Background: Commonly, intramedullary nails are made of nondegradable materials, and hence they need to be removed once the bone fracture is healed. We propose a novel composite material consisting of poly-L-lactide matrix modified with carbon and alginate fibers to be used for biodegradable intramedullary fixation. The aim of this study was to make in vitro and in vivo biocompatibility assessments. Methods: In the in vitro conditions, biocompatibility of biomaterials was compared using normal human osteoblasts. After 3 and 7 days, cytotoxicity, viability and proliferation tests were performed, as well as cell morphology and adhesion observations. In the in vivo experiments, Californian rabbits (approx. 9 months old) were used. The composite nails and controls (Kirschner wires) were used for fixation of distal femoral osteotomy. The evaluation was made on the basis of clinical observations, radiographs taken after 2, 4, 6 and 8 weeks post implantation, and macroscopic and histological observations. Results: Cell tests indicated that both modifiers had a positive influence on cell viability. Biodegradable composite nails led to bony union when used for fixation of distal diaphysis osteotomy in rabbits. Histological analysis showed that the initial focal necrosis should be fully compensated for by the osteoblast proliferation and trabeculae formation. Conclusions: Both in vitro and in vivo tests confirmed biocompatibility and potential applicability of novel biodegradable intramedullary nails modified with long carbon and alginate fibers for osteosynthesis of bone epiphysis.

In the study the impact of manufacturing technology of alloy Ti6Al4V implants on the effectiveness of "fusion, treatment on the defined tissue biocompatibility and on the osseointegration with the bone” was analyzed. Models and samples made by material removal processing and electron beam technology EBT were tested in vitro biological and in vivo animals tests with histopathological assessment of tissues. The results confirmed the biocompatibility of the Ti6Al4V 3D-T alloy, and thus safety in bone surgery. On the basis of CTt examinations of preparates taken from animals after 3÷4M implantation it has been shown a very good osseointegration of truss structures with the bone. The introduction of EBT technology extends the capabilities of designing of a safe implant which is matched to the anatomy, exhibits complex spatial structure and surfaces that are conducive to the propagation of union/overgrowth of bone in accordance with the proposed hypothesis: Ivy-like mechanism.

Bone cysts are rare orthopaedic problems in dogs. There are no clear treatment guidelines. A young male Shih Tzu was referred to Small Animal Clinic with fifth-degree lameness (5/5) of the left thoracic limb, and with swelling and deformation of the distal humeral region. The radiological assessment revealed an enlargement of the distal brachium and an extensive hypodense osteolytic lesion in the distal metaphyseal region of the humerus. Diagnosis of the bone cyst was formulated and treated with a mini-invasive method using autologous non-concentrated bone marrow injections. The treatment was successful, and at the three weeks, the cyst significantly changed its structure. The follow-up at 12 weeks after the first injection, and at one year revealed complete recovery. To our knowledge, this is the first evidence of a bone cyst in a young dog successfully treated with a minimally-invasive method by using a non-concentrated autologous bone marrow injection.

Background: Luxation of the rib head with intrusion into the intervertebral foramen seems to be rare in cats. Only one report has been published describing a cat with non-ambulatory paraparesis, which was managed conservatively. Here we report a case of rib head luxation that was managed surgically. Case presentation: A 4-year-old, female domestic shorthair cat with a two-week history of non-ambulatory paraparesis was presented at our clinic. Based on history and neurological examination, a diagnosis of thoracolumbar spinal cord lesion of traumatic origin was made. Computed tomography scanning revealed mild scoliosis, a luxation of the 3rd and 4th right rib heads and penetration into the spinal canal through intervertbral foramina. Surgical management using right dorsal approach to the spine was performed. The spinal cord was decompressed by cutting and removing of proximal ribs’ fragments by rotation and pulling out from the intervertebral foramina. The cat was ambulatory and paraparetic four weeks after surgery. Two years after surgery the cat regained functional gait, but ataxia remained. Conclusions: We report the first case of a surgical treatment of rib head luxation and intrusion into the spinal canal in a cat. The applied procedure resulted in an improvement of neurological signs.