[Primary malignant bone tumors]. / Primär maligne Knochentumoren.

Primary malignant bone tumors are rare. Due to an associated worsening of the prognosis by diagnostic delay, these tumors must not be overlooked in the routine clinical practice and should therefore always be included in the differential diagnosis for the clarification of musculoskeletal complaints. A correct interpretation of the diagnostic procedure, radiological investigations and a biopsy of doubtful lesions can confirm the diagnosis. Osteosarcoma, chondrosarcoma and Ewing's sarcoma are the three most frequent primary malignant bone tumors and other entities occur only sporadically. While the prognosis of osteosarcoma and Ewing's sarcoma has been vastly improved with chemotherapy, chondrosarcomas mostly respond only poorly or not at all to systemic chemotherapy. Wide resection represents the gold standard in the surgical management of all primary malignant bone tumors. In addition, Ewing's sarcoma responds well to irradiation. The multidisciplinary management of primary malignant bone tumors should be performed at dedicated and specialized centers.

Extra-abdominal desmoid tumor fibromatosis: a multicenter EMSOS study.

BACKGROUND: Extra-abdominal desmoid tumor fibromatosis (DTF) is a rare, locally aggressive soft tissue tumour. The best treatment modality for this patient cohort is still object of debate. QUESTIONS/PURPOSE: This paper aimed to (1) to compare the outcomes of DTF after different treatment modalities, (2) to assess prognostic factors for recurrence following surgical excision, and (3) to assess prognostic factors for progression during observation. METHODS: This was a retrospective multicenter study under the patronage of the European Musculoskeletal Oncology Society (EMSOS). All seven centres involved were tertiary referral centres for soft tissue tumours. Baseline demographic data was collected for all patients as well as data on the diagnosis, tumour characteristics, clinical features, treatment modalities and whether they had any predisposing factors for DTF. RESULTS: Three hundred eighty-eight patients (240 female, 140 male) with a mean age of 37.6 (±18.8 SD, range: 3-85) were included in the study. Two hundred fifty-seven patients (66%) underwent surgical excision of ADF, 70 patients (18%) were observed without therapy, the residual patients had different conservative treatments. There were no significant differences in terms of tumour recurrence or progression between the different treatment groups. After surgical excision, younger age, recurrent disease and larger tumour size were risk factors for recurrence, while tumours around the shoulder girdle and painful lesions were at risk of progression in the observational group. CONCLUSION: Local recurrence rate after surgery was similar to progression rates under observation. Hence, observation in DTF seems to be justified, considering surgery in case of dimensional progression in 2 consecutive controls (3 and 6 months) and in painful lesions, with particular attention to lesions around the shoulder girdle.

Efficacy of different revision procedures for infected megaprostheses in musculoskeletal tumour surgery of the lower limb.

PURPOSE: The incidence of recurrent infections in patients following one or two stage revision for infected megaprostheses after resection of bone tumours was investigated. The difference between retaining at least one well fixed stem and a complete removal of the megaprosthesis during a two stage revision was also analysed. METHODS: 627 patients who experienced a replacement of a musculoskeletal tumour by megaprostheses were recorded. An infection occurred in 83 of 621 patients available for follow-up. 61 patients underwent one stage revision, and 16 patients two stage revision for the first revision surgery. In the entire study period, two stage revision was performed 32 times (first, second, and third revision). RESULTS: The cumulative incidence analysis showed a reinfection probability after one stage revision of 18% at one year, 30% at two years, 39% at five years, 46% at ten years, and 56% at 15 years. After two stage revision, a reinfection probability of 28% at two years, and 48% at five years was calculated. Cumulative incidence curves did not differ significantly (Gray's test; p = 0.51) between one and two stage revision (with and without complete removal of the stems). In two stage revision (n = 32), a statistically significant difference in infection rates between patients treated with complete removal of the megaprosthesis (n = 18) including anchorage stems and patients with at least one retained stem (n = 14) was shown (Fisher's exact test, p = 0.029). CONCLUSION: Two stage revisions with complete removal of the megaprosthesis showed the best results among limb salvage procedures for the treatment of infected megaprosthesis.

C-reactive protein: An independent predictor for dedifferentiated chondrosarcoma.

Dedifferentiated chondrosarcoma is a rare primary bone malignancy with a very poor prognosis. The aim of the study was to identify pretreatment serum markers as prognostic factors for the overall survival (OS) of patients with dedifferentiated chondrosarcoma. We retrospectively reviewed 33 patients with histologically confirmed dedifferentiated chondrosarcoma treated at our department from 1977 to 2015. Kaplan-Meier estimation, uni- and multivariable Cox proportional hazard model were performed to evaluate the association between serum markers such as the C-reactive protein and OS. In univariable analysis, CRP was strongly associated with OS (HR 1.35; 95%CI 1.13-1.61; p = 0.001). This association prevailed after adjustment for AJCC tumor stage (HR 1.31; 95%CI 1.02-1.57; p = 0.031) in multivariable analysis. In conclusion, our data gave evidence that baseline CRP is an independent predictor for OS in patients with dedifferentiated chondrosarcoma. CRP could be exploited for the clinical prediction of this disease in the future. © 2018 The Authors. Journal of Orthopaedic Research® Published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res 36:2797-2801, 2018.

Is Total Femur Replacement a Reliable Treatment Option for Patients With Metastatic Carcinoma of the Femur?

BACKGROUND: The majority of metastatic bone lesions to the femoral bone can be treated without surgery or with minimally invasive intramedullary nailing. In rare patients with extensive metastatic disease to the femur, total femur replacement may be the only surgical alternative to amputation; however, little is known about this approach. QUESTIONS/PURPOSES: In a highly selected small group of patients with metastatic carcinoma of the femur, we asked: (1) What was the patient survivorship after this treatment? (2) What was the implant survivorship free from all-cause revision and amputation, and what complications were associated with this treatment? (3) What functional outcomes were achieved by patients after total femur replacement for this indication? METHODS: Eleven patients (three men, eight women) with a mean age of 64 years (range, 41-78 years) received total femur replacements between 1986 and 2016; none were lost to followup. The most common primary disease was breast cancer. In general, during this period, our indications for this procedure were extensive metastatic disease precluding internal fixation or isolated proximal or distal femur replacement, and an anticipated lifespan exceeding 6 months. Our contraindication for this procedure during this time was expected lifespan less than 6 months. Patient survival was assessed by Kaplan-Meier analysis; implant survival free from revision surgery and amputation were assessed by competing risk analysis. Function was determined preoperatively and 6 to 12 weeks postoperatively with the Musculoskeletal Tumor Society (MSTS) score normalized to a 100-point scale, with higher scores representing better function from a longitudinally maintained institutional database. RESULTS: Eleven patients died at a median of 5 months (range, 1-31 months) after surgery. One-year revision-free and limb survival were 82% (95% CI, 51%-98%) and 91% (95% CI, 61%-99%), respectively. Reasons for reoperation were hip dislocation, infection and local recurrence in one patient each. The latter two complications resulted in amputation in two patients. The median MSTS score was 32 (range, 13-57). CONCLUSIONS: Despite attempts to select patients who might have anticipated greater life expectancy, eight of 11 patients died by 6 months after surgery, and an additional two patients had undergone an amputation at 8 and at 17 months postoperatively. Most patients undergoing total femur replacement in this series did not recover from the procedure by the time they died, despite our best attempts to perform the procedure in patients whom we thought would live at least 6 months. Based on this, we believe that most patients with extensive metastatic disease to the femur should be offered palliative care, rather than major reconstruction. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Serum creatinine and albumin predict sarcoma-specific survival in patients with myofibroblastic and fibroblastic sarcomas.

Recent evidence suggests that common prognostic factors predicting disease progression and survival in soft tissue sarcomas (STS) are not applicable to all STS entities, indicating the need for histotype specific evaluation of new prognosticators. This study aimed at evaluating preoperative serum creatinine, albumin, and the albumin-creatinine ratio (ACR) as markers for survival in patients with malignant fibroblastic and myofibroblastic sarcomas. One hundred and thirty-two patients who underwent sarcoma resection have been included. Statistical analysis comprised uni- and multivariable Cox proportional hazard models, competing risk analysis and Kaplan-Meier estimates. The 5-year overall survival (OS) was estimated at 64.1% (95%CI: 53.7-72.8) and the 5-year sarcoma-specific mortality was 19.9% (95%CI: 12.8-28.1). Elevated serum creatinine levels were significantly associated with an impaired sarcoma-specific survival (SSS) adjusted for tumor stage (subdistribution hazard ratio (SHR) per 1 mg/dl increase: 3.27; 95%CI: 1.87-5.73; p < 0.0001). Low serum albumin levels were associated with a shorter recurrence-free survival (RFS) experience (HR per 10 g/L increase: 0.62; 95%CI: 0.41-0.94; p = 0.024). The ACR emerged as an AJCC-stage-independent prognosticator of SSS (SHR per 1 unit increase: 0.94; 95%CI: 0.90-0.98; p = 0.003). In conclusion, serum albumin and creatinine have been confirmed as predictive biomarkers for disease-specific outcomes in myofibroblastic and fibroblastic sarcomas. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2815-2824, 2017.

Total Femur Replacement After Tumor Resection: Limb Salvage Usually Achieved But Complications and Failures are Common.

BACKGROUND: Primary bone or soft tissue tumors of the femur sometimes present with severe and extensive bone destruction, leaving few limb-salvage options other than total femur replacement. However, there are few data available regarding total femur replacement and, in particular, regarding implant failures. QUESTIONS/PURPOSES: We asked: (1) What are the revision-free and overall implant survival rates of conventional total femur replacements in patients treated for sarcoma of the femur or soft tissues? (2) What are the revision-free and overall implant survival rates of expandable total femur replacements in skeletally immature patients? (3) Using the comprehensive International Society of Limb Salvage failure-mode classification, what types of complications occur with conventional and expandable total femur replacements? PATIENTS AND METHODS: Our retrospective, single-center cohort study was based on data prospectively collected for 50 patients who received a total femur replacement after tumor resection for indications other than carcinoma or metastatic disease. Of the 50 patients, six (12%) were lost to followup before 6 months. Ten of the remaining 44 patients received expandable implants. The mean followup was 57 months (range, 1-280 months) and 172 months (range, 43-289 months) for patients who underwent conventional and expandable total femur replacements, respectively. For implant survival, competing risk analyses were used. RESULTS: At 5 years, revision-free implant survival of conventional total femur replacements was 48% (95% CI, 0.37-0.73), and overall implant survival was 97% (95% CI, 0.004-0.20). Five-year revision-free implant survival of expandable total femur replacements was 30% (95% CI, 0.47-1.00) and overall implant survival was 100%. With conventional total femur replacements soft tissue failures occurred in 13 of 34 patients, structural failures in three, infection in six, and local tumor progression in one. No patient had aseptic loosening with conventional total femur replacements, but hip disarticulation occurred in two patients owing to extensive wound-healing problems and infection. With expandable total femur replacements soft tissue failure, aseptic loosening, and infection occurred in one patient each of 10, and structural failures in three of 10 (two periprosthetic fractures, one loosening of an enhanced tendon anchor). No hip disarticulations were performed. Additionally expandable total femur replacement-related failures included hip instability in eight of 10 patients, contractures attributable to massive scar tissue in six, and defect of the implant's expansion mechanism in four patients. CONCLUSIONS: Although the indications for total femoral resection are rare, we think that total femur replacement is a reasonable treatment option for reconstruction of massive femoral bone defects after tumor resection in adults and skeletally immature patients, and results in limb salvage in most patients. LEVEL OF EVIDENCE: Level IV, therapeutic study.