Comparison of three techniques for decellularization of porcine bone-tendon-bone grafts.

Anterior cruciate ligament injuries are frequent afflictions related to sports or physical trauma. Autograft reconstruction strategies cause secondary injury to the patient. One alternative, supported by clinical evidence, is porcine xenografts. For clinical use, xenografts must be conditioned to avoid immune rejection. The most widely accepted procedure is tissue decellularization. We analyzed three decellularization strategies: the application of the anionic detergent sodium dodecyl sulfate (SDS), sonication, and freezing and thawing cycles. The treated tissues were evaluated histologically using H&E, Masson's trichrome, Verhoeff-van Gieson staining, and DAPI for fluorescent staining of nuclei. Finally, collagen fiber preservation was evaluated by quantifying this protein by colorimetry. The most efficient decellularization techniques were sonication and SDS. Collagen fibers were preserved in all experimental conditions.

A comparison of three techniques for the osteosynthesis after minimal invasive osteotomies for hallux valgus.

PURPOSE: Third and fourth-generation minimal invasive osteotomies (MIO) for the treatment of hallux valgus (HV) have become popular procedures worldwide with promising results due to the improvement in the fixation method. The tricortical cannulated screw placement remains a complex procedure that is technically challenging and requires a long skill learning curve with high radiation exposure mainly in the form of intensifier shots (IS) required for the MIO fixation. This study aims to compare the number of X-ray IS required using three different techniques for the cannulated guide placement. METHODS: A retrospective cross-sectional observational and comparative study was conducted to assess the number of X-rays IS required for correct cannulated screw guide placement using three different techniques: traditional perforator, the drill and joystick, and K-wire first techniques. RESULTS: A total of 53 MIS procedures from thirty-one patients in two different hospitals were included. IS X-rays were 155.1 ± 29.7 in the traditional technique (n = 14), 143.0 ± 43.2 in the drill and joystick technique (n = 22), and 85 ± 18.7 in the K-wires first technique (n = 17), p = < 0.001 using one-way ANOVA. CONCLUSIONS: The K-wire first technique statistically significantly decreases X-ray IS numbers p ≤ 0.001. There were no statistically significant differences between the traditional (after osteotomy K-wire placement) and the drill and joystick techniques (p = 0.36).

Preliminary tribological results of a new total temporary hip joint prosthesis spacer.

Temporary antibiotic-loaded cement spacers are widely used for treating chronic periprosthetic hip infections. The aim of this study is to evaluate the short-term tribological performance of ultra-high-molecular-weight polyethylene (UHMWPE) and (60Co) gamma-irradiated cross-linked UHMWPE (XLPE) self-mated systems as frictional pairs for temporary total hip spacers. A three-axial hip joint simulator, FIME II, was used to test the UHMWPE and XLPE self-mated systems under variable load profiles. A fetal bovine serum solution was used as a lubricant. After simulation tests, wear measurements of damaged coupled surfaces were made with a coordinate measuring machine. Finally, surfaces were characterized with scanning electron microscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, and nanoindentation tests. The mass loss test results for UHMWPE were 11.91 ± 3.43 mg for the cups and 4.57 ± 0.92 mg for the heads. Whereas, the results for XLPE showed a significant reduction, with mean mass loss values of 6.59 ± 0.14 mg for the cups and 2.82 ± 0.59 mg for the heads, suggesting the viability of the self-mated XLPE contact pair for a temporary total hip spacer.

Anatomical variations of the sacro-iliac joint: a computed tomography study.

PURPOSE: To identify, describe, and compare the prevalence of sacroiliac joint anatomical variants. METHODS: A retrospective study was performed on computed tomography scans. Joint space was measured, and variants were classified as accessory joint, ileosacral complex, bipartite bony plate, semicircular defect, iliac bony plate, and ossification centers. RESULTS: 400 scans were analyzed. Mean age was 49 years, 180 men (45%), and 220 women (55%). 209 (52.2%) patients presented an anatomical variant with higher prevalence in women (65.4% vs 36.2%), and those older than 40 years of age (60% vs 40%). Mean joint space was similar bilaterally (right 2.41 ± 0.65 mm vs. left 2.37 ± 0.65 mm). Prevalence was: 19.8% accessory joint, 6.5% ileosacral complex, 12.3% bipartite bony plate, 8% semicircular defect, 5% iliac bony plate, and 0.8% for ossification centers. CONCLUSION: Prevalence of anatomical variants of the SIJ is higher in the Hispanic population, women, and those older than 40 years.

Anatomical variations of the acromial and coracoid process: clinical relevance.

PURPOSE: The acromial and coracoid process morphology is of clinical relevance due to associations with functional limitations and shoulder pathology. Our objective was to describe the anatomical characteristics of the acromial and coracoid process using computed tomography (CT). METHODS: Descriptive, observational, transversal and retrospective study. A total of 155 CT of patients without shoulder pathology, of both genders, and indistinct age were evaluated and grouped by age: Group 1 < 25 years; group 2 25-40 years; group 3 > 40 years. The following parameters were evaluated: Acromial type (AcT), vertical coracoid distance (VCD), acromial tilt (AT), acromial projection (AP), critical shoulder angle (CSA), type of the subcoracoid outlet (TSO), and the area of the subcoracoid outlet (ASO). RESULTS: Statistically significant differences were found between men and women for VCD (14.44 ± 4.79 vs. 11.76 ± 4.00 mm; p < 0.001) and AP (3.66 ± 4.71 vs. 1.62 ± 4.99 mm; p < 0.05) as well as between age groups 1 and 3 for AT (35.08 ± 11.53 vs. 28.41 ± 6.60; p < 0.05) and ASO (398.99 ± 153.91 vs. 255.56 ± 124.58 mm2; p < 0.001). An unexpected high ASO variation was identified with 11% of S-shaped acromion and 1.3% clock-shaped TSO. CONCLUSION: The age group between 25-40 years had the most uniform distribution of data. There is a high morphological variability present in an asymptomatic population, which should be considered in the clinical assessment such as shoulder impingement syndrome.

Anatomy of foot Compartments: a systematic review.

INTRODUCTION: There are discrepancies regarding the anatomy of the foot which complicate standardizing foot compartment treatment. We synthesized the existing evidence regarding the compartmental anatomy of the foot MATERIALS AND METHODS: A systematic review was performed evaluating the anatomy of the foot compartments in non-pathologic specimens. The search strategy was performed in MEDLINE, Scopus, Web of Science, and EMBASE. Three reviewers worked independently and in duplicate to screen all references via a title/abstract and full-text phase. The risk of bias was assessed with the Anatomical Quality Assurance (AQUA) checklist. RESULTS: Ten studies were included. All were performed in cadavers except one. Half of them evaluated the plantar section of the foot and the other half evaluated the whole foot. Methods employed across studies tended to vary: anatomical dissections, dye infusion, imaging studies, or a combination of these. Five studies directly addressed the anatomic limits of each compartment and eight addressed the anatomical structures inside each of them. There seems to be an agreement regarding the number of compartments in the plantar region (three major compartments divided by the medial and lateral intermuscular septum), nevertheless, disagreements across authors tend to arise when describing its dorsal section. Only two studies were ranked with an overall low risk of bias, agreeing on nine compartments. CONCLUSION: This review provides the best available anatomical evidence regarding the anatomy of the foot compartments for compartment syndrome management. Future research should focus on settling the discrepancies highlighted to reach a more accurate anatomical description.

Decellularization of human umbilical arteries / Descelularización de las arterias umbilicales humanas

SUMMARY: Arterial obstruction in small diameter (<6 mm) vessels are many times treated with grafts, however autologous aren't always available and synthetic have a high rate of complications. Decellularization of umbilical arteries may provide a solution, but the ideal method is debatable. We compare effectiveness between SDS and Triton X-100. Umbilical cords obtained from full term pregnancies with normal development and no evident complications in the newborn, were micro-dissected within 12 h and stored in phosphate buffered saline without freezing. Arteries were then processed for decellularization using 0.1 % and 1 % SDS, and 1 % Triton X100 protocols. Evaluation of cellular and nuclear material, collagen fibers, elastic fibers, and glycosoaminoglycans of the extracellular matrix (ECM) were evaluated as well as morphometric analysis under histological and immunohistochemical techniques. Triton X-100 was ineffective, preserving nuclear remains identified by immunofluorescence, had the most notable damage to elastic fibers, and decrease in collagen. SDS effectively eliminated the nuclei and had a less decrease in elastic fibers and collagen. Laminin was preserved in all groups. No significant differences were identified in luminal diameters; however the middle layer decreased due to decellularization of muscle cells. In conclusion, 0.1 % SDS decellularization was the most effective in eliminating cells and preserving the main components of the ECM.

RESUMEN: La obstrucción arterial en vasos de pequeño diámetro (<6 mm) se trata muchas veces con injertos, sin embargo, los autólogos no siempre están disponibles y los sintéticos tienen una alta tasa de complicaciones. La descelularización de las arterias umbilicales puede proporcionar una solución, pero el método ideal es discutible. Comparamos la efectividad entre los métodos SDS y Triton X-100. Cordones umbilicales obtenidos a partir de embarazos a término con evolución normal y sin complicaciones evidentes del recién nacido, se microdiseccionaron en 12 horas y se almacenaron en solución salina con fosfato sin congelación. Las arterias se procesaron luego para la descelularización usando los protocolos de SDS al 0,1 % y 1 %, y Triton X-100 al 1 %. Se realizó la evaluación de material celular y nuclear, fibras de colágeno, fibras elásticas y glucosoaminoglicanos de la matriz extracelular (MEC), así como el análisis morfométrico bajo técnicas histológicas e inmunohistoquímicas. Triton X-100 fue ineficaz, conservando los restos nucleares identificados por inmunofluorescencia, tuvo el daño más notable a las fibras elásticas y la disminución del colágeno. SDS efectivamente eliminó los núcleos y tuvo una disminución menor en las fibras elásticas y el colágeno. Laminina fue preservado en todos los grupos. No se identificaron diferencias significativas en los diámetros luminales; sin embargo, la capa media disminuyó debido a la descelularización de las células musculares. la descelularización con SDS al 0,1 % fue la más efectiva para eliminar células y preservar los principales componentes de la MEC.

[Platelet-rich plasma in knee osteoarthritis treatment]. / El plasma rico en plaquetas en osteoartrosis de rodilla: una alternativa de tratamiento. Artículo de revisión.

The biological changes that commonly cause degenerative articular cartilage injuries in the knee are primarily associated to misalignment of the joint and metabolic changes related to age, as occurs in osteoarthritis. Furthermore, the capacity for cartilage self-regeneration is quite limited due to the lack of vascularity of the tissue. To date there is no ideal treatment capable to stimulate cartilage regeneration; thus there is a need to seek alternative therapies for the treatment of such conditions. The number of publications demonstrating the therapeutic and regenerative benefits of using platelet-rich plasma as a treatment for knee osteoarthritis has been increasing in recent years. In spite of encouraging results, there are still only a few randomised control studies with strong clinical evidence, lacking clarity on points such as the optimum formulation or the mechanism of action of platelet-rich plasma. Up to this point and based on the results of clinical studies, not all patients can benefit from this therapy. It is important to consider aspects such as the age and grade of cartilage degeneration. The aim of the present paper is to review the recent scientific literature on the treatment of knee osteoarthritis with platelet-rich plasma, and the biological bases of this therapy, as well as presenting the current opinion on this subject.