Spontaneous healing of an osteochondroma fracture

Osteochondroma is the most common benign tumor of bone, usually asymptomatic. Fracture of an osteochondroma is a rare complication and has been recognized as a cause of pain. Treatment of this fracture is controversial and some authors suggest fracture as an indication for surgical excision. We present a case of fractured osteochondroma that healed without complication.

Electrochemotherapy treatment of locally advanced and metastatic soft tissue sarcomas: results of a non-comparative phase II study

AIMS

Our aim was to evaluate the activity, toxicity, and feasibility of electrochemotherapy (ECT) in patients with soft-tissue sarcomas (STS).

METHODS

A two-stage phase II trial was conducted between October 2006 and March 2012. Patients (N = 34) with locally advanced or metastatic STS, unsuitable for standard oncological treatments and with maximum 3-cm deep tumors, received an intravenous bolus of bleomycin (15,000 IU/m(2)), followed by tumor electroporation according to the European Standard Operating Procedures of ECT. Outcome measures included local response according to response evaluation criteria in solid tumors (RECIST), toxicity and tumor control. Feasibility measures included the accuracy of electrode placement and the intensity of electric current flowing in tumor tissue.

RESULTS

Median tumor size was 4.0 cm (range 2-12). Objective response, assessed on 71 target lesions, was 92.2 % (complete 32.3, 95 % CI 28-64). A total of 15 patients received up to four cycles due to incomplete response, but re-treatment did not significantly improve outcome (p = 0.205). After a median follow-up of 19.3 months, 2-year local control rate was 72.5 %. Median time to local failure (N = 11 patients) was 5.1 months. Tumor response (p = 0.041) and control (p = 0.047) correlated with histological grading. Relevant toxicity consisted of G3 skin ulceration and soft tissue necrosis (35 and 23 % of patients, respectively), although this was manageable on an outpatient basis. The accuracy of electrode placement was 47.1 %, and the adequacy of electroporative current 85.3 %.

CONCLUSIONS

ECT may represent an active and safe treatment to achieve local control in advanced STS patients with symptomatic disease. Future research challenges include the improvement of electrode placement and voltage delivery together with the containment of soft tissue toxicity.

Minimally invasive technique for curettage of chondroblastoma using endoscopic technique

Chondroblastoma is a rare benign bone tumor. The treatment for chondroblastoma usually consists of curettage of the lesion and packing the tumor cavity with bone grafts or bone cement. However, chondroblastomas are known to recur in 10% to 20% of cases after excision, possibly because the incomplete removal of pathological tissue at surgery. We present a case of chondroblastoma in the distal femur treated by endoscopic curettage, which allowed a complete resection of tumor tissue and a minimal damage of the bone. The patient had relief of symptoms, rapid function restoration and no local recurrence. Endoscopic curettage is a promising new treatment for chondroblastoma. In fact, the extra-articular technique enters the tumor cavity via a tunnel drilled through the medullary canal, allowing to visualize possible residual tumor tissue or defects of the articular surface, without violating the joint and without taking away a much bigger cortical window.

Prognostic significance of miR-34a in Ewing sarcoma is associated with cyclin D1 and ki-67 expression

BACKGROUND

At diagnosis, identification of reliable biological indicators of prognosis to allow stratification of patients according to different risks is an important but still unresolved aspect in the treatment of Ewing sarcoma (EWS) patients. This study aimed to explore the role of miR-34A expression on prognosis of EWS patients.

PATIENTS AND METHODS

Specimens from 109 patients with non-metastatic EWS treated at the Rizzoli Institute with neoadjuvant chemotherapy (protocols ISG/SSGIII, EW-1, EW-2, EW-REN2, EW-REN3, EW-PILOT) and 17 metastases were studied. Sixty-eight patients (62%) remained disease-free and 41 (38%) relapsed (median follow-up: 67 months, range 9-241 months). Expression of miR-34a and of some of its targets (cyclin D1, bcl-2, SIRT1 and YY1) was evaluated by qRT-PCR using TaqMan MicroRNA Assays and/or by immunohistochemistry on tissue microarrays from the same patients.

RESULTS

High expression of miR-34a in localized tumors was significantly related to better event-free and overall survival (P = 0.004). Relevance of miR-34a was confirmed by using different calibrators (normal mesenchymal stem cells and different normal tissues). By multivariate Cox regression analysis, low miR-34a expression as well as nontotal necrosis and high levels of lactate dehydrogenase were all confirmed as independent risk factors associated with poor outcome. Expression of miR-34a was lower in metastases than in primary tumors. It inversely correlated with expression of cyclin D1 and Ki-67.

CONCLUSIONS

By demonstrating its relationship with clinical outcome, we propose evaluation of miR-34a at diagnosis of EWS patients to allow early risk stratification. Validation of these results would nonetheless ultimately need a prospective assessment.

Secreted adiponectin as a marker to evaluate in vitro the adipogenic differentiation of human mesenchymal stromal cells

BACKGROUND AIMS

Multipotency is one of the hallmarks of mesenchymal stromal cells (MSCs). Given the widespread adoption of MSC-based clinical applications, the need for rapid and reliable methods to estimate MSC multipotency is demanding. Adipogenic potential is commonly evaluated by staining cell lipid droplets with oil red O. This cytochemical assay is performed at the terminal stage of adipogenic induction (21-28 days) and necessitates the destruction of the specimen. In this study, we investigated whether it is possible to assess MSC adipogenic differentiation in a more efficient, timely and non-destructive manner, while monitoring in vitro secretion of adiponectin, a hormone specifically secreted by adipose tissue.

METHODS

A commercially available enzyme-linked immunosorbent assay kit was used to quantify adiponectin secreted in the culture medium of adipo-induced human bone marrow-derived MSCs. Oil red O staining was used as a reference method.

RESULTS

Adiponectin is detectable after 10 days of induction at a median concentration of 5.13 ng/mL. The secretion of adiponectin steadily increases as adipogenesis proceeds. Adiponectin is undetectable when adipogenic induction is pharmacologically blocked, inefficient or when human MSCs are induced to differentiate toward the osteogenic lineage, proving the specificity of the assay. Furthermore, the results of adiponectin secretion strongly correlate with oil red O quantification at the end of induction treatment.

CONCLUSIONS

Our results demonstrate that quantification of secreted adiponectin can be used as a reliable and robust method to evaluate adipogenic potential without destroying samples. This method provides a useful tool for quality control in the laboratory and in clinical applications of human MSCs.

In vitro biosafety profile evaluation of multipotent mesenchymal stem cells derived from the bone marrow of sarcoma patients

Background

In osteosarcoma (OS) and most Ewing sarcoma (EWS) patients, the primary tumor originates in the bone. Although tumor resection surgery is commonly used to treat these diseases, it frequently leaves massive bone defects that are particularly difficult to be treated. Due to the therapeutic potential of mesenchymal stem cells (MSCs), OS and EWS patients could benefit from an autologous MSCs-based bone reconstruction. However, safety concerns regarding the in vitro expansion of bone marrow-derived MSCs have been raised. To investigate the possible oncogenic potential of MSCs from OS or EWS patients (MSC-SAR) after expansion, this study focused on a biosafety assessment of MSC-SAR obtained after short- and long-term cultivation compared with MSCs from healthy donors (MSC-CTRL).

Methods

We initially characterized the morphology, immunophenotype, and differentiation multipotency of isolated MSC-SAR. MSC-SAR and MSC-CTRL were subsequently expanded under identical culture conditions. Cells at the early (P3/P4) and late (P10) passages were collected for the in vitro analyses including: sequencing of genes frequently mutated in OS and EWS, evaluation of telomerase activity, assessment of the gene expression profile and activity of major cancer pathways, cytogenetic analysis on synchronous MSCs, and molecular karyotyping using a comparative genomic hybridization (CGH) array.

Results

MSC-SAR displayed comparable morphology, immunophenotype, proliferation rate, differentiation potential, and telomerase activity to MSC-CTRL. Both cell types displayed signs of senescence in the late stages of culture with no relevant changes in cancer gene expression. However, cytogenetic analysis detected chromosomal anomalies in the early and late stages of MSC-SAR and MSC-CTRL after culture.

Conclusions

Our results demonstrated that the in vitro expansion of MSCs does not influence or favor malignant transformation since MSC-SAR were not more prone than MSC-CTRL to deleterious changes during culture. However, the presence of chromosomal aberrations supports rigorous phenotypic, functional and genetic evaluation of the biosafety of MSCs, which is important for clinical applications.

Analysis of the karyotype of expanded human adipose-derived stem cells for bone reconstruction of the maxillo-facial region

Mesenchymal stem cells (MSC) and adipose-derived stem cells (ASC) were recently proposed for bone maxillofacial reconstruction in association with biomaterials. For this application MSC must be ex-vivo expanded in order to obtain, for a given volume of implanted biomaterial, a relevant number of bone forming cells. Previously conducted pre-clinical studies suggested that a concentration of 6 x 10(8) ASC associated with 900 mg of anorganic bovine bone (ABB) could be effective for human maxillary sinus floor elevation. A keystone issue to guarantee the quality and safety of Advanced Therapy Medicinal Products containing expanded MSC and ASC is their chromosome stability in culture: this topic has been widely investigated and conflicting results have been published. Abnormal karyotype of human ex-vivo expanded MSC and ASC was found by some authors, while, at the same time, several other studies showed the MSC and ASC karyotype to be normal. It is therefore important that all the results obtained on MSC and ASC karyotype analysis be published. Given this context, the aim of this manuscript, aim of this manuscript is to verify the karyotype stability of ASC in view of their applications in clinical trials. ASC obtained from the adipose tissue of 4 donors were expanded over extended culture time. Based on previous ASC expansions we hypothesized to be able to obtain 6 x 10(8) cells by passage 7. Karyotype analysis of 30 metaphases was planned to be investigated at passage 2, 7, and 15 in all the cultures. No abnormalities were found in the karyotype of two donors at all the passages tested, while a translocation was found in 2 metaphases of a donor at passage 7, but not at passage 15, and in the fourth donor in 5 metaphases a trisomy was found at passage 15. Chromosomal abnormalities were detected only after extended ASC expansion. Whether these anomalies can be related to risk for the patient's safety will have to be demonstrated by in-vivo studies.

Wound drainages in total hip arthroplasty: to use or not to use? Review of the literature on current practice

Aim of this study is to analyze data reported in literature concerning the efficacy of using wound low-vacuum suction drainages in orthopedic surgery after total hip arthroplasty. We analyzed studies concerning the use of drainages in prosthetic hip replacement surgery, performing our research through Pubmed, Cochrane database and Google Scholar, and selecting the ones evaluating the following parameters: bleeding, the need for blood transfusions, number or reinforcement of post-operative medications, length of hospitalization, functional results, periprosthetic and surgical wound infection, post-operative hematoma. Our review did not show any demonstrated advantage from the use of wound drainages in total hip arthroplasty. Moreover, some studies enlighted a possible complication related to their employment, represented by the greater need for blood transfusions. Despite the absence of a statistically demonstrated positive influence on wound outcome using suction drains after total hip replacement, many orthopedic surgeons still recommend using drainages, just because there is no certified proof of a negative effect.

The posterior iliac crest outperforms the anterior iliac crest when obtaining mesenchymal stem cells from bone marrow

BACKGROUND

The clinical application of freshly isolated connective-tissue progenitors, as well as the potential preparation of culture-expanded mesenchymal stem cell populations for therapeutic applications, will benefit from clinical methods that maximize the yield of the starting population. We compared the number of cells, concentration, and prevalence of colony-founding connective-tissue progenitors from the anterior and posterior iliac crest. In addition, we compared the expansion kinetics and multilineage differentiation potential of their culture-expanded progeny when processed to form mesenchymal stem cells.

METHODS

Marrow aspirate was collected from both the anterior and posterior iliac crest of twenty-two patients. The concentration and prevalence of colony-founding connective-tissue progenitors were estimated with use of a colony formation assay. The expansion kinetics and multilineage differentiation potential of the culture-expanded mesenchymal stem cell populations derived from these starting samples were compared.

RESULTS

The yield of colony-founding connective-tissue progenitors was 1.6 times greater in the posterior compared with the anterior iliac crest. No differences were found with respect to the viability, phenotype, expansion kinetics, or multilineage differentiation potential of mesenchymal stem cell populations derived from these two sites.

CONCLUSIONS

The concentration and yield of colony-founding connective-tissue progenitors were greater when aspirate was obtained from the posterior compared with the anterior iliac crest, whereas the biological potential of the cells derived from these sites appeared comparable.

CLINICAL RELEVANCE

The harvesting of bone marrow from the posterior iliac crest appears to be preferred, as it provided a modestly higher concentration of colony-founding connective-tissue progenitors than comparable aspirate from the anterior iliac crest.

Comparison of allograft-prosthetic composite reconstruction and modular prosthetic replacement in proximal femur bone tumors: functional assessment by gait analysis in 20 patients

BACKGROUND AND PURPOSE

The methods of reconstruction for proximal femur bone tumors that are used most often include modular prosthetic replacement and allograft-prosthesis composite reconstruction. In modular prostheses, the abductors are detached from the insertion and then reinserted into the implant, and the iliopsoas is detached and left free. In the allograft-prosthesis composite, the detached tendons are fixated to the graft. We assessed whether the latter procedure provides functional advantages regarding gait.

PATIENTS AND METHODS

We studied 2 groups of 10 patients, each with prosthetic reconstruction of the proximal femur either with modular prosthetic replacement or with allograft-prosthesis composite. Functional performance was analyzed by gait analysis 2.5-10 years after surgery. At that time, all the patients had good function according to the Musculoskeletal Society score.

RESULTS

Walking speed was reduced in all patients, and especially in patients with modular prosthetic replacement. Different hip extension patterns during late stance were found in the 2 groups. Surface EMG showed a typical prolonged muscle co-contraction pattern during gait, which was more evident in modular prosthetic patients.

INTERPRETATION

Although both procedures provided good functional outcome in the long-term follow-up, gait analysis revealed mechanical changes during gait that were probably related to the muscle reinsertion procedure. Direct fixation of the muscles to the bone graft appeared to result in a more efficient muscular recovery.

Mesenchymal stem cells as delivery vehicle of porphyrin loaded nanoparticles: effective photoinduced in vitro killing of osteosarcoma

Mesenchymal stem cells (MSC) have the unique ability to home and engraft in tumor stroma. These features render them potentially a very useful tool as targeted delivery vehicles which can deliver therapeutic drugs to the tumor stroma. In the present study, we investigate whether fluorescent core-shell PMMA nanoparticles (FNPs) post-loaded with a photosensitizer, namely meso-tetrakis (4-sulfonatophenyl) porphyrin (TPPS) and uploaded by MSC could trigger osteosarcoma (OS) cell death in vitro upon specific photoactivation. In co-culture studies we demonstrate using laser confocal microscopy and time lapse imaging, that only after laser irradiation MSC loaded with photosensitizer-coated fluorescent NPs (TPPS@FNPs) undergo cell death and release reactive oxygen species (ROS) which are sufficient to trigger cell death of all OS cells in the culture. These results encourage further studies aimed at proving the efficacy of this novel tri-component system for PDT applications.

Fresh osteochondral allograft is a suitable alternative for wide cartilage defect in the knee

INTRODUCTION

There are several surgical options to restore a wide osteochondral defect in the knee. Fresh osteochondral allografts are usually considered a poor alternative due to their difficulties in surgical application. The aim of this work is first to present our experience including the surgical technique and the functional results of patients receiving fresh osteochondral allograft to restore major knee lesions, then, to compare our results with other results presented in literature.

METHODS

Between 2006 and 2011, we treated 11 patients with osteochondral lesion of the knee (Outerbridge IV°). The average lesion size was 10.3 cm(2) (range 3-20 cm(2)). The average age was 34 years (range 18-66). Patients were followed from 12 to 55 months (average of 26.5) through clinical examination, X-ray film and MRI every 3 months for the first year, then every 6 months.

RESULTS

The treatment was successful in 10 patients showing pain regression and mean IKDC subjective score improvements from 27.3 to 58.7. The IKDC objective score also improved of at least one class for each patient except the who failed. The radiographs show good osteointegration in all cases but one.

CONCLUSIONS

Fresh allograft is an effective therapy for osteochondral defects repair because it allows functional recovery in a considerable number of patients. This technique obtains better results in lesion smaller than 8 cm(2). However larger lesion show good results.

LEVEL OF EVIDENCE

Therapeutic study, Level IV.

Protein kinase B/AKT isoform 2 drives migration of human mesenchymal stem cells

This study was designed to investigate the migratory behavior of adult human mesenchymal stem cells (MSC) and the underlying mechanism. Cell migration was assessed by transwell, wound healing and time-lapse in vivo motility assays. Pharmacological inhibitors were used to determine the potential mechanism responsible for cell migration and invasion. The tests that were implemented revealed that MSC were fairly migratory. Protein kinase B (AKT) was strongly activated at the basal level. Through our analyses we demonstrated that pharmacological inactivation of AKT2 but not AKT1 significantly decreased cell migration and invasion. Although preliminary, collectively our results indicate that AKT2 activation plays a critical role in enabling MSC migration.

Conservative versus surgical treatment of osteogenesis imperfecta: a retrospective analysis of 29 patients

The aim of our study was to compare the surgical and conservative treatment of patients affected by fragility fractures and deformities of long bones in osteogenesis imperfecta (OI).Our series consisted of 29 consecutive OI patients treated at our Institute. The series comprised 14 females and 15 males of different ages. The mean age at the time of the first treatment was 8 years (median 6 years; SD ± 15; range 1 to 75). The mean follow-up was 88 months. The Sillence classification was used to classify OI. Fifteen patients were classified as Type I; five as Type III and nine as Type IV.A total number of 245 procedures were recorded. Of these, 147 were surgical (pinning; intramedullary nailing and plating) while 98 were conservative (cast, braces and bandages). Bisphosphonate use was a major variable in the study. Clinical charts and radiographic films were analyzed for complications (delayed union, nonunion, malunion, hardware loosening). We recorded 58 complications: 13 in Type I; 28 in Type III and 17 in Type IV OI. The rate of each complication was: 15/245 nonunions (6.1%), 14/245 delayed unions (5.7%), 14/245 malunions (5.7%) and 15/245 hardware loosenings (6.1%).We found no statistically significant differences between surgical and conservative treatments. Type III OI, which is a very crippling form of the disease, was associated with radiographically poorer results than the other types. In our analysis, the two groups were unbalanced and only five patients were treated with bisphosphonates. Nevertheless, bisphosphonate use can be considered a good adjuvant to both the conservative and surgical treatment of OI in order to reduce the rate of complications.

A rapid method for obtaining mesenchymal stem cells and platelets from bone marrow aspirate

Mesenchymal stem cells (MSCs) and platelet-rich plasma (PRP) are currently used alone or in combination for therapeutic applications especially for bone repair. We tested whether MSCs can be isolated from bone marrow (BM) aspirate using a commercially available kit commonly used to obtain PRP from peripheral blood (PB). Results revealed that mononuclear cells and platelets from both PB and BM could be efficiently isolated by obtaining a mononuclear and platelet rich fraction (PB-MPRF and BM-MPRF, respectively). Starting with comparable volumes, the number of platelets increased 1.5-fold in BM-MPRF compared to PB-MPRF. The number of clonogenic cells in BM-MPRF samples was significantly higher than whole BM samples as revealed by CFU-F assay (54.92 ± 8.55 CFU-F/1.5 x 10(5) nucleated cells and 32.50 ± 12.43 CFU-F/1.5 x 10(5) nucleated cells, respectively). Cells isolated from BM-MPRF after in vitro expansion fulfilled the definition of MSCs by phenotypic criteria, and differentiated along osteogenic, adipogenic and chondrogenic lineages following induction. Results showed that the kit isolated MSCs and platelets from BM aspirate. Isolated MSCs were further expanded in a laboratory and BM-MPRF was used clinically following BM withdrawal for rapid intra-operative cell therapy for the treatment of bone defects.

Efficient isolation and enrichment of mesenchymal stem cells from bone marrow

BACKGROUND AIMS

Bone marrow (BM) mesenchymal stromal cells (MSC) have been identified as a source of pluripotent stem cells used in clinical practice to regenerate damaged tissues. BM MSC are commonly isolated from BM by density-gradient centrifugation. This process is an open system that increases the risk of sample contamination. It is also time consuming and requires technical expertise that may result in variability regarding cellular recovery. The BD Vacutainer® Cell Preparation Tube™ (CPT) was conceived to separate mononuclear cells from peripheral blood. The main goal of this study was to verify whether MSC could be isolated from BM using the CPT.

METHODS

BM was harvested, divided into two equal aliquots and processed using either CPT or a Ficoll-Paque™ PREMIUM density gradient. Both methods were compared regarding cell recovery, viability, proliferation, differentiation capacities and the presence of MSC progenitors.

RESULTS

Similar numbers of mononuclear cells were isolated from BM when comparing the two methods under study. No differences were found in terms of phenotypic characterization, viability, kinetics and lineage differentiation potential of MSC derived by CPT or Ficoll. Surprisingly, a fibroblast-colony-forming unit (CFU-F) assay indicated that, with CPT, the number of MSC progenitors was 1.8 times higher compared with the Ficoll gradient separation.

CONCLUSIONS

The CPT method is able to isolate MSC efficiently from BM, allowing the enrichment of MSC precursors.

CAD-CAM-generated hydroxyapatite scaffold to replace the mandibular condyle in sheep: preliminary results

In this study, rapid CAD-CAM prototyping of pure hydroxyapatite to replace temporomandibular joint condyles was tested in sheep. Three adult animals were implanted with CAD-CAM-designed porous hydroxyapatite scaffolds as condyle substitutes. The desired scaffold shape was achieved by subtractive automated milling machining (block reduction). Custom-made surgical guides were created by direct metal laser sintering and were used to export the virtual planning of the bone cut lines into the surgical environment. Using the same technique, fixation plates were created and applied to the scaffold pre-operatively to firmly secure the condyles to the bone and to assure primary stability of the hydroxyapatite scaffolds during masticatory function. Four months post-surgery, the sheep were sacrificed. The hydroxyapatite scaffolds were explanted, and histological specimens were prepared. Different histological tissues penetrating the scaffold macropores, the sequence of bone remodeling, new apposition of bone and/or cartilage as a consequence of the different functional anatomic role, and osseointegration at the interface between the scaffold and bone were documented. This animal model was found to be appropriate for testing CAD-CAM customization and the biomechanical properties of porous, pure hydroxyapatite scaffolds used as joint prostheses.

Report of four simultaneous pancreas-kidney transplants in HIV-positive recipients with favorable outcomes

The advent of combined antiretroviral therapy (cART) dramatically changed the view of human immunodeficiency virus (HIV) infection as an exclusion criterion for solid organ transplantation, resulting in worldwide reports of successful transplants in HIV-infected individuals. However, there are few reports on simultaneous pancreas-kidney transplant in HIV-positive recipients detailing poor outcomes. A series of four pancreas-kidney transplant performed on HIV-infected individuals between 2006 and 2009 is presented. All recipients reached stably undetectable HIV-RNA after transplantation. All patients experienced early posttransplant infections (median day 30, range 9-128) with urinary tract infections and bacteremia being most commonly observed. In all cases, surgical complications led to laparotomic revisions (median day 18, range 1-44); two patients underwent cholecystectomy. One steroid-responsive acute renal rejection (day 79) and one pancreatic graft failure (month 64) occurred. Frequent dose adjustments were required due to interference between cART and immunosuppressants. At a median follow-up of 45 months (range, 26-67) we observed 100% patient survival with CD4 cell count >300 cells/mm(3) for all patients. Although limited by its small number, this case series represents the largest reported to date with encouraging long-term outcomes in HIV-positive pancreas-kidney transplant recipients.

Advance in the treatment of aneurysmal bone cyst of the sacrum

OBJECTIVE

The objective of this study was the review of 11 patients with two different treatment methods used historically for aneurysmal bone cyst in the sacrum. The outcome of both procedures is reported. In addition, the treatment technique of CT-guided percutaneous injections of demineralized bone matrix mixed with bone marrow concentrate is described.

MATERIALS AND METHODS

From 1997 to 2008, 11 patients with sacral aneurysmal bone cyst were treated at the Rizzoli Institute, Bologna, Italy. The first seven patients had surgical curettage without bone grafting, chemical adjuvants, or arterial embolization. The last four patients had arterial embolization. The last patient did not respond to arterial embolization and was treated by CT-guided injection of demineralized bone matrix mixed with bone marrow concentrate.

RESULTS

Curettage was successful in five out of seven patients. Two patients suffered complications, and two cases had recurrence. Arterial embolization was successful in three of four patients. The patient treated with injection had a good clinical and radiographic result.

CONCLUSION

Both surgical and arterial embolization are effective for aneurysmal bone cyst in the sacrum. However, these treatments may lead to complications and recurrence. The use of CT-guided injections of demineralized bone matrix mixed with bone marrow concentrate may be a safe and effective alternative for treatment of these destructive and problematic lesions.

Mesenchymal stem cells and platelet lysate in fibrin or collagen scaffold promote non-cemented hip prosthesis integration

The objective of this study was to evaluate whether mesenchymal stem cells (MSC) and platelet lysate (PL) seeded in a fibrin or collagen scaffold could improve the new bone (NB) formation around an uncemented hip prosthesis stem in a sheep model. In vitro expanded MSC were suspended in PL and either mixed with collagen or fibrin gel as delivery vehicle. The cell-gel composites were inserted inside the femoral canal, then the prosthesis was press-fit inserted inside the femur. Identical procedures were performed in a control group, but only the prosthesis was implanted. Histomorphometrical analysis performed 4 months after surgery indicated that the newly formed bone inside the medullary canal, between the inner cortex and the prosthetic stem, was significantly higher in the MSC-PL-collagen group (mean 18.7 ± 4.5%) and in the MSC-PL-fibrin group (mean 18.8 ± 15.2%) when compared to the control group (mean 4.6 ± 2.0%). There was a significantly higher bone-prosthesis contact in the MSC-PL-collagen group (mean 2.7 ± 2.6%) and in the MSC-PL-fibrin group (mean 2.3 ± 3.1%) compared to the control group (mean 0.2 ± 0.1%). The results indicate that MSC and PL in a fibrin or collagen scaffold can promote NB formation around an uncemented hip prosthesis stem.

Osteogenic protein-1 associated with mesenchymal stem cells promote bone allograft integration

Limited incorporation and modest bone remodeling can cause allograft failure. We investigated whether mesenchymal stem cells (MSCs) and osteogenic protein-1 (OP-1) can improve allograft integration. A 3-cm full-size intercalary bone defect was created in the mid-diaphysis of the metatarsal bone of the sheep and it was replaced with an allograft alone (control group), or with MSCs (MSC group), OP-1 (OP-1 group), or MSCs and OP-1 (MSC + OP-1 group). Radiographic results showed a faster and complete integration of the allograft in the MSC + OP-1 group. Histology demonstrated that the amount of new bone was significantly greater inside the graft and a longer vessel penetration in the MSC + OP-1 group than in others. Mechanical strength of the allograft was not compromised by the high rate of bone remodeling. These results demonstrated that the association of MSCs and OP-1 improve bone allograft integration promoting an almost complete bone restoring.

A recently developed bifacial platelet-rich fibrin matrix

Platelet-rich plasma (PRP) is used clinically in liquid or gel form to promote tissue repair. Because of the poor mechanical properties, conventional PRP is often difficult to handle when used in clinical settings and requires secure implantation in a specific site, otherwise when released growth factors could be washed out during an operation. In this study, we analyzed the end product of a recently developed commercially available system (FIBRINET), which is a dense pliable, platelet-rich fibrin matrix (PRFM). We characterized the mechanical properties of PRFM and tested whether PRFM releases growth factors and whether released factors induce the proliferation of mesenchymal stem cells (MSC). Mechanical properties as well as platelet distribution were evaluated in PRFM. PRFM demonstrated robust mechanical properties, with a tear elastic modulus of 937.3 +/- 314.6 kPa, stress at a break of 1476.0 +/- 526.3 kPa, and an elongation at break of 146.3 +/- 33.8 %. PRFM maintained its mechanical properties throughout the testing process. Microscopic observations showed that the platelets were localized on one side of the matrix. Elevated levels of PDGF-AA, PDGF-AB, EGF, VEGF, bFGF and TGF-beta1 were measured in the day 1-conditioned media (CM) of PRFM and growth factor levels decreased thereafter. BMP2 and BMP7 were not detectable. MSC culture media supplemented with 20% PRFM-CM stimulated MSC cell proliferation; at 24 and 48 hours the induction of the proliferation was significantly greater than the induction obtained with media supplemented with 20% foetal bovine serum. The present study shows that the production of a dense, physically robust PRFM made through high-speed centrifugation of intact platelets and fibrin in the absence of exogenous thrombin yields a potential tool for accelerating tissue repair.

Dose-dependent effect of adipose-derived adult stem cells on vertical bone regeneration in rabbit calvarium

Previous in vivo studies have shown a limited potential for vertical bone regeneration using osteoconductive scaffolds alone. In the present study, we investigated whether the association of adipose-derived adult stem cells (ASCs) with anorganic bovine bone (ABB) scaffold improved bone formation and implant osseointegration in a vertical guided bone regeneration model. Two pre-formed titanium domes were placed on the calvaria of 12 rabbits. Four treatment modalities were evenly distributed among the 24 domes: ABB alone, and ABB containing 3 x 10(5), 3 x 10(6), or 3 x 10(7) cells/graft. After 1 month, the domes were removed and one titanium implant was placed into each augmented site. One month after the second operation, the animals were killed and biopsy specimens were examined by histomorphometric and micro-CT analyses. Results indicated that at all concentrations, the ASC-loaded groups showed significantly more new bone formation and higher mean values of bone-implant contact and bone density inside threads than the ABB group. Furthermore, ASCs demonstrated a dose-response relationship, with the highest dose chosen inducing more robust bone regeneration. This study suggests that the delivery of ASCs on ABB might effectively increase vertical bone regeneration and implant osseointegration, versus ABB alone.

Bone morphogenetic proteins and tissue engineering: future directions

As long as bone repair and regeneration is considered as a complex clinical condition, the administration of more than one factor involved in fracture healing might be necessary. The effectiveness or not of bone morphogenetic proteins (BMPs) in association with other growth factors and with mesenchymal stem cells in bone regeneration for fracture healing and bone allograft integration is of great interest to the scientific community. In this study we point out possible future developments in BMPs, concerning research and clinical applications.

Nonmetastatic osteosarcoma of the extremity with pathologic fracture at presentationLocal and systemic control by amputation or limb salvage after preoperative chemotherapy

To determine whether a pathologic fracture in osteosarcoma of long bones has prognostic importance, and limb salvage can be safely performed in such cases, we reviewed the surgical treatment and oncologic results in 46 patients with nonmetastatic osteosarcoma of the extremity and pathologic fracture at presentation who had been treated in our Institution with neoadjuvant chemotherapy, between 1983 and 1999. Neoadjuvant chemotherapy was given according to 6 consecutive protocols. Surgery consisted of limb salvage (34 patients), amputation (11 patients) and rotationplasty (1 patient). The average follow-up was 11 (3-20) years. 28 patients remained continuously disease-free, 17 patients relapsed and 1 died of chemotherapy-related toxicity. Despite the high rate of limb salvage, only 2 local failures occurred, 1 after amputation and 1 after limb salvage. The 5-year disease-free survival and overall survival rates were 59% and 65%, respectively, with no differences between amputated and resected patients. These results are similar to those obtained in 689 contemporary patients having an osteosarcoma without a pathologic fracture treated in our Institution, and using the same protocols for chemotherapy. We conclude that with neoadjuvant chemotherapy, osteosarcoma patients presenting with a pathologic fracture can be surgically treated like those with no fracture, and that limb salvage procedures do not increase the risk of local recurrence or death of these patients.

Effect of mesenchymal stem cells and platelet-rich plasma on the healing of standardized bone defects in the alveolar ridge: a comparative histomorphometric study in minipigs

PURPOSE

The purpose of this study was to test the effect of the combination of mesenchymal stem cells (MSCs) and platelet-rich plasma (PRP) incorporated into a fluorohydroxyapatite (FHA) scaffold on bone regeneration in cylindrical defects in the edentulous mandibular ridge of minipigs.

MATERIALS AND METHODS

Two mandibular premolar teeth were extracted bilaterally in 8 adult minipigs. After 2 months, 4 standardized defects of 3.5 mm diameter and 8 mm depth were created in each root site. The defects were randomly grafted with autogenous mandibular bone, FHA alone, PRP-FHA, or MSCs-PRP-FHA. A resorbable collagen membrane was placed over the defect area and the flaps were sutured. The animals were sacrificed 3 months later and biopsy samples were taken from the defect sites for histologic and histomorphometric assessment.

RESULTS

There was no evidence of inflammation or adverse tissue reaction with either treatment. MSCs-PRP-FHA-treated sites showed new vital bone between residual grafting particles. PRP-FHA- and FHA-treated sites showed residual particles in a background of marrow soft tissue with a moderate quantity of newly formed bone. Autogenous bone (46.97%) and MSCs-PRP-FHA (45.28%) produced a significantly higher amount of vital bone than PRP-FHA (37.95%), or FHA alone (36.03%). Further, the MSCs-PRP-FHA-treated defects showed a significantly higher percentage of contact between graft particles and newly formed bone compared with PRP-FHA and FHA group (59.23% vs 48.37% and 46.43%, respectively).

CONCLUSIONS

Our results suggest that, in this animal model, the addition of MSCs to PRP-FHA enhances bone formation after 3 months.

The use of unicondylar osteoarticular allografts in reconstructions around the knee

Unicondylar osteoarticular allografts (UOA) of the knee are mainly used after bone tumour resections for benign aggressive tumours or small malignant tumours with clearly defined margins. They are also used less often in large posttraumatic condylar defects. Between 1989 and 2004, 12 deep-frozen UOA reconstructions (in 11 patients) were performed at our Institute. The diagnosis was chondrosarcoma in four cases, giant cell tumour in three, osteosarcoma in three, posttraumatic defect in one, and one failed UOA. The involved site was the medial femoral condyle in six cases, the lateral femoral condyle in three, the medial side of the tibial plateau in two, and the lateral in one case. One allograft was removed after 29 months because of an intra-articular displaced fracture, and substituted with a new UOA. One patient died of metastatic disease at 24 months. We report the functional and radiographical outcome of the remaining 10 UOAs with a minimum follow-up of 4 years (average 11 years). Two of the 10 patients had excellent results, five were good and three were fair. Radiographically, five patients had "mild" and five had "severe" degenerative changes. One patient with severe degenerative changes had pain and stiffness, therefore the UOA was converted into a prosthesis allograft composite, using a conventional total knee prosthesis. In selected cases of distal femoral and proximal tibial tumours, UOA reconstructions give good functional outcomes with relatively few major complications.

Management of pelvic giant cell tumours involving the acetabular bone

The purpose of this study was to establish the optimal surgical treatment in patients with a Giant Cell Tumour (GCT) involving the acetabular bone. The surgical outcome in 10 patients with GCT involving the acetabular bone was reviewed. Patients were divided into two groups: group 1 in which 5 patients were primarily treated by curettage, and group 2, in which 5 patients were treated by resection and pelvic reconstruction. In group 1, local recurrence occurred in two cases. The functional outcome was excellent or good in 4, and poor in one case. There were no recurrences in group 2, in which the functional outcome was excellent or good in 4 and poor in one patient. The optimal surgical treatment modality should be based upon the tumour extension. Tumours located primarily in the ischiopubic region and not extending proximally beyond the supra-acetabular line can be adequately treated by extended curettage while those with further proximal extension are better treated by en-bloc resection. However, the possible complications of the different methods of pelvic reconstruction should always be considered.

Historical review of bone prefabrication

Prefabricated tissue represents a bridge between traditional reconstructive surgery and tissue engineering. Initially used in the 1960s in reconstructive plastic surgery, in the 1980s it was also used in orthopedics. The term "prefabricated" indicates a process of neovascularization of a tissue by implanting a vascular pedicle inside the tissue itself; this tissue can be then reimplanted either at a short distance through the pedicle itself, or as a free graft by microvascular anastomosis. The purpose of prefabrication is to build a tissue (muscle, bone, skin, or composite) with characteristics as similar as possible to those of the defect to fill, thus minimizing morbidity in the donor site and improving the reconstructive effectiveness. We present a review of the literature that includes the main experiments performed until now in which a bone segment has been reconstructed using scaffolds and growth factors in relationship to the local blood supply or to the use of a vascular pedicle.

Prediction of adherence to antiretroviral therapy: can patients' gender play some role? An Italian pilot study

Recent literature has shown that adherence to HAART is a multi-faceted phenomenon, which involves both behavioural and psychological features. Therefore, the results obtained so far, though promising, have not yet unambiguously identified the factors that could predict non-adherence. Since any support for strengthening the adherence should take into account the HIV+ patients' perception of both their state of health and their relational style, this study tried to identify some psychological characteristics involved in the adherence phenomenon. A self-administered battery of tests including the Attachment Style Questionnaire (ASQ) and the Multidimensional Health Locus of Control Form-C (MHLC-C) was administered to an Italian sample. Results showed significant gender differences between non-adherent and adherent subjects. Specifically, the psychological profile of non-adherent males seemed focused less on relational aspects and perceived relevance of physicians and of 'significant other people', whilst that of non-adherent females seemed more 'relationship-oriented'. This study means to encourage clinicians to plan specific, gender-focused support for enhancing adherence.

The use of fluoride cement: preliminary experimental study and clinical application

One of the most common complications of cemented prostheses is aseptic loosening of the implant, which is often due to mechanical breakdown at the bone-cement interface. To improve the characteristics of PMMA, the addition of fluoride has been proposed, which, without jeopardising its mechanical qualities, should provide better integration with the surrounding bone. An experimental study was performed in 4 sheep. A cylinder of cement (with and without fluoride) was inserted in the meta-epiphysis of the distal femur. A clinical study followed 7 patients. The cement with added fluoride was used as a filler after the curettage of a benign tumour located in the meta-epiphysis around the knee. Histological results in animals combined with long-term radiographic results in humans have shown the positive influence of fluoride in the cement, as it allows better integration of the cement with the surrounding bone.

Mesenchymal stem cells and platelet-rich plasma enhance bone formation in sinus grafting: a histomorphometric study in minipigs

OBJECTIVES

Autologous, allogenic, and alloplastic materials for sinus augmentation have specific drawbacks, which has stimulated an ongoing search for new materials and tissue-engineering constructs. We investigated whether mesenchymal stem cells (MSCs) and platelet-rich plasma (PRP) seeded on a fluorohydroxyapatite (FH) scaffold can improve bone formation and bone-to-implant contact (BIC) in maxillary sinus grafting.

MATERIAL AND METHODS

Bilateral sinus augmentation procedures were performed in eight minipigs. MSCs, PRP, and FH scaffold (test site) or FH alone (control site) were grafted in each maxillary sinus. Distal to the osteotomy, one dental implant per sinus was placed in the grafting material through the facial sinus wall. The animals were killed 3 months after grafting, and block sections of the implant sites were harvested and prepared for histomorphometric analysis.

RESULTS

After 12 weeks, a significant increase in bone formation occurred in the test sites compared with the control sites (42.51%versus 18.98%; p=0.001). In addition, BIC was significantly greater in the test sites compared with the control sites in the regenerated area (23.71%versus 6.63%; p=0.028).

CONCLUSIONS

These findings show that sinus augmentation with MSCs-PRP, combined with FH may enhance bone formation and osseointegration of dental implants compared with FH alone in minipigs.

Clear cell chondrosarcoma of bone: long time follow-up of 18 cases

INTRODUCTION

Clear cell chondrosarcoma is a variant of conventional chondrosarcoma behaving as low grade malignant bone tumor. We reviewed our cases of clear cell chondrosarcoma with the aim to assess the best diagnostic and curative approach to this rare tumor.

MATERIALS AND METHODS

We report 18 cases of clear cell chondrosarcoma treated at the authors' institution. Pertinent clinical information, pre and postoperative serum alkaline phosphatase (SAP) level were obtained from the patients charts. Available imaging studies including plain roentgenograms, computed tomography (CT) images (in 6 patients) and magnetic resonance imaging (MRI) images (in 2 patients).

RESULTS

Eight cases were firstly treated in other institutions, seven with one or more curettage, while one, presented with pathologic fracture, was treated with repeated osteosynthesis. Of the seven patients treated with curettage, five were referred with local recurrence, the mean time between surgical treatment and local recurrence was 52.2 months (from 12 to 132). The other two patients were curetted out 4 and 1 month before, respectively, and were then referred to us to decide about further treatment after incidental diagnosis. Of these cases, three (37.5%) recurred again after our treatment and two of them presented with late bone metastases. Eight patients were originally treated with wide (six) or marginal (two) surgical margins by us. Among them only one proximal humerus (wide margins) had local recurrence 26 months from the first operation. Two patients underwent curettage in our institution, and one of them had a local recurrence. Pre-operative SAP level were obtained in 17 patients. Among them, 11 patients had high pre-operative SAP level (64.7%) and 6 cases were normal. Post-operative SAP levels were obtained in nine patients. After removal of the tumors; SAP levels decreased to normality in seven of the nine patients with high pre-operative SAP. In the other two patients, although the SAP levels were normal, post-operative SAP levels were decreased.

CONCLUSION

Serum alkaline phosphatase can be used as a good tumor marker in diagnosis and follow-up. Due to the occurrence of local recurrences and distant metastasis after curettage, we suggest surgical treatment with "en bloc" resection from the first presentation.

Allograft-prosthetic composite in the proximal tibia after bone tumor resection

We consider an allograft-prosthesis composite in the proximal tibia one of the better reconstructive options in this site because it combines the mechanical stability of a prosthesis with the biologic reconstruction of the extensor mechanism. We retrospectively reviewed 62 patients who had proximal tibia reconstructions with allograft-prosthesis composites to ascertain the complications and functional outcomes. By combining an allograft with a prosthesis, placing cement in the graft, and press-fitting the prosthesis in the tibial diaphysis, we obtained satisfactory Musculoskeletal Tumor Society scores in 90.4% of patients, with a 5-year survival rate (73.4%) comparable to that of reconstruction with a modular prosthesis. However, we observed high infection rates (24.2%) and rotation of the medial gastrocnemius seemed not to reduce this complication. For this reason, we do not recommend using this reconstructive technique in patients who will receive postoperative chemotherapy or in patients in whom a previous reconstructive method failed. We believe the ideal candidate is the young patient with a benign aggressive or malignant low-grade tumor who has not undergone previous surgery.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.