Composition of encephalic arteries and origin of the basilar artery are different between vertebrates.

Intracranial arterial anatomy is lacking for most mammalian and non-mammalian model species, especially concerning the origin of the basilar artery (BA). Enhancing the knowledge of this anatomy can improve animal models and help understanding anatomical variations in humans. We have studied encephalic arteries in three different species of birds and eight different species of mammals using formalin-fixed brains injected with arterial red latex. Our results and literature analysis indicate that, for all vertebrates, the internal carotid artery (ICA) supplies the brain and divides into two branches: a cranial and a caudal branch. The difference between vertebrates lies in the caudal branch of the ICA. For non-mammalian, the caudal branch is the origin of the BA, and the vertebral artery (VA) is not involved in brain supply. For mammals, the VA supplies encephalic arteries in two different ways. In the first type of organization, mostly found in ungulates, the carotid rete mirabile supplies the encephalic arteries, the caudal branch is the origin of the BA, and the VA is indirectly involved in carotid rete mirabile blood supply. The second type of encephalic artery organization for mammals is the same as in humans. The caudal branch of the ICA serves as the posterior communicating artery, and the BA originates from both VAs. We believe that knowledge of comparative anatomy of encephalic arteries contributes to a better understanding of animal models applicable to surgical or radiological techniques. It improves the understanding of rare encephalic variations that may be present in humans.

Synovial calprotectin: A potentially useful biomarker for the diagnosis of Kingella kingae native arthritis.

Kingella kingae is a bacteria involved in developing arthritis in children. Its diagnosis remains difficult. We report a case for which a new biomarker, calprotectin measured in the synovial fluid, was strongly positive and a specific molecular test was the only way to diagnose it specifically.

Comparison of MRI T1, T2, and T2* mapping with histology for assessment of intervertebral disc degeneration in an ovine model.

An easy, reliable, and time-efficient standardized approach for assessing lumbar intervertebral disc (IVD) degeneration with relaxation times measurements in pre-clinical and clinical studies is lacking. This prospective study aims to determine the most appropriate method for lumbar IVD degeneration (IDD) assessment in sheep by comparing three quantitative MRI sequences (variable-flip-angle T1 mapping, and multi-echo T2 and T2* mapping), correlating them with Pfirrmann grading and histology. Strong intra- and interrater agreements were found for Nucleus pulposus (NP) regions-of-interest (ROI). T1, T2, and T2* mapping correlated with Pfirrmann grading and histological scoring (p < 0.05) except for the most ventral rectangular ROI on T2 maps. Correlations were excellent for all of the T1 ROIs and the T2* NP ROIs. Highly significant differences in T1 values were found between all Pfirrmann grades except between grades I/II and between grades III/IV. Significant differences were identified in the T2 and the T2* values between all grades except between grades I/III. T1, T2, and T2* relaxation times measurements of the NP are an accurate and time-efficient tool to assess lumbar IDD in sheep. Variable-flip-angle T1 mapping may be further considered as a valuable method to investigate IDD and to assess the efficacy of regenerative treatments in longitudinal studies.

Arthroscopic suture-fixation of anterior tibial intercondylar eminence fractures by retensioning of the ACL and hollowing of the tibial footprint: Objective and subjective clinical results in a paediatric population.

INTRODUCTION: Anterior tibial intercondylar eminence fractures (ATIEF) of the knee are rare in children. They are associated with prefracture intraligamental distention of the anterior cruciate ligament (ACL). OBJECTIVE: The objective of this study was to evaluate the subjective and objective clinical results of an arthroscopic surgical technique by suture-fixation of the fracture and tensioning of the ACL through hollowing of the tibial footprint. HYPOTHESIS: Suture-tensioning of ATIEF arthroscopically helps to achieve treatment objectives by leaving the knee joint free of any hardware. MATERIALS AND METHODS: This single-operator monocentric retrospective study involved twenty children operated on over a period of 2-years and 10 months, from March 2013, and with a minimum of one-year follow-up. Surgery was indicated for Stage II to IV fractures according to the Meyers and McKeever classification. Type I fractures were excluded. Seventeen out of 20 patients were reviewed. The median age was 12 years at the time of surgery and the mean follow-up was 28 months. The fractures were 5 of stage II, 9 of III and 3 of IV. The scores of Lysholm, objective and subjective IKDC were collected. Residual objective laxity was measured using the GNRB arthrometer at 150N. A standard X-ray evaluation permitted detection of possible growth disorders. RESULTS: At 28 months of mean follow-up, the mean scores of Lysholm and subjective IKDC were 99 (95; 100) and 97 (92; 100), respectively. As for the objective IKDC, 14 knees were rated A and 3 were rated B. The mean differential residual laxity via GNRB was 0.94mm (0; 2.4). No radiological growth disorder was observed at the last follow-up. CONCLUSION: The ACL suture-tensioning technique is simple and reliable. It also preserves the joint of the adult to remain free of any residual hardware. LEVEL OF EVIDENCE: IV; retrospective cohort study.

Collateral effects of targeting the nucleus pulposus via a transpedicular or transannular surgical route: a combined X-ray, MRI, and histological long-term descriptive study in sheep.

PURPOSE: In the context of regenerative medicine strategies, based in particular on the injection of regenerative cells, biological factors, or biomaterials into the nucleus pulposus (NP), two main routes are used: the transpedicular approach (TPA) and the transannular approach (TAA). The purpose of our study was to compare the long-term consequences of the TPA and the TAA on intervertebral disc (IVD) health through a longitudinal follow-up in an ovine model. METHODS: The TPA and the TAA were performed on 12 IVDs from 3 sheep. Six discs were left untreated and used as controls. The route and injection feasibility, as well as the IVD environment integrity, were assessed by MRI (T2-weighted signal intensity), micro-CT scan, and histological analyses (Boos' scoring). The sheep were assessed at 1, 3, and 7 months. RESULTS: Both the TPA and the TAA allowed access to the NP. They both induced NP degeneration, as evidenced by a decrease in the T2wsi and an increase in the Boos' scores. The TPA led to persistent end-plate defects and herniation of NP tissue (Schmorl's node-like) after 7 months as well as the presence of osseous fragments in the NP. CONCLUSIONS: The TPA induced more severe lesions in IVDs and vertebrae compared to the TAA. The lesions induced by the TPA are reason to consider whether or not this route is optimal for studying IVD regenerative medicine approaches.

Posterior cruciate ligament: Anatomy, femoral insertion and relationships with the anterior menisco-femoral ligament in 23 cadaver knees.

BACKGROUND: Abundant anatomic descriptions exist of the posterior cruciate ligament (PCL) and menisco-femoral ligaments (MFLs). There is broad agreement that the PCL is composed of two bundles and inserts on the femur near the distal cartilage. However, a different configuration with a single bundle and a complex femoral insertion has been reported. The main objective of our cadaver study was to determine the number of anatomical bundles forming the PCL. We also described the insertion of the PCL and its relationships with the anterior menisco-femoral ligament (AMFL). HYPOTHESIS: The PCL consists of a single ribbon-like bundle and inserts on the femur separately from the AMFL. MATERIAL AND METHODS: We used 23 knees of fresh unembalmed cadavers, which we dissected under a microsurgery loupe. Inclusion criteria for the knees were freedom from trauma and scars. No age limits were set. The features of the PCL were studied using the clock method. Measurements were taken using callipers with a precision of 0.01mm. RESULTS: No knees were excluded from the final analysis. Macroscopically, the PCL appeared as a single bundle forming a slender flat ribbon. With the knee flexed at 90°, the ligament footprint extended from 58min to 25min on the right and from 48min to 2min on the left. The femoral insertion of the AMFL started 2.07mm from the distal cartilage and masked the distal insertion of the PCL. After removal of the AMFL, the middle of the femoral insertion of the PCL started on average 5.99mm from the distal cartilaginous rim when the knee was flexed at 90°. DISCUSSION: Our study confirms descriptions of the PCL as a single bundle shaped as a flat ribbon. The presence of the AMFL gives the appearance of a double bundle and partially masks the femoral insertion of the PCL, which is located further back relative to the distal joint cartilage. LEVEL OF EVIDENCE IV: Experimental cadaver study.

Dural arteries of the dorsoclival area.

OBJECTIVE: In the literature, there is a lack of complete description of dural arteries of the dorsoclival area with contradictory data. However, dorsoclival area is a site of tumors and vascular malformation or the skull base. That is why, the knowledge of dural arteries is very important. METHODS: Using a colored silicone mix preparation, fifteen sides of eight cranial bases were studied using 4-20× magnification of the surgical microscope. RESULTS: Dorsoclival area is supplying by three arterial complexes, internal carotid artery complex with always the dorsal meningeal artery for the superior two-third of the clivus, medial clival artery for the dorsum sellae, the external carotid artery complex with the hypoglossal and jugular branches of the ascending pharyngeal artery for the inferior one-third of the clivus, and the vertebral artery complex with the anterior meningeal artery for the most inferior part of the clivus and the anterior edge of the foramen magnum. Moreover, there are many anastomoses between those three arterial complexes at this area. CONCLUSION: Dural arterial supply of the dorsoclival area is very opulent. Its knowledge is important for surgical approaches and endovascular procedures.

Implication of the inferolateral trunk of the cavernous internal CAROTID artery in cranial nerve blood supply: Anatomical study and review of the literature.

The inferolateral trunk (ILT) is one of the two more common branches of the cavernous internal carotid artery (ICA). Its knowledge is important for skull base surgery and endovascular interventional procedures. The ILT is described with superior, anterior and posterior branch, which is the complete form. These branches vascularize the oculomotor, trochlear, trigeminal and abducens nerves into the cavernous sinus and superior orbital fissure (SOF) courses, and through the foramens rotundum and ovale. We performed 21 injected embalmed cadaveric dissections combined with six specimen tomodensitometry. The ILT originates from the horizontal ICA segment and passes above the abducens nerve. Three branches arise from the ILT between the cavernous ICA and the ophthalmic and maxillary nerves initial courses. The main differences with the literature are the number of branches and their cranial nerves' blood supply. The more frequent ILT conformation is the incomplete form with anterior and posterior branch (13/21); the complete form is present in 5/13 sides (38%) and the ILT is in common with the meningohypophyseal trunk in 3/21 (14%) sides. The anterior branch always vascularizes the cranial nerves into the SOF course and most often the maxillary nerve through the foramen rotundum. The posterior branch always vascularizes the mandibular nerve through the foramen ovale course and sometimes the maxillary nerve. This study has demonstrated that there are anastomoses between these branches and arteries arising from the external carotid. This study explains why the sacrifice of a branch of the ILT does not implicate cranial nerve palsy.

Descriptive and dynamic study of the medial patellofemoral ligament (MPFL).

PURPOSE: The goal of this study was to evaluate the anatomy of the medial patellar retinaculum and the medial patellofemoral ligament (MPFL) to provide an anatomical validation of a pediatric reconstruction technique. METHODS: Fifteen knees were dissected to study the MPFL and its relationship with the medial patellar retinaculum and the femoral insertion of the medial collateral ligament (MCL). The distances between the insertions of the MPFL of eight knees, and the patellar insertion of the MPFL and the femoral insertion of the MCL of four knees, were measured during the flexion to evaluate the isometricity of the native and reconstructed MPFL. RESULTS: The medial patellar retinaculum includes four structures: the fascia, fibrous expansions of the vastus muscles, the MPFL and the medial patellomeniscal ligament. The femoral insertion of the MPFL was located just behind the femoral insertion of the MCL in 12 knees. During flexion, the distance between the insertion on the upper patella and the femoral insertion of the MPFL increased while the distance between the insertion on the lower patella and the femoral insertion of the MPFL decreased. The variation in the distances measured during the flexion was greater between the MPFL insertions (nsup = 6.5 mm, ninf = 6.5 mm) than between the patellar insertion of the MPFL and the femoral insertion of the MCL (n'sup = 2.5 mm, n'inf = 5.75 mm). CONCLUSION: The MPFL is not isometric. Even though the results were obtained from knees of elderly specimens, this study demonstrates reconstruction of the MPFL should take into account its anatomy and biomechanical role in the knee.

In vitro and in vivo evaluation of an electrospun-aligned microfibrous implant for Annulus fibrosus repair.

Annulus fibrosus (AF) impairment is associated with reherniation, discogenic pain, and disc degeneration after surgical partial discectomy. Due to a limited intrinsic healing capacity, defects in the AF persist over time and it is hence necessary to adopt an appropriate strategy to close and repair the damaged AF. In this study, a cell-free biodegradable scaffold made of polycaprolactone (PCL), electrospun, aligned microfibers exhibited high levels of cell colonization, alignment, and AF-like extracellular matrix deposition when evaluated in an explant culture model. The biomimetic multilayer fibrous scaffold was then assessed in an ovine model of AF impairment. After 4 weeks, no dislocation of the implants was detected, and only one sample out of six showed a partial delamination. Histological and immunohistochemical analyses revealed integration of the implant with the surrounding tissue as well as homogeneously aligned collagen fiber organization within each lamella compared to the disorganized and scarcer fibrous tissue in a randomly organized control fibrous scaffold. In conclusion, this biomimetic electrospun implant exhibited promising properties in terms of AF defect closure, with AF-like neotissue formation that fully integrated with the surrounding ovine tissue.