Effects of mesenchymal stromal cells versus serum on tendon healing in a controlled experimental trial in an equine model.

BACKGROUND: Mesenchymal stromal cells (MSC) have shown promising results in the treatment of tendinopathy in equine medicine, making this therapeutic approach seem favorable for translation to human medicine. Having demonstrated that MSC engraft within the tendon lesions after local injection in an equine model, we hypothesized that they would improve tendon healing superior to serum injection alone. METHODS: Quadrilateral tendon lesions were induced in six horses by mechanical tissue disruption combined with collagenase application 3 weeks before treatment. Adipose-derived MSC suspended in serum or serum alone were then injected intralesionally. Clinical examinations, ultrasound and magnetic resonance imaging were performed over 24 weeks. Tendon biopsies for histological assessment were taken from the hindlimbs 3 weeks after treatment. Horses were sacrificed after 24 weeks and forelimb tendons were subjected to macroscopic and histological examination as well as analysis of musculoskeletal marker expression. RESULTS: Tendons injected with MSC showed a transient increase in inflammation and lesion size, as indicated by clinical and imaging parameters between week 3 and 6 (p < 0.05). Thereafter, symptoms decreased in both groups and, except that in MSC-treated tendons, mean lesion signal intensity as seen in T2w magnetic resonance imaging and cellularity as seen in the histology (p < 0.05) were lower, no major differences could be found at week 24. CONCLUSIONS: These data suggest that MSC have influenced the inflammatory reaction in a way not described in tendinopathy studies before. However, at the endpoint of the current study, 24 weeks after treatment, no distinct improvement was observed in MSC-treated tendons compared to the serum-injected controls. Future studies are necessary to elucidate whether and under which conditions MSC are beneficial for tendon healing before translation into human medicine.

Characterisation and intracellular labelling of mesenchymal stromal cells derived from synovial fluid of horses and sheep.

Multipotent mesenchymal stromal cells (MSCs) derived from synovial fluid (SF) are considered to be a promising cell type for therapeutic applications in joint disease. However, despite their potential relevance for clinical and experimental studies, there is insufficient knowledge about SF-derived MSCs isolated from horses and sheep. In this study, cells were recovered from healthy SF and bone marrow (BM) of sheep, and from healthy and osteoarthritic SF of horses. Ovine SF-MSCs were used to assess the efficiency of intracellular labelling with quantum dots (QDs). Colony forming units, generation times, trilineage differentiation potential and expression of CD73, CD90 and CD105 at mRNA level were assessed. QD labelling was efficient, with >98% positive cells directly after labelling at 10 nmol/L and >95% positive cells directly after labelling at 2 nmol/L. The label decreased over 7 days of culture, with more persistence at the higher labelling concentration. No significant differences in proliferation were observed. All MSCs had trilineage differentiation potential, but adipogenesis was more distinct in equine samples and chondrogenesis was most pronounced in ovine SF-MSCs. CD73, CD90 and CD105 were expressed in equine and ovine MSCs.

[Tumor prostheses : Important in modern revision arthroplasty]. / Tumorendoprothetik : Stellenwert in der modernen Revisionsendoprothetik.

BACKGROUND: Due to demographic aging, an increasing number of revision arthroplasty procedures is expected during upcoming years. While the use of a megaprosthesis for bone reconstruction after tumor resection is gold standard, this type of prosthesis still meets with reservation in the field of revision arthroplasty because of numerous risk factors. OBJECTIVES: The purpose of this article is to present the importance of modular megaprostheses in revision arthroplasty, taking into consideration the risks of periprosthetic infection, aseptic loosening, material failure, and hip dislocation. RESULTS: Because of improvements in the field of megaprostheses during the last 30 years, the risks after implantation of this type of prosthesis have significantly decreased. The risk of periprosthetic infection has been reduced about 1/3 by the use of silver surface coating. Improvements in stem design, cement technique, and the additional use of locking screws have minimized the risk of aseptic loosening. Improvements in material composition have reduced the risk of material failure. The risk of hip dislocation could also be minimized by careful tissue preparation and appropriate suture technique. CONCLUSION: There is no need for the conservative use of megaprostheses in revision arthroplasty. There are many benefits in the use of megaprostheses in multimorbid patients (i.e., reduced operating time, the possibility of early full weight bearing, and a reduced risk of periprosthetic infection by the use of silver surface coating) instead of complex bone reconstruction during revision arthroplasty.

[Benign bone tumors. General principles]. / Gutartige Knochentumoren. Allgemeine Prinzipien.

BACKGROUND: Benign bone tumors and tumor-like lesions are much more frequent than malignant bone tumors among the total number of tumors of the skeleton. OBJECTIVE: This article gives a presentation of the characteristics and treatment modalities of benign bone tumors. MATERIAL AND METHODS: In this article in-house treatment principles are compared with those in the currently available literature. RESULTS: Benign bone tumors are frequently found incidentally; however, the term benign does not always signify that a purely observational role is needed. Benign bone tumors differ in their biological behavior and can be latent, active or aggressive which determines the treatment approach. Some benign bone tumors are just as aggressive locally as malignant tumors. The most important diagnostic feature is still conventional radiography and a thorough systematic analysis is necessary. Therapy options range from ignore, wait and see up to wide resection. In contrast to malignant tumors the radicalism of resection can be weighed against the accompanying local control and loss of function. CONCLUSION: The treatment of benign bone tumors depends on the histological type and the biological activity. Most benign bone tumors are diagnosed incidentally and do not necessitate any treatment.

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.

The effect of rotationplasty on the ankle joint: long-term results.

In patients with rotationplasty the biomechanical conditions in the ankle joint are altered dramatically. By displacement and reduction of the weight-bearing area of the joint, the stress affecting its cartilage is increased. The use of an exoprothesis results in skin and soft tissue irritation. Due to these biomechanical changes, a prearthrotic deformity or skin problems could be expected. The current study examines changes in 21 patients treated with rotationplasty (mean follow-up 13.5 years) because of a malignant bone tumour or a femoral segmental defect. Local tenderness, skin and soft tissue changes, problems with exoprostheses, and pain was assessed by clinical examination and documented. Osseous changes were evaluated by plain X-ray. A MRI-scan was also obtained in five patients. Hardened skin and blisters were located at the main loading areas of the rotated foot. These changes could be reduced by optimizing the exoprosthetic fit. Radiographically, a slight asymptomatic attenuation of the articular space was observed in four patients and a slight coexistent subchondral sclerosis with small osteophytes in one patient. No degenerative changes were observed on X-ray and no cartilaginous changes were observed on MRI. The results suggest that the foot is able to adapt to the load changes after this procedure and that rotationplasty does not cause an inevitable arthrosis in the ankle joint.

Free vascularized fibular grafting for reconstruction after tumor resection in the upper extremity.

BACKGROUND: Limb salvage is viable in the majority of patients with malignant bone tumors, but especially in case of extensive tumors and bad soft tissue conditions, it is challenging in upper extremity. OBJECTIVES/METHOD: The clinical and radiological results of 21 patients, who had free vascularized fibular grafts (VFG), for diaphyseal (14), and epipyseal (7) defect reconstruction of the upper extremity, are presented. The indications for VFG were resection after osteosarcoma (9 cases), Ewings sarcoma (9 cases), chondrosarcoma (1 case), rhabdomyosarcoma (1 case), and 1 case of fibrous dysplasia. The 20 malignant tumors were staged as follows: 2a (1), 2b (18), 3 (1). The mean follow-up was 43.6 months (min 6.0-max 131.9). Functional results were described and graded quantitatively according to the MSTS-score. RESULTS: Results were satisfactory with regard to pain, emotional acceptance, manual dexterity, and function. Lifting ability was decreased in two patients. Hypertrophy index was 31% (min 13%-max 71%). Main complications were fracture (5), pseudoarthrosis (4), prolonged wound healing (4), temporary nerve irritation (2), and deep infection (1). Re-operation was required in eight patients (12 operations). CONCLUSION: VFG offers a good possibility for biological reconstruction of large skeletal defects, with an acceptable complication and re-operation rate. When conservative treatment of complications was not successful, further surgery led to recovery in the majority of cases.

Comparative RNA expression analyses from small-scale, single-donor platelet samples.

BACKGROUND: Comparisons of platelet RNAs could provide crucial information on platelet function, thrombopoiesis and the etiology of megakaryocyte (MK) or platelet disorders. OBJECTIVES: We developed a method for stringent purification of platelets from small blood samples from single donors. Purity of the platelet preparations was verified by an RT-PCR assay. We tested three methods to identify the differences in RNA between platelet sources. METHODS: Differential hybridization to cDNA macro-arrays and suppressive-subtractive hybridization PCR (SSH-PCR) were used to compare RNAs from normal platelets to those from a Bernard-Soulier syndrome (BSS) patient. Affymetrix GeneChip U133 plus 2.0 arrays were used to compare male and female platelet RNAs. RESULTS: Macroarrays identified approximately 7500 platelet transcripts, but failed to identify differentially expressed transcripts with confidence. SSH-PCR produced libraries almost exclusively of mitochondrial-derived transcripts, but included nuclear-encoded genes that could not be confirmed by immunoblotting of normal and BSS platelet lysates. The Affymetrix platform gave reproducible profiles from our small-scale purified platelet preparations, whereas a partially purified platelet preparation produced a drastically skewed transcript profile. The microarray analysis identified the heparanase precursor transcript as overexpressed in female platelets, and we observed variable yet consistently higher levels of heparanase protein in female platelets compared with male platelets in four independent donor pairs. CONCLUSIONS: This demonstrates for the first time that differential platelet transcript levels can identify changes in expression level of platelet proteins. Combined with our small-scale platelet preparation method, this establishes a system to compare platelets from the limited clinical sources to help elucidate molecular bases for platelet or megakaryocyte pathologies.

[Rotationplasty in the surgical treatment plan of primary malignant bone tumors. Possibilities and limits]. / Umkehrplastik im operativen Behandlungsplan der primär malignen Knochentumoren. Möglichkeiten und Grenzen.

Long-term survival of patients with a malignant bone tumor increased with a combined therapeutic approach using chemotherapy and possibly radiation therapy. Today up to 80% of patients with an osteosarcoma or Ewing's sarcoma survive. Therefore, it is important that the functional outcome and the quality of life are good after resection of the tumor. Before the era of endoprosthetic devices, rotationplasty, which was introduced in 1974 by Salzer for surgery of malignant bone tumors and modified by Winkelmann, protected many patients from an amputation. Although many authors favor limb-saving procedures today, rotationplasty obtained excellent functional and psychosocial results. Rotationplasty can be recommended in tumors with a large soft tissue component, in tumors located in the proximal femur and proximal tibia, and in children under 10 years of age. Furthermore, rotationplasty can be used in patients in whom a limb-salvage procedure failed because of infection or repeated changes of the endoprosthesis.

Tumors of the pelvis: complications after reconstruction.

INTRODUCTION: Complications after pelvic sarcoma surgery are frequent; however, the reports on complications are limited. Results of the authors' experience with 110 primary pelvic tumor resections and methods to achieve low complication rates for pelvic reconstruction are reported. MATERIALS AND METHODS: From 1982 to 1996, 110 patients with pelvic sarcoma (42 Ewing sarcomas, 40 chondrosarcomas, 21 osteosarcomas, and 7 other malignant tumors) underwent surgery. Sixteen patients underwent implantation of a hemipelvic megaprosthesis, 13 patients had implantation of an allograft for sacroiliac arthrodesis, 12 patients had implantation of an autograft for sacroiliac arthrodesis, and 17 patients underwent hip transposition. There were 9 hindquarter amputations, 6 implantations of allograft and total hip endoprosthesis, 1 implantation of prosthesis with autograft, and 1 implantation of allograft and autograft. No skeletal reconstruction was done in 35 patients. RESULTS: Postoperative function was as follows: 37% in patients with prosthesis, 60% in allograft, 66% in autograft, 66% in hip transposition, 37% in amputation, and 79% without reconstruction. In total, 10/16 patients with prosthetic replacement, 9/13 with allograft implantation, 4/12 with autograft implantation, 7/17 with hip transposition, 5/9 with amputation, 6/6 with prosthesis and allograft, and 12/35 without skeletal reconstruction had complications. Frequent complications depending on the reconstruction were infection in 6/10 prostheses and in 5/13 allografts, leg length discrepancy in 2/12 autografts and 4/17 hip transpositions, hematoma in 3/9 amputations, and infection (6) and skin problems (5) in 6 prostheses with allograft. CONCLUSION: Because of the small number of complications and good function, autograft implantation after iliac resection and hip transposition after acetabular resection are advisable.

Fractionated perioperative high dose rate brachytherapy using a tissue equivalent bendy applicator.

Intraoperative radiation techniques allow an additional local dose in areas at high-risk for local failure. With brachytherapy techniques, perioperative radiation can be fractionated. Fractionated treatment might offer an interesting alternative to a single dose, both to increase the therapeutic ratio and to protect late reacting tissues at risk. The dose distribution for brachytherapy applicators can be optimized using spacer materials. In this prospective study a new tissue equivalent bendy applicator (TEBA) that can remain in situ for several days is introduced, and the feasibility of fractionated perioperative high dose rate (HDR) brachytherapy is examined. 31 patients with different tumours (soft tissue sarcoma, Ewings sarcoma, rectal cancer, and locally infiltrating diseases) were treated. The TEBA was applied, depending on resection status and intraoperative findings. Planning was based on digitized radiographs and CT scans. Perioperative HDR brachytherapy was performed using an individual treatment schedule. In 29 patients perioperative radiation was given and in 26 cases fractionated brachytherapy application was possible. TEBA application time varied from 1 day to 11 days. During this time between 1 and 8 fractions were given with total doses from 10 Gy to 25 Gy. Fractionated perioperative brachytherapy with this technique is feasible and adequate. Further studies will show whether fractionated perioperative treatment using the TEBA technique fulfils its theoretical advantages over single dose intraoperative radiotherapy by decreased late toxicity and increased local tumour control.

Revision hip arthroplasty in a patient with a hip rotationplasty (type B III b).

We report for the first time a patient who underwent a revision hip arthroplasty after a hip rotationplasty (Winkelmann type B III b) because of a chondrosarcoma in 1988. The clinical symptoms and radiographic findings (X-ray, bone scintigraphy, arthrography) of the aseptic loosening of the acetabular component are presented in detail. Furthermore, we present the functional results after hip revision.

Sweet's syndrome associated with pigmented villonodular synovitis.

Sweet's syndrome (acute febrile neutrophilic dermatosis) was first described in 1964. The typical symptoms of Sweet's syndrome are high temperature, peripheral leucocytosis, painful cutaneous rashes (papules, plaques) and arthralgia. Sweet's syndrome has particularly been described in association with neoplastic, infectious and immunological diseases. The pathogenesis of Sweet's syndrome can be explained by a reaction to an antigenic structure with accumulation of immunological complexes and liberation of inflammatory mediators. For the first time we report on a patient with Sweet's syndrome and pigmented villonodular synovitis, which is believed to play the antigenic role in the Sweet syndrome.

Stump lengthening after hip disarticulation using a modular endoprosthesis in 5 patients.

To reduce the disability after hip disarticulation, we developed a special surgical procedure in patients having a proximal femoral tumor with a large tumor involving the sciatic nerve or neoplasms involving the tibia and femur. The hip was disarticulated, but we preserved a musculocutaneous flap. A modular endoprosthesis was then placed in the acetabulum or, in case of an extraarticular resection of the hip joint, it was placed in the iliac bone. A trevira tube was used for reconstruction of the joint capsule and fixation of soft tissues. We performed this procedure in 5 patients who had a good functional outcome.

[An extended CT scale technique for evaluating periprosthetic bone lesions - an in vitro study]. / Extended-field CT-Technik zur Evaluation von periprothetischen Knochenläsionen--In-vitro-Untersuchung.

PURPOSE: In the present study the reduction of artifacts using an extended CT scale technique was examined in 5 vitallium and 5 titanium-aluminium-vanadium tumor prostheses. METHODS: 5 titanium-aluminium-vanadium and 5 vitallium distal femur Mutars(R) tumor prostheses (Mutars(R) - Modular Universal Tumor And Revision System) were implanted in 10 human femur specimens. 110 artifical drill hole lesions of 1 mm, 2 mm, 3 mm, 5 mm and 8 mm diameter were placed in the bone around the hexagonal stem of the tumor prosthesis and furthermore in the proximal part of the femur. All specimens were examined using conventional CT and an extended CT scale technique in a slice thickness of 3 mm. RESULTS: In the proximal part of the femur all drill holes could be detected using 3 mm slices, no artefacts were observed. Along the hexagonal stem smooth lines arising from each hexagonal plane could be observed. This made it impossible to detect a 1 mm drill in 1 vitallium and in 1 titanium-aluminium-vanadium stem. There was no difference between the extended CT scale and conventional CT. CONCLUSION: The extended CT scale did not significantly (p > 0.05, t-test) improve the imaging of artificial drill hole lesions along the hexagonal Mutras(R) stem.

[Clinical value of positron emission tomography (PET) in the diagnosis of bone and soft tissue tumors. 3rd Interdisciplinary Consensus Conference "PET in Oncology": results of the Bone and Soft Tissue Study Group]. / Klinische Wertigkeit der Positronenemissionstomographie (PET) in der Diagnostik der Knochen- und Weichteiltumore. 3. Interdisziplinäre Konsensuskonferenz "PET in der Onkologie". Ergebnisse der Arbeitsgruppe Knochen- und Weichteiltumore.

PURPOSE: In the framework of the 3rd Consensus Conference "PET in Oncology" the bone and soft-tissue tumors study group evaluated the present position of PET for these tumor entities on the basis of international publications. METHODS: After a systematic review of the literature, publications were evaluated according to previously defined quality criteria. For various indications the clinical usefulness of PET was assessed using a classification system. RESULTS: Most studies had been performed with a small number of patients (n < 35). Therefore, only 8 of 46 publications were judged relevant. On the basis of these literature data, use of FDG-PET for grading was classified 1b (literature results predominantly show clinical usefulness). As before (1995/97), all other indications were categorized with 3 (assessment not yet possible, literature data inadequate). OUTLOOK: According to the opinion of experts, the detection of osseous metastases of Ewing's sarcoma, therapy monitoring and the diagnosis of recurrences are potentially useful clinical indications for FDG-PET. Therefore, prospective studies with large patient groups are essential to further evaluate the benefit of FDG-PET in these indications.

Genetic imbalances revealed by comparative genomic hybridization in Ewing tumors.

Ewing tumors are characterized by reciprocal translocations involving the EWS gene on 22q12 fused to ETS transcription-factor family members. Little is known about further aberrations contributing to tumor development and progression. Sixty-two frozen tumors with known EWS rearrangements (52 primary tumors, 10 relapses) of ET patients registered in the EICESS protocol were analyzed by comparative genomic hybridization (CGH). The median number of changes in 52 primary and 10 relapsed cases was 2.5 and 5.0 per tumor (P = 0.153). Frequent abnormalities included gains of chromosomes 8, 12, 20, and 1q and losses of 16q and 19q. Neither number nor type of aberration was associated with histology, tumor size, disease stage, tumor localization, or histologic tumor response to chemotherapy. Among the 52 primary tumors, 26 with Type I fusion (EWS exon 7 to FLI1 exon 6) and 26 with other fusion types had a median of 2.0 and 3.0 aberrations per tumor, respectively (P = 0.031). Combinations of gains of chromosomes 8 and 12, gains of chromosome 20, and either gains of 8q or 18q and losses of 16q and 17p frequently occurred. The cumulative overall survival (OAS) was different between 35 patients with <5 aberrations and 13 patients with > or =5 aberrations (P = 0.009). Univariate analysis showed that patients with gains of 1q, 2q, 12, and 20 or losses of 16q and 17p had significantly lower OAS than those without aberrations. By multivariate analysis, loss of 16q (relative risk [RR] = 5.3; P = 0.0006) was an independent prognostic factor.

Periosteal chondroma: MR characteristics.

PURPOSE: The purpose of this study was to describe the MR characteristics of periosteal chondroma. METHOD: MR images of 12 proven cases of periosteal chondroma were analyzed with reference to tumor morphology and size. MR features were correlated with radiographic and pathologic findings. RESULTS: Tumor size ranged from 1 to 7 cm in maximum diameter with a mean value of 2.6 cm. On MR images, a soft tissue mass at the bone surface with pressure erosion of adjacent cortical bone could be identified in all cases. All lesions were bordered by a hypointense rim (100%) and frequently showed a lobulated configuration (75%). Edema of medullary bone or soft tissues was not observed in any of the cases. Signal intensity of cartilaginous tumor tissue was typically hypo-or isointense relative to muscle on T1-weighted (100%) and hyperintense relative to fat on T2-weighted (92%) and T2*-weighted (100%) MR images. Radiographically significant calcifications of the tumor matrix, present in half of the cases, caused focal signal loss on MR images of all pulse sequences. Contrast enhancement was observed predominantly at the periphery of the lesions (100%), which on pathologic examinations typically contained fibrovascular bundles, surrounding the cartilage lobules. CONCLUSION: Periosteal chondroma appears to have a relatively typical MR appearance, which reflects the histologic composition of the lesion. In addition to radiography, MRI therefore can substantially aid in the preoperative diagnosis of this rare bone lesion.