Automatic 3D analysis of the ex-vivo porcine lumbar interbody fusion based on X-ray micro computed tomography data.

Spinal fusion is a surgical procedure used to join two or more vertebrae to prevent movement between them. This surgical procedure is considered in patients suffering from a wide range of degenerative spinal diseases or vertebral fractures. The success rate of spinal fusion is frequently evaluated subjectively using X-ray computed tomography. The pig was chosen as an animal model for spinal fusion, since its spinal structure is similar to the human spine. Our paper presents an automatic approach for pig's spinal fusion evaluation in 3D. The proposed approach is based on the determination of the vertebral fused area, which reflects the fusion quality. The approach was applied and tested on microCT (µCT) data of fused porcine vertebrae ex-vivo. In our study, three types of implants were used to perform spinal fusion: the iliac crest bone graft used as the gold standard, and two types of novel scaffold implants based on the polymer/ceramic porous foam involving either growth factors or polyphosphates. The evaluation worked automatically for all three types of used implants, and the fusion quality was determined quantitatively. The calculation is based on the detection of the fused area and area of facies intervertebralis, so the percentual representation of the vertebral joint can be determined. Since this approach is versatile and is described in detail as a guide for image processing the data of vertebrae fusion, this methodology has the potential to establish a standard approach for evaluating the fusion quality in ex-vivo samples that can be tested on clinical data.

Lumbar Interbody Fusion Conducted on a Porcine Model with a Bioresorbable Ceramic/Biopolymer Hybrid Implant Enriched with Hyperstable Fibroblast Growth Factor 2.

Many growth factors have been studied as additives accelerating lumbar fusion rates in different animal models. However, their low hydrolytic and thermal stability both in vitro and in vivo limits their workability and use. In the proposed work, a stabilized vasculogenic and prohealing fibroblast growth factor-2 (FGF2-STAB®) exhibiting a functional half-life in vitro at 37 °C more than 20 days was applied for lumbar fusion in combination with a bioresorbable scaffold on porcine models. An experimental animal study was designed to investigate the intervertebral fusion efficiency and safety of a bioresorbable ceramic/biopolymer hybrid implant enriched with FGF2-STAB® in comparison with a tricortical bone autograft used as a gold standard. Twenty-four experimental pigs underwent L2/3 discectomy with implantation of either the tricortical iliac crest bone autograft or the bioresorbable hybrid implant (BHI) followed by lateral intervertebral fixation. The quality of spinal fusion was assessed by micro-computed tomography (micro-CT), biomechanical testing, and histological examination at both 8 and 16 weeks after the surgery. While 8 weeks after implantation, micro-CT analysis demonstrated similar fusion quality in both groups, in contrast, spines with BHI involving inorganic hydroxyapatite and tricalcium phosphate along with organic collagen, oxidized cellulose, and FGF2- STAB® showed a significant increase in a fusion quality in comparison to the autograft group 16 weeks post-surgery (p = 0.023). Biomechanical testing revealed significantly higher stiffness of spines treated with the bioresorbable hybrid implant group compared to the autograft group (p < 0.05). Whilst histomorphological evaluation showed significant progression of new bone formation in the BHI group besides non-union and fibrocartilage tissue formed in the autograft group. Significant osteoinductive effects of BHI based on bioceramics, collagen, oxidized cellulose, and FGF2-STAB® could improve outcomes in spinal fusion surgery and bone tissue regeneration.

Ex-vivo biomechanical testing of pig femur diaphysis B type fracture fixed by novel biodegradable bone glue.

AIMS: The aim of this study was to answer the question whether our newly developed injectable biodegradable "self-setting" polymer-composite as a bone adhesive is a good "bone-glue" candidate to efficiently fix comminuted fractures of pig femoral bones used as an ex-vivo experimental model. METHODS: Mechanical properties of adhesive prepared from α-tricalcium phosphate (TCP) powder and thermogelling copolymer were optimized by selecting the appropriate composition with adhesion enhancers based on dopamine and sodium iodinate. Setting time and injectability were controlled by rheology. Ex-vivo experiments of fixed pig bones were provided in terms of either the three-point bending test of bending wedge type fractured pig femurs (with LCP) or the axial compression test of 45° oblique fractured femurs (without LCP) in physiological saline solution at 37 °C. Fractured bones treated with optimized adhesive before and after bending tests were imaged by X-ray microtomography (µCT). RESULTS: Based on the rheological measurement, the adhesive modified with both dopamine and sodium iodinate exhibited optimal thixotropic properties required for injection via thin 22 G needle. This optimal adhesive composition showed an 8 min lag phase (processing time) followed by fast increase in storage modulus at 37 °C up to 1 GPa within 110 min. Self-setting of dopamine/iodinate modified adhesive was completed in 48 h exhibiting the maximum strength at compression of 7.98 MPa ± 1.39 MPa. Whereas unmodified adhesive failed in glue-to-bone adhesion, dopamine and dopamine/iodinate modified adhesive used for 45° oblique fracture fixation showed good and similar strength at compression (3.05 and 2.79 MPa, respectively). However, significantly higher elasticity of about 250% exhibited adhesive with iodinate enhancer. Moreover, mechanical properties of B2 fractures fixed with both LCP and dopamine/iodinate adhesive were approaching closely to the properties of original bone. Excellent adhesion between the adhesive and the bone fragments was proved by µCT. CONCLUSION: The polymer-composite bone adhesive modified with dopamine/iodinate exhibited very good fixation ability of femoral artificial comminuted fractures in an experimental model.

The Effect of the Thermosensitive Biodegradable PLGA⁻PEG⁻PLGA Copolymer on the Rheological, Structural and Mechanical Properties of Thixotropic Self-Hardening Tricalcium Phosphate Cement.

The current limitations of calcium phosphate cements (CPCs) used in the field of bone regeneration consist of their brittleness, low injectability, disintegration in body fluids and low biodegradability. Moreover, no method is currently available to measure the setting time of CPCs in correlation with the evolution of the setting reaction. The study proposes that it is possible to improve and tune the properties of CPCs via the addition of a thermosensitive, biodegradable, thixotropic copolymer based on poly(lactic acid), poly(glycolic acid) and poly(ethylene glycol) (PLGA⁻PEG⁻PLGA) which undergoes gelation under physiological conditions. The setting times of alpha-tricalcium phosphate (α-TCP) mixed with aqueous solutions of PLGA⁻PEG⁻PLGA determined by means of time-sweep curves revealed a lag phase during the dissolution of the α-TCP particles. The magnitude of the storage modulus at lag phase depends on the liquid to powder ratio, the copolymer concentration and temperature. A sharp increase in the storage modulus was observed at the time of the precipitation of calcium deficient hydroxyapatite (CDHA) crystals, representing the loss of paste workability. The PLGA⁻PEG⁻PLGA copolymer demonstrates the desired pseudoplastic rheological behaviour with a small decrease in shear stress and the rapid recovery of the viscous state once the shear is removed, thus preventing CPC phase separation and providing good cohesion. Preliminary cytocompatibility tests performed on human mesenchymal stem cells proved the suitability of the novel copolymer/α-TCP for the purposes of mini-invasive surgery.

A Comparative Study of Conservative Functional Treatment versus Acute Ligamentous Repair in Simple Dislocation of the Elbow in Adults.

BACKGROUND: Elbow dislocation is the second most frequent type of large joint dislocations in adults. Standard treatment of simple elbow dislocation (SED) without manifestation of instability includes closed reduction, short-term immobilization of the elbow followed by functional aftercare. This study evaluates SED treatment, comparing outcomes of conservative functional treatment and surgical therapy. MATERIALS AND METHODS: 54 adult patients with SED without manifest instability treated in tertiary hospital between January 2008 and June 2015 were analyzed in this retrospective study. 28 patients were treated conservatively. Closed elbow reduction was followed by short-term plaster splint and active rehabilitation. Twenty six patients underwent closed elbow reduction and subsequent reconstruction of torn collateral ligaments. Postoperatively, plaster splint was applied followed by rehabilitation. RESULTS: Patients who were treated conservatively reached statistically significant better scores in Quick Disability Arm Shoulder Hand, Oxford Elbow Score, and Mayo Elbow Performance Score. Functional conservative treatment resulted in a higher range of motion. The complication rate was higher in the group of surgically treated patients. CONCLUSIONS: Careful examination of elbow stability after closed reduction of SED is crucial for further therapy. Patients with stable SED should be treated with functional conservative therapy. Surgical collateral ligaments revision and reconstruction are indicated only for patients with manifestation of elbow instability.

[Remission of steroid-resistant Stills disease treated with anakinra, evidenced by FDG-PET/CT examination: case report]. / Remise steroid-rezistentní Stillovy nemoci pri lécbe anakinrou dokumentovaná FDG-PET/CT vysetrením: kazuistika.

After elimination of infectious causes, neoplastic causes and the systemic autoimmune disease of connective tissue, a patient with high fevers over 39 °C was diagnosed with Stills disease. High doses of prednisone led to resolution of symptoms, however after reducing the doses of prednisone to 15 mg, high fevers over 39 °C returned, as well as joint pains. The high doses of prednisone led to decompensation of diabetes mellitus even with 4 daily insulin dosages. Therefore it was proceeded to regular subcutaneous administration of anakinra once a day. Anakinra enabled the reduction of prednisone to as much as the currently administered 2.5 mg a day, but it has not so far allowed for removing glucocorticoids from the treatment completely. Activity of the disease is shown by the findings within the FDG-PET/CT examination. At the time of maximum activity of the disease there was distinct lymphadenopathy with pathological accumulation of FDG visible as well as increased accumulation of FDG in the hematopoietic bone marrow. As the disease activity decreased, the size of nodules regressed and FDG accumulation in both the lymphatic nodes and bone marrow declined. FDG-PET/CT is a suitable method for monitoring the activity of Stills disease.Key words: anakinra - Adult-onset Stills disease.