's sarcoma, three female and five male, with a mean age of 18y (±13SD), and seven osteosarcoma, two female and five male, with a mean age of 19y(±9SD). We screened the patients for deficits in their bone status using DEXA (dual-energy-x-ray-absorptiometry) to gain the T-and Z-Scores of the proximal femur and the lumbal spine. Additionally we took blood samples for endocrinological analysis and utilised a questionnaire to scan the patient's liefestyle. The mean time between diagnosis and investigation was 95months (±79SD) in Ewing's sarcoma and 105months (±54 SD) in osteosarcoma. The results of the age and gender matched lumbal measurement (Z-Score) of the Ewing's sarcoma patients showed a reduction of the BMD in six cases (6/8), including three times osteopenia (3/8) and two times osteoporosis (2/8). The osteosarcoma patients presented a BMD-decline in four cases (4/7) with two times osteopenia (2/7) and one osteoporosis (1/7). In the proximal femur six Ewing's sarcoma (6/8) and six osteosarcoma patients (6/7) showed a BMD-decrease including three osteopenic (3/8) and one osteoporotic (1/8) Ewing's sarcoma and four osteopenic osteosarcoma (4/7). We found two cases of pathologic fractures (2/15), one Ewing's sarcoma 29 months after diagnosis with a fracture of the distal femur and the proximal Tibia (1/8) and one osteosarcoma with a fractured distal femur after 72 months (1/7). As presented in our case series osteoporosis after chemotherapy is an underestimated long-term effect of the chemotherapeutic treatment. In our series BMD-reduction seems to be independent of tumour-type and chemotherapeutic agent like MTX

Aims

The early mortality in patients with hip fractures from bony metastases is unknown. The objectives of this study were to quantify 30- and 90-day mortality in patients with proximal femoral metastases, and to create a mortality prediction tool based on biomarkers associated with early death.

Previously, we showed that case-specific non-linear finite element (FE) models are better at predicting the load to failure of metastatic femora than experienced clinicians. In this study we improved our FE modelling and increased the number of femora and characteristics of the lesions. We retested the robustness of the FE predictions and assessed why clinicians have difficulty in estimating the load to failure of metastatic femora. A total of 20 femora with and without artificial metastases were mechanically loaded until failure. These experiments were simulated using case-specific FE models. Six clinicians ranked the femora on load to failure and reported their ranking strategies. The experimental load to failure for intact and metastatic femora was well predicted by the FE models (R² = 0.90 and R² = 0.93, respectively). Ranking metastatic femora on load to failure was well performed by the FE models (τ = 0.87), but not by the clinicians (0.11 < τ < 0.42). Both the FE models and the clinicians allowed for the characteristics of the lesions, but only the FE models incorporated the initial bone strength, which is essential for accurately predicting the risk of fracture. Accurate prediction of the risk of fracture should be made possible for clinicians by further developing FE models.