This case series highlights the use of the Ganz approach and surgical dislocation for excision of fibrous dysplasia of the femoral neck, pigmented villonodular synovitis and synovial chrondromatosis of the hip, which has never been described for use with all three tumours together. These are rare benign tumours, which were found incidentally and required excision. We demonstrate that it is possible to obtain excellent exposure of the femoral neck, head and acetabulum allowing easy inspection, exploration and debridement of these three tumours of the hip

Introduction and Objective

Curative resection of proximal humerus tumours is now possible in this era of limb salvage with endoprosthetic replacement considered as the preferred reconstructive option. However, it has also been linked with mechanical and non-mechanical failures such as stem fracture and aseptic loosening. One of the challenges is to ensure that implants will endure the mechanical strain under physiological loading conditions, especially crucial in long surviving patients. The objective is to investigate the effect of varying prosthesis length on the bone and implant stresses in a reconstructed humerus-prosthesis assembly after tumour resection using finite element (FE) modelling.

Osteochondromas are benign chondrogenic lesions arising on the external surface of the bone with aberrant cartilage (exostosis) from the perichondral ring that may contain a marrow cavity also. In a few cases, depending on the anatomical site affected, different degrees of edema, redness, paresthesia, or paresis can take place due to simple contact or friction. Also, depending on their closeness to neurovascular structures, the procedure of excision becomes crucial to avoid recurrence. We report a unique case of recurrent osteochondroma of the proximal humerus enclosing the brachial artery which makes for an important case and procedure to ensure that no relapse occurs. We report a unique case of a 13-year-old female who had presented with a history of pain and recurrent swelling for 5 years. The swelling size was 4.4 cm x 3.7 cm x 4 cm with a previous history of swelling at the same site operated in 2018. CT reports were suggestive of a large well defined broad-based exophytic diaphyseal lesion in the medial side of the proximal humerus extending posteriorly. Another similar morphological lesion measuring approximately 9 mm x 7 mm was noted involving the posterior humeral shaft. The minimal distance between the lesion and the brachial artery was 2 mm just anterior to the posterio-medial growth. Two intervals were made, first between the tumor and the neurovascular bundle and the other between the anterior tumor and brachial artery followed by exostosis and cauterization of the base. Proper curettage and excision of the tumor was done after dissecting and removing the soft tissue, blood vessels, and nerves so that there were very less chances of relapse. Post-operative X-ray was done and post 6 months of follow-up, there were no changes, and no relapse was observed. Thus, when presented with a case of recurrent osteochondroma of the proximal humerus, osteochondroma could also be in proximity to important vasculature as in this case enclosing the brachial artery. Thus, proper curettage and excision should be done in such cases to avoid recurrence

Decreasing the chance of local relapse or infection after surgical excision of bone metastases is a main goals in orthopedic oncology. Indeed, bone metastases have high incidence rate (up to 75%) and important cross-relations with infection and bone regeneration. Even in patients with advanced cancer, bone gaps resulting from tumor excision must be filled with bone substitutes. Functionalization of these substitutes with antitumor and antibacterial compounds could constitute a promising approach to overcome infection and tumor at one same time. Here, for the first time, we propose the use of nanostructured zinc-bone apatite coatings having antitumor and antimicrobial efficacy. The coatings are obtained by Ionized Jet Deposition from composite targets of zinc and bovine-derived bone apatite. Antibacterial and antibiofilm efficacy of the coatings is demonstrated in vitro against S. Aureus and E. Coli. Anti-tumor efficacy is investigated against MDA- MB-231 cells and biocompatibility is assessed on L929 and MSCs. A microfluidic based approach is used to select the optimal concentration of zinc to be used to obtain antitumor efficacy and avoid cytotoxicity, exploiting a custom gradient generator microfluidic device, specifically designed for the experiments. Then, coatings capable of releasing the desired amount of active compounds are manufactured. Films morphology, composition and ion-release are studies by FEG- SEM/EDS, XRD and ICP. Efficacy and biocompatibility of the coatings are verified by investigating MDA, MSCs and L929 viability and morphology by Alamar Blue, Live/Dead Assay and FEG-SEM at different timepoints. Statistical analysis is performed by SPSS/PC + Statistics TM 25.0 software, one-way ANOVA and post-hoc Sheffe? test. Data are reported as Mean ± standard Deviation at a significance level of p <0.05. Results and Discussion. Coatings have a nanostructured surface morphology and a composition mimicking the target. They permit sustained zinc release for over 14 days in medium. Thanks to these characteristics, they show high antibacterial ability (inhibition of bacteria viability and adhesion to substrate) against both the gram + and gram – strain. The gradient generator microfluidic device permits a fine selection of the concentration of zinc to be used, with many potential perspectives for the design of biomaterials. For the first time, we show that zinc and zinc-based coatings have a selective efficacy against MDA cells. Upon mixing with bone apatite, the efficacy is maintained and cytotoxicity is avoided. For the first time, new antibacterial metal-based films are proposed for addressing bone metastases and infection at one same time. At the same time, a new approach is proposed for the design of the coatings, based on a microfluidic approach. We demonstrated the efficacy of Zn against the MDA-MB-231 cells, characterized for their ability to form bone metastases in vivo, and the possibility to use nanostructured metallic coatings against bone tumors. At the same time, we show that the gradient-generator approach is promising for the design of antitumor biomaterials. Efficacy of Zn films must be verified in vivo, but the dual-efficacy coatings appear promising for orthopedic applications

An isolated avulsion fracture of the peroneus longus tendon is seldom seen and potentially can go undiagnosed using basic imaging methods during an initial emergency visit. If not managed appropriately it can lead to chronic pain, a reduced range of motions and eventually affect mobility. This article brings to light the effectiveness of managing such injuries conservatively. A 55 year old postman presented to clinic with pain over the instep of his right foot for 2 months with no history of trauma. Clinically the pain was confined to the right first metatarsophalangeal joint with occasional radiation to the calf. X-ray films did not detect any obvious bony injury. MR imaging revealed an ununited avulsion fracture of the base of the 1st metatarsal. The patient was subsequently injected with a mix of steroid and local anesthetic injections at the painful nonunion site under fluoroscopic guidance. Post procedure there was no neurovascular deficit. The patient was reviewed at three months and his pain score and functional outcome improved significantly. Moreover following our intervention, the Manchester Oxford Foot Questionnaire reduced from 33 to 0. At the one year follow up he remained asymptomatic and was discharged. The peroneus longus tendon plays a role in eversion and planter flexion of foot along with providing stabilization to arches of foot. The pattern of injury to this tendon is based on two factors one is the mechanism of insult, if injured, and second is the variation in the insertion pattern of peroneus longus tendon itself. There is no gold standard treatments by which these injuries can be managed. If conservative management fails we must also consider surgery which involves percutaneous fixation, or excision of the non-healed fracture fragment and arthrodesis. To conclude isolated avulsion fractures of peroneus longus tendon are rare injuries and it is important to raise awareness of this injury and the diagnostic and management challenges faced. In this case conservative management was a success in treating this injury however it is important to take factors such as patient selection, patient autonomy and clinical judgement into account before making the final decision

To analyse bone stresses in humerus-megaprosthesis construct in response to axial loading under varying implant lengths in proximal humeral replacement following tumour excision. CT scans of 10 cadaveric humeri were processed in 3D Slicer to obtain three-dimensional (3D) models of the cortical and cancellous bone. Megaprostheses of varying body lengths (L) were modelled in FreeCAD to obtain the 3D geometry. Four FE models: group A consisting of intact bone; groups B (L=40mm), C (L=100mm) and D (L=120mm) comprising of humerus-megaprosthesis constructs were created. Isotropic linear elastic behaviour was assigned for all materials. A tensile load of 200N was applied to the elbow joint surface with the glenohumeral joint fixed with fully bonded contact interfaces. Static analysis was performed in Abaqus. The bone was divided at every 5% bone length beginning distally. Statistical analysis was performed on maximum von Mises stresses in cortical and cancellous bone across each slice using one-way ANOVA (0-45% bone length) and paired t-tests (45-70% bone length). To quantify extent of stress shielding, average percentage change in stress from intact bone was also computed. Maximum stress was seen to occur distally and anteriorly above the coronoid fossa. Results indicated statistically significant differences between intact state and shorter megaprostheses relative to longer megaprostheses and proximally between intact and implanted bones. Varying levels of stress shielding were recorded across multiple slices for all megaprosthesis lengths. The degree of stress shielding increased with implant lengthening being 2-4 times in C and D compared to B. Axial loading of the humerus can occur with direct loading on outstretched upper limbs or indirectly through the elbow. Resultant stress shielding effect predicted in longer megaprosthesis models may become clinically relevant in repetitive axial loading during activities of daily living. It is recommended to use shorter megaprosthesis to prevent failure

The anatomy of the femur shows a high inter-patient variability, making it challenging to design standard prosthetic devices that perfectly adapt to the geometry of each individual. Over the past decade, Statistical Shape Models (SSMs) have been largely used as a tool to represent an average shape of many three-dimensional objects, as well as their variation in shape. However, no studies of the morphology of the residual femoral canal in patients who have undergone an amputation have been performed. The aim of this study was therefore to evaluate the main modes of variation in the shape of the canal, therefore simulating and analysing different levels of osteotomy. To assess the variability of the femoral canal, 72 CT-scans of the lower limb were selected. A segmentation was performed to isolate the region of interest (ROI), ranging from the lesser tip of the trochanter to the 75% of the length of the femur. The canals were then sized to scale, aligned, and 16 osteotomy levels were simulated, starting from a section corresponding to 25% of the ROI and up to the distal section. For each level, the main modes of variations of the femoral canal were identified through Principal Component Analysis (PCA), thus generating the mean geometry and the extreme shapes (±2 stdev) of the principal modes of variation. The shape of the canals obtained from these geometries was reconstructed every 10 mm, best- fitted with an ellipse and the following parameters were evaluated: i) ellipticity, by looking at the difference between axismax and axismin; ii) curvature of the canal, calculating the arc of circumference passing through the shapes’ centroids; iii) conicity, by looking at the maximum/minimum diameter; iv) mean diameter. To understand the association between the main modes and the shape variance, these parameters were compared, for each level of osteotomy, between the two extreme geometries of the main modes of variation. Results from PCA pointed out that the first three PCs explained more than the 87% of the total variance, for each level of simulated osteotomy. By analysing the extreme geometries for a distal osteotomy (e.g. 80% of the length of the canal), the first PC was associated to a combination of ROC (var%=41%), conicity (var%=28%) and ellipticity (var%=7%). PC2 was still associated with the ROC (var%=16%), while PC3 turned out to be associated with the diameter (var%=38%). Through the SSM presented in this study, a quantitatively evaluation of the deformation of the intramedullary canal has been made possible. By analysing the extreme geometries obtained from the first three modes of variance, it is clear that the first three PCs accounted for the variations in terms of curvature, conicity, ellipticity and diameter of the femoral canal with a different weight, depending on the level of osteotomy. Through this work, it was also possible to parametrize these variations according to the level of excision. The results given for the segment corresponding to the 80% of the length of the canal showed that, at that specified level, the ROC, conicity and ellipticity were the anatomical parameters with the highest range of variability, followed by the variation in terms of diameter. Therefore, the analysis carried out can provide information about the relevance of these parameters depending on the level of osteotomy suffered by the amputee. In this way, optimal strategies for the design and/or customization of osteo-integrated stems can be offered depending on the patient's residual limb

We evaluated the possible induction of a systemic immune response to increase anti-tumour activity by the re-implantation of destructive tumour tissue treated by liquid nitrogen in a murine osteosarcoma (LM8) model. The tumours were randomised to treatment by excision alone or by cryotreatment after excision. Tissue from the tumour was frozen in liquid nitrogen, thawed in distilled water and then re-implanted in the same animal. In addition, some mice received an immunological response modifier of OK-432 after treatment. We measured the levels of interferon-gamma and interleukin-12 cytokines and the cytotoxicity activity of splenocytes against murine LM8 osteosarcoma cells. The number of lung and the size of abdominal metastases were also measured. Re-implantation of tumour tissue after cryotreatment activated immune responses and inhibited metastatic tumour growth. OK-432 synergistically enhanced the anti-tumour effect. Our results suggest that the treatment of malignant bone tumours by reconstruction using autografts containing tumours which have been treated by liquid nitrogen may be of clinical value

Although most peripheral nerve sheath tumours are benign, some are malignant. The management of malignant tumours usually involves wide excision and is facilitated by knowledge of the diagnosis prior to operation. Imaging modalities, including MRI, give anatomical information but do not distinguish between benign and malignant nerve tumours. We therefore introduced the use of ultrasound guided needle biopsy for suspected nerve tumours to our unit in 2004. Prior to this, excision biopsy was carried out in all cases. We aimed to review our experience with needle biopsy and determine whether it has an effective role in the management of peripheral nerve tumours. All patients who had a needle biopsy for suspected peripheral nerve tumours from January 2004 to December 2011 were identified from our tumour database and clinical notes reviewed. In all cases, biopsy was carried out under ultrasound guidance with local anaesthesia to obtain a 1mm core of tissue. From 25 patients reviewed, 21 (84%) had a successful biopsy. In 3 cases the biopsy was unable to be completed due to pain and in 1 patient insufficient tumour tissue was obtained. 1 patient had a temporary radial nerve palsy following needle biopsy which recovered fully. In biopsies that were successful, 19 (90%) showed a benign peripheral nerve tumour. Following diagnosis of a benign lesion, only 2 patients required to have surgical excision of the tumour due to pain. The remainder were managed non-operatively. In the 2 cases of malignant tumours detected by biopsy, a successful wide surgical excision was performed. Ultrasound guided core needle biopsy appears safe and gives a tissue diagnosis in most cases of suspected peripheral nerve tumours. In malignant cases it facilitates surgical planning, while most benign tumours could be managed non-operatively, therefore avoiding potential complications of nerve surgery

Primary bone tumours of the clavicle are rare. Currently the existing literature is limited to a single case series and case reports or cases. Information regarding the patient's demographics and tumour types is therefore limited. The aim of this study was to investigate the and also suggest a management protocol for suspected primary bone tumours of the clavicle. We retrospectively reviewed the Scottish Bone Tumour Register from January 1971 to January 2012 and included all primary bone tumours of the clavicle. We identified only sixteen primary bone tumours over forty one year's highlighting the rarity of these tumours. There were ten benign and six malignant tumours with a mean age of 32 years (Range 4 to 66). The average presentation to orthopaedics after onset of symptoms was two months with five patients presenting following a pathological fracture. Malignant tumour types identified were consistent with previous literature with two cases of Ewing's sarcoma and osteosarcoma and a single case of osteosarcoma post radiotherapy and a single case of chondrosarcoma. Benign tumours were treated effectively with intralesional procedures. Malignant tumours were treated with wide local excision and subtotal or total clavicle excision. We suggest an investigatory and treatment protocol for patients with a suspected primary bone tumour of the clavicle. This is the largest series of primary bone tumours of the clavicle in the literature

Introduction. Hand tumors are usually rare and there is not much literature about series of cases. We have studied a series of 110 cases. Hand tumors do consists of both benign and malignant cases. Methods. We studied series of 110 cases at Karnataka Institute of Medical Sciences, Hubli and Mysore Medical College & Research Institute, Mysore. We retrospectively reviewed the records of 110 patients who underwent double ray amputations at our center over few years: few had amputations of the fourth and fifth rays and others amputation of the second and third rays. Mean age at surgery was 34 years (range, 10–45 years), and minimum follow up was 64 months (mean, 98 months; range, 64–136 months). Some patients had high-grade soft tissue sarcomas of the hand, synovial sarcomas, malignant peripheral nerve sheath tumors, and undifferentiated sarcoma. No patients had detectable metastases at surgery. Results. All patients were completely disease-free at latest follow up. One patient was alive with lung metastases detected 32 months after surgery. No patients developed local tumor recurrence. Functional assessment showed a mean Musculoskeletal Tumor Society score of 24 (range, 19–28) and mean grip strength 24% of the contra lateral side (range, 17%–35%). Conclusions. The majority of osseous tumors of the hand are benign. The surgeon who evaluates and treats osseous tumors of the hand has to be familiar with limb anatomy, tumor biology, various presentations of the tumors and the range of treatment possibilities and their limitations. Lesions in the hand more often present earlier in their course than those at other sites, just because they are more likely to superficial and easily noticed. Ganglion cyst is the most frequently encountered comprising 50–70% of benign tumors of hand. Enchondroma was the next common benign bone tumour followed by osteoid osteoma, osteoblastoma, aneurismal bone cyst, giant cell tumor, epidermoid cyst, and osteochondroma. Although malignant neoplasms in the hand that arise from tissues other than the skin are very rare, the hand may be the site of distant breast, lung, kidney, esophagus, or colon adenocarcinoma metastases, most of which have a predilection for the distal phalanges. Malignant tumours of the hand are rare, although there remain many instances in which marginal excisions are performed for unsuspected malignant hand lesions. Suboptimal biopsy incisions and inadvertent contamination during these excisions may result in larger resections or amputations being necessary to ensure complete removal of the tumour with negative margins

The Cobb Stainsby forefoot arthroplasty for claw and hammer toes combines excision arthroplasty (Stainsby) with extensor tendon transfer to the metatarsal head (Cobb). We present a retrospective, three surgeon case series of 218 toes in 128 patients over four years. Clinical notes were reviewed for all patients and 77 could be contacted for a telephone survey. Follow up ranged from 12–82 months. All patients presented with pain and shoe wear problems from dislocated metatarsophalangeal joints either from arthritis, hallux valgus, Freiberg's disease or neurological disorders. Ipsilateral foot procedures were performed simultaneously in 24 (30%) patients. Seventy-two patients (94%) were satisfied, 72 (94%) reported pain relief, 55 (71%) were happy with toe control, 61 (79%) were pleased with cosmesis, 59 (77%) returned to normal footwear and 56 (73%) reported unlimited daily activities. Minor complications occurred in 17 (13%) and 3 (2%) developed complex regional pain syndrome. Four (5%) developed recurrent clawing. The Stainsby procedure permits relocation of the plantar plate under the metatarsal head for cushioned weight-bearing but can create a floppy, unsightly toe. By combining this with the Cobb procedure, our case series demonstrates improved outcomes from either procedure alone with benefits over alternatives such as the Weil's osteotomy. Oxford Level 4 evidence – retrospective case series

Background. Radial head fractures are the commonest fractures involving the elbow. The goals of treatment are to restore stability, preserve motion, and maintain the relative length of the radius. Fortunately, most simple uncomplicated fractures can be treated non-operatively. Choosing between fixation and radial head replacement for comminuted fractures remains difficult. Excision of radial head fractures is not an ideal option in unstable elbow injuries. The purpose of this systematic review was to search for and critically appraise articles directly comparing functional outcomes and complications for fixation (open reduction internal fixation, ORIF) versus arthroplasty for comminuted radial head fractures (Mason type 3) in adults. Method. A comprehensive search of Medline, Embase and Cochrane databases using specific search terms and limits was conducted. Strict eligibility criteria were applied to stringently screen resultant articles. Three comparative studies were identified and reviewed. Results. Three comparative studies were identified and reviewed: two studies found significantly better Broberg & Morrey functional scores after replacement compared with ORIF in Mason type 3 fractures. The third study found no significant differences in Mayo functional score or range of motion, but did find that grip strength was better after ORIF. Complication rates were too heterogenous for conclusion. Conclusion. Fixation with good reduction may be attempted in unstable Mason type 3 fractures, and arthroplasty may be considered if this is not possible. Further randomised comparative trials are required to clarify the decision-making between fixation and replacement. Functional outcomes and complications were conflicting in the studies included here. Ideally, treatment decision should take into account elbow stability and degree of comminution

Background. Acetabular labral tears can cause pain and microinstability and are the most common indication for hip arthroscopy. Hip labral repair demonstrates better clinical outcome scores at a mean of 3.5 years post surgery than labral excision and tends to be performed in a younger age group. While different labral stitch configurations are possible, the most frequently used are a mattress stitch passed though the hip labrum at its widest part, or a simple loop surrounding the labrum. To determine the strength of variousrepair techniques and the impact suture passer sizesonhip labrum failure after cyclic loading. Methods. 35 unattached fresh-frozen bovine hip labrums were assigned to 5 repair techniques (7 specimens each): Group 1: horizontal mattress using a penetrating grasper; Group 2: vertical mattress using a penetrating grasper; Group 3: vertical mattress using asuture lasso; Group 4: Oblique repair using a penetrating grasper; Group 5: vertical mattress using a penetrating grasper and monopolar radio frequency device. Using a materials testing machine and after a 10N preload, each contruct was subjected to 20 cycles at 5N–80N. Cyclic elongation, peak-to-peak displacement, ultimate failure load, stiffness, and failure mode were recorded. Results. Group 1 (249N) had lower ultimate load than groups 2 (277N), 3 (289N), 4 (281N), and 5 (278N) (p<0.05) and higher peak to peak displacement, cyclic elongation (14mm) than group 3 (12mm) (p<0.05). Group 2 (15mm) had higher peak to peak displacement than group 3 (p<0.05). Group 3 had lower cyclic elongation and peak to peak displacements than group 4 (p<0.05). Conclusion. A horizontal mattress hip labrum repair demonstrates lower ultimate failure load than a vertical mattress or an oblique suture repair. A smaller diameter suture passing device demonstrated less cyclic displacement but no difference in ultimate failure load than a large diameter device. Radiofrequency treatment did not have any effect on the strength of the suture repair configuration. Level of evidence. Level 5

Bone grafts are crucial for the treatment of bone defects caused by tumor excision. The gold standard is autograft but their availability is limited. Allografts are an alternative, but there is a risk of rejection by the immune system. The tissue engineering field is trying to develop vascularized bone grafts, using innovative biomaterials for surgery applications. While the gold standard in bone graft in dentistry is the use of decellularized bovine bone particles (Bio-Oss®), our work has produced a polysaccharide-based composite matrix (composed of PUllulan, DextraNand particles of HydroxyApatite (PUDNHA), as a new scaffold for promoting bone formation and vascularization of the tissue. In the context of bone tissue regeneration, the function of osteoblast and endothelial cells has been extensively studied, while the impact of osteocytes has been regarded as secondary. Nonetheless, the osteocytes represent 90–95% of bone cells and are responsible for orchestration of bone remodeling. Here, we propose an original method to analyze the interaction between bone and biomaterials, after in vivo implantation of the matrix PUDNHA in an experimental sheep model. Our objectives are to analyze the network established by osteocytes in the newly formed tissue induced by the matrix, as well as their interactions with the blood vessels. Sheep have been implanted with the Bio-Oss® or the PUDNHA using the sinus lift technique. After 3 (3M) and 6 months (6M), the animals were euthanazied and the explants were fixed, analyzed by X-ray, embedded in Methylmetacrylate/Buthylmetacrylate and analyzed histologically by Trichrome staining. Thereafter, the samples (n=3/group) were polished using different sand papers. A final polish was realized using a 1µm Diamond polishing compound. The blocks were incubated 10 or 30s with 37% phosphoric acid to remove the mineral on the surface, then dipped in 2.6% sodium hypochlorite to remove the collagen. The samples were air dried overnight, metallized with Gold palladium the following day, before being imaged with a SEM. As expected, PUDNHA activates bone regeneration in this sinus lift model after 3M and 6M. X-ray analysis and histological data revealed more bone regeneration at 6M versus 3M in both groups. With this acid eching technique, we were able to visualize the interface of bone with the biomaterials. This treatment coupled with SEM analysis, confirmed the increase of bone formation with time of implantation in both groups. In addition, SEM images revealed that osteocyte alignment and their network were different in the new regenerated bone compared to the host bone. Moreover, images showed the direct contact of the osteocytes with the blood vessels formed in the new regenerated bone. This acid eching technique can be useful in the field of biomaterials to see the relationship between cells, blood vessels and the material implanted and understand how the new bone is forming around the different biomaterials

Mesenchymal stem cells (MSCs) are believed to be immune-privileged due to lack of antigen-presenting-cell related markers, however, evidence suggests that MSCs are immunogenic and are attacked by the immune system. Our research investigates the hypothesis that there are differences between MSC clones from the same individual in terms of their morphology, proliferation, differentiation and immune profile. Our goal is to discover immune-privileged stem cells, which can act as a universal allogenic mesenchymal stem cell donor to facilitate bone ingrowth for osteosarcoma patients status post tumor excision and prosthesis implantation. Serial dilutions of bone-marrow derived (BMMSCs) and adipose derived mesenchymal stem cells (ADMSCs) from same animal were carried out in order to isolate single-cell clones. From a single animal we obtained 3 clones from BMMSCs and 3 from ADMSCs. This procedure was repeated for another other 2 animals. The proliferation rate and cell doubling time of each clonal culture was measured. The proliferation rate of mixed clonal cultures was also measured. The tri-differentiation potential of the clonal cultures was compared and a comparison was also made with the original isolates from bone marrow and fat. The immune-privileged properties were measured by flow cytometry and immuno-staining for the major histocompatibility complex (MHC) antigens. To measure the immune response a mixed leucocyte reaction was used but where leucocytes from a different individual were mixed with the clonal MSC cells. All isolates were able to differentiate into osteoblasts, chondrocytes and adipocytes. All clonal cultures revealed significantly different proliferation rates and doubling times when compared with each other and with mixed cultures. All clonal cultures showed different surface marker presentations, which included differences in the expression of MHC antigens. One clone isolated from ADMSCs showed lack of MHCI and MHCII. Our mixed leucocyte reaction and MHC staining showed variety of immune-modulation and this was related to the expression of the MHC antigens. All clones tri-differentiated and therefore show a degree of ‘stemness’. MSCs are generally are believed not to express MHC II and to be immune-privileged. However, this study shows that the expression of these antigens in clones isolated from bone marrow and from fat is variable. A heterogeneous result indicates individual differences between MSCs, even from same origin. The immune response elicited by MSCs is complicated. MSCs have been shown to release interleukin 10, which could inhibit the immune response but on the other hand interferon-gamma could enhance MHCII presentation in some MSCs. Our results confirmed our hypothesis because clonal cultures isolated from different sources of MSCs in the same animal showed significant differences in proliferation rate, morphology and surface marker presentation. Mesenchymal stem cells are not immunogenic or immune-privileged. Individual differences highlighted through single-cell clonal cultures may be the key to finding a universal immune-privileged MSCs for allogeneic transplantation

For the treatment of irreparable meniscal injuries, we developed a novel multilayer meniscal scaffold, consisting of collagen, strontium and cellulose derived from Luffa Cylindirica; and we evaluated its effects on meniscal regeneration and arthritic changes in a rabbit partial meniscectomy model. The meniscus has a key role in shock absorbtion, load distribution, chondroprotection and stability of the knee joint. Meniscal injuries are one of the most common orthopedic injuries and may lead to degenerative cartilage changes and eventually osteoarthritis. Repair of the meniscal tissue is the treatment of choice for patients with a meniscus lesion, however, this is not always possible, especially for degenerative tears or injuries located on the inner avascular zone. To overcome the devastating outcomes of meniscectomy for such injuries, several materials have been developed and tried to replace the resected meniscal tissue. These scaffolds were designed primarily to relieve pain after meniscectomy, and later on were aimed to prevent osteoarthritis and cartilage damage that may develop in the future. In the quest for optimum scaffold material small intestine, tendons and other isolated tissues, collagen and polyurethane have been researched. Nevertheless, none of these materials have absolutely proven satisfying identical replacement of resected meniscal tissue. Therefore, we developed and investigated a novel multilayer meniscal scaffold, consisting of collagen, strontium and cellulose derived from Luffa Cylindirica (a cucumber shaped and sized plant, known as sponge gourd). The aim of the study was to evaluate the meniscal regeneration and arthritic changes after partial meniscectomy and application of novel multilayer meniscal scaffold in a rabbit model and to compare the results with clinically used polyurethane scaffold (Actifit, Orteq Ltd, London, UK). Sixteen male, mature, NewZealand rabbits weighing between 2600–3500 g were randomly divided into three groups. All groups underwent knee surgery via a medial parapatellar approach and a reproducible 1.5-mm cylindrical defect was created in the avascular zone of the anterior horn of the medial meniscus bilaterally. Defects were filled with the polyurethane scaffold in Group 1 and novel multilayer scaffold was applied to fill the defects in Group 2(n:6). Four rabbits in Group 3 did not receive any treatment and defects were left empty. Animals were sacrified after 8 weeks and bilateral knee joints were taken for macroscopic, biomechanical, and histological analysis. No signs of inflammation or infection were observed in all animals. Macroscopic evaluation of tibial plateaus after excision of menisci was performed with digital images of inked condylar surfaces. No significant degenerative changes were detected between groups. Digital photographs of excised menisci were also obtained and surface areas were measured by a computer software (Image J version 1.46, National Institute of Health, Bethesda, MD). There was a slightly larger meniscus area in the first two groups than the no treatment group, however, this was not found significant. Indentation testing of the tibial condyle and compression tests for the relevant meniscal areas with a diameter of 3mm was also performed in all groups. Histological analysis was made and all specimens were stained with safranin O and scored according to a scoring system. In this study, the initial evaluation of novel multilayer meniscal scaffold demonstrated promising biomechanical and histological results; besides no adverse events related to scaffold material was observed

Summary Statement. In this study we suggested a possible role of prion proteins genes in osteosarcoma. Therefore, the inhibition of prion proteins expression must be tested because it could represent a new approach to the molecular treatment of osteosarcoma. Introduction. Although osteosarcoma is the most common bone malignancy, the molecular and cellular mechanisms influencing its pathogenesis have remained elusive. Prion proteins (PRNP and PRND), known mostly for its involvement in neurodegenerative spongiform encephalopathies, have been recently demonstrated to be involved in resistance to apoptosis, tumorigenesis, proliferation and metastasis. Patients & Methods. The main aim of research was to study whether prion proteins were over-expressed in human osteosarcoma, and if prion proteins could have a role also in osteosarcomas. We evaluated differential gene expression between 22 cases of osteosarcoma and 40 cases of normal bone specimens through cDNA microarray analysis spanning a substantial fraction of the human genome. Results. PRNP and PRND are significantly over-expressed in osteosarcoma. PRNP and PRND appear involved with some important genes related to tumorigenesis and apoptosis. PRNP is linked to PTK2, RBBP9 and TGFB1 while PRND is linked to TNFSF10, BCL2A1, NFKB2 and TP53RK. Discussion/Conclusion. Increased expression on Affymetrix arrays of prion proteins seems to be associated with the development of osteosarcoma. Prions seem to induce a negative regulation of apoptosis, thus promoting osteosarcoma development and progression. Osteosarcoma is a very aggressive tumor and even after modern chemotherapy and excision of tumors efforts are needed to improve clinical outcome. Since Prion proteins seem to be related to osteosarcoma development, their inhibition could represent a new approach to the molecular treatment of osteosarcoma

Soft tissue balancing is critical to successful knee arthroplasty. Pre-operative planning ensures that the surgeon is prepared for any eventuality. We report a large femoral exostosis resulting in gross instability, requiring revision to a constrained implant. An 81 year old female presented with osteoarthritis of the left knee. Xray showed a medial bony mass. CT noted a large bony exostosis arising from the posteromedial femoral condyle. Review showed the exostosis was not related to the medial collateral ligament (MCL). At surgery, the exostosis was noted to be tenting the MCL – excision resulted in complete flaccidity. A trial of the Biomet AGC prosthesis revealed gross medial instability. The decision was taken to convert to a DePuy Sigma TC3 system. Whilst removing TC3 trial components, a lateral condyle fracture occurred. This was fixed with a 1/3 tubular plate and interfragmentary screw. The TC3 system and an AGC patellar button were found to be congruent. A small lateral release was performed, the deep MCL was replaced with tagging sutures through the MCL and the pes anserinus. At 9 weeks post operatively, the patient was pain free and mobilising independently. The knee was stable, with range of movement from 0 to 110 degrees. To our knowledge, this is the first report of such a complication in the literature. It highlights that despite optimal preoperative planning, the surgeon must be prepared to adapt to the situation at hand. It also highlights the importance of having ‘bail out’ options available on shelf when performing routine surgery