Evaluation qualitative macroscopique et microscopique du grasset chez un modèle expérimental d'arthrose canine 90 jours après section du ligament croisé crânial

La transection du ligament croisé crânial (CCLT) est une méthode couramment admise d'induction expérimentale d'arthrose (OA) au niveau du grasset chez le chien. Le but principal de cette étude était d'évaluer qualitativement les lésions d'arthrose induites par la CCLT par macroscopie et histologie 90 jours après chez 21 jeunes femelles de race beagle. Les lèvres de la trochlée fémorale présentaient le plus haut score ostéophytique tandis que la patelle présentait le plus bas et celui du condyle fémoral médial était supérieur à celui du condyle latéral. Les lésions méniscales ont été observées uniquement sur le ménisque médial de 5 genoux opérés. Les lésions macroscopiques du cartilage (stade de fibrillation) ont été notées dans un ordre de fréquence décroissant sur les condyles tibiaux médial et latéral, le condyle fémoral latéral, la trochlée fémorale, le condyle fémoral médial et enfin la patelle. L'examen histologique a révélé que la couche superficielle du cartilage était fibrillée et discontinue. La plupart des cellules étaient rondes et disposées tangentiellement à la surface. Dans les zones transitionnelle et profonde, quelques chondrocytes étaient modérément hypertrophiques et des amas de chondrocytes ont été uniquement observés dans la couche profonde. Concernant la membrane synoviale, un épaississement du mésothélium et une importante densité de collagène ont été notés et le rapport des épaisseurs mésothélium/fibres était entre 1/0.15 et 1/0.10 sur les genoux opérés et 1/0.05 sur les genoux témoins. Les images fournies ici pourront servir de références pour des travaux ultérieurs portant notamment sur les thérapies contre l'arthrose

Unusual presentation of an avulsion of the long digital extensor tendon in a dog: radiographic, computed tomographic, arthroscopic, surgical and histological findings

A long digital extensor tendon avulsion is reported in a 15-month-old intact male Great Dane with a right pelvic limb lameness of 2-week duration. The orthopedic, radiographic, computed tomographic, arthroscopic, surgical and histological findings are described. Surgical excision of the avulsed bone fragment and re-attachment of the tendon to the lateral joint capsule of the stifle joint was successful and the dog was free of lameness 6 and 12 months after therapy

Popliteus impingement after TKA may occur with well-sized prostheses

To determine the mechanisms and extents of popliteus impingements before and after TKA and to investigate the influence of implant sizing. The hypotheses were that (1) popliteus impingements after TKA may occur at both the tibia and the femur, and (2) even with an apparently well-sized prosthesis, popliteal tracking during knee flexion is modified compared to the preoperative situation. The location of the popliteus in three cadaver knees was measured using computed tomography, before and after implantation of plastic TKA replicas, by injecting the tendon with radiopaque liquid. The pre- and post-operative positions of the popliteus were compared from full extension to deep flexion using normosized, oversized, and undersized implants (one size increments). At the tibia, TKA caused the popliteus to translate posteriorly, mostly in full extension: 4.1 +/- 2 mm for normosized implants, and 15.8 +/- 3 mm with oversized implants, but no translations were observed when using undersized implants. At the femur, TKA caused the popliteus to translate laterally at deeper flexion angles, peaking between 80A degrees and 120A degrees: 2 +/- 0.4 mm for normosized implants and 2.6 +/- 0.5 mm with oversized implants. Three-dimensional analysis revealed prosthetic overhang at the posterosuperior corner of normosized and oversized femoral components (respectively, up to 2.9 mm and 6.6 mm). A well-sized tibial component modifies popliteal tracking, while an undersized tibial component maintains more physiologic patterns. Oversizing shifts the popliteus considerably throughout the full arc of motion. This study suggests that both femoro- and tibio-popliteus impingements could play a role in residual pain and stiffness after TKA

Discrepancies in Knee Joint Moments Using Common Anatomical Frames Defined by Different Palpable Landmarks

The aim was to investigate the effects of three anatomical frames using palpable anatomical landmarks of the knee on the net knee joint moments. The femoral epicondyles, femoral condyles, and tibial ridges were used to define the different anatomical frames and the segment end points of the distal femur and proximal tibia, which represent the origin of the tibial coordinate system. Gait data were then collected using the calibrated anatomical system technique (CAST), and the external net knee joint moments in the sagittal, coronal, and transverse planes were calculated based upon the three anatomical frames. Peak knee moments were found to be significantly different in the sagittal plane by approximately 25% (p ≤0.05), but no significant differences were seen in the coronal or transverse planes. Based on these findings it is important to consider the definition of anatomical frames and be aware that the use of numerous anatomical landmarks around the knee can have significant effects on knee joint moments

Determination of regional bone blood flow by means of fluorescent microspheres using an automated sample-processing procedure

The determination of regional blood flow utilizing fluorescent microspheres (FMs) is an established method for numerous organs. Recent progress, in particular the automation of sample processing, has further improved this method. However, the FM method (reference sample technique), which allows repetitive measurement of regional organ blood flow, has so far not been used for the determination of blood flow in bone. The aim of the present study was to establish FM for the quantification of regional bone blood flow (RBBF). Female, anesthetized New Zealand rabbits (n = 6) received left ventricular injections of different amounts of FM at six subsequent time points. In order to examine the precision of RBBF determination, two different FM species were injected simultaneously at the sixth injection. At the end of the experiments the femoral and tibial condyles of each hind limb were removed and the fluorescence intensity in the tissue samples was measured by an automated procedure. In an in vitro study we have shown that acid digestion of the crystalline matrix has no effect on the fluorescence characteristics of FM. The determination of the number of spheres per tissue sample revealed that depending on the tissue sample size up to 3 x 10(6) spheres/injection were necessary to obtain about 400 microspheres in the individual bone samples. RBBF values of the tibial and femoral condyles did not differ at various injection intervals. The tibial blood flow values varied between 6.6 +/- 1.1 and 8.5 +/- 1.4 ml/min/100 g and were significantly higher than those of the femur (4.3 +/- 1.1 to 6.0 +/- 1.8 ml/min/100 g). The bone blood flow values obtained by simultaneous injection of two FM species correlated significantly (r = 0.96, slope = 1.06, intercept = 0.05), the mean difference was 0.39 +/- 1.11 ml/min/100 g. Our data demonstrate that the measurement of RBBF by means of FM allows a valid determination of RBBF. Copyright (C) 2003 S. Karger AG, Basel

Health-related quality of life, adiposity, and sedentary behavior in patients with early schizophrenia: Preliminary study

Objective: To examine adiposity and sedentary behavior in relation to health-related quality of life (QoL) in patients with early schizophrenia. Methods: A cross-sectional study was used to assess adiposity by dual-energy X-ray absorptiometry scans, habitual physical activity and idle sitting time by the Short Form International Physical Activity Questionnaire, and health-related QoL by the RAND Medical Outcomes Study SF-36. QoL scores were compared with age-adjusted Canadian normative population data. Results: There were 36 participants with early schizophrenia, average age 25.1 (±3.6). Twenty-nine (72.5%) were males. Mean illness duration was 30 (±18) months, and mean body mass index was 28.3 (±5). Females had higher body fat content than males (30.8±6.9 vs 24.7±10.6; t=-2.6, df=34; P=0.015). Total body fat (F=14; P=0.001), lean body mass (F=10.2; P=0.001), and sedentary behavior (F=5; P=0.013) significantly increased across body mass index categories. Total body fat was correlated with sedentary behavior (r=0.62; P=0.001), and total lean body mass was negatively correlated with sedentary behavior (r=0.39; P=0.03). Based on SF-36scores, participants had significantly lower physical functioning (P=0.0034), role physical (P=0.0003), general health (P,0.0001), vitality (P=0.03), and physical component scores (P=0.003) than Canadian population comparisons. Habitual sedentary behavior, more than activity or adiposity levels, was associated with health-related QoL in early schizophrenia. Conclusion: Health-related QoL is lower in early schizophrenia and is predominantly experienced in the physical domain. QoL in early schizophrenia relates to sedentary behavior more than to activity and adiposity levels. © 2012 Strassnig etal, publisher and licensee Dove Medical Press Ltd

Magnetic resonance imaging study on temporomandibular joint morphology [Studija o morfologiji čeljusnog zgloba pomoću magnetske rezonancije]

Magnetic resonance imaging (MRI) has enabled the accomplishment of a more effective diagnostics of temporomandibular disorders (TMD). The sample included 40 patients with clinical symptoms of disc displacement (DD) of temporomandibular joint (TMJ) and 25 subjects included in our study were asymptomatic. DD were diagnosed by clinical examinations which were subsequently confirmed by MRI. DD was found in 18% of the TMJs of the asymptomatic patients. The highest prevalence of total DD without reduction was found in 44.1% of the patients' joints subsequently followed by total DD with reduction comprising 34.9% of the TMJs and by partial DD with reduction comprising 21% of the TMJs. This study may help us clarify the complicated relationship which exists between the radiographic and clinical findings of TMJ disorders

Cephalometric studies of the mandible, its masticatory muscles and vasculature of growing Göttingen Minipigs — A comparative anatomical study to refine experimental mandibular surgery

Over many decades, the Göttingen Minipig has been used as a large animal model in experimental surgical research of the mandible. Recently several authors have raised concerns over the use of the Göttingen Minipig in this research area, observing problems with post-operative wound healing and loosening implants. To reduce these complications during and after surgery and to improve animal welfare in mandibular surgery research, the present study elucidated how comparable the mandible of minipigs is to that of humans and whether these complications could be caused by specific anatomical characteristics of the minipigs’ mandible, its masticatory muscles and associated vasculature. Twenty-two mandibular cephalometric parameters were measured on CT scans of Göttingen Minipigs aged between 12 and 21 months. Ultimately, we compared this data with human data reported in the scientific literature. In addition, image segmentation was used to determine the masticatory muscle morphology and the configuration of the mandibular blood vessels. Compared to data of humans, significant differences in the mandibular anatomy of minipigs were found. Of the 22 parameters measured only four were found to be highly comparable, whilst the others were not. The 3D examinations of the minipigs vasculature showed a very prominent deep facial vein directly medial to the mandibular ramus and potentially interfering with the sectional plane of mandibular distraction osteogenesis. Damage to this vessel could result in inaccessible bleeding. The findings of this study suggest that Göttingen Minipigs are not ideal animal models for experimental mandibular surgery research. Nevertheless if these minipigs are used the authors recommend that radiographic techniques, such as computed tomography, be used in the specific planning procedures for the mandibular surgical experiments. In addition, it is advisable to choose suitable age groups and customize implants based on the mandibular dimensions reported in this study

Lateral cephalometric analysis of asymptomatic volunteers and symptomatic patients with and without bilateral temporomandibular joint disk displacement

Few studies of dentofacial and orthodontic structural relationships relative to temporomandibular joint (TMJ) dysfunction have been reported. We undertook this investigation to determine any correlation of orthodontic and dentofacial characteristics with TMJ bilateral disc displacement. The population of patients was selected from a TMJ clinic where a control group of asymptomatic volunteers had been previously established and standardized. Differences in skeletal structural features were determined among three study groups: (1) asymptomatic volunteers with no TMJ disk displacement, (2) symptomatic patients with no TMJ disc displacement, and (3) symptomatic patients with bilateral TMJ disk displacement. Thirty-two asymptomatic volunteers without disk displacement (25 female, 7 male) were compared with the same number each of symptomatic patients without TMJ disk displacement and symptomatic patients with bilateral TMJ disk displacement. All subjects had undergone a standardized clinical examination, bilateral TMJ magnetic resonance imaging, and lateral cephalometric radiographic analysis. The groups were matched according to sex, TMJ status, age, and Angle classification of malocclusion. Seventeen lateral cephalometric radiographic cranial base, maxillomandibular, and vertical dimension variables were evaluated and compared among the study groups. The mean angle of SNB, or the intersection of the sella-nasion plane and the nasion–point B line (indicating mandibular retrognathism relative to cranial base), of the symptomatic patients-with-displacement group was significantly smaller than that in the asymptomatic volunteers and symptomatic patients without bilateral disk displacement (p \u3c 0.05). Female subjects showed smaller linear measurements of mandibular length, lower facial height, and total anterior facial height than male subjects in all three groups (p \u3c 0.05). The mean angle of ANB, or the intersection of the nasion–point A and nasion–point B planes (indicating retrognathism of mandible relative to maxilla), was significantly greater in female than in male subjects, in all groups (p \u3c 0.05). Symptomatic patients with bilateral disk displacement had a retropositioned mandible, indicated by a smaller mean SNB angle compared with that in asymptomatic volunteers and symptomatic patients with no disk displacement on either side. Lateral cephalometric radiographic assessment may improve predictability of TMJ disk displacement in orthodontic patients but is not diagnostic; nor does the assessment explain any cause-and-effect relationship. (Am J Orthod Dentofacial Orthop 1998;114:248-55.

Spectrum of arthroscopic findings in 84 canine elbow joints diagnosed with medial compartment erosion

Elbow dysplasia is an important cause of forelimb lameness in large breed dogs. The aim of this study was to report on the arthroscopic findings associated with medial compartment erosion (MCE) of the canine elbow joint. Retrospectively, records of 84 elbow joints from 66 dogs diagnosed arthroscopically with MCE were retrieved from a medical records database (2008 - 2012). The radiographic degree of osteoarthritis was determined. Arthroscopic images and videos were evaluated in detail. In nine joints (10.7%), MCE was the only pathological finding (= group 1). Group 2 (n = 50, 59.5%) consisted of elbows with MCE concomitant with medial coronoid process (MCP) pathology. In group 3 (n = 25 joints, 29.8%), MCE was diagnosed during a second-look arthroscopy in dogs presented with lameness after arthroscopic treatment for medial coronoid disease. There was a significant age difference (p < 0.001) between the groups, with dogs in group 1 being the oldest. Complete erosion of the medial compartment was most commonly found in group 1, whereas focal cartilage erosion was mostly identified in group 2. Overall, additional cartilage pathology of the lateral part of the humeral condyle and/or the radial head was recognized in 58.3% of the joints (49/84)