Tibial tubercle osteotomy in primary total knee arthroplasty: a safe procedure or not?

The objective of this study was to investigate the influence of tibial tubercle osteotomy on postoperative outcome, intra- and postoperative complications, as well as postoperative clinical results and failures in primary total knee arthroplasty (TKA). In a continuous, consecutive series of 1474 primary TKA, we analysed 126 cases where a tibial tubercle osteotomy approach was performed and 1348 cases without tibial tubercle osteotomy. Before surgery, all patients underwent a systematic assessment that included a clinical examination, radiographs (stress hip-knee-ankle film [pangonogram], weight bearing, anteroposterior knee view, schuss view, profile and patellar axial view at 30 degrees, stress valgus and varus view) and International Knee Society scores. When analysing intraoperative complications, tibial plateau fissures or fractures and tibial tubercle fracture were considered as complications relating to the tibial tubercle osteotomy group (p<0.001, p=0.007). With a 2-year minimum follow-up, there was no statistical difference in the number of revisions carried out in the two study groups (p=0.084). However, postoperative tibial tubercle fracture and skin necrosis were significantly related to the osteotomy (p=0.001 and p相似文献   

Neuromodulatory role of acetylcholine in visually-induced cortical activation: behavioral and neuroanatomical correlates

Acetylcholine is released in the primary visual cortex during visual stimulation and may have a neuromodulatory role in visual processing. The present study uses both behavioral and functional neuroanatomy investigations to examine this role in the rat. In the first set of experiments the cholinergic system was lesioned with 192 immunoglobulin G (IgG) saporin and the visual acuity and performance in a visual water maze task were assessed. The cholinergic lesion did not affect the visual acuity measured pre- and post-lesion but it did reduce the efficiency to learn a novel orientation discrimination task measured post-lesion. In order to better understand the involvement of the cholinergic system in the neuronal activity in the visual cortex c-Fos expression induced by patterned visual stimulation was further investigated. Results obtained following lesion of the cholinergic fibers (192 IgG-saporin or quisqualic acid), muscarinic inhibition (scopolamine), or NMDA receptor inhibition (CPP) were compared with control conditions. Double and triple immunolabeling was used in order to determine the neurochemical nature of the activated cortical cells. The results demonstrated that patterned stimulation elicited a significant increase in c-Fos immunolabeled neurons in layer IV of the contralateral primary visual cortex to the stimulated eye which was completely abolished by cholinergic fibers lesion as well as scopolamine administration. This effect was independent of NMDA receptor transmission. The c-Fos activation was predominantly observed in the glutamatergic spiny stellate cells and less frequently in GABAergic interneurons. Altogether, these results demonstrate a strong involvement of the basal forebrain cholinergic system in the modulation of post-synaptic visual processing, which could be related to cognitive enhancement or attention during visual learning.     

Early activation of invariant natural killer T cells in a rheumatoid arthritis model and application to disease treatment

Invariant NKT (iNKT) cells are a distinctive subtype of CD1d‐restricted T cells involved in regulating autoimmunity and capable of producing various T helper type 1 (Th1), Th2 and Th17 cytokines. Activation of iNKT cells by their exogenous ligand α‐galactosylceramide (α‐GalCer) exerts therapeutic effects in autoimmune diseases such as rheumatoid arthritis (RA). However, the pathophysiological role of iNKT cells in RA, in the absence of exogenous stimulation, is incompletely understood. We investigated the potential pathophysiological effects of iNKT cells in mice with collagen‐induced arthritis (CIA), a model of RA. We found that iNKT cells underwent activation only in the early phases of the disease (6 days post‐induction). In the liver, but not the spleen or lymph nodes, this early activation led to the release of interleukins ‐4, ‐17A and ‐10 and of interferon‐γ; and an increased CD69 expression. Importantly, clinical and histological signs of arthritis were improved by the functional blockade of iNKT cells by a monoclonal antibody to CD1d at the early phase of the disease. This improvement was associated on day 6 post‐induction with decreased expression of co‐stimulatory molecules (CD80, CD86, CD40) on splenic dendritic cells and macrophages, whereas regulatory T‐cell suppressive effects and proportions were not modified. Taken in concert, these findings suggest that iNKT cells are activated early in the course of CIA and contribute to the pathogenesis of arthritis. Therefore, iNKT‐cell activation may be a valid treatment target in RA.     

Postmortem computed tomography angiography vs. conventional autopsy: advantages and inconveniences of each method

Purpose

Postmortem computed tomography angiography (PMCTA) was introduced into forensic investigations a few years ago. It provides reliable images that can be consulted at any time. Conventional autopsy remains the reference standard for defining the cause of death, but provides only limited possibility of a second examination. This study compares these two procedures and discusses findings that can be detected exclusively using each method.

Materials and methods

This retrospective study compared radiological reports from PMCTA to reports from conventional autopsy for 50 forensic autopsy cases. Reported findings from autopsy and PMCTA were extracted and compared to each other. PMCTA was performed using a modified heart–lung machine and the oily contrast agent Angiofil® (Fumedica AG, Muri, Switzerland).

Results

PMCTA and conventional autopsy would have drawn similar conclusions regarding causes of death. Nearly 60 % of all findings were visualized with both techniques. PMCTA demonstrates a higher sensitivity for identifying skeletal and vascular lesions. However, vascular occlusions due to postmortem blood clots could be falsely assumed to be vascular lesions. In contrast, conventional autopsy does not detect all bone fractures or the exact source of bleeding. Conventional autopsy provides important information about organ morphology and remains the only way to diagnose a vital vascular occlusion with certitude.

Conclusion

Overall, PMCTA and conventional autopsy provide comparable findings. However, each technique presents advantages and disadvantages for detecting specific findings. To correctly interpret findings and clearly define the indications for PMCTA, these differences must be understood.     

The effect of pelvic movement on the accuracy of hip centre location acquired using an imageless navigation system

Objective  

The aim of this study was to assess the accuracy of an imageless navigation system in localising the hip centre and to evaluate the effect of pelvic movement on the accuracy of hip centre acquisition.     

Sensitivity and specificity of NT-proBNP to detect heart failure at post mortem examination

NT-proBNP, a marker of cardiac failure, has been shown to be stable in post mortem samples. The aim of this study was to assess the accuracy of NT-proBNP to detect heart failure in the forensic setting. One hundred sixty-eight consecutive autopsies were included in the study. NT-proBNP blood concentrations were measured using a chemiluminescent immunoassay kit. Cardiac failure was assessed by three independent forensic experts using macro- and microscopic findings complemented by information about the circumstances of body discovery and the known medical story. Area under the receiving operator curve was of 65.4% (CI 95%, from 57.1 to 73.7). Using a standard cut-off value of >220?pg/mL for NT-proBNP blood concentration, heart failure was detected with a sensitivity of 50.7% and a specificity of 72.6%. NT-proBNP vitreous humor values were well correlated to the ones measured in blood (r (2)?=?0.658). Our results showed that NT-proBNP can corroborate the pathological findings in cases of natural death related to heart failure, thus, keeping its diagnostic properties passing from the ante mortem to the post mortem setting. Therefore, biologically inactive polypeptides like NT-proBNP seem to be stable enough to be used in forensic medicine as markers of cardiac failure, taking into account the sensitivity and specificity of the test.     

Total knee arthroplasty for secondary osteoarthritis following ACL reconstruction: a matched-pair comparative study of intra-operative and early post-operative complications

Injury to the anterior cruciate ligament (ACL) is associated with increased risk of osteoarthritis and subsequent need for total knee arthroplasty (TKA). The impact of prior ACL reconstruction on TKA has been rarely studied. Twenty-two patients undergoing TKA, with a mean of 26 years following ACL reconstruction, were compared to a matched control group. Tibial exposure was more difficult in the study group, requiring tibial tubercle osteotomy in three cases (14%). Manipulation under anesthesia was required in five patients in the study group (23%) and none in the control group (p=0.048). No differences in final range of motion, outcomes scores, or alignment were noted 2 to 3 year post-operative. Total knee arthroplasty following ACL reconstruction is effective. Difficulties in obtaining tibial exposure and post-operative stiffness requiring manipulation under anesthesia are common.