Resilient anatomy and local plasticity of naive and stress haematopoiesis.

The bone marrow adjusts blood cell production to meet physiological demands in response to insults. The spatial organization of normal and stress responses are unknown owing to the lack of methods to visualize most steps of blood production. Here we develop strategies to image multipotent haematopoiesis, erythropoiesis and lymphopoiesis in mice. We combine these with imaging of myelopoiesis1 to define the anatomy of normal and stress haematopoiesis. In the steady state, across the skeleton, single stem cells and multipotent progenitors distribute through the marrow enriched near megakaryocytes. Lineage-committed progenitors are recruited to blood vessels, where they contribute to lineage-specific microanatomical structures composed of progenitors and immature cells, which function as the production sites for each major blood lineage. This overall anatomy is resilient to insults, as it was maintained after haemorrhage, systemic bacterial infection and granulocyte colony-stimulating factor (G-CSF) treatment, and during ageing. Production sites enable haematopoietic plasticity as they differentially and selectively modulate their numbers and output in response to insults. We found that stress responses are variable across the skeleton: the tibia and the sternum respond in opposite ways to G-CSF, and the skull does not increase erythropoiesis after haemorrhage. Our studies enable in situ analyses of haematopoiesis, define the anatomy of normal and stress responses, identify discrete microanatomical production sites that confer plasticity to haematopoiesis, and uncover unprecedented heterogeneity of stress responses across the skeleton.

Anterior Tibial Artery Danger Zone During Anterolateral Plate Fixation of the Distal Tibia: A 3D Computed Tomography Angiogram Modeling Study.

OBJECTIVES: The objective of this study was to define the danger zone at which the anterior tibial artery (ATA) is at risk during anterolateral plating of the distal tibia using a novel 3D computed tomography angiography (CTA) modeling technique. METHODS: 116 patients (232 lower extremities) who underwent lower extremity CTAs between April 2020 and April 2022 were identified. Those with lower extremity trauma, evidence of a previously healed tibial fracture, or poor visualization of the ATA were excluded. The remaining 150 lower extremities (92 patients) were modeled with an anterolateral distal tibia plate using Sectra IDS7 software. The distance of the ATA from bony landmarks was measured perpendicular to the level at which the vessel intersected the plate. RESULTS: The ATA intersected the plate proximally at a mean distance of 10.5 cm (95% confidence intervals, 10.2-10.9) and at a mean distance of 4.6 cm (95% confidence intervals, 4.4-4.9) distally from the central tibial plafond. The ATA intersected with the plate as far distal as hole number 1 and as proximal as hole 14 of the plate. The greatest injury risk was associated with plate holes 3-8. In this region, the artery was at risk in 46-99 percent of specimens. CONCLUSIONS: The ATA is at risk when screws are placed percutaneously in an anterolateral distal tibia plate. The artery can be as close as 4.4 cm and as far as 10.9 cm proximal to the tibial plafond when crossing the plate, correlating to a risk of injury to the ATA at plate holes 1 through 14.

Synovium and blood capillaries at the femoral attachment of anterior cruciate ligament are significantly abundant than those at the tibial attachment / Sinovial y capilares sanguíneos en la inserción femoral del ligamento cruzado anterior son significativamente más abundantes que los de la inserción tibial

SUMMARY: The anterior cruciate ligament (ACL) is a ligament that mainly controls the anterior and rotational mobility of the knee joint, and its surface is covered by a synovial membrane with large number of blood vessels. In general, nutritional supply to the ligament is from many capillaries in the adjacent synovium. However, statistical studies of the capillaries distributed to the ACL are insufficient. In this study, we examined cross-sectional histological images of the femoral attachment (femoral level), middle level of the tendon (middle level), and tibial attachment (tibial level) of the ACL and statistically analyzed blood capillary distribution among the three levels. The ACLs of 10 cadavers were divided into 5 equal sections, and 4mm-thick paraffin sections were made at the femoral level, middle level, and tibial level, and then hematoxylin-eosin (HE) staining were performed. The area of each transverse section was measured using Image-J 1.51n (U. S. National Institutes of Health, Bethesda, MD, USA). Fiber bundles of the ACL were relatively small and sparse in cross-sectional area at the femoral level and became larger and denser toward the tibial level. Many blood levels. The synovium at the attachment of ACL covered the surface of the fiber bundle and also penetrated deeply between the fiber bundles. In particular, the blood capillaries were densely distributed in the synovium at the femoral attachment rather than another two levels. Indeed, the number of capillaries were also most abundant in the femoral level. The cross-sectional ACL area at the femoral level is significantly small, however, the blood capillaries were most abundant. Therefore, when the ACL is injured, its reconstruction with preservation of the femoral ligamentous remnant may be clinically useful for remodeling of the grafted tendon.

El ligamento cruzado anterior (LCA) es un ligamento que controla principalmente la movilidad anterior y rotacional de la articulación de la rodilla, y su superficie está cubierta por una membrana sinovial con gran cantidad de vasos sanguíneos. En general, el suministro de nutrientes al ligamento proviene de muchos capilares en la sinovial adyacente. Sin embargo, los estudios estadísticos de los capilares distribuidos en el LCA son insuficientes. En este estudio, examinamos imágenes histológicas trans- versales de la inserción femoral (nivel femoral), el nivel medio del tendón (nivel medio) y la inserción tibial (nivel tibial) del LCA y analizamos estadísticamente la distribución de los capilares sanguíneos entre los tres niveles. Los LCA de 10 cadáveres se dividieron en 5 secciones iguales y se realizaron cortes en parafina de 4 µm de espesor a nivel femoral, medio y tibial, y luego se realizó tinción con hematoxilina-eosina (HE). El área de cada sección transversal se midió utilizando Image-J 1.51n (Institutos Nacionales de Salud de EE. UU., Bethesda, MD, EE. UU.). Los haces de fibras del LCA eran relativamente pequeños y escasos en el área de la sección transversal a nivel femoral y se hicieron más grandes y más densos hacia el nivel tibial. La membrana sinovial en la unión del LCA cubría la superficie del haz de fibras y también penetraba profundamente entre entre los haces de fibras. En particular, los capilares sanguíneos estaban densamente distribuidos en la unión femoral de la sinovial respecto a los otros dos niveles. De hecho, el número de capilares también fue más abundante a nivel femoral. El área transversal del LCA a nivel femoral era significativamente pequeña, sin embargo, los capilares sanguíneos fueron los más abundantes. Por lo tanto, cuando hay una lesión del LCA su reconstrucción con preservación del ligamento femoral remanente puede ser clínicamente útil para remodelar el tendón injertado.

Anomalous Posterior Tibial Artery Course-Anatomic Considerations for the Posterolateral Ankle Approach: A Case Report.

CASE: We report a unique anatomical case of an anomalous course of the posterior tibial artery found on dissection during the posterolateral approach to the ankle. To the best of our knowledge, no such case has been documented. CONCLUSION: The vascular bundle consistent with that of the posterior tibial artery and vein was encountered in the far lateral aspect of the deep posterior compartment, which suggests physicians should proceed with caution when performing the posterolateral approach to the ankle so as to avoid iatrogenic injury of this named anatomic structure.

Method for generating transparent porcine tibia showing the intraosseous artery.

BACKGROUND: The occurrence of nonunion after tibial fracture surgery is mainly related to insufficient blood supply. Therefore, anatomical study of the internal and external tibial artery is very important, but there is no good method for displaying the intraosseous artery clearly and intuitively. This hinders the protection and reconstruction of it by surgeons, as well as the development of new instruments and techniques by researchers. OBJECTIVE: To develop a transparent specimen that could clearly display the intraosseous artery of the tibia. METHODS: In 10 isolated pig calves with popliteal vessels, the popliteal artery was exposed and a tube was placed. A casting agent was then injected at constant pressure, and the tissue around the blood vessel was preliminarily removed after solidification. The perivascular tissue and periosteum were further removed via alkali corrosion, and the tibia was fixed with an external fixator to protect the non-corrosive areas at both ends. Alternate acid corrosion and flushing were then applied until the intraosseous artery was completely exposed. The distribution and branches of intraosseous nutrient arteries were observed with the naked eye and via microscopy. Three-dimensional (3D) scanning and 3D printing filling techniques were used to make transparent tibia specimens with preservation of intraosseous arteries. RESULTS: A cast specimen of the intraosseous artery of porcine tibia was successfully generated via epoxy resin perfusion combined with acid-alkali etching, and the intraosseous artery was clearly visible. The 3D printing and filling technique successfully produced a transparent tibia specimen with preservation of internal bone arteries, and accurately restored the external shape of the tibia. The foramen of the nutrient artery appeared near the middle upper third of the lateral edge of the tibia. After entering the tibia, the nutrient artery proceeded forward, medial, and downward for a certain distance, twisted and turned near the midpoint of the medullary cavity, and divided into the ascending and descending branches. After going in the opposite direction for a distance, the ascending trunk sent out 2-3 branches, and the descending trunk sent out 2-3 branches. CONCLUSION: The cast specimen of pig intraosseous artery generated via the above-described perfusion corrosion method provides methodological guidance for the study of anatomical characteristics of the intraosseous artery, and a theoretical basis for the study of new methods of internal fixation and reconstruction of the blood supply of the lower tibia.

A Composite Deferoxamine/Black Phosphorus Nanosheet/Gelatin Hydrogel Scaffold for Ischemic Tibial Bone Repair.

Introduction: Bone delay union is mostly caused by lack of blood supply. Although autografts, allografts and artificial bone have been widely used to treat bone delay union, the bone regeneration fails in the ischemic site accompanied by the bone donor site complications and disease transmission. Recently, there is a growing recognition of the importance of hydrogel scaffolds which are regarded as an eligible engineer tissue for bone repair. However, hydrogel is still limited in improving neovascularization. Methods: In this work, black phosphorus nanosheet and deferoxamine (BPN-DFO) were loaded in the gelatin hydrogel to overcome the high risk of bone delay union and systemically investigated the regeneration capability of BPN-DFO hydrogel in vitro and vivo. Results: The resulting BPN-DFO hydrogel scaffold showed superior swollen, degradation and release rate, as well as satisfied biocompatibility. BPN-DFO hydrogel shown the significant up-expression of mRNA related to bone regeneration and cell proliferation. In vivo, the proposed BPN-DFO hydrogel significantly improved osteogenesis and neovascularization in the ischemic tibial bone site of SD rats with acute femoral artery occlusion. Both macroscopic and histological evaluation of new regenerated bone showed newly formed blood vessel and collagen using BPN-DFO hydrogel. The immunohistochemistry and RT-PCR revealed that the bone regeneration could be improved via BMP/Runx2 pathway. Conclusion: The BPN-DFO hydrogel possesses potential tissue engineer material for ischemic bone defect treatment. However, furthermore studies are needed to testify the safety and efficacy of BPN-DFO hydrogel.

Nerve and Arterial Supply Pattern of the Popliteus Muscle and Clinical Implications.

INTRODUCTION: The aim of this study was to investigate the nerve and artery supply and the tibial attachment of the popliteus muscle using anatomical methods. METHODS: Forty-four nonembalmed and embalmed extremities were dissected for this study. To measure the attachment area of the popliteus, the most prominent points of the medial epicondyle of the femur and the medial malleolus of the tibia were identified before dissection. A line connecting these two prominent points was used as the reference line, with the most prominent point of the medial epicondyle of the femur as the starting point. This study also investigated the area where the popliteus attaches to the bone and the points where nerves and arteries enter the popliteus muscle when it is divided into three equal parts in the coronal plane. RESULTS: The mean length of the reference line was 34.6 ± 2.1 cm. The origin of the popliteus was found to be at a distance of 16.6% to 35.2% on the tibial bone from the proximal region. The popliteus was innervated by only the tibial nerve in 90% of the cases and by the tibial and the sciatic nerves in the remaining 10% of the cases. The inferior medial genicular artery and the posterior tibial artery supplied blood to the popliteus in 90% and 65% of the cases, respectively. When the popliteus muscle was divided into three equal parts in the coronal plane, the nerve and the artery were found to enter the muscle belly in zones II and III and zones I and II in 92% and 98% of the specimens, respectively. Discussion. The anatomical investigation of the popliteus in this study will help identify patients with clinically relevant syndromes.

Measuring tibial hemodynamics and metabolism at rest and after exercise using near-infrared spectroscopy.

The bone vascular system is important, yet evaluation of bone hemodynamics is difficult and expensive. This study evaluated the utility and reliability of near-infrared spectroscopy (NIRS), a portable and relatively inexpensive device, in measuring tibial hemodynamics and metabolic rate. Eleven participants were tested twice using post-occlusive reactive hyperemia technique with the NIRS probes placed on the tibia and the medial gastrocnemius (MG) muscle. Measurements were made at rest and after 2 levels of plantarflexion exercise. The difference between oxygenated and deoxygenated hemoglobin signal could be reliably measured with small coefficients of variation (CV; range 5.7-9.8%) and high intraclass correlation coefficients (ICC; range 0.73-0.91). Deoxygenated hemoglobin rate of change, a potential marker for bone metabolism, also showed good reliability (CV range 7.5-9.8%, ICC range 0.90-0.93). The tibia was characterized with a much slower metabolic rate compared with MG (p < 0.001). While exercise significantly increased MG metabolic rate in a dose-dependent manner (all p < 0.05), no changes were observed for the tibia after exercise compared with rest (all p > 0.05). NIRS is a suitable tool for monitoring hemodynamics and metabolism in the tibia. However, the local muscle exercise protocol utilized in the current study did not influence bone hemodynamics or metabolic rate. Novelty: NIRS can be used to monitor tibial hemodynamics and metabolism with good reliability. Short-duration local muscle exercise increased metabolic rate in muscle but not in bone. High level of loading and exercise volume may be needed to elicit measurable metabolic changes in bone.

Associations of blood pressure and arterial stiffness with knee cartilage volume in patients with knee osteoarthritis.

OBJECTIVE: To describe the associations of blood pressure and arterial stiffness with knee cartilage volume in patients with knee OA. METHODS: A secondary analysis was performed on the data from participants in a randomized controlled trial that identified the effects of vitamin D supplementation on knee structures and symptoms among patients with symptomatic knee OA. Brachial and central blood pressure, arterial stiffness indicators and knee cartilage volume were measured at baseline and the 2 year follow-up. Associations were assessed using generalized estimating equations. RESULTS: Among 231 participants (average age 63.2 years), 48.9% were females. Higher supine systolic and diastolic pressures were significantly associated with lower tibial cartilage volume (systolic: lateral ß -6.23, medial ß -5.14, total ß -11.35 mm3/mmHg; diastolic: lateral ß -10.25, medial ß -11.29, total ß -21.50 mm3/mmHg). Higher supine systolic pressure was associated with lower femoral cartilage volume (lateral ß -17.35, total ß -28.31 mm3/mmHg). Central systolic pressure and arterial stiffness indicators (including pulse wave velocity, central pulse pressure and peripheral pulse pressure) were largely not associated with knee cartilage volume; however, higher augmentation index was associated with lower tibial and femoral cartilage volume (tibial: medial ß -8.24, total ß -19.13 mm3/%; femoral: lateral ß -23.70, medial ß -26.42, total ß -50.12 mm3/%). CONCLUSIONS: Blood pressure and arterial stiffness are associated with knee cartilage volume at several sites in knee OA patients. This supports that blood pressure and arterial stiffness may involve in the progression of knee OA.

Anatomic characterization of the tibial and fibular nutrient arteries in humans.

The location of nutrient foramina has been extensively studied in long bones; however, accurate information on the origin and extra-osseous course of the nutrient artery remains clearly defined in some long bones, although it is crucial to protect the nutrient arteries during operative procedures. In this study, we elucidated the origin and extra-osseous course of tibial and fibular nutrient arteries based on the 54 cadaveric legs. The tibial nutrient artery typically arose from the posterior tibial artery. Some of the tibial nutrient arteries arose from the anterior tibial, popliteal, and fibular arteries. The tibial nutrient artery arose from these parent arteries as a long descending branch. It penetrated the most proximal portion of the tibialis posterior or flexor digitorum longus to enter the tibial nutrient foramen. The fibular nutrient artery arose from the fibular artery as a short descending branch in all the cases. The fibular nutrient artery penetrated the flexor hallucis longus to enter the fibular nutrient foramen. Our present and previous findings provide new insight into the anatomical characteristics for the nutrient arteries in the long bones of upper and lower extremities. Namely, the nutrient arteries of the long bones go away from the elbow or knee to enter the nutrient foramina.

A Case of an Aggressive Intraosseous Arteriovenous Malformation in the Lower Extremity: Special Considerations for Diagnosis and Management.

BACKGROUND: Arteriovenous malformations (AVMs) are rare, congenital vascular anomalies. Intraosseous AVMS most frequently arise in the head and neck, with only a small fraction occurring in the extremities. Herein, we report the findings of a combined soft tissue and intraosseous AVM involving the lower extremity of a 13-year-old child. This case highlights the necessity of an interdisciplinary approach for the effective treatment and management of these rare vascular anomalies. CASE DESCRIPTION: A 13-year-old female presented with a 4-year history of intermittent pain and swelling over her right lateral malleolus. The patient was evaluated with radiologic imaging revealing an AVM involving the right distal leg, ankle, and hindfoot with intraosseous involvement of the distal tibia and talus. She was then referred to Vascular and Plastic Surgery and an angiogram was performed demonstrating shunting from the anterior tibial, peroneal, and posterior tibial arteries to the AVM. Venous drainage was to the anterior tibial and greater saphenous veins. Three embolizations were performed over the course of 6 months. Following the third embolization, the patient was taken to the operating room where Plastic and Orthopedic Surgery performed total resection of the nidus and involved bone which was then grafted with injectable synthetic bone graft. RESULTS: Successful resection of the nidus was achieved, and the patient had an uncomplicated recovery. Within 6 months postoperatively, the patient demonstrated full range of lower extremity motion and was able to participate in age appropriate gross motor activities. Radiologic evaluation 7 months postoperatively showed no evidence of nidus recurrence. CONCLUSION: Intraosseous involvement of AVMS is rare and presents a therapeutic challenge due to its invasive potential and high incidence of recurrence. Wide local excision with bone grafting and interdisciplinary management are paramount for complete resection.

Unheralded Lower limb threatening ischemia in a COVID-19 patient.

Acute thromboembolic events appear to be frequent in patients with SARS-CoV-2 infection. We report a case of an intubated patient, who developed a threatening lower limb ischemia. Intra-arterial fibrinolysis and intravenous heparin infusion did not lead to complete recanalization of the tibial arteries, which were successfully treated by surgical embolectomy.

Neural regulation of the contractility of nutrient artery in the guinea pig tibia.

Nutrient arteries provide the endosteal blood supply to maintain bone remodelling and energy metabolism. Here, we investigated the distribution and function of perivascular nerves in regulating the contractility of the tibial nutrient artery. Changes in artery diameter were measured using a video tracking system, while the perivascular innervation was investigated using fluorescence immunohistochemistry. Nerve-evoked phasic constrictions of nutrient arteries were suppressed by phentolamine (1 µM), an α-adrenoceptor antagonist, guanethidine (10 µM), a blocker of sympathetic transmission, or fluoxetine (10 µM), a serotonin (5-hydroxytryptamine, 5-HT) reuptake inhibitor. In arteries pretreated with guanethidine, residual nerve-evoked constrictions were abolished by a high concentration of propranolol (10 µM) that is known to inhibit 5-HT receptors, or ketanserin (100 nM), a 5-HT2 receptor antagonist, but not SB207216 (1 µM), an antagonist of 5-HT3 and 5-HT4 receptors. Bath-applied 5-HT (100 nM) induced arterial constriction that was suppressed by propranolol (10 µM) or ketanserin (100 nM). Nerve-evoked arterial constrictions were enhanced by spantide (1 µM), a substance P (SP) receptor antagonist, or L-nitro arginine (L-NA; 100 µM), an inhibitor of nitric oxide synthase (NOS). Immunohistochemistry revealed 5-HT-positive nerves running along the arteries that are distinct from perivascular sympathetic or substance P-positive primary afferent nerves. For the first time, functional serotonergic nerves are identified in the tibial nutrient artery of the guinea pig. Thus, it appears that tibial nutrient arterial calibre is regulated by the balance between sympathetic and serotonergic vasoconstrictor nerves and vasodilator afferent nerves that release substance P-stimulating endothelial nitric oxide (NO) release.

Assessment of neovascularization during bone healing using contrast-enhanced ultrasonography in a canine tibial osteotomy model: a preliminary study.

Blood perfusion of skeletal muscle and callus was evaluated using contrast-enhanced ultrasonography (CEUS) in a canine osteotomy model to determine the applicability of CEUS in the assessment of neovascularization during fracture healing and to compare the vascular signals on CEUS between external skeletal fixation and cast-applied dogs. In 6 Beagle dogs, a simple transverse osteotomy was performed at the left tibial shaft and external skeletal fixation (n = 3) or a cast (n = 3) was applied. Radiography, power Doppler ultrasonography (power Doppler), and CEUS were performed until complete union was achieved. On CEUS, vascular changes were quantitatively evaluated by measuring peak intensity (PI) and time to PI in the soft tissue and callus and by counting the vascular signals. Vascular signals from the soft tissue were detected on power Doppler and CEUS on day 2. Significantly more vascular signals were detected by CEUS than by power Doppler. On CEUS, PI in the surrounding soft tissue was markedly increased after the fracture line appeared indistinctively changed on radiography in all dogs. In the cast-applied dogs, vascular signals from the periosteal and endosteal callus were detected on CEUS before mineralized callus was observed on radiography. CEUS was useful in assessing the vascularity of soft tissue and callus, particularly in indirect fracture healing, and provided indications of a normally healing fracture.

Simplified Endovascular Deep Venous Arterialization for Non-option CLI Patients by Percutaneous Direct Needle Puncture of Tibial Artery and Vein Under Ultrasound Guidance (AV Spear Technique).

The following case report describes the AV spear technique for percutaneous deep venous arterialization. After an ultrasound survey was performed to find the puncture point adjacent to the ankle joint where the posterior tibial vein (PTV) runs superficially to the posterior tibial artery (PTA), percutaneous penetration of the PTV and PTA was conducted. Then a microguidewire was inserted from the distal puncture site into the PTA and advanced into the arterial sheath, establishing a through-and-through wire. A microcatheter was then advanced antegradely over the through-and-through wire. After removing the wire, a hydrophilic guidewire was utilized in order to identify the venous lumen. Finally, a balloon angioplasty was conducted to create an AV fistula, which was reinforced by stent placement.

Variz Intra-Óssea ­ um achado raro diagnosticado pela ressonância magnética / Intraosseous Varicose Vein ­ A rare finding diagnosed by magnetic resonance imaging

Introdução: As varizes são veias que após submetidas a períodos de pressão aumentada no sistema venoso periférico se tornam dilatadas, tortuosas e alongadas. Pacientes acometidos irão referir dor no membro, além de sinais de insuficiência venosa. O exame de imagem comumente utilizado é o ultrassom com Doppler, no entanto, na presença de anomalias de drenagem venosa intraóssea, deve-se preferir a ressonância magnética. Objetivo: Relatar um caso e revisar a literatura acerca desta lesão incomum. Materiais e Métodos: Revisão do prontuário do paciente no Hospital América, registro fotográfico do método diagnóstico e revisão da literatura. Resultados: Homem de 46 anos com dor e queimação constantes, além de edema na perna e no pé esquerdos há dois meses Ao exame físico apresenta edema da perna, tornozelo e pé esquerdos, com discreto aumento de temperatura ao toque, sem alteração da coloração da pele. A ressonância magnética demonstra varicosidades das veias tibiais posteriores com comunicação através de veia perfurante com varicosidade da veia intraóssea posterior da tíbia ­ variz intraóssea. Conclusão: Este relato demonstra a dificuldade de diagnosticar a variz intra-óssea que, além de ser uma lesão rara, é diagnosticada apenas pela ressonância magnética.

Introduction: Varicose veins are veins that after being submitted to high pressure on the peripheral venous system become dilated, tortuous and elongated. Patients affected will report pain and venous insufficiency signs in the area. The imaging exam commonly used is the Doppler ultrasound, however, when in front of an intraosseous venous drainage anomaly ­ intraosseous varix, magnetic resonance should be preferred. Objective: Report a case and review the literature about this uncommon lesion. Materials and Methods: We carried out a review of medical records at Hospital América, a photographic record of diagnostic methods, and a review from the literature. Results: A 46-year-old man with constant pain and burning, as well as edema in his left leg and foot for two months. On physical examination, he had edema in his left leg, ankle, and foot, with a slight increase in temperature at the touch, without changing the skin color. Magnetic resonance imaging shows varicosities of the posterior tibial veins with communication through a perforating vein with varicosity of the posterior tibial intraosseous vein - intraosseous varicose vein. Conclusion: This report demonstrates the difficulty of diagnosing intraosseous varices, which, in addition to being a rare lesion, are diagnosed only by magnetic resonance imaging.

Widely Divergent Congenital Inferior Tibiofibular Diastasis with Separate Soft-Tissue Cover and Persistent Sciatic Artery: A Previously Unreported Combination: A Case Report.

CASE: We report a case of a child with widely divergent congenital inferior tibiofibular diastasis with persistent sciatic artery (PSA). The dysplastic tibia and fibula were widely divergent, and the fibula was displaced proximally and medially with the foot alongside the thigh between the 2 legs, with PSA diagnosed on computed tomography angiogram. The child was treated with fibula-foot complex excision and below-knee prosthesis and was ambulating independently at 1-year follow-up. CONCLUSIONS: The combination of a major structural anomaly (tibiofibular diastasis with a separate soft-tissue cover) and an unusual vascular malformation (PSA) has not been reported previously and made surgical reconstruction challenging.

Utilidad de las imágenes híbridas SPECT/TC en el infarto óseo / Utility of single-photon emission computed tomography and computed tomography imaging in bone infarction

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The role of blood vessels in broiler chickens with tibial dyschondroplasia.

Tibial dyschondroplasia (TD) is an intractable tibiotarsal bone disorder of rapid growing avian species, which leads to huge economic losses and compromised poultry welfare. However, the exact pathogenesis and treatment of TD remain largely unknown. Based on continuous research findings, we propose the TD pathogenesis hypothesis: during skeletal development of TD chickens, due to the absence of vasculature of proximal tibial growth plates (TGP), hypertrophic chondrocytes of the TGP are unable to complete calcification in normal bone development and less dead chondrocytes in the corresponding area can be timely transported through the blood vessels. Moreover, recent studies demonstrate that the TD formation mechanism gradually tends to a large number of dead chondrocytes in the TGP region or apoptosis occur due to various factors (such as, reduction of vascular invasion and blood cells, and increased weight or mechanical force of the tibia), while the reduction of blood vessels is insufficient to remove these chondrocytes and eventually leads to the TD formation. Recognizing the possible role of the blood vessels in the incidence of TD and can propose that the improvement in vasculature might be a novel therapeutic approach for ending TD in chickens.