Osteoarticular Tissues Research Articles

Treatment of congenital syndactyly

Defined as the union of two adjacent digits, syndactyly is one of the most common congenital deformities. The severity of the malformation depends on the fusion level, the tissues involved in the union, and whether it is isolated or syndromic. In order to improve the hand's appearance and function, surgery is recommended in the great majority of cases, ideally during early childhood (i.e., before entering school). Web space reconstruction is done using local flaps. Depending on the flap design, digital resurfacing can be done with or without skin grafts. While graftless techniques have shorter operating times and no morbidity associated with skin harvesting, their cosmetic outcomes seem to be worse than those of traditional grafting techniques, with more postoperative complications; furthermore, such techniques cannot be used in all cases, especially those with osteoarticular fusions. When the fingertip is involved, paronychial reconstruction is carried out with pulp flaps. The prognosis for these deformities directly depends on their severity, with excellent outcomes in cases of cutaneous fusion, and much less predictable ones when osteoarticular and/or tendinous tissues are involved.

Short Interfering RNA (siRNA)-Based Therapeutics for Cartilage Diseases

Articular cartilage injury, as a hallmark of arthritic diseases, is difficult to repair and causes joint pain, stiffness, and loss of mobility. Over the years, the most significant problems for the drug-based treatment of arthritis have been related to drug administration and delivery. In recent years, much research has been devoted to developing new strategies for repairing or regenerating the damaged osteoarticular tissue. The RNA interference (RNAi) has been suggested to have the potential for implementation in targeted therapy in which the faulty gene can be edited by delivering its complementary Short Interfering RNA (siRNA) at the post-transcriptional stage. The successful editing of a specific gene by the delivered siRNA might slow or halt osteoarthritic diseases without side effects caused by chemical inhibitors. However, cartilage siRNA delivery remains a challenging objective because cartilage is an avascular and very dense tissue with very low permeability. Furthermore, RNA is prone to degradation by serum nucleases (such as RNase H and RNase A) due to an extra hydroxyl group in its phosphodiester backbone. Therefore, successful delivery is the first and most crucial requirement for efficient RNAi therapy. Nanomaterials have emerged as highly advantage tools for these studies, as they can be engineered to protect siRNA from degrading, address barriers in siRNA delivery to joints, and target specific cells. This review will discuss recent breakthroughs of different siRNA delivery technologies for cartilage diseases.

Salt Bridges Regulate in Silico Dimers Formation for β2-Microglobulin Amyloidogenic Variants

β2-microglobulin is a paradigmatic amyloidogenic protein responsible fordialysis-related amyloidosis, a disease associated to long-term hemodialyzedpatients and characterized by accumulation of amyloid deposits in the osteoar-ticular tissues. In the early stages of amyloid fibril formation, β2-microglobulinassociates into dimers and higher oligomers, but clarifications are still neededfor the triggering conditions, mechanisms and specificity of dimer forma-tion. To characterize the dimeric association process, the protein-proteininteractions between three different species are investigated: namely, thenative protein and the two amyloidogenic variants ΔN6 and D76N. Thedimerization process is rationalized relying on state of the art computationalmethods. A comparative mechanism for how different mutations in the threevariants can affect protein dimerization and thus fibril formation is proposed. The number of salt bridges involved at the protein-protein interface correlateswith the degree of amyloidogenicity of each individual species. The findingscan offer possible strategies in controlling the dimerization mechanism basedon different β2-microglobulin protein mutations, which have significant rolesin the fibrillogenical process.

2297. The Diagnostic Yield of 16/18S rRNA PCR of Sterile Site Samples in Pediatric Patients

Background16S ribosomal RNA (rRNA) and 18S rRNA gene polymerase chain reaction (16/18S PCR) with sequencing can provide expeditious bacterial or fungal pathogen identification from sterile site samples (cost $474/PCR). Our objective was to assess the utilization and diagnostic yield of 16/18S PCR of sterile site samples in pediatric patients.MethodsPatients’ sterile site fluid or direct tissue specimens were collected and cultured at Lurie Children’s Hospital of Chicago and sent to Northwestern Memorial Hospital for 16/18S PCR as clinically indicated. Clinical data were reviewed including PCRs, cultures, and medical conditions.Results16/18S PCR testing increased over the study period. In total, 177 samples were sent for 16S and/or 18S PCR from 146 patients (January 2016–April 2018). Osteoarticular, CSF, pleural fluid and organ tissue (n = 28; lung=19, chest mass=2, liver=2, spleen=2, etc.) sites were most frequent. The yield of 16/18S PCR by source is listed in Table 1. Twenty-eight of 156 samples for 16S PCR were positive (17.9%); 21 with a single organism ID, one with two organisms, and 6 indeterminate. (Table 2). Of negative 16S PCR samples, one grew Mycobacterium avium complex in culture. 18S PCR was performed on 108 unique samples; 7 were positive (6.5%, Table 3). For 4 positive 18S PCRs, a fungus also grew in culture with 3 concordant results and one discordant. Two negative 18S PCR samples grew molds (Phellinus spp.; Blastomyces dermatitidis). All patients (100%) with positive 18S PCR were immunocompromised compared with 21% (6/28) with positive 16S PCR. Both 16S and 18S PCRs were sent on 87 samples of which 16S PCR was positive in 5, 18S PCR was positive in 3, and none had both 16/18S PCRs positive.Conclusion16/18S PCR can provide important infectious pathogen diagnostics. 16S PCR should be sent only if bacterial culture is negative with higher yield sites being brain, abscess, pleural effusion, bone/joint and CSF. 16S PCR appears useful if an anaerobic pathogen is likely but conditions are not optimal for recovery. 18S PCR is highest yield in patients at risk of fungal disease. 16 and 18S PCRs were often sent together, likely reflexively. Selective or sequential testing may be advisable for most cases, guided by the clinical index of suspicion. Best practices to optimize resource utilization and clinical impact are evolving. Disclosures All authors: No reported disclosures.

Role of the autonomic nervous system in osteoarthritis.

Joint homeostasis is affected by local and systemic processes. Catecholaminergic and cholinergic fibers innervate the synovium, trabecular bone, and periosteum. Several studies have investigated the involvement of the autonomic nervous system (ANS) in joint homeostasis and the pathophysiology of osteoarthritis (OA). Various resident cells of osteoarticular tissues express receptors for sympathetic and parasympathetic neurotransmitters (norepinephrine/epinephrine and acetylcholine, respectively), which enables them to respond to autonomic stimuli. Furthermore, some of these cells are also able to synthesize neurotransmitters locally and secrete them, which may then act locally regardless of autonomic innervation. The sympathetic nervous system (SNS) is known for promoting bone loss, which has also been demonstrated in the subchondral bone during OA. However, it could interfere with other mechanisms in joint homeostasis. Indeed, intake of beta-blockers decreases pain sensation in individuals with OA; hence, the SNS could be one of the systemic links between hypertension and OA. Parasympathetic fibers may also be implicated in joint homeostasis and local control of inflammation. The vagus nerve has been found to have a strong anti-inflammatory action in other rheumatic diseases through the nicotinic alpha-7 receptor, which is locally expressed by most joint resident cells. Altogether, these data suggest that the ANS is involved in joint homeostasis and OA pathogenesis.

Selection of DNA Aptamer That Blocks the Fibrillogenesis of a Proteolytic Amyloidogenic Fragment of β2 m.

Dialysis-related amyloidosis (DRA) is a severe complication of hemodialysis that results in progressive destruction of bones and joints. Elevated concentrations of the β2 -microglobulin (β2 m) level in the serum of subjects on hemodialysis promote the formation of amyloid fibrils in osteoarticular tissues. β2 m lacking the N-terminal six residues of the mature protein (ΔN6β2 m) constitutes 25-30% of β2 m in ex vivo DRA amyloid. Unlike full-length wild-type β2 m, ΔN6β2 m forms amyloid fibrils at neutral pH in vitro. However, the role of ΔN6β2 m in DRA is, at present, poorly understood. In the present study, we screened novel phosphorothioate-modified aptamers directed against ΔN6β2 m using combinatorial chemistry in vitro. We identified 11 ΔN6β2 m aptamers; among the identified aptamers, clone #2, #8, and #10 aptamers had higher binding affinity to ΔN6β2 m than the others. Biolayer interferometry analysis revealed that KD values of clone #2, #8, and #10 aptamers were 56, 23, and 44nM, respectively. Furthermore, the clone #8 aptamer inhibited fibril formation in a dose-dependent manner, as assessed by Thioflavin T fluorescence assay. Fibrils formed from ΔN6β2 m bind to Congo red, displaying changes in the absorbance spectrum of the dye characteristic of binding to amyloid fibrils, which was completely blocked by treatment with clone #8 aptamer. These results suggest the potential of ΔN6β2 m aptamers as tools for elucidating co-assembly mechanisms in amyloid formation.

Scintigraphic imaging of Staphylococcus aureus infection using 99mTc radiolabeled aptamers

Staphylococcus aureus is a specie of great medical importance associated with many infections as bacteremia and infective endocarditis as well as osteoarticular, skin and soft tissue, pleuropulmonary, and device related infections. Early identification of infectious foci is crucial for successful treatment. Scintigraphy could contribute to this purpose since specific radiotracers were available. Aptamers due to their high specificity have great potential for radiopharmaceuticals development. In the present study scintigraphic images of S. aureus infectious foci were obtained using specific S. aureus aptamers radiolabeled with 99mTc.

A Simple Approach for Diagnosis of Chronic Tuberculous Osteomyelitis: A Case Report

Introduction: Osteomyelitis is a secondary complication in 1% to 3% of patients with pulmonary tuberculosis (TB). Definite diagnosis of TB-associated osteomyelitis is challenging for clinicians, as biopsies of deep osteoarticular tissues are necessary. Case Presentation: We present the case of a 50-year-old man, admitted to Imam Khomeini hospital, Tehran, Iran in March 2014. According to his self-report, he had a chronic ulcer on his left foot since September 2012. In physical examinations, there was a painful sinus tract orifice (2 × 2 cm) on the left medial malleolus. Magnetic resonance imaging (MRI) of the foot revealed osteomyelitis in the left ankle. Two biopsies were taken from the wound edge, and Mycobacterium tuberculosis was detected via polymerase chain reaction (PCR) assay. Conclusions: Today, in the diagnosis of TB-associated osteomyelitis, it is a common practice to obtain 3 osteoarticular tissue biopsies for microbiological evaluation, PCR analysis, and histopathological assessment. We suspect that biopsies from the edge of the sinus tract orifice may help diagnose TB osteomyelitis.

Clinical and epidemiological differences between implant-associated and implant-free orthopaedic infections.

Although there have been many publications regarding the risk factors for implant-associated orthopaedic infections, none have investigated how clinical presentations and epidemiology may differ between infections with and without osteosynthetic material. We pooled clinical data from several databases of adult patients with orthopaedic infections hospitalized at Geneva University Hospitals from January 2004 to December 2014. Among 2740 episodes of orthopaedic infections, 76% were implant-free osteoarticular or soft tissue infections. Among the 665 (24% of the total episodes) infections that involved osteosynthetic material, 319 (49%) were total joint arthroplasties, 143 single plates, and 50 single nails. The remainders were mixed implant infections, pins, wires, screws, cerclages or spondylodeses. The implant-associated, compared to the implant-free, infections were significantly more frequently associated with female sex, older age, bacteraemia and skin commensal infections, e.g. coagulase-negative staphylococci, corynebacteria or propionibacteria. In contrast, implant-associated infections were significantly less frequently associated with immune suppression, abscess formation, infections due to Staphylococcus aureus or streptococci, polymicrobial pathogens and foot infections. The serum CRP levels at admission were similar (median 82 vs. 75mg/L). Compared to implant-free infections, implant-associated orthopaedic infections are more likely monomicrobial, bacteraemic and due to skin commensals. They involve more often female and older patients, but are less often associated with immune suppression, abscess formation and foot infections.

Application of blistering cupping

Blistering cupping is special as eliminating wind and dampness as well as removing phlegm and blood stasis, and it achieves effects through suction. In this paper we reviewed relevant literature combined with clinical experience so as to summarize its operation attention through exploring the origin, mechanism and application. We divide the progress into the blistering period, the phlegm-stasis-eliminating period, and the escharosis period according to the changes of bubble and the things pulled out. Blistering cupping creates ways to eliminate concrete unhealthy influences through smoothing meridians and collaterals, such as phlegm and retained fluid, dampness and blood stasis. Thus chronic diseases are relieved. Also,we propose the rules of "blistering acupoints being related to disease location as well as the nature of acupoints and diseases". The therapy has been used to treat diseases of respiratory system, osteoarticular, skin and subcutaneous tissue, mental and behavioral disorders, and tumor, among which the effects of intractable diseases of respiratory and osteoarticular systems are definite. It deserves to be further explored and promoted.

Pathophysiological Mechanisms of Staphylococcus Non-aureus Bone and Joint Infection: Interspecies Homogeneity and Specific Behavior of S. pseudintermedius.

Implicated in more than 60% of bone and joint infections (BJIs), Staphylococci have a particular tropism for osteoarticular tissue and lead to difficult-to-treat clinical infections. To date, Staphylococcus aureus internalization in non-professional phagocytic cells (NPPCs) is a well-explored virulence mechanism involved in BJI chronicity. Conversely, the pathophysiological pathways associated with Staphylococcus non-aureus (SNA) BJIs have scarcely been studied despite their high prevalence. In this study, 15 reference strains from 15 different SNA species were compared in terms of (i) adhesion to human fibronectin based on adhesion microplate assays and (ii) internalization ability, intracellular persistence and cytotoxicity based on an in vitro infection model using human osteoblasts. Compared to S. aureus, S. pseudintermedius was the only species that significantly adhered to human fibronectin. This species was also associated with high (even superior to S. aureus) internalization ability, intracellular persistence and cytotoxicity. These findings were confirmed using a panel of 17 different S. pseudintermedius isolates. Additionally, S. pseudintermedius internalization by osteoblasts was completely abolished in β1 integrin-deficient murine osteoblasts. These results suggest the involvement of β1 integrin in the invasion process, although this mechanism was previously restricted to S. aureus. In summary, our results suggest that internalization into NPPCs is not a classical pathophysiologic mechanism of SNA BJIs. S. pseudintermedius appears to be an exception, and its ability to invade and subsequently induce cytotoxicity in NPPCs could explain its severe and necrotic forms of infection, notably in dogs, which exhibit a high prevalence of S. pseudintermedius infection.

Insights on the properties of levofloxacin-adsorbed Sr- and Mg-doped calcium phosphate powders.

Several types of biodegradable materials have been investigated for the treatment of osteomyelitis. Calcium phosphate (CaP) ceramics are among the most performing materials due to their resemblance to human hard tissues in terms of mineralogical composition, and proven ability to adsorb and deliver a number of drugs. This research work was intended to study the suitability of modified CaP powders loaded with a fluoroquinolone as drug delivery systems for osteomyelitis treatment. Levofloxacin (LEV) was chosen due to the well-recognized anti-staphylococcal activity and adequate penetration into osteoarticular tissues. Substituted CaP powders (5mol% Sr(2+) or 5mol% Mg(2+)) were synthesised through aqueous precipitation. The obtained powders were characterised by X-ray diffraction, SEM and FTIR analysis. The X-ray diffraction patterns confirmed the presence of HA and β-tricalcium phosphates (β-TCP) phases in doped compositions, especially in the case of Mg-doped system. The fixation of LEV at the surface of the particles occurred only by physisorption. Both the in vitro microbiological susceptibility, against Staphylococcus spp, and biocompatibility of LEV-loaded CaP powders have not been compromised.

Interferon-γ Autoantibodies as Predisposing Factor for Nontuberculous Mycobacterial Infection

Interferon-γ Autoantibodies as Predisposing Factor for Nontuberculous Mycobacterial Infection

Treatment With Dithiothreitol Improves Bacterial Recovery From Tissue Samples in Osteoarticular and Joint Infections

BackgroundProsthetic implants, periprosthetic and osteoarticular tissues are specimens of choice for diagnosis of bone and joint infections. Homogenization is considered the best procedure for treatment of tissues samples, but, it is not always performed in all laboratories. Dithiothreitol (DTT) has been proposed as an alternative treatment to sonication for microbiological diagnosis of prosthetic joint infections. In this study, the applicability of DTT treatment for processing of periprosthetic and osteoarticular tissues for diagnosis of bone and joint infections was evaluated and compared with normal saline solution treatment. MethodsPeriprosthetic tissue samples were collected from 70 consecutive patients (25 infected and 45 not infected). For each patient, samples from the same site were randomly allocated to DTT or saline treatment. Treated samples were centrifuged at 3000 rpm for 10 minutes. Aliquots from the concentrated samples were plated on agar plates and inoculated in broths. Sensitivity and specificity were calculated for each treatment. ResultsMicrobial growth was observed in samples from 14 and 11 infected patients after DTT and saline treatments, respectively. Concordance between the 2 methods was observed in the 85.7% of cases. Sensitivity was 88.0% for DTT and 72.0% for saline. Specificity was 97.8% and 91.1% for DTT and saline, respectively. Treatment with DTT showed higher sensitivity and specificity with respect to the method routinely used in our laboratory. ConclusionDTT treatment may be considered a practicable strategy for microbiological analysis of tissues for diagnosis of bone and joint infections.

Estudio y valoración de los cambios introducidos en el nuevo baremo relativos a las secuelas traumatológicas en los cuatro miembros

The orthopaedic sequelae affecting any of the members of the sections are of more prevalence and interest in the valuation of bodily harm. They are usually present in any multisystem trauma patients as well in any kind of aggression in both the aggressor and the aggrieved. These aftereffects result from any damage or injury either osteo-articular soft tissue either of the aforementioned members. Whatever the damaged structure the result will be a deficit or limitation in mobility in this segment with the consequent loss of function. When we use the word ‘deficit’ we are referring to any type of residual state (amputation, joint limitation, stiffness, deviation, pains, etc.) altering and impairing the functionality of that member. The purpose of this scale is none other than to serve the coroner to frame and weigh any sequel with the sole purpose of ‘trying’ to financially compensate the injured. This scale object of this study has been able to improve the above in certain respects. It has been rearranged and has added different effects that did not exist in the previous one, and improved their score in both the average value and the limits of each range to avoid any overlaps. However, there is no uniformity in the joint sequels, the burden of some of them is not adequately assessed and there are gaps in relation to certain deficits and deformities that are not included in this new scale.

Endocytosed β2-Microglobulin Amyloid Fibrils Induce Necrosis and Apoptosis of Rabbit Synovial Fibroblasts by Disrupting Endosomal/Lysosomal Membranes: A Novel Mechanism on the Cytotoxicity of Amyloid Fibrils

Dialysis-related amyloidosis is a major complication in long-term hemodialysis patients. In dialysis-related amyloidosis, β2-microglobulin (β2-m) amyloid fibrils deposit in the osteoarticular tissue, leading to carpal tunnel syndrome and destructive arthropathy with cystic bone lesions, but the mechanism by which these amyloid fibrils destruct bone and joint tissue is not fully understood. In this study, we assessed the cytotoxic effect of β2-m amyloid fibrils on the cultured rabbit synovial fibroblasts. Under light microscopy, the cells treated with amyloid fibrils exhibited both necrotic and apoptotic changes, while the cells treated with β2-m monomers and vehicle buffer exhibited no morphological changes. As compared to β2-m monomers and vehicle buffer, β2-m amyloid fibrils significantly reduced cellular viability as measured by the lactate dehydrogenase release assay and the 3-(4,5-di-methylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction assay and significantly increased the percentage of apoptotic cells as measured by the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling method. β2-m amyloid fibrils added to the medium adhered to cell surfaces, but did not disrupt artificial plasma membranes as measured by the liposome dye release assay. Interestingly, when the cells were incubated with amyloid fibrils for several hours, many endosomes/lysosomes filled with amyloid fibrils were observed under confocal laser microscopy and electron microscopy, Moreover, some endosomal/lysosomal membranes were disrupted by intravesicular fibrils, leading to the leakage of the fibrils into the cytosol and adjacent to mitochondria. Inhibition of actin-dependent endocytosis by cytochalasin D attenuated the toxicity of amyloid fibrils. These results suggest that endocytosed β2-m amyloid fibrils induce necrosis and apoptosis by disrupting endosomal/lysosomal membranes, and this novel mechanism on the cytotoxicity of amyloid fibrils is described.

Treatment Outcomes with Cefazolin versus Oxacillin for Deep-Seated Methicillin-Susceptible Staphylococcus aureus Bloodstream Infections

Clinical preference for a semisynthetic penicillin (oxacillin or nafcillin) over cefazolin for deep-seated methicillin-susceptible Staphylococcus aureus (MSSA) bloodstream infections (BSI) perseveres despite limited data to support this approach. A retrospective cohort study of patients treated for MSSA BSI with either oxacillin or cefazolin was performed across two medical centers in Chicago, IL. The outcome measures included documented in-hospital treatment failure, all-cause in-hospital mortality, duration of MSSA BSI, and incidence of documented adverse events. Of 161 patients with MSSA BSI, 103 (64%) received cefazolin, and 58 (36%) received oxacillin. The identified sources of BSI were central line (37.9%), osteoarticular (18%), and skin and soft tissue (17.4%). Patients with endocarditis (29/52 [44.2%]) and other deep-seated infections (23/52 [55.8%]) were classified under the subset of deep-seated infections (52/161 [32.3%]). Multivariate models found deep-seated infection (adjusted odds ratio [aOR], 4.52; 95% confidence interval [CI], 1.23 to 16.6; P = 0.023), metastatic disease (aOR, 4.21; 95% CI, 1.13 to 15.7; P = 0.033), and intensive care unit (ICU) onset of infection (aOR, 4.80; 95% CI, 1.26 to 18.4; P = 0.022) to be independent risk factors for in-hospital treatment failure. Treatment group was not an independent predictor of failure (aOR, 3.76; 95% CI, 0.98 to 14.4; P = 0.053). The rates of treatment failure were similar among cefazolin-treated (5/32 [15.6%]) and oxacillin-treated (4/20 [20.0%]) patients (P = 0.72) in the subset of deep-seated infections. Mortality was observed in 1 (1%) and 3 (5.2%) cases of cefazolin- and oxacillin-treated patients, respectively (P = 0.13). Cefazolin was not associated with higher rates of treatment failure and appears to be an effective alternative to oxacillin for treatment of deep-seated MSSA BSI.

Staphylococcus aureus infections: epidemiology, pathophysiology, clinical manifestations, and management.

Staphylococcus aureus is a major human pathogen that causes a wide range of clinical infections. It is a leading cause of bacteremia and infective endocarditis as well as osteoarticular, skin and soft tissue, pleuropulmonary, and device-related infections. This review comprehensively covers the epidemiology, pathophysiology, clinical manifestations, and management of each of these clinical entities. The past 2 decades have witnessed two clear shifts in the epidemiology of S. aureus infections: first, a growing number of health care-associated infections, particularly seen in infective endocarditis and prosthetic device infections, and second, an epidemic of community-associated skin and soft tissue infections driven by strains with certain virulence factors and resistance to β-lactam antibiotics. In reviewing the literature to support management strategies for these clinical manifestations, we also highlight the paucity of high-quality evidence for many key clinical questions.

Novel doped calcium phosphate-PMMA bone cement composites as levofloxacin delivery systems

Antibiotic-loaded acrylic bone cements (ALABCs) are well-established and cost-effective materials to control the occurrence of bone and joint infections. However, the inexistence of alternative antibiotics other than those already commercially available and the poor ability to bind to bone tissue hampering its biological function are still major drawbacks of ALABCs clinical application. The concept of this research work is to develop a novel bone cement (BC) drug delivery system composed by Mg- and Sr-doped calcium phosphate (CaP) particles as drug carriers loaded into a lactose-modified acrylic BC, which, to the best of our knowledge, has never been reported. CaP particles are known to promote bone ingrowth and current research is focused on using these carriers as antibiotic delivery systems for the treatment of bone infections, like osteomyelitis. Levofloxacin is a fluoroquinolone with anti-staphylococcal activity and adequate penetration into osteoarticular tissues and increasingly being recommended to manage bone-related infections. Also, the lactose-modified BC matrix, with a more porous structure, has already proved to enhance antibiotic release from the BC inner matrix. This novel BC composite biomaterial has shown improved mechanical integrity, biocompatibility maintenance, and sustained release of levofloxacin, with concentrations over the minimum inhibitory concentration values after a 48h while maintaining antibacterial activity over an 8-week period against Staphyloccocus aureus and Staphyloccocus epidermidis, common pathogens associated with bone infections.

Living donor bone banking: processing and discarding--from procurement to therapeutic use.

Skeletal muscle and osteoarticular tissue banks are responsible to procure, process, store and distribute tissues, from living and cadaveric donors. The procedures involve the application of protocols covering all aspects of the banking, ensuring the best tissue quality and maximum safety for the recipient. An analysis on the causes of bone tissue discarded by Biotar Tissue Bank between January 2005 and December 2012 was carried. Bone tissue was obtained from both hip and knee replacement (femoral heads and tibial plateau respectively) in living donors treated at different medical-surgical institutions in Argentina. These tissues were processed at the Bank to produce both frozen and lyophilized cancellous bone. Out of 3413 donated bones received by the Bank, 77.55% resulted in final product, while the remaining 22.44% was discarded in compliance with the quality standards of both the Bank and the regulatory authority. Comparing the last and the first year of the studied period, the number of discarded tissue increased 3.6 times, while the number of collected bones was approximately 10 times higher. Related to total disposed tissue, reactive serology was the most frequent cause (62.14%), followed by inappropriate collection/storage of blood sample (30.81%). A progressive reduction in the percentages of total discard was observed, and this was proportional to inappropriate collection/storage of blood sample. No significant differences were found in the discard rates due to positive serology throughout all the years studied. The success of a tissue bank requires full commitment of all the personnel especially the team members responsible for donor selection and the processing of allografts. It is important to critically screen donors in the early stages of donor recruitment. All of the procedures carried out by the tissue bank are parts of the quality control system which must be strictly carried out. Biotar Tissue Bank is continuously committed to ensure safety to the recipients.