Legg‐Calvé‐Perthes Disease Produces Chronic Hip Synovitis and Elevation of Interleukin‐6 in the Synovial Fluid

Legg‐Calvé‐Perthes disease (LCPD) is a childhood hip disorder of ischemic osteonecrosis of the femoral head. Hip joint synovitis is a common feature of LCPD, but the nature and pathophysiology of the synovitis remain unknown. The purpose of this study was to determine the chronicity of the synovitis and the inflammatory cytokines present in the synovial fluid at an active stage of LCPD. Serial MRI was performed on 28 patients. T2‐weighted and gadolinium‐enhanced MR images were used to assess synovial effusion and synovial enhancement (hyperemia) over time. A multiple‐cytokine assay was used to determine the levels of 27 inflammatory cytokines and related factors present in the synovial fluid from 13 patients. MRI analysis showed fold increases of 5.0 ± 3.3 and 3.1 ± 2.1 in the synovial fluid volume in the affected hip compared to the unaffected hip at the initial and the last follow‐up MRI, respectively. The mean duration between the initial and the last MRI was 17.7 ± 8.3 months. The volume of enhanced synovium on the contrast MRI was increased 16.5 ± 8.5 fold and 6.3 ± 5.6 fold in the affected hip compared to the unaffected hip at the initial MRI and the last follow‐up MRI, respectively. In the synovial fluid of the affected hips, IL‐6 protein levels were significantly increased (LCPD: 509 ± 519 pg/mL, non‐LCPD: 19 ± 22 pg/mL; p = 0.0005) on the multi‐cytokine assay. Interestingly, IL‐1β and TNF‐α levels were not elevated. In the active stage of LCPD, chronic hip synovitis and significant elevation of IL‐6 are produced in the synovial fluid. Further studies are warranted to investigate the role of IL‐6 on the pathophysiology of synovitis in LCPD and how it affects bone healing. © 2015 American Society for Bone and Mineral Research     

A New Type of Dual Atrioventricular Nodal Nonreentrant Tachycardia

Dual atrioventricular nodal nonreentrant tachycardia (DAVNNT) is very rarely observed clinically. The first review of this arrhythmia was published in 2011 by Wang, where four types of DAVNNT were described. Our case report presents a phenomenon that has never been published before. We revealed a very specific sequence of double fire phenomenon, 1:1 atrioventricular (AV) conduction and AV block.     

Total Hip Arthroplasty via direct anterior approach for osteonecrosis; comparison with primary hip osteoarthritis in a mid term follow up

BackgroundTo determine the mid-term outcomes of conventional cementless Total Hip Arthroplasty (THA) in patients with avascular necrosis (AVN) of the femoral head and compare to patients with primary hip osteoarthritis (OA).MethodA total of 330 consecutive primary THA procedures (AVN and OA) performed between 2010 and 2013 by a single surgeon and in a single center using the direct anterior approach (DAA) were included. Assessments including SF-36, WOMAC, and Harris Hip Scores (HHS) were retrieved from patients before the surgery and at the latest follow-up. Clinical and functional outcomes were compared between the AVN and OA groups.ResultsA total of 294 consecutive THA (AVN = 107, OA = 187) with 104.4 ± 6.2 months follow-up were analyzed, which AVN patients were significantly younger (32.0 vs. 59.6 y/o). Corticosteroid 34 (31.8%), idiopathic AVN 31 (29.0%) and use of unapproved weight gain supplements (UWGS) 23 (21.5%) were the main reasons for AVN. Despite that preoperative scores were comparable (P > 0.05), the HHS, SF-36, and WOMAC scores are significantly higher in the AVN group after THA surgery (P < 0.05). Moreover, flexion and abduction ROM were significantly higher in the AVN group (P < 0.05). Regarding each complication, no significant difference was observed between groups. In the whole sample, there were 5 (1.7%) revisions due to loosening of acetabular components, all the OA group (P > 0.05).ConclusionConventional cementless THA with highly cross-linked polyethylene provides satisfactory mid-term results in patients with AVN with a low rate of postoperative complications. Compared to primary OA patients, this group reaches superior postoperative scores.     

Traumatic bilateral posterior hip dislocation in 10 year old male child

Traumatic bilateral posterior hip dislocation in skeletally immature patient is reported very less in literature. We report a 10 yr old boy presented to us following farmyard injury with bilateral posterior hip dislocation, which was reduced manually under sedation with uneventful follow-up and complete hip range of motion at 2 year.     

激素性股骨头坏死模型的建立及病理和影像学特征

目的建立兔激素性股骨头坏死动物模型,观察激素性股骨头坏死的病理及影像学特征。方法将20只健康新西兰兔随机分成两组,每组10只。A组:模型组,注射马血清及醋酸泼尼松龙造模;B组:正常对照组。采用X片及CT观察股骨头形态的变化,处死动物,标本进行常规组织病理学检查,并进行动脉墨汁灌注观察。结果X片及CT结果显示:造模组两侧股骨头密度不均一,关节面模糊;墨汁灌注血管造影显示股骨头血管显著减少;病理组织学观察结果显示:骨小梁骨细胞陷窝空疏,骨细胞核固缩,部分血管栓塞,骨髓腔内造血组织明显减少。结论马血清、激素诱导的激素性股骨头坏死动物模型病理变化、影像学改变符合临床典型股骨头坏死的特征,为进一步研究股骨头坏死发病机制及治疗方法提供基础。     

导管射频消融改良房室结治疗快心室率心房颤动结果的评价

采用房室结有效不应期和文氏点、心房肌波长指数，心室率等指标的变化评价导管射频消融改良房室结治疗心房颤动的疗效。方法９例患者，８例为阵发性房颤，１例持续发性房颤。７例诊断特发性房颤。电生理检查与导管射频消融一次完成。     

Clinical cardiac electrophysiologic effects of adenosine

Adenosine is very useful for the acute diagnosis and treatment of tachycardias in humans. Adenosine's major cardiac effect, when given as a bolus, is to produce transient atrioventricular block. It can be used either to terminate tachycardias that involve the atrioventricular node or to transiently reveal an atrial tachycardia by slowing the ventricular response, and so to allow the diagnosis to be made. Adenosine is effective in the diagnosis of broad complex tachycardias, revealing and terminating supraventricular tachycardias, with usually no effect on ventricular tachycardia. Adenosine's great advantages over verapamil are its safety, especially in haemodynamically unstable patients, and its short half-life. Is major disadvantage is the somatic side effects it produces: chest pain, deep breathing, flushing, and a variety of other sensations. Adenosine's effects on other tachycardias also gives an insight into their mechanisms. Right ventricular outflow tachycardia is terminated by adenosine, which supports the thesis that it is due to triggered afterdepolarizations. This may be the explanation for the termination of some atrial tachycardias by adenosine. Sinus node reentry tachycardia is slowed and terminated by adenosine, suggesting that at least part of the tachycardia circuit is in the sinus node. To conclude, the ability of adenosine to selectively block atrioventricular conduction, combined with its very short half-life, make it a very useful drug both clinically and in the electrophysiology laboratory. © 1993 Wiley-Liss, Inc.     

Characteristics of slow pathway conduction after successful AVNRT ablation

Background: AV node slow pathway conduction can persist following successful ablation for AV node reentrant tachycardia (AVNRT). We hypothesized that careful examination of AV nodal conduction curves before and after effective AVNRT ablation in patients with persistent slow pathway conduction could shed light on this apparent paradox.
Methods and Results: Thirty patients (age 40.9 ± 14.3; 8 male) were included. AV node function curves were created based on pre- and postablation atrial extrastimulus testing. Analysis of slow pathway function curves demonstrated significant decrease in AH for any given coupling interval after ablation (mean difference –68.1 [–94.5, –41.7] P < 0.001), graphically indicated by downward displacement of the curve. In addition, mean slow pathway effective refractory period (ERP) increased from 247.9 ± 36.1 msec to 288.6 ± 56.0 msec (P < 0.001); mean maximum AH interval decreased from 361.3 ± 114.2 msec to 306.9 ± 65.2 msec (P = 0.013 ) ; mean difference in minimum and maximum AH interval during slow pathway conduction decreased (from 94.5 ± 75.8 msec to 59.6 ± 46.2 msec (P = 0.016 ). Finally, mean difference between the fast and slow pathway effective refractory periods, the span of coupling intervals over which slow pathway conduction occurred, decreased (from 113.9 ± 61.4 msec to 63.2 ± 41.5 msec, P = 0.001).
Conclusions: Ablation, which successfully eliminates inducible and spontaneous AVNRT in the presence of persistent slow pathway conduction, is associated with significantly altered slow pathway conduction characteristics, indicating the presence of a damaged or different slow pathway after ablation, incapable of sustaining tachycardia.