Extendible Prostheses for Children After Resection of Primary Malignant Bone Tumor: Twenty-seven Years of Experience.

BACKGROUND: Endoprosthetic replacement in children following resection of a malignant bone tumor still is controversial because of the high number of reoperations. The aim of this study was to evaluate the long-term outcome with respect to limb-lengthening potential, satisfaction rate, and complications after implantation of extendible devices. METHODS: Seventy-one patients with a sarcoma in an extremity who had been followed for more than twenty-four months (mean, 131.6 months; range, 27.2 to 281.8 months) after tumor resection and prosthetic reconstruction with an extendible device were analyzed. The mean age at the time of the operation was ten years (range, four to sixteen years). The complication-free survival rate was evaluated with competing-risk analysis. Clinical outcomes and complications were rated with use of the Musculoskeletal Tumor Society (MSTS) score and a failure mode classification for segmental tumor endoprostheses, respectively. RESULTS: Twelve of seventy-one patients died of their disease. The overall MSTS score averaged 87.8% (range, 23.3% to 100%). The most common mode of failure was soft-tissue failure (46%), followed by structural failure (28%), infection (17%), and aseptic loosening (8%); only 2% of the children had local recurrence. An average of 4.4 lengthening operations per patient were required for an average limb elongation of 70.8 mm (range, 0 to 224 mm). An average of 2.5 operations (range, zero to eleven) per patient were performed for complications. CONCLUSIONS: Although limb lengthening with an extendible endoprosthesis seems to be effective, many children have related complications. These data will be a source of preoperative information for children and parents, and will provide a benchmark for further clinical improvements.

Pt nanoparticles supported on Sb-doped SnO2 porous structures: developments and issues.

In this work, high surface area antimony doped tin oxide (Sb-SnO2) has been synthesized using a modified sol-gel synthesis method. The bulk and surface properties of the metal oxide support have been investigated as a function of the processing conditions. A change in the Sb-SnO2 processing conditions, while preserving an overall invariant bulk composition, led to substantial modification of the surface stoichiometry. Accelerated stability test protocols have shown that the surface composition represents a crucial parameter for the electrochemical stability of Sb-SnO2. Model Pt/Sb-SnO2 electrodes have been developed depositing Pt nanoparticles by magnetron sputtering on the optimized Sb-SnO2 porous surface. A significant enhancement in the corrosion stability upon 1000 potential cycles between 0.5 and 1.5 V (RHE) at 50 mV s(-1) has been observed for the Pt/Sb-SnO2 system compared to Pt/carbon.

The influence of tumor- and treatment-related factors on the development of local recurrence in osteosarcoma after adequate surgery. An analysis of 1355 patients treated on neoadjuvant Cooperative Osteosarcoma Study Group protocols.

BACKGROUND: Local recurrence (LR) in osteosarcoma is associated with very poor prognosis. We sought to evaluate which factors correlate with LR in patients who achieved complete surgical remission with adequate margins. PATIENTS AND METHODS: We analyzed 1355 patients with previously untreated high-grade central osteosarcoma of the extremities, the shoulder and the pelvis registered in neoadjuvant Cooperative Osteosarcoma Study Group trials between 1986 and 2005. Seventy-six patients developed LR. RESULTS: Median follow-up was 5.56 years. No participation in a study, pelvic tumor site, limb-sparing surgery, soft tissue infiltration beyond the periosteum, poor response to neoadjuvant chemotherapy, failure to complete the planned chemotherapy protocol and biopsy at a center other than the one performing the tumor resection were significantly associated with a higher LR rate. No differences were found for varying surgical margin widths. Surgical treatment at centers with small patient volume and additional surgery in the primary tumor area, other than biopsy and tumor resection, were significantly associated with a higher rate of ablative surgery. CONCLUSIONS: Patient enrollment in clinical trials and performing the biopsy at experienced institutions capable of undertaking the tumor resection without compromising the oncological and functional outcome should be pursued in the future.

[Megaprostheses: KMFTR to GMRS]. / Megaprothesen: KMFTR® bis GMRS®

The first trend-setting development of megaprostheses was initiated by Martin Salzer who introduced a ceramic prosthesis system in Vienna in 1972 for proximal humeral resection in patients with sarcoma and Ewing's sarcoma. Up until 1982, custom-made prostheses for the distal but also for the proximal femur were used for cementless implants with stem and side plates with screws. The Howmedica Modular Resection System (HMRS) exists since 1988. At the same time as the HMRS system was developed for the lower extremity, a system was also devised for the upper extremity, the Howmedica Humerus Modular Resection System, and the Global Modular Replacement System (GMRS) has been available since 2002.

[Upper-extremity amputation in tumours of the shoulder and upper arm--experiences of the Vienna Bone Tumour Registry]. / Die Amputation an der oberen Extremität bei Tumoren der Schulter und des Oberarmes--Erfahrungen aus dem Wiener Knochengeschwulstregister.

Malignant lesions of the bones and soft tissues require radical or wide resection to achieve adequate therapy. Due to the many developments in terms of adjuvant modalities, diagnostics and surgical expertise today there are several modes of therapy as alternatives to amputation in the treatment of malignant tumours of the shoulder and upper arm. After resection of smaller tumours excellent functional results can be obtained by the use of modular endoprostheses, whereas large neoplasms adjacent to the neurovascular bundle require resection-replantation to allow salvage of the hand. Within the Vienna Bone Tumour Registry, 100 patients out of a total of more than 6500 have been treated for such lesions: 62 received an endoprostheses, 18 resection-replantation and 20 amputation. In cases of primary malignant tumours the incidence of lung metastases was higher in the resection-replantation group (50 %) and amputation group (42 %) than in the prostheses group (11 %), which has been linked to larger tumour size in the former two groups. Radical or wide resections were obtained in 95 % of the prostheses group, as compared to 75 % and 78 % in the amputation group and the resection-replantation group, respectively, due to invasion into the neurovascular bundle. Over time the number of amputations decreased simultaneously with the increase of endoprostheses whereas the number of resection-replantations remained equal at our institution. Amputation today still plays a crucial role in the treatment of intralesionally resected tumours, as surgical contamination can make limb salvage impossible. Therefore, the importance of biopsy in the therapeutical algorithm of bone and soft tissue tumours has to be emphasised again.

Livin and Bcl-2 expression in high-grade osteosarcoma.

AIMS: The evaluation of prognosis in patients with osteosarcoma is limited to clinical parameters. Although numerous molecular markers have been studied, none are currently in routine clinical use. The aim of this study was to determine if Livin and Bcl-2, acting as antiapoptotic proteins through different mechanisms, are expressed in osteosarcoma, and whether they can be used as prognostic markers in human osteosarcoma. METHODS: Tumor specimens of 29 patients with high-grade central osteosarcoma, with complete clinical follow-up for a minimum of 5 years, were studied. The localization and distribution of Livin and Bcl-2 were investigated using immunohistochemistry. Results were correlated with the histological response to chemotherapy, 5-year disease-free and 5-year overall survival. RESULTS: Bcl-2 was expressed only in the cytoplasm of 16/29 cases and there was no statistically significant correlation between expression and any of the studied parameters. Livin was detected in 17/29 cases, in the cytoplasm of all 17 and in the nucleus of only 3 cases. Nuclear expression was significantly correlated with a decreased overall survival (P < 0.0002) compared with those patients without nuclear expression. CONCLUSIONS: The results of this study indicate that Bc1-2 and Livin are highly expressed in osteosarcoma cells and that possibly, the evaluation of nuclear Livin expression might be a useful prognostic marker in osteosarcoma.

Metastatic bone disease: a 36-year single centre trend-analysis of patients admitted to a tertiary orthopaedic surgical department.

BACKGROUND AND OBJECTIVES: The treatment and outcome of primary malignant bone tumours has changed with the advances in diagnostic and treatment modalities. A trend-analysis on a large cohort of patients with metastatic bone disease was performed. METHODS: A retrospective chart review of all cases with metastatic bone disease admitted to a single tertiary orthopaedic referral centre, registered with the Vienna Bone and Soft Tissue Tumour Registry between 1968 and 2003 was conducted. For trend-analysis of frequency, survival, primary site, treatment methods, and others, the 36-year study duration was divided into four periods. RESULTS: The study identified 601 females and 580 males (mean: 60 years) with metastatic bone disease. The most common metastases were secondary to breast cancer (n = 275; 23%) and renal cell carcinoma (n = 242; 21%) and the majority were located in the femur (n = 332; 28%) and spine (n = 348; 29%). Overall, the proportion of patients who underwent surgery decreased. At follow-up, 887 (75%) patients were verified to have died of their disease. CONCLUSIONS: Over the 36-year period, the frequency of bone metastases has increased at our centre. Although survival increased over time, the difference was not significant; this was most likely attributable to the seriousness of cases referred to our tertiary care centre.

[Minimally invasive hip replacement--a meta-analysis]. / Der minimalinvasive Hüftersatz - eine Metaanalyse.

AIM: A systematic review of randomized controlled trials reporting on the comparison of minimally invasive THA and standard incision technique. METHOD: An online search in Medline, CINAHL,EMBASE, and the Cochrane Controlled Trials Register was performed. Data concerning the endpoints duration of procedure, blood loss,complications, and Harris Hip Score (HHS) were extracted and pooled using a random effects model. RESULTS: 8 Studies observing a total of 917 patients(481 MIS, 436 Std.) were included. The weighted mean difference in duration of the procedures was 4 min, which is not significant(p = 0.21). There was significantly less blood loss in the mini group (p < 0.001). The difference in increases in HHS of averagely 4.14 pts. was only borderline significant (p = 0.06). The complication odds ratio showed no significance (p = 0.71). CONCLUSION: There is only a marginal difference between these techniques. The minimally invasive total hip replacement is a variance of the standard procedure with better cosmesis. Differences in postoperative rehabilitation, however,are not within the scope of this study.

Serum aluminium and cobalt levels after ceramic-on-ceramic and metal-on-metal total hip replacement.

In a randomised study, 28 patients with a mean age of 62.2 years (32 to 81) with osteoarthritis or avascular necrosis of the hip received either a ceramic-on-ceramic or a metal-on-metal total hip replacement. Apart from the liners the acetabular and femoral components were made of Ti-Al-Nb alloy. The serum aluminium and cobalt levels were measured before, and at one year after surgery. The 15 patients in the ceramic-on-ceramic group had a median pre-operative aluminium level of 1.3 microg/l (0.25 to 8.4) and a cobalt level below the detection limit. At one year the aluminium level was 1.1 microg/l (0.25 to 2.3) and the cobalt level was 0.4 microg/l (0.15 to 0.7). The 13 patients in the metal-on-metal group had a median pre-operative aluminium level of 1.9 microg/l (0.25 to 4.4) and a cobalt level below the detection limit. At one year the median aluminium level was 0.9 microg/l (0.25 to 3.9) whereas the cobalt level was 1.4 microg/l (0.5 to 10.5). This increase in the cobalt level at one year was significant (p < 0.001). Our findings indicate that ceramic-on-ceramic bearings do not cause elevated levels of serum aluminium in the first post-operative year.

STRO-1+ mesenchymal precursor cells located in synovial surface projections of patients with osteoarthritis.

OBJECTIVE: To investigate the presence of mesenchymal precursor cells (MPCs) in synovial surface projections of patients with osteoarthritis (OA), to characterize their phenotype and to show their localization. METHODS: Progenitor cells in synovial surface projections were identified by immunohistochemistry, morphometric analysis and confocal laser scanning microscopy using the following phenotypic markers: STRO-1, CD34, and alpha smooth muscle actin (alpha-SMA). RESULTS: In the synovial tissue of all 21 patients with OA MPCs were detected. Immunohistochemistry and subsequent morphometric analysis showed that approximately twice as many STRO-1+ cells/mm2 were observed in synovial tissue of patients with OA as compared to healthy organ donors and that number of STRO-1+ cells/mm2 correlated with total cell number/mm2. Interestingly, in the synovial tissue of patients with OA, twice as many STRO-1+ cells/mm2 were found in synovial surface projections as compared to the sublining area without villi. Using confocal laser scanning microscopy two populations of STRO-1+ MPCs could be detected in synovial surface projections. Single STRO-1+ cells that co-expressed alpha-SMA resemble a population of pericyte precursors required to stabilize the immature vasculature. The second STRO-1+ cell population that was found lacked alpha-SMA but co-expressed CD34 on their surface with low intensity. CONCLUSION: Here we can show that in the synovial tissue of patients with OA twice as many STRO-1+ MPCs can be found in synovial surface projections as compared to the sublining area. These cells are preferentially located at the basis and in the protruding end of the synovial surface projection.

Anticancer effects of zoledronic acid against human osteosarcoma cells.

Based on neoadjuvant chemotherapy, the prognosis of osteosarcoma patients has improved dramatically. However, due to therapy resistance in patient subgroups, the development of new treatment strategies is still of utmost importance. The aim of our study was to test the effects of the nitrogen-containing bisphosphonate zoledronic acid (ZOL) on osteosarcoma cell lines (N = 9). Exposure to ZOL at low micromolar concentrations induced a dose- and time-dependent block of DNA synthesis and cell cycle progression followed by microfilament breakdown and apoptosis induction. The ZOL-induced cell cycle accumulation in S phase was accompanied by significant changes in the expression of cyclins and cyclin-dependent kinase inhibitors with a prominent loss of cyclin E and D1. ZOL not only inhibited growth but also migration of osteosarcoma cells. The mevalonate pathway intermediary geranyl-geraniol (GGOH) but not farnesol (FOH) significantly inhibited the anticancer effects of ZOL against osteosarcoma cells. Correspondingly, ZOL sensitivity correlated with the blockade of protein geranylgeranylation indicated by unprenylated Rap1. Overexpression of even high levels of P-glycoprotein, as frequently present in therapy-resistant osteosarcomas, did not impair the anticancer activity of ZOL. Summarizing, our data suggest that ZOL, which selectively accumulates in the bone, represents a promising agent to improve osteosarcoma therapy.

Three-year clinical outcome after chondrocyte transplantation using a hyaluronan matrix for cartilage repair.

Repair of articular cartilage represents a significant clinical problem and although various new techniques - including the use of autologous chondrocytes - have been developed within the last century the clinical efficacy of these procedures is still discussed controversially. Although autologous chondrocyte transplantation (ACT) has been widely used with success, it has several inherent limitations, including its invasive nature and problems related to the use of the periosteal flap. To overcome these problems autologous chondrocytes transplantation combined with the use of biodegradable scaffolds has received wide attention. Among these, a hyaluronan-based scaffold has been found useful for inducing hyaline cartilage regeneration. In the present study, we have investigated the mid-term efficacy and safety of Hyalograft C grafts in a group of 36 patients undergoing surgery for chronic cartilage lesions of the knee. Clinical Outcome was assessed prospectively before and at 12, 24, and 36 months after surgery. No major adverse events have been reported during the 3-year follow-up. Significant improvements of the evaluated scores were observed (P < 0.02) at 1 year and a continued increase of clinical performance was evident at 2 and 3 years follow-up. Patients under 30 years of age with single lesions showed statistically significant improvements at all follow-up visits compared to those over 30 with multiple defects (P < 0.01). Hyalograft C compares favorably with classic ACT and is particularly indicated in younger patients with single lesions. The graft can be implanted through a miniarthrotomy and needs no additional fixation with sutures except optional fibrin gluing at the defect borders. These results suggest that Hyalograft C is a valid alternative to ACT.

[Functional tendon repair in orthopedic tumor surgery]. / Funktionelle Sehnenersatzoperationen in der Tumorchirurgie.

Large defects of functional soft tissue structures, e.g., extensor mechanism, ligaments, muscles, and joint capsule, may occur in tumor surgery or revision surgery following conventional joint replacement. Reconstruction can be performed using biological grafts such as free or pedicled tendon-muscle flaps, allografts, or synthetic material. Prerequisites for synthetic material are good biologic tolerance with fibroblastic ingrowth, mechanical resistance to fatigue, and a maximum of tension force with a minimum of elongation. In this study we used a nonresorbable band of longitudinal polyester fibers with a minimal rupture level of 4000 N and an elongation rate less than 7% of its original length. The shape of the band was designed for universal use with 40 cm length and 6 cm width. Its primary indication was augmentation or complete reconstruction of the extensor mechanism of the knee joint after large extra-articular tumor resections in primary bone tumors. Furthermore, its use for hip joint capsule reconstruction in luxation, coverage of megaprostheses of the humerus, and augmentation after biological reconstruction of tendons achieved excellent results.

Soluble p185(HER-2) in patients with malignant bone tumours.

BACKGROUND: This study was initiated to test the hypothesis that soluble p185(HER-2) could be of value as a diagnostic or predictive marker for patients with malignant bone tumours. PROCEDURE: Sera of 35 patients with high-grade malignant osteosarcoma (n = 27) and Ewing Sarcoma (n = 8) were tested at the time of diagnosis by ELISA and compared with sera of controls (n = 38) and clinical data. RESULTS: In patients with osteosarcoma and Ewing Sarcoma, levels of sp185(HER-2) did not differ significantly from levels in controls. These results were irrespective of the type of tumour, survival chemotherapy or other clinical variables. CONCLUSION: p185(HER-2) serum levels do not appear to be of diagnostic or predictive value for differentiation of high-grade osteosarcoma and Ewing Sarcoma.

[Mid-term results of autologous chondrocyte transplantation in knee and ankle. A one- to six-year follow-up study]. / Mittelfristige Ergebnisse mit der autologen Knorpelzelltransplantation an Knie- und SprunggelenkEin- bis Sechsjahresergebnisse.

BACKGROUND: The reimplantation of autologous chondrocytes is a new technique in reconstruction of cartilage defects; initial results achieved with this technique have been promising. In an arthroscopic procedure, scales of cartilage are obtained from intact cartilage. The chondrocytes are then multiplied in special laboratories. A few weeks later, in a second procedure, the cartilage defect is filled with the cell suspension and closed with a flap of periosteum. METHOD: At our department, autologous chondrocyte transplantation (ACT) has been used in 10 patients since 1996, in 6 cases in the knee joint, and in 4 cases in the ankle joint. The mean age of the patients was 30 years. The mean size of the defect was 4 cm(2). In 4 patients, a parallel surgical procedure was required at the time of removal. RESULTS: The mean duration of follow-up was 21/2 years. Six patients had good to excellent results, 3 patients had moderate results, and one patient a poor result. The modified Cincinnati rating scale was improved from 2.4 to 7.1 points, and the Lysholm score from 59.2 to 86.6 points. The AOFAS score for ankle joints had improved from 33 to 76. CONCLUSION: We were able to show that ACT achieves improvement in the knee as well as ankle joint in the majority of patients. ACT appears to be a promising therapeutic concept for both joints.

In vivo and in vitro cellular ingrowth into a new generation of artificial ligaments.

Artificial ligaments are a useful tool in ligament reconstruction. Although the new generation of artificial ligaments shows encouraging clinical results, in contrast to earlier generations studies on the biological properties are lacking. Biopsies were taken from a ligament advancement reinforcement system (LARS) 6 months after implantation and investigated by histochemistry. An in vitro study seeding human fibroblasts or osteoblast-like cells (up to 10(6) cells for 21 days) on ligament pieces (5 x 5 mm) was conducted and analyzed by histochemistry. The biopsies showed complete cellular and connective tissue ingrowth in the LARS ligament. In vitro fibroblasts and osteoblast-like cells encapsulated the fibers by building a cellular net around them. To our knowledge, these findings demonstrate for the first time the cellular ingrowth into the LARS ligament. This mechanism might explain the strength and the inert behavior of the ligament without the synovialitis shown in clinical studies.

[Endoprosthesis management of the extremities of children after resection of primary malignant bone tumors]. / Die endoprothetische Versorgung an den Extremitäten bei Kindern nach Resektion primär maligner Knochentumoren.

In recent years, significant progress has been made in the treatment of primary malignant bone tumors. The surgeon is confronted with increasing demand for limb-sparing surgery by patients and parents alike. In the skeletally immature, resection of the growing physis will ultimately result in leg length discrepancies and functional impairment. An adequate reconstruction therefore calls for the compensation of the expected growth deficit to achieve symmetry and an optimized function of the extremity. Between 1975 and 2000, 55 patients (24 female, 31 male) were referred and treated at our institution. All patients were not older than 10 years (4.2-10, mean: 7.9 years). Histological diagnosis was Ewing's tumors ( n=19) and osteosarcoma ( n=36). Localization in the extremities was predominantly in the lower extremity with 63.6% around the knee joint (distal femur and proximal tibia). Surgical treatment was performed in all patients. Endoprosthetic reconstruction was performed in 34 patients (lower extremity n=30, 29 Howmedica Modular Reconstruction System, HMRS, 1 Pafford prosthesis; upper extremity n=4, 4 HMRS); in another case of humeral tumor involvement a resection replantation procedure was carried out. The other patients received a rotationplasty ( n=7), a biologic reconstruction ( n=6), resection replantation of the humerus ( n=1), no reconstruction ( n=3), or had to be amputated ( n=4). After a mean follow-up of 114 months (24-256 months) 11 patients had died. Even in young children endoprosthetic reconstruction with relatively early mobilization and high quality of life can be a very successful method for limb salvage. Optimal reconstructive results following resection of primary malignant bone tumors in children are reached when indications and limitations of each method are carefully considered on an individual basis taking into account the patients' expectations.

[Arthroscopic menisectomy in older patients: assessing health-related quality of life]. / Die arthroskopische Teilmenisektomie bei älteren Patienten: Erfassung der gesundheitsbezogenen Lebensqualität.

AIM: Little information is available on partial arthroscopic menisectomy in patients 60 years of age or older. Due to the co-morbidity of meniscal tears and osteoarthritis in this age group, the effectiveness of this procedure is controversial. The purpose of this study was to evaluate the outcome of this procedure in terms of function and mobility in patients 60 years of age or older. METHOD: Between 1990 and 1999, 1920 arthroscopies of the knee were performed in a single primary care institution, and 51 patients, 60 years of age or older, had a partial arthroscopic menisectomy done. Outcomes were rated using the SF-36 Health Survey and a specially designed questionnaire including items of published scores. RESULTS: The mean age at surgery was 67 years (range: 60.3 - 78.9) and the mean follow-up was 5 years (range: 2 - 12). Due to persistent pain, 4 patients underwent a second operation including knee replacement in 3 cases and a high tibial osteotomy in 1 case. 41 patients (87.1 %) stated the arthroscopy had improved their quality of life. In terms of pain and daily life activities, the majority of the subjects showed an improvement after surgery. The SF-36 showed no clinically relevant difference compared to the control in all but one subscale. CONCLUSION: Despite of the presence of osteoarthritis in this age group, arthroscopic partial menisectomy can improve pain, function and mobility in the mid-term course.

Dura resection in combination with en bloc spondylectomy for primary malignant tumors of the spine.

STUDY DESIGN: Resection of a primary malignant tumor of the bone with wide surgical margins has become the golden standard in oncological surgery. In the case of a spinal tumor with tumor invasion of the spinal canal, a wide resection could necessitate resection and subsequent replacement of part of the dura. SUMMARY OF BACKGROUND DATA: Dura replacement is a consequent surgical step in the treatment of primary malignant tumors of the spine. METHODS: We present the case of a 27-year-old male with a tumor of the dorsal elements of D6. After paraplegic symptoms, a laminectomy of D5 to D7 was performed and histologic examination revealed the presence of an osteosarcoma. After neoadjuvant polychemotherapy, a wide resection of the dorsal elements from D4 to D7 combined with a resection of the dorsal part of the dura was planned. Replacement of the dura was performed with Lyodura (B. Braun Melsungen AG, Melsungen, Germany). The spine was stabilized with an ISOLA instrumentation (Depuy International Ltd., Leeds, England). For wound closure, a pedicled latissimus dorsi flap and split skin graft were necessary. In a second step, ventral spondylodesis with Texas Scottish Rite Hospital instrumentation (Sofamor Danek, Memphis, TN) was performed. RESULTS: One hundred sixteen months after surgery the patient is alive without evidence of disease, is pain free, and has returned to his profession and life without any restrictions.

Serum levels of TNF-beta and sTNF-R in patients with malignant bone tumours.

OBJECTIVE: To determine serum levels of TNF-beta and soluble TNF-R in patients with primary highly malignant bone tumours. PATIENTS AND METHODS: Sera of 27 patients with highly malignant osteosarcoma and Ewing sarcoma were taken at the time of diagnosis and analysed by ELISA. RESULTS: Both TNF-beta and sTNF-R levels were lower in sera from osteosarcoma patients as compared to those from Ewing sarcoma. In patients with high-grade osteosarcoma, but not Ewing sarcoma, high levels of TNF-beta correlated with bad response to neoadjuvant chemotherapy. CONCLUSION: In patients with high-grade osteosarcoma TNF-beta levels seem to be of predictive value and both TNF-beta and sTNF-R seem to be of diagnostic value for differentiation between high-grade osteosarcoma and Ewing sarcoma.