Aim. Debridement, Antibiotics, Irrigation, and implant Retention (DAIR) is a surgical treatment protocol suitable for some patients with fracture related infection (FRI). Clinically relevant pre-clinical models of DAIR are scarce and none have been developed in large animals. Therefore, this project aimed to develop a large animal model for FRI including a DAIR approach and compare outcomes after 2 or 5 weeks of infection. Method. Swiss Alpine
Chronic rotator cuff tears are a major problem especially in the elderly population. Refixation is associated with high re-rupture rates. Therefore new implants or healing methods are needed. For a control of success biomechanical characteristics of native as well as treated tendons are of particular importance. Currently, tensile tests with static material testing machines are the most common technique for the biomechanical characterization of tendons. Resulting values are the maximum force (Fmax), stiffness and the Young´s modulus. However, no information is given about the allocation of strains over the tendon area. In addition, the determination of Fmax results in tissue destruction thus foreclosing further evaluation like histology. The Digital Image Correlation (DIC) is a contact-free non-destructive optical measuring method which gives information about distribution of strains by tracking the areal shift of an applied speckle pattern. The needed speckle pattern has to have a high contrast, a homogeneous distribution and a good adhesion to the surface. The method is established for the characterization of construction materials [1] to detect e.g. weak points. The present study examined if DIC is applicable for the complementary biomechanical evaluation of the
Biphasic calcium phosphate (BCP) with a characteristic needle-shaped submicron surface topography (MagnetOs) has attracted much attention due to its unique bone-forming ability which is essential for repairing critical-size bone defects such as those found in the posterolateral spine. Previous in vitro and ex-vivo data performed by van Dijk LA and Yuan H demonstrated that these specific surface characteristics drive a favorable response from the innate immune system. This study aimed to evaluate and compare the in vivo performance of three commercially-available synthetic bone grafts, (1) i-FACTOR Putty. ®. , (2) OssDsign. ®. Catalyst Putty and (3) FIBERGRAFT. ®. BG Matrix, with that of a novel synthetic bone graft in a clinically-relevant instrumented
Objectives. We sought to determine if a durable bilayer implant composed of trabecular metal with autologous periosteum on top would be suitable to reconstitute large osteochondral defects. This design would allow for secure implant fixation, subsequent integration and remodeling. Materials and Methods. Adult
Summary. Timing for the application and use of fentanyl patches for pre-emptive analgesia and sedation is crucial to obtain good clinical outcomes. Placement and timing is important to maximise clinical effect and apparent levels of analgesia. Introduction. The use of
The purpose of the study was to assess the incorporation of defatted, and deproteinated bovine cancellous bone in a
Introduction Magnetic resonance imaging (MRI) is a valid investigation for the diagnosis of intervertebral disc disease, including infection, but it is expensive and difficult to access conveniently for research studies on live animals under anaesthesia. The aim of this study was to compare the MRI signal changes in spines from living and recently deceased
Purpose: To determine if an adenovirus vector expressing BMP-7 can alter the progression of post-traumatic osteoarthritis. Method: Preliminary dose-response studies were done in ovine metacarpal-phalangeal joints using 10^9, 10^10, and 10^11 virus particles (VP). In-vitro transfection efficiency studies were done using ovine synovial cells, chondrocytes and HEK293 cells. In-vivo studies were conducted in 16
Aim. The treatment of chronic orthopedic device-related infection (ODRI) often requires multiple surgeries and prolonged antibiotic therapy. In a two-stage exchange procedure, the treatment protocol includes device removal and placement of an antibiotic-loaded bone cement spacer to achieve high local antibiotic concentrations. At the second stage, further surgery is required to remove the spacer and replace it with the definitive device. We have recently developed a thermo-responsive hyaluronan hydrogel (THH) that may be loaded with antibiotics and used as delivery system. Since the material is bio-resorbable, it does not require surgical removal and may therefore be suitable for use as treatment strategy in a single-stage exchange. This aim of this study was to evaluate gentamicin sulphate (Genta)-loaded THH (THH-Genta) for treating a chronic Staphylococcus aureus ODRI in
Summary Statement. An autologous thrombin activated 3-fold PRP, mixed with a biphasic calcium phosphate at a 1mL:1cc ratio, is beneficial for early bone healing in older age
Scientific Background: Adult articular cartilage, critical to proper joint function, has minimal self-repair ability. No adequate repair technique exists for large defects. Cryopreservation which is a process of deep-freezing of cells and tissues, enables the preservation of a high proportion of cells when the tissue is thawed and implanted. Aim: To evaluate a novel method for cryopreservation of articular cartilage in the form of osteochondral
INTRODUCTION:. To avoid the early onset of osteoarthritis after partial meniscectomy an effective replacement of injured meniscal tissue would be desirable. The present study investigates the behaviour of a new silk derived scaffold supplied by Orthox Ltd. (Abingdon, UK) in an in vivo
The aim of this study was to determine the function of the meniscofemoral ligament in the cranio-caudal and rotatory laxity of the ovine stifle. Twenty fresh cadaveric ovine stifles were harvested from fully mature
Introduction: Pin loosening is a common complication associated with external fixation. Various attempts such as coating the pins with calcium phosphates, have been made to modify the pin surface in order to reduce pin loosening and provide good fixation. Animal and clinical studies showed that fixation using tapered external fixation pins coated with hydroxyapatite is superior to standard pins. However, there is no data on cylindrical pins either fully or partially coated with HA. A partial coating could be a solution to optimize pin fixation with the advantage of easier removal compared to fully coated pins. Our purpose was to compare standard and partially coated cylindrical Apex pins implanted in a
Surgical reattachment of torn rotator cuff tendons can lead to satisfactory clinical outcome but failures remain common. Ortho-R product is a freeze-dried formulation of chitosan (CS) that is solubilized in platelet-rich plasma (PRP) to form injectable implants. The purpose of the current pilot study was to determine Ortho-R implant acute residency, test safety of different implant doses, and assess efficacy over standard of care in a
Introduction: Vertebral compression fractures are common in osteoporosis, resulting in spinal deformities, severe back pain and decreased mobility. Vertebroplasty and kyphoplasty procedures aim to restore the integrity of the deformed vertebral body by injection of biocompatible cement. To date, there have been no long-term studies of the bone-cement interaction in this setting. A reliable large animal model of vertebral osteoporosis would be useful to fully characterise the disease process, to assess potential treatment regimens and to investigate the biocompatibility of bone cements used in kyphoplasty and vertebroplasty. The aim of this pilot study was to develop such a model with ovariectomy, low calcium diet and continuous steroid treatment. Methods: To induce osteoporosis, ten lactating ewes (mean age 8 years) were ovariectomised, injected weekly with 9 mg dexamethasone (Dexafort, Intervet, Australia) and fed low calcium diet. Weekly serum samples were taken to quantify generalised bone resorption (Type 1 collagen C-telopeptide [CTX], ‚-Cross Laps assay, Roche Diagnostics, Australia). Dual-energy X-ray absorptiometry (DEXA, Hologic QDR 1000+, USA) was used to monitor bone mineral density (BMD) in the lumbar spine (L3-L6) after 0, 2, 4, 6 and 9 months of treatment. At each time interval two
Short Summary. The present study demonstrated the feasibility of culturing a large number of standardised granular MSC-containing constructs in a packed bed/column bioreactor that can produce
Introduction: Modern imaging techniques have demonstrated that up to 28% of patients with spinal cord injury develop syringomyelia. Cyst formation and enlargement are thought to be related to abnormalities of cerebrospinal fluid hydrodynamics, however the exact mechanism and route of entry into the spinal cord remain incompletely understood. Previous work in rats has demonstrated that experimental post-traumatic syrinxes occur more reliably and are larger when the excitotoxic injury is combined with arachnoiditis produced by subarachnoid kaolin injection. A
INTRODUCTION: Modern imaging techniques have demonstrated that up to 28% of patients with spinal cord injury develop syringomyelia. Cyst formation and enlargement are thought to be related to abnormalities of cerebrospinal fluid hydrodynamics, however the exact mechanism and route of entry into the spinal cord remain incompletely understood. Previous work in rats has demonstrated that experimental post-traumatic syrinxes occur more reliably and are larger when the excitotoxic injury is combined with arachnoiditis produced by subarachnoid kaolin injection. A
An experimental model was established to investigate the possibility of repairing cervical nerve roots avulsed from the spinal cord, as occurs in traction injuries of the brachial plexus. In five