[Differential diagnosis of bone and soft tissue tumors by MRI]

Musculoskeletal neoplasms are rare, and both the medical history and complaints of the patients are usually uncharacteristic and of limited information. After a clinical evaluation and biplane conventional radiography, the clinician must classify the patient as having a nonprogressive or progressive primary benign, primary malignant, or metastatic bone tumor. In the case of a probably benign, nonprogressive bone tumor, the patient has to be observed continuously or an additional biopsy should be performed. In the case of a probably malignant lesion, the patient should be referred for further staging and treatment to an orthopedic oncologist. Conventional biplane radiography, scintiscan, computed tomography scan, and magnetic resonance imaging (MRI) are indispensable in staging and treatment planning for patients with musculoskeletal tumors. For limb salvage procedures, delineation of the tumor from adjacent tissue structures is crucial. Hence, MRI of the entire anatomic structure involved, together with adjacent joints, is of the utmost importance, both in the coronal and axial planes. The significance of MRI in clinical follow-up depends on keeping the sequences and imaging planes used constant. Differentiating pseudotumors from true neoplasms still poses a challenge. The cellular pattern and matrix characteristics of a lesion cannot definitely be identified as neoplastic even with application of all imaging modalities including MRI. Information on epidemiology, clinical picture, radiology, and histology of the lesion is necessary to draw a firm conclusion. Biopsy is still the first choice in making the diagnosis

[Diagnosis of malignant bone and soft tissue tumors].

Primary sarcoma of bone is a rare entity but nevertheless a significant cause of mortality in children and adolescents. The focus of the preoperative evaluation is to set up a histological diagnosis, define local tumor extent and develop a therapy regimen. In addition to patient history and clinical findings a radiograph in two orthogonal planes is still of great importance. MRI plays a major role in the further clarification of the diagnosis, while CT is valuable in the diagnosis of tumors of the axial skeleton as well as in systemic staging. A PET-CT can be performed to obtain an overview of further tumor sites. Open bone biopsy is the final diagnostic step and should be carried out at the institution where the definitive treatment will be performed. Complications such as fracture, neural lesions and spread of tumor cells are relatively rare if the biopsy is performed appropriately; however, patients should be instructed to strictly avoid weight-bearing on the affected extremity

[Soft tissue sarcoma--epidemiology, diagnosis and treatment]

On account of the considerable variability of the clinical situation, treatment of soft tissue sarcoma requires an individually oriented multimodal approach. In the case of patients with superficial low-grade tumors measuring less than 5 cm in diameter, resection alone is usually adequate. In the event of medium-grade lesions, resection with negative margins, resection in combination with radiotherapy achieves excellent local control rates associated with an overall survival rate of almost 80%. In patients with high-grade sarcomas measuring more than 5 cm in diameter, local control can be achieved with resection and radiotherapy, although every second such patient develops metastases. For patients with local recurrence, further resection should be considered/performed. Radiotherapy is all the more effective, the smaller the postoperative tumor cell burden

Custom made total knee-replacement in patients with primary and secondary bone tumors.

The authors present an account of a group of 51 patients to whom an individual endoprosthesis of the knee joint was implanted on account of a tumour. A primary bone tumour was involved in 42 cases and a metastatic process in 9 cases. Twenty-four endoprostheses were cemented, 26 were implanted without cement. The mean follow-up period was 43 months. Functional results excellent and good in 61%, poor results only in 5%

[Soft tissue carcinoma : Epidemiology, diagnostics and therapy.]

The treatment of soft tissue sarcoma requires an individually tailored, multimodal therapy due to the high variability in the clinical situation. Resection is the usual treatment for patients with superficial, low grade tumors with a diameter of 5 cm, local control can be attained by resection and radiotherapy, however every second patient will develop metastases. Patients with a local recurrence should consider a new resection. Radiotherapy is the more effective the lower the remaining postoperative tumor burden

[Development of hip resurfacing]

Total hip replacement in its current form has proved to be very effective in late middle-aged and elderly patients. However, in the younger patient population the survival rate is still not acceptable. Since the very beginning of hip resurfacing, the procedure has been advocated as an attractive concept to preserve proximal femoral bone stock. Furthermore, it is supposed to optimize stress transfer to the proximal femur and because of the large head size improves joint stability and range of motion. The failure of previous resurfacings has been described to be due to inappropriate materials, poor design, and poor instrumentation and not as an inherent problem of the procedure itself.Progress in materials and material design (metal-on-metal) as well in experience in surgical technique seem to have overcome formerly experienced difficulties. This means a lower rate of femoral neck fractures and aseptic loosenings, at least in the short-term and midterm follow-up of patients with good function.High manufacturing standards are required to consistently produce low-wear metal-on-metal bearings and it is still unclear whether high metal ion levels, which occur in all patients with metal-on-metal hip replacements, have any biologic effect. At least so far there is no evidence of any negative clinical effect in this regard. Only long-term results in a higher number of patients and a more widespread use of this procedure will tell whether early success is durable or it is just a bone-preserving, intermittent step before conventional total hip replacement