Comparison of synthetic ceramic products formulated with autologous blood coagulum containing rhBMP6 for induction of bone formation.

PURPOSE: Osteogrow, an osteoinductive device containing recombinant human Bone Morphogenetic Protein 6 (rhBMP6) in autologous blood coagulum, is a novel therapeutic solution for bone regeneration. This study aimed to evaluate different commercially available calcium phosphate synthetic ceramic particles as a compression-resistant matrix (CRM) added to Osteogrow implants to enhance their biomechanical properties. METHODS: Osteogrow implants with the addition of Vitoss, ChronOs, BAM, and Dongbo ceramics (Osteogrow-C, where C stands for ceramics) were evaluated in the rodent subcutaneous ectopic bone formation assay. Osteogrow-C device was prepared as follows: rhBMP6 was added to blood, and blood was mixed with ceramics and left to coagulate. Osteogrow-C was implanted subcutaneously in the axillary region of Sprague-Dawley rats and the outcome was analyzed 21 days following implantation using microCT, histology, morphometric analyses, and immunohistochemistry. RESULTS: Osteogrow-C implants with all tested ceramic particles induced the formation of the bone-ceramic structure containing cortical bone, the bone between the particles, and bone at the ceramic surfaces. The amount of newly formed bone was significant in all experimental groups; however, the highest bone volume was measured in Osteogrow-C implants with highly porous Vitoss ceramics. The trabecular number was highest in Osteogrow-C implants with Vitoss and ChronOs ceramics while trabeculae were thicker in implants containing BAM and Dongbo ceramics. The immunological response and inflammation were comparable among ceramic particles evaluated in this study. CONCLUSION: Osteogrow-C bone regenerative device was effective with a broad range of commercially available synthetic ceramics providing a promising therapeutic solution for the regeneration of long bone fracture nonunion, large segmental defects, and spinal fusion surgeries.

Association of the matrix metalloproteinase 3 (MMP3) single nucleotide polymorphisms with tendinopathies: case-control study in high-level athletes.

BACKGROUND: Matrix metalloproteinases (MMPs) play an important role in matrix remodelling, as well as in tendon integrity. Due to overuse, athletes often develop chronic tendinopathies. If not treated, they lead to severe impairment, even complete tendon ruptures. AIM: The main purpose of this study was to investigate whether three functional polymorphisms within the MMP3 gene are associated with increased risk of developing tendinopathies in high-level Croatian athletes. METHODS: We have recruited one hundred fifty-five (63 high-level athletes with diagnosed tendinopathies and 92 asymptomatic controls) unrelated Caucasians for this case-control genetic study. All participants were genotyped for three single nucleotide polymorphisms (SNP) within the MMP3 gene: rs591058 C/T, rs650108 A/G and rs679620 G/A using the pyrosequencing method. RESULTS: The MMP3 rs650108 GG (P = 0.0074) and rs679620 AA (P = 0.0119) genotypes were significantly over-represented in cases compared with controls, while rs591058 TT (P = 0.0759), as well as haplotype variant T - G - A (P = 0.06), implicated that there is an indication of predisposition for tendinopathies. CONCLUSION: These results support association between functional variants within the MMP3 gene and the risk of tendinopathies in high-level athletes. Further research is needed to replicate these results in a larger population.

Importance of shear-wave elastography in prediction of Achilles tendon rupture.

PURPOSE: It was demonstrated that about 6% of patients with a ruptured Achilles tendon experience the rupture of contralateral tendon in the future; the aim of this study was to estimate the risk for rupture of contralateral tendon in patients who underwent surgical reconstruction of ruptured Achilles tendon by using subjective questionnaires and shear-wave elastography. METHODS: Twenty-four patients who underwent surgical repair of the ruptured Achilles tendon and twelve age-matched healthy controls were examined with ultrasound SWE. Functional outcomes were assessed with American Orthopedic Foot and Ankle Society (AOFAS) scoring system and subjective rating system which we introduced and validated. RESULTS: The elasticity of injured tendon was markedly decreased (by 42%) compared to the contralateral tendon of the patient, as expected. Both AOFAS score and our novel subjective assessment scale positively correlate with ultrasound SWE values in ruptured Achilles tendons. The elasticity of contralateral Achilles tendons in patients was 23% lower than among healthy individuals. CONCLUSION: Irrespective of the lack of difference in the subjective feeling assessed by AOFAS, the contralateral tendon in the patients with reconstructed Achilles tendon has significantly lower stiffness than healthy individuals. Therefore, contralateral tendons in patients who suffered from rupture are more prone to future ruptures.

Synthetic ceramic macroporous blocks as a scaffold in ectopic bone formation induced by recombinant human bone morphogenetic protein 6 within autologous blood coagulum in rats.

PURPOSE: We have recently developed an autologous bone graft substitute (ABGS) containing recombinant human bone morphogenetic protein 6 (rhBMP6) in autologous blood coagulum (ABC) that induces new bone formation in vivo. In order to improve biomechanical properties of the implant, compression resistant matrix (CRM) consisting of synthetic ceramics in the form of macroporous cylinders was added to the ABGS and we evaluated the biomechanical properties and the quantity and quality of bone formation following subcutaneous implantation in rats. METHODS: ABGS implants containing rhBMP6 in ABC with cylindrical ceramic blocks were implanted subcutaneously (n = 6 per time point) in the axillary region of Sprague-Dawley rats and removed at specified time points (7, 14, 21, 35, and 50 days). The quantity and quality of newly formed bone were analyzed by microCT, histology, and histomorphometric analyses. Biomechanical properties of ABGS formulations were determined by employing the cut test. RESULTS: MicroCT analyses revealed that ABGS implants induced formation of new bone within ceramic blocks. Histological analysis revealed that on day seven following implantation, the endochondral ossification occupied the peripheral part of implants. On days 14 and 21, newly formed bone was present both around the ceramic block and through the pores inside the block. On both days 35 and 50, cortical bone encircled the ceramic block while inside the block, bone covered the ceramic surface surrounding the pores. Within the osseous circles, there were few trabeculae and bone marrow containing adipocytes. ABGS containing cylindrical ceramic blocks were more rigid and had significantly increased stiffness compared with implants containing ceramic particles as CRM. CONCLUSION: We demonstrated that macroporous ceramic blocks in a form of cylinders are promising CRMs with good handling and enhanced biomechanical properties, supporting bone formation with ABGS containing rhBMP6 within autologous blood coagulum. Hence, ABGS containing ceramic blocks should be tested in preclinical models including diaphyseal segmental defects and non-unions in larger animals.

Bone morphogenetic proteins in fracture repair.

Bone fractures represent a significant medical morbidity among aged population with osteoporosis. Bone morphogenetic proteins (BMPs) are suggested to have therapeutic potential to enhance fracture healing in such patients. Though BMP-mediated fracture healing has been well-documented in preclinical models, there has been no clinical study that demonstrated unequivocally that indeed a BMP when presented with an appropriate scaffold could provide basis for robust outcome for delayed or non-union diaphyseal bone fractures. This review presents a comprehensive insight towards the existing knowledge on the role of BMP signaling in bone formation and maintenance. Also therapeutic options based on BMP biology are discussed.A novel osteoinductive autologous bone graft substitute (ABGS) aimed to accelerate bone regeneration was developed and is currently being tested in the clinical setting. It comprises of a biologically compatible autologous carrier made from the patient's peripheral blood (autologous blood coagulum, ABC) and of rhBMP6 as an active ingredient. Such formulation circumvents the use of animal-derived materials, significantly limits inflammatory processes common in commercial bone devices and renders the carrier flexible, malleable, and injectable ensuring the ease of use. The ongoing clinical trials result will provide more detailed insights into the safety, tolerability, pharmacokinetics, and bone healing effects in humans and potentially provide novel and safe therapeutic options for bone repair.

NOTALGIA PARESTHETICA.

- Notalgia paresthetica is a common, although under-recognized condition characterized by localized chronic pruritus in the upper back, most often affecting middle-aged women. Apart from pruritus, patients may present with a burning or cold sensation, tingling, surface numbness, tenderness and foreign body sensation. Additionally, patients often present with hyperpigmented skin at the site of symptoms. The etiology of this condition is still poorly understood, although a number of hypotheses have been described. It is widely accepted that notalgia paresthetica is a sensory neuropathy caused by alteration and damage to posterior rami of thoracic spinal nerves T2 through T6. To date, no well-defined treatment has been found, although many treatment modalities have been reported with varying success, usually providing only temporary relief.

Marshall R. Urist and the discovery of bone morphogenetic proteins.

Over the last 40 years International Orthopaedics has published a series of articles on bone morphogenetic proteins (BMPs) covering topics from basic research to clinical applications. This includes also work submitted from the Laboratory for Mineralized Tissues of the School of Medicine University of Zagreb. Accordingly, we felt obliged to give a short summary of Dr. Urist's life and work as our gratitude to his discovery that demineralized bone matrix (DBM) activity induces bone when implanted ectopically into the muscle or under the skin due to bone inducing proteins, named BMPs.

Capacity of muscle derived stem cells and pericytes to promote tendon graft integration and ligamentization following anterior cruciate ligament reconstruction.

PURPOSE: The aim of this study is to examine the capacity of muscle tissue preserved on hamstring tendons forming candy-stripe grafts in order to improve tendon to bone ingrowth and ligamentization. We hypothesized that muscle tissue does possess a stem cell population that could enhance the healing process of the ACL graft when preserved on the tendons. METHODS: Human samples from gracilis and semitendinosus muscles were collected during ACL surgery from ten patients and from these tissue samples human muscle-derived stem cells and tendon-derived stem cells were isolated and propagated. Both stem cell populations were in-vitro differentiated into osteogenic lineage. Alkaline phosphatase activity was determined at days zero and 14 of the osteogenic induction and von Kossa staining to assess mineralization of the cultures. Total RNA was collected from osteoblast cultures and real time quantitative PCR was performed. Western-blot for osteocalcin and collagen type I followed protein isolation. Immunofluorescence double labeling of pericytes in muscle and tendon tissue was performed. RESULTS: Mesenchymal stem cells from muscle and tendon tissue were isolated and expanded in cell culture. More time was needed to grow the tendon derived culture compared to muscle derived culture. Muscle derived stem cells exhibited more alkaline phosphatase actvity compared to tendon derived stem cells, whereas tendon derived stem cells formed more mineralized nodules after 14 days of osteoinduction. Muscle derived stem cells exhibited higher expression levels of bone sialoprotein, and tendon derived stem cells showed higher expression of dental-matrix-protein 1 and osteocalcin. Immunofluorescent staining against pericytes indicated that they are more abundant in muscle tissue. CONCLUSIONS: These results indicate that muscle tissue is a better source of stem cells than tendon tissue. Achievement of this study is proof that there is vast innate capacity of muscle tissue for enhancement of bone-tendon integration and ligamentization of ACL hamstring grafts and consequently muscle tissue should not be treated as waste after harvesting.

Only one health, and so many omics.

The development of new approaches based on wide profiling methods in studying biological and medical systems is bringing large amounts of data on a daily basis. The causes of complex diseases have been directed to the genome examination bringing formidable knowledge. We can study genome, but also proteome, exome, transcriptome, epigenome, metabolome, and newcomers too such as microbiome, connectome and exposome. The title of this editorial is paraphrasing the famous saying of Victor Schlichter from Buenos Aires children hospital in Argentina who said "How unfair! Only one health, and so many diseases". Today there is indeed a whole lot of omics. We think that we are lucky to have all the omics possible, but we also wanted to stress the importance of future holistic approach in integrating the knowledge omics has rewarded us.

Impact and alternative metrics for medical publishing: our experience with International Orthopaedics.

PURPOSE: This paper compares the traditional tools of calculation for a journal's efficacy and visibility with the new tools that have arrived from the Internet, social media and search engines. The examples concern publications of orthopaedic surgery and in particular International Orthopaedics. METHODS AND RESULTS: Until recently, the prestige of publications, authors or journals was evaluated by the number of citations using the traditional citation metrics, most commonly the impact factor. Over the last few years, scientific medical literature has developed exponentially. The Internet has dramatically changed the way of sharing and the speed of flow of medical information. New tools have allowed readers from all over the world to access information and record their experience. Web platforms such as Facebook® and Twitter® have allowed for inputs from the general public. Professional sites such as LinkedIn® and more specialised sites such as ResearchGate®, BioMed Central® and OrthoEvidence® have provided specific information on defined fields of science. Scientific and professional blogs provide free access quality information. Therefore, in this new era of advanced wireless technology and online medical communication, the prestige of a paper should also be evaluated by alternative metrics (altmetrics) that measure the visibility of the scientific information by collecting Internet citations, number of downloads, number of hits on the Internet, number of tweets and likes of scholarly articles by newspapers, blogs, social media and other sources of data. CONCLUSIONS AND DISCUSSION: This article provides insights into altmetrics and informs the reader about current tools for optimal visibility and citation of their work. It also includes useful information about the performance of International Orthopaedics and the bias between traditional publication metrics and the new alternatives.

Acute and chronic injuries among senior international rowers: a cross-sectional study.

PURPOSE: The aim of the study was to define the types of musculoskeletal injuries present in senior international rowers. According to the literature, no such study has been performed in this group. METHODS: Injury data were obtained from a total of 634 rowers (33 % female, 67 % male) who completed a 12-month retrospective questionnaire on injury incidence while participating in the Senior World Rowing Championships in Munich, Germany, in 2007. RESULTS: The mean injury rate per one year was 0.92 injuries per rower (1.75 injuries per 1,000 training sessions per rower). The vast majority of self-reported injuries were chronic injuries (acute vs chronic ratio was 1:2.63), and the majority of reported injuries did not result in loss of time from training or competition. Of all acute injuries, 58.1 % were sustained during rowing-specific training, with 20.6 % injuries sustained in the gym and 21.3 % during cross-training. The most common site of injury was the low back followed by the knee and the chest/thoracic spine. Senior open weight rowers who sustained chronic injuries achieved significantly better final ranking at the 2007 Senior World Rowing Championships compared to the same group of rowers who did not sustain any injury. CONCLUSION: Senior international rowers participating in World Rowing Championships sustained predominantly chronic (overuse) injuries during the rowing season studied. Those were mainly low severity injuries, with the low back being the most frequently injured site. This study may will help in prevention and early diagnosis of eventual injuries in top-level rowers.

Biological aspects of segmental bone defects management.

Segmental bone defect management is among the most demanding issues in orthopaedics and there is a great medical need for establishing an appropriate treatment option. Tissue transfer, including bone autografts or free flaps, depending on the size of the bone deficiency, is currently the "gold standard" for treatment of such defects. Osteogenic cells in combination with adequate growth factors and a suitable scaffold, from the aspect of osteoinductivity, osteoconductivity and mechanical stability, are mandatory to successfully restore a bone defect as determined in the "diamond concept". Our current knowledge on this topic is limited and mostly based on retrospective studies, case reports and a few small randomised clinical trials due to the lack of large and accurately designed randomised clinical trials using novel approaches to regenerative orthopaedics. However, preclinical research on different animal models for critical size defects is abundant, showing emerging candidate cells and cytokines for defect rebridgement. In this article we provide an overview on existing clinical studies and promising preclinical experiments that utilised osteogenic cells, growth factors and biomaterials, as well as their combination for repair of segmental bone defects.

The Balkan beam - Florschütz frame and its use during the Great War.

We remember the military medical practice of Croatian surgeon, Vatroslav Florschütz (1879-1967), known for his invention of the traction frame for repositioning bone fracture fragments of the upper and lower extremities. The method, known as the Balkan frame / beam or Balkan splint, was introduced and published in 1911 and used in war medicine thereafter. The memory of this invention adds to our orthopaedic heritage and sheds light on its creator working under the most demanding war circumstances. On the occasion of the 100th anniversary of the outbreak of World War I, reminiscence of Florschütz's war experience, his orthopaedic innovation and other innovations contributes to our understanding of human efforts to save lives and restore bodily function of the wounded during wars.

Setting standards for medical writing in orthopaedics.

Once the privilege of few clinical scholars in the field of orthopaedics, medical writing has become a must for career advancement. The number of papers submitted and published yearly has increased steadily, and with the development of the Internet, manuscript and journals have become easily accessible. Medical writing has risen to become a discipline in itself, with rules and standards. However, heterogeneity in the quality of papers submitted still prevails, with large variations in both form and content. With countries such as China and India submitting an exponential number of manuscripts, it is important and helpful that standards of medical writing be emphasised to help writers who do not always have the required support to produce an outstanding manuscript. In this paper, we summarise what may become standards for medical writing in the field of orthopaedics.

The clinical use of bone morphogenetic proteins revisited: a novel biocompatible carrier device OSTEOGROW for bone healing.

PURPOSE: The purpose of this study was to revise the clinical use of commercial BMP2 (Infuse) and BMP7 (Osigraft) based bone devices and explore the mechanism of action and efficacy of low BMP6 doses in a novel whole blood biocompatible device OSTEOGROW. METHODS: Complications from the clinical use of BMP2 and BMP7 have been systemically reviewed in light of their role in bone remodeling. BMP6 function has been assessed in Bmp6-/- mice by µCT and skeletal histology, and has also been examined in mesenchymal stem cells (MSC), hematopoietic stem cells (HSC) and osteoclasts. Safety and efficacy of OSTEOGROW have been assessed in rats and rabbits. RESULTS: Clinical use issues of BMP2 and BMP7 have been ascribed to the limited understanding of their role in bone remodeling at the time of device development for clinical trials. BMP2 and BMP7 in bone devices significantly promote bone resorption leading to osteolysis at the endosteal surfaces, while in parallel stimulating exuberant bone formation in surrounding tissues. Unbound BMP2 and BMP7 in bone devices precipitate on the bovine collagen and cause inflammation and swelling. OSTEOGROW required small amounts of BMP6, applied in a biocompatible blood coagulum carrier, for stimulating differentiation of MSCs and accelerated healing of critical size bone defects in animals, without bone resorption and inflammation. BMP6 decreased the number of osteoclasts derived from HSC, while BMP2 and BMP7 increased their number. CONCLUSIONS: Current issues and challenges with commercial bone devices may be resolved by using novel BMP6 biocompatible device OSTEOGROW, which will be clinically tested in metaphyseal bone fractures, compartments where BMP2 and BMP7 have not been effective.