Implantation of bovine hydroxyapatite and secretome with different oxygen concentration may improve massive bone defect regeneration: An experimental study on animal model

The most widely used biomaterials in the treatment of massive bone defects are allograft bone or metal implants. The current problem is that the availability of allographs is limited and metal implants are very expensive. Mass production of secretome can make bone reconstruction of massive bone defects using a scaffold more effective and efficient. This study aims to prove bone regeneration in massive bone defects using bovine hydroxyapatite reconstruction with normoxic and hypoxic secretome conditions using collagen type 1 (COL1), alkaline phosphate (ALP), osteonectin (ON), and osteopontin (OPN) parameters. This is an in vivo study using male New Zealand white rabbits aged 6–9 months. The research was carried out at the Biomaterials Center—Tissue Bank, Dr. Soetomo Hospital for the manufacturer of bovine hydroxyapatite (BHA) and secretome BM-MSC culture under normoxic and hypoxic conditions, and UNAIR Tropical Disease Institute for implantation in experimental animals. Data analysis was carried out with the one-way ANOVA statistical test and continued with the Post Hoc test LSD statistical test to determine whether or not there were significant differences between groups. There were significant differences between hypoxic to normoxic group and hypoxic to BHA group at day-30 observation using ALP, COL 1, ON, and OPN parameters. Meanwhile, there is only osteonectin parameter has significant difference at day-30 observation. At day-60 observation, only OPN parameter has significant differences between hypoxic to normoxic and hypoxic to BHA group. Between day-30 and day-60 observation, BHA and normoxic groups have a significant difference at all parameters, but in hypoxic group, there are only difference at ALP, COL 1, and ON parameters. Hypoxic condition BM-MSC secretome with BHA composite is superior and could be an option for treating bone defect.

In vivo experimental study of the arterial supply of the rabbit posterior limb

Background: The use of bone graft has been a successful step in the treatment of a large number of diseases of the osteoarticular system. But a massive bone defect remains a dilemma for modern reconstructive surgery. Present methods used have a high level of morbidity and complication. Literature indicates the absence of an optimal solution in massive bone defects healing. The aim of this study: to perform an in vivo preliminary study of vascularization of the hind limb in the rabbit model, for obtaining a graft able for further inclusion in the host blood circulation, without immunosuppression by decellularization. Material and methods: The study was performed on the 12 laboratory rabbits. After euthanasia of the rabbit, the femoral and tibiofibular bone was collected without soft tissue, only with the vascular pedicle, and keeping the passage through the vessels. In the abdominal aorta was injected contrast material, with the subsequent preparation of the arterial vessels, succeeded by anatomical, morphological, radiography, and microangiography study of this vascularized bone segment. Results: The principal nutrient artery of the rabbit femur springs from the lateral circumflex femoral artery. The optimal segment for vascularized allografting (the rabbit model) was determined the upper third of the femur with the up to the level of the internal iliac artery. So, it could be used as a bone graft for further conservation and decellularization. Conclusions: The vascularized allogeneic bone without immunosuppression would be a perfect alternative in the treatment of the massive bone defects.

Failure of dual plating in a complex open distal femur fracture as the result of major trauma

A 61-year-old polytrauma patient was admitted with a right distal comminuted metaphyseal femoral fracture with intra-articular extension (Orthopaedic Trauma Association 33C2.3 classification) among other injuries. Due to the high degree of comminution and massive bone loss, this was initially managed with a dual plating open reduction internal fixation. Dual plating has shown to be a superior fixation method than single variable angle locking compression plate (VA-LCP) plating providing greater fixation in metaphyseal bone. Our case reports the failure of dual plating which required removal of metalwork and subsequent fixation using intramedullary nail and plate technique. Failure of dual plating is not well documented in the literature. The most recent radiographs taken 15 months postrevision surgery show that the bone has started to heal with evidence of callus formation.

EARLY RESEARCH OF PALEOZOIC AGNATHANS AND FISHES: THE STUDIES OF STEPAN SEMYONOVICH KUTORGA (1805-1861)

Agnathans and fishes with massive bone armors were widely spread among the vertebrates in the Early Paleozoic. Their remains were well preserved in fossil state. At present, many species of Devonian agnathans and fishes have been described and studied. Different taxonomic systems have been suggested based on their fossil exoskeletal elements. But in the first part of the nineteenth century, when scientists first came across such remains, their nature was not immediately understood. Discovered remains of armored ichthyofauna were identified as bones of reptiles and amphibians even by outstanding scientists of that time. Professor of the Imperial St. Petersburg University Stepan Semyonovich Kutorga was among them. This article supplies a brief biography of the scientist and an analysis of his works in the formative period of vertebrate paleontology in Russia. S. S. Kutorga was at the origin of the system of monographic descriptions and collections - the most important source of information in fundamental paleontological research. Kutorga’s collection, currently stored at the St. Petersburg State University, is the first monographic collection of Devonian ichthyofauna in our country.

A Unique Salvage Operation Strategy: Implantation of the Ulnar Total Elbow Component to the Radius to Overcome Large Ulnar Bone Defect Caused by Infection After Total Elbow Arthroplasty

ABSTRACT The elbow joints of patients with rheumatoid arthritis (RA) are often destroyed, and total elbow arthroplasty (TEA) is one treatment for these patients. However, patients with RA tend to develop surgical site infections due to immunosuppression. Once an implant is infected, reoperation may be difficult because of the risk of reinfection. In such patients, the infected site must be debrided thoroughly, although this might reduce the bone scaffold needed for re-TEA. We used a unique method to manage a large ulnar bone defect and an infected implant. The patient with RA had undergone TEA 15 years earlier. Etanercept was initiated to control disease activity; however, this treatment led to infection of the elbow prosthesis. Several surgical debridements were performed to eradicate the bacteria, which improved the symptoms of infection. However, most of the proximal ulna was lost, and it seemed impossible to fix the prosthesis using the remaining small ulna after debridement. Therefore, we planned to implant the ulnar component into the radius as a salvage technique. With this procedure, we provided the patient with elbow mobility and eradicated the infection. This is an alternative method for restoring function in an elbow with a massive bone defect in the ulna.

Tetraodontiformes (Osteichthyes, Actinopterygii) from the Miocene of Argentina: with the southernmost record of fossil Tetraodontidae

Teleostean evolution produced enormous variation in tooth morphology. This variation is related to the exploration and exploitation of very diverse dietary niches. Among extant fishes, several taxa of the order Tetraodontiformes (e.g. pufferfishes, porcupinefishes and ocean sunfishes) have evolved highly specialized beak-like tooth structures. Here we provide the first description of tetraodontiform crushing beaks from Argentina. A single complete premaxillary beak recovered from the early Miocene Gaiman Formation in Chubut Province is assigned to Molidae based on its premaxillaries being completely fused to one another along the midline, general morphology, and size. Moreover, due to the putative presence of rows of teeth fused to the thick and massive bone structure, the specimen might belong to the genus Ranzania Nardo, 1840. Several premaxillary beaks recovered in the late Miocene Paraná Formation of Entre Ríos Province are assigned to Tetraodontidae Bonaparte, 1832 based on the presence of long, slender, rod-like, and parallel dental units; premaxillae not fused in the midline but articulated by interlocking emarginations, and a few small and one large trituration dental units. Argentinian tetraodontiform fishes inhabited the warm-temperate Paranense and Patagoniense Seas (marine transgressions developed in southeastern South America) during the early-late Miocene; these specimens are the southernmost fossil record of the group worldwide. Tetraodontiforms are extremely rare in recent Argentinian marine waters. The new fossil records agree with the higher sea water surface temperatures suggested both locally and worldwide for the Miocene.