Correction to: Routine versus on demand removal of the syndesmotic screw; a protocol for an international randomised controlled trial (RODEO-trial).

An amendment to this paper has been published and can be accessed via the original article.

Routine versus on demand removal of the syndesmotic screw; a protocol for an international randomised controlled trial (RODEO-trial).

BACKGROUND: Syndesmotic injuries are common and their incidence is rising. In case of surgical fixation of the syndesmosis a metal syndesmotic screw is used most often. It is however unclear whether this screw needs to be removed routinely after the syndesmosis has healed. Traditionally the screw is removed after six to 12 weeks as it is thought to hamper ankle functional and to be a source of pain. Some studies however suggest this is only the case in a minority of patients. We therefore aim to investigate the effect of retaining the syndesmotic screw on functional outcome. DESIGN: This is a pragmatic international multicentre randomised controlled trial in patients with an acute syndesmotic injury for which a metallic syndesmotic screw was placed. Patients will be randomised to either routine removal of the syndesmotic screw or removal on demand. Primary outcome is functional recovery at 12 months measured with the Olerud-Molander Score. Secondary outcomes are quality of life, pain and costs. In total 194 patients will be needed to demonstrate non-inferiority between the two interventions at 80% power and a significance level of 0.025 including 15% loss to follow-up. DISCUSSION: If removal on demand of the syndesmotic screw is non-inferior to routine removal in terms of functional outcome, this will offer a strong argument to adopt this as standard practice of care. This means that patients will not have to undergo a secondary procedure, leading to less complications and subsequent lower costs. TRIAL REGISTRATION: This study was registered at the Netherlands Trial Register (NTR5965), Clinicaltrials.gov ( NCT02896998 ) on July 15th 2016.

Cast immobilization with and without immobilization of the thumb for nondisplaced and minimally displaced scaphoid waist fractures: a multicenter, randomized, controlled trial.

PURPOSE: The aim of this prospective randomized trial was to test the null hypothesis that there was no difference in the percentage of the fracture line of scaphoid waist fractures that demonstrated bridging bone on computed tomography (CT) 10 weeks after injury between patients treated in a below-elbow cast including or excluding the thumb. METHODS: A total of 62 patients with a CT or magnetic resonance image-confirmed nondisplaced or minimally displaced fracture of the scaphoid were enrolled in a prospective, multicenter, randomized trial comparing treatment in a below-elbow cast including or excluding the thumb. There were 55 waist and 7 distal fractures (owing to a miscommunication at 3 of the centers). We adhered to intention-to-treat principles. The primary outcome was the extent of union on CT performed after 10 weeks of cast treatment, expressed as a percentage of the fracture line that had bridging bone, determined by musculoskeletal radiologists blinded to treatment. Secondary study outcomes included wrist motion; grip strength; the Mayo Modified Wrist Score; the Disabilities of the Arm, Shoulder and Hand score; a visual analog scale for pain; and radiographic union at 6 months after injury. RESULTS: There was a significant difference in the average extent of union on CT at 10 weeks (85% vs 70%) favoring treatment with a cast excluding the thumb. The overall union rate was 98%. The 1 exception was a patient in the thumb immobilization group who elected operative treatment 1 week after enrollment, used crutches, and failed to heal. There were no significant differences between groups for wrist motion; grip strength; Mayo Modified Wrist Score; Disabilities of the Arm, Shoulder, and Hand score; or pain intensity. CONCLUSIONS: Immobilization of the thumb appears unnecessary for CT or magnetic resonance image-confirmed nondisplaced or minimally displaced fractures of the waist of the scaphoid. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic I.

Atrial therapies reduce atrial arrhythmia burden in defibrillator patients.

BACKGROUND: Approximately 25% of patients who receive an implantable cardioverter-defibrillator (ICD) to treat ventricular tachyarrhythmias have documented atrial tachyarrhythmias before implantation. This study assessed the ability of device-based prevention and termination therapies to reduce the burden of spontaneous atrial tachyarrhythmias. METHODS AND RESULTS: Patients with a standard indication for the implantation of an ICD and 2 episodes of atrial tachyarrhythmias in the preceding year received a dual-chamber ICD (Medtronic 7250 Jewel AF) that uses pacing and shock therapies for prevention and/or termination of atrial tachyarrhythmias. In a multicenter trial, patients were randomized to 3-month periods with atrial therapies "on" or "off" and subsequently crossed over. Analysis was performed on the 52 of 269 patients who had episodes of atrial tachyarrhythmia and had >/=30 days of follow-up with atrial therapies on and off. The atrial therapies resulted in a reduction of atrial tachyarrhythmia burden from a mean of 58.5 to 7.8 h/mo. A paired analysis (Wilcoxon signed-rank test) showed that the median difference in burden (1.1 h/mo) was highly significant (P=0.007). When the subgroup of 41 patients treated only with atrial pacing therapies was analyzed, the reduction in burden persisted (P=0.01). CONCLUSIONS: In this study, patients with a standard ICD indication and atrial tachyarrhythmias had a significant reduction in atrial tachyarrhythmia burden with use of atrial pacing and shock therapies.

Detection of atrial fibrillation and flutter by a dual-chamber implantable cardioverter-defibrillator. For the Worldwide Jewel AF Investigators.

BACKGROUND: To distinguish prolonged episodes of atrial fibrillation (AF) that require cardioversion from self-terminating episodes that do not, an atrial implantable cardioverter-defibrillator (ICD) must be able to detect AF continuously for extended periods. The ICD should discriminate between atrial tachycardia/flutter (AT), which may be terminated by antitachycardia pacing, and AF, which requires cardioversion. METHODS AND RESULTS: We studied 80 patients with AT/AF and ventricular arrhythmias who were treated with a new atrial/dual-chamber ICD. During a follow-up period lasting 6+/-2 months, we validated spontaneous, device-defined AT/AF episodes by stored electrograms in all patients. In 58 patients, we performed 80 Holter recordings with telemetered atrial electrograms, both to validate the continuous detection of AT/AF and to determine the sensitivity of the detection of AT/AF. Detection was appropriate in 98% of 132 AF episodes and 88% of 190 AT episodes (98% of 128 AT episodes with an atrial cycle length <300 ms). Intermittent sensing of far-field R waves during sinus tachycardia caused 27 inappropriate AT/AF detections; these detections lasted 2.6+/-2.0 minutes. AT/AF was detected continuously in 27 of 28 patients who had spontaneous episodes of AT/AF (96%). The device memory recorded 90 appropriate AT/AF episodes lasting >1 hour, for a total of 2697 hours of continuous detection of AT/AF. During Holter monitoring, the sensitivity of the detection of AT/AF (116 hours) was 100%; the specificity of the detection of non-AT/AF rhythms (1290 hours) was 99.99%. Of 166 appropriate episodes detected as AT, 45% were terminated by antitachycardia pacing. CONCLUSIONS: A new ICD detects AT/AF accurately and continuously. Therapy may be programmed for long-duration AT/AF, with a low risk of underdetection. Discrimination of AT from AF permits successful pacing therapy for a significant fraction of AT.

Epicardial left ventricular lead placement for cardiac resynchronization therapy: optimal pace site selection with pressure-volume loops.

OBJECTIVES: Patients in heart failure with left bundle branch block benefit from cardiac resynchronization therapy. Usually the left ventricular pacing lead is placed by coronary sinus catheterization; however, this procedure is not always successful, and patients may be referred for surgical epicardial lead placement. The objective of this study was to develop a method to guide epicardial lead placement in cardiac resynchronization therapy. METHODS: Eleven patients in heart failure who were eligible for cardiac resynchronization therapy were referred for surgery because of failed coronary sinus left ventricular lead implantation. Minithoracotomy or thoracoscopy was performed, and a temporary epicardial electrode was used for biventricular pacing at various sites on the left ventricle. Pressure-volume loops with the conductance catheter were used to select the best site for each individual patient. RESULTS: Relative to the baseline situation, biventricular pacing with an optimal left ventricular lead position significantly increased stroke volume (+39%, P =.01), maximal left ventricular pressure derivative (+20%, P =.02), ejection fraction (+30%, P =.007), and stroke work (+66%, P =.006) and reduced end-systolic volume (-6%, P =.04). In contrast, biventricular pacing at a suboptimal site did not significantly change left ventricular function and even worsened it in some cases. CONCLUSIONS: To optimize cardiac resynchronization therapy with epicardial leads, mapping to determine the best pace site is a prerequisite. Pressure-volume loops offer real-time guidance for targeting epicardial lead placement during minimal invasive surgery.

The accuracy of serum chlamydial antibodies in the diagnosis of tubal pathology: a meta-analysis.

OBJECTIVE: To assess the discriminative capacity of Chlamydia antibody titers in the diagnosis of tubed pathology in subfertile patients. DESIGN: Meta-analysis of studies comparing Chlamydia antibody titers and laparoscopy for tubal patency and peritubal adhesions. PATIENTS: A total of 2,729 patients with subfertility in 23 studies. INTERVENTION(S): Chlamydia antibody titer and laparoscopy as part of subfertility work-up. MAIN OUTCOME MEASURE: Sensitivity and specificity of Chlamydia antibody titers in the diagnosis of tubal pathology using laparoscopy with chromopertubation as the reference standard. RESULT(S): The discriminative capacity of Chlamydia antibody titers depended on the type of assay that was used. Summary receiver operating characteristic (ROC) curves of studies using ELISA or (micro)immunofluorescence revealed a better discrimination than the summary ROC-curve of studies using immunoperoxidase assay. CONCLUSION(S): The discriminative capacity of Chlamydia antibody titers by means of ELISA, microimmunofluorescence, or immunofluorescence in the diagnosis of any tubal pathology is comparable to that of hysterosalpingography (HSG) in the diagnosis of tubal occlusion. Chlamydia antibody testing involves little burden but provides no details on the anatomy of uterus and tubes. Whether or not Chlamydia antibody testing can replace HSG depends on the perspective taken in the diagnostic work-up of subfertility.

Minimal invasive epicardial lead implantation: optimizing cardiac resynchronization with a new mapping device for epicardial lead placement.

To optimize resynchronization in biventricular pacing with epicardial leads, mapping to determine the best pacing site, is a prerequisite. A port access surgical mapping technique was developed that allowed multiple pace site selection and reproducible lead evaluation and implantation. Pressure-volume loops analysis was used for real time guidance in targeting epicardial lead placement. Even the smallest changes in lead position revealed significantly different functional results. Optimizing the pacing site with this technique allowed functional improvement up to 40% versus random pace site selection.

Merits and limitations of the mode switching rate stabilization pacing algorithms in the implantable cardioverter defibrillator.

BACKGROUND: The 7250 Jewel AF Medtronic model of ICD is the first implantable device in which both therapies for atrial arrhythmias and pacing algorithms for atrial arrhythmia prevention are available. Feasibility of that extensive atrial arrhythmia management requires correct and synergic functioning of different algorithms to control arrhythmias. METHODS AND RESULTS: The ability of the new pacing algorithms to stabilize the atrial rate following termination of treated atrial arrhythmias was evaluated in the marker channel registration of 600 spontaneously occurring episodes in 15 patients with the Jewel AF. All patients (55+/-15 years) had structural heart disease and documented atrial and ventricular arrhythmias. Dual chamber rate stabilization pacing was present in 245 (41 %) of episodes following arrhythmia termination and was a part of the mode switching operation during which pacing was provided in the dynamic DDI mode. This algorithm could function as the atrial rate stabilization pacing only when there was a slow spontaneous atrial rhythm or in presence of atrial premature beats conducted to the ventricles with a normal AV time. In case of atrial premature beats with delayed or absent conduction to the ventricles and in case of ventricular premature beats, the algorithm stabilized the ventricular rate. The rate stabilization pacing in DDI mode during sinus rhythm following atrial arrhythmia termination was often extended in time due to the device-based definition of arrhythmia termination. This was also the case in patients, in whom the DDD mode with true atrial rate stabilization algorithm was programmed. CONCLUSIONS: The rate stabilization algorithms in the Jewel AF applied after atrial arrhythmia termination provide pacing that is not based on the timing of atrial events. Only under certain circumstances the algorithm can function as atrial rate stabilization pacing. Adjustments in availability and functioning of the rate stabilization algorithms might be of benefit for the clinical performance of pacing as part of device therapy for atrial arrhythmias.

Interactions between pacing and arrhythmia detection algorithms in the dual chamber implantable cardioverter defibrillator.

Dual chamber implantable cardioverter defibrillator (ICD) combines the possibility to detect and treat ventricular and atrial arrhythmias with the possibility of modern heart stimulation techniques. Advanced pacing algorithms together with extended arrhythmia detection capabilities can give rise to new types of device-device interactions. Some of the possible interactions are illustrated by four cases documented in four models of dual chamber ICDs. Functioning of new features in dual chamber devices is influenced by the fact that the pacemaker is not a separate device but a part of the ICD system and that both are being used in a patient with arrhythmia. Programming measures are suggested to optimize use of new pacing algorithms while maintaining correct arrhythmia detection.

Inguinal hernia repair in the Amsterdam region 1994-1996.

In the Netherlands, approximately 30,000 inguinal hernia repairs are performed yearly. At least 15% are for recurrence. New procedures are being introduced creating discussion on which technique is the best. Currently it is not possible to choose on evidence alone because of the long follow-up that is needed. In 1996 an inventory was taken of all inguinal hernia repairs that were performed in the Amsterdam region (9 hospitals). These results were compared with the results from a similar study performed in 1994. Major changes in treatment strategy were noted. The Bassini repair was replaced by Shouldice and Lichtenstein techniques. There was a significant increase in the use of prostheses for both primary and recurrent inguinal hernias. There was no significant decrease in the percentage of operations performed for recurrent hernia from 19.5% to 16.8%. However, there was a significant decrease in operations performed for early recurrences (5.1%-3.4%) (p = 0.05). These results suggest that the Shouldice and Lichtenstein repairs may be superior to the Bassini repair in terms of early hernia recurrence.

Performance of time delay estimation methods for small time shifts in ultrasonic signals.

In this study several time delay estimation (TDE) methods were investigated for estimation of time shifts of less than 10 ns at a frequency of 30 MHz. Using simulated and experimental echosignals we investigated the performance of five methods: two phase related methods (phase shift and phase difference method); two correlation methods (cross-correlation and correlation interpolation method); and a demodulation method. The results showed that the correlation interpolation method is by far the most accurate for all time delays. With this method, estimation errors of about 200 ps are achievable with an signal-to-noise ratio (SNR) of 40 dB (f0 = 30 MHz, bandwidth = 20 MHz) for time shifts of up to 10 ns.

[Radiofrequency energy as treatment for arrhythmias in patients with accessory atrioventricular pathways]. / Radiofrequente energie als behandeling voor hartritmestoornissen bij patiënten met extra atrioventriculaire verbindingen.

OBJECTIVE: Evaluation of the use of radiofrequency energy to interrupt accessory atrioventricular pathways. DESIGN: Prospective study. SETTING: University Hospital Maastricht. METHOD: The outcome is presented of radiofrequency catheter ablation of accessory atrioventricular pathways in our first 50 consecutive patients, with a total of 54 accessory pathways. All but one patient suffered from symptomatic tachycardias. A catheter electrode was positioned next to the accessory pathway and 30 second pulses of 40 W radiofrequency energy were used to interrupt the connection. RESULTS: Complete block in conduction was accomplished in 44/54 (81%) of accessory pathways. No complications occurred. Success rate, procedure time and radiation dose were found to be related to the location of the accessory connection. The highest success rate was found in left free wall pathways (24/26; 92%), the lowest in right lateral pathways which seldom occur (1/4; 25%). The total procedure took 1-6 hours. The maximal duration of radiographic imaging was 2.5 hours. CONCLUSION: Although insufficient information on long-term efficacy is available, current results support the use of radiofrequency ablation of accessory pathways in institutions with expertise in the invasive management of cardiac arrhythmias. Technical improvements leading to reduction in procedure time and radiation dose will facilitate acceptance of this technique by patient and operator.

Recommendations for pacemaker implantation for the treatment of atrial tachyarrhythmias and resynchronisation therapy for heart failure: A report from the task force on pacemaker indications of the Dutch Working Group on Cardiac Pacing.

Today, new pacing algorithms and stimulation methods for the prevention and interruption of atrial tachyarrhythmias can be applied on patients who need bradycardia pacing for conventional reasons. In addition, biventricular pacing as additive treatment for patients with severe congestive heart failure due to ventricular systolic dysfunction and prolonged intraventricular conduction has shown to improve symptoms and reduce hospital admissions. These new pacing technologies and the optimising of the pacing programmes are complex, expensive and time-consuming. Based on many clinical studies the indications for these devices are beginning to emerge. To support the cardiologist's decision-making and to prevent waste of effort and resources, the 'ad hoc committee' has provided preliminary recommendations for implantable devices to treat atrial tachyarrhythmias and to extend the treatment of congestive heart failure respectively.

Incidence and characteristics of distal radial fractures in an urban population in The Netherlands.

The increasing incidence of distal radius fracture is thought to be due to the aging population. Surprisingly, some authors have reported a decrease in the incidence of distal radius fracture. Moreover, the type-specific incidence of distal radial fracture classified according to fracture severity is not well documented. The aim of this population-based study was to estimate the overall and type-specific incidences of distal radius fracture in a urban population in The Netherlands. During 2009, all persons aged ≥18 years old with an acute distal radius fracture in two hospitals in The Netherlands were prospectively registered. In 2009, the mid-year study population consisted of 245,559 inhabitants ≥18 years old. Fractures were categorized according to the AO classification. 494 patients with acute distal radius fractures were registered in the two participating hospitals during the 1-year study period. The overall incidence of distal radius fracture was 20 per 10,000 person-years. Among women, the incidence rate increased from the age of 50 and reached a peak of 124 per 10,000 person-years in women 80 years and older. Among men, the incidence rate was low until the age of 80 years and older, and reached a peak of 24 per 10,000 person-years. The incidence rate among women between 50 and 79 years was 54/10,000 person-years. Extra-articular AO type A fractures were most common among all age groups, comprising 50 % of all fractures (40 % in men and 53 % in women). The overall incidence rate of distal radius fracture was 20 per 10,000 person-years. This incidence increases with age for both women and men. A lower incidence rate among women 50-79 years of age was found than previously reported, which may indicate a declining incidence in this age group. Extra-articular AO type A fractures were the most common fracture types.

Importance of the atrial channel for ventricular arrhythmia therapy in the dual chamber implantable cardioverter defibrillator.

INTRODUCTION: Performance of dual chamber implantable cardioverter defibrillator (ICD) systems has been judged based on functioning of the ventricular tachycardia:supraventricular tachycardia (VT:SVT) discrimination criteria and DDD pacing. The purpose of this study was to evaluate the use of dual chamber diagnostics to improve the electrical and antiarrhythmic therapy of ventricular arrhythmias. METHODS AND RESULTS: Information about atrial and ventricular rhythm in relation to ventricular arrhythmia occurrence and therapy was evaluated in 724 spontaneous arrhythmia episodes detected and treated by three types of dual chamber ICDs in 41 patients with structural heart disease. Device programming was based on clinically documented and induced ventricular arrhythmias. In ambulatory patients, sinus tachycardia preceded ventricular arrhythmias more often than in the hospital during exercise testing. The incidence of these VTs could be reduced by increasing the dose of a beta-blocking agent in only two patients. In five patients in whom sinus tachycardia developed after onset of hemodynamic stable VT, propranolol was more effective than Class III antiarrhythmics combined with another beta-blocking agent with regard to the incidence of VT and pace termination. In all but three cases, atrial arrhythmias were present for a longer time before the onset of ventricular arrhythmias. During atrial arrhythmias, fast ventricular rates before the onset of ventricular rate were observed more often than RR irregularities and short-long RR sequences. Dual chamber diagnostics allowed proper interpretation of detection and therapy outcome in patients with different types of ventricular arrhythmia. CONCLUSION: The advantages of the dual chamber ICD system go further than avoiding the shortcomings of the single chamber system. Information from the atrial chamber allows better device programming and individualization of drug therapy for ventricular arrhythmia.

Diagnosis and therapy of atrial tachyarrhythmias in the dual chamber implantable cardioverter defibrillator.

INTRODUCTION: Devices capable of monitoring and treating atrial tachyarrhythmias provide information about the natural history of the arrhythmias and potentially can influence their natural course by electrical therapy early after onset. METHODS AND RESULTS: Types of atrial arrhythmias and efficacy of device therapies were evaluated in 30 patients implanted with the Medtronic model 7250 Jewel AF implantable cardioverter defibrillator (ICD). All patients had structural heart disease and documented sustained ventricular and atrial arrhythmias (27 with atrial fibrillation [AF]) before implant. Twenty patients were taking amiodarone, and three were taking sotalol. During 20+/-10 months of follow-up, 600 atrial arrhythmia recurrences were documented in 50% of patients. AF was diagnosed in 19%, fast polymorphic atrial tachycardia (AT) in 20%, fast monomorphic AT in 57%, and slow AT in 4% of episodes. The two adaptive pacing therapies, burst and ramp, together with the 50-Hz burst, were successful in 57% of detected atrial arrhythmias. Burst and ramp were responsible for 49% and 50-Hz burst for 51% of successfully treated arrhythmias; 33% of the episodes terminated spontaneously. No ventricular proarrhythmia was observed due to atrial pacing therapies. In 30% of episodes, dual chamber pacing was required due to post termination bradycardia. Atrial arrhythmia recurrences in patients with dilated cardiomyopathy were not amenable to pacing therapies. Several aspects of atrial arrhythmia diagnosis, therapy, and documentation that are specific for functioning of the Jewel AF are discussed. CONCLUSION: Atrial arrhythmias in ICD patients with diseased hearts who are taking Class III antiarrhythmics frequently had longer cycle lengths than AF. Half of these arrhythmias could be terminated with pacing therapies; one third terminated spontaneously.

Dual chamber arrhythmia detection in the implantable cardioverter defibrillator.

INTRODUCTION: Dual chamber implantable cardioverter defibrillator (ICD) technology extended ICD therapy to more than termination of hemodynamically unstable ventricular tachyarrhythmias. It created the basis for dual chamber arrhythmia management in which dependable detection is important for treatment and prevention of both ventricular and atrial arrhythmias. METHODS AND RESULTS: Dual chamber detection algorithms were investigated in two Medtronic dual chamber ICDs: the 7250 Jewel AF (33 patients) and the 7271 Gem DR (31 patients). Both ICDs use the same PR Logic algorithm to interpret tachycardia as ventricular tachycardia (VT), supraventricular tachycardia (SVT), or dual (VT+ SVT). The accuracy of dual chamber detection was studied in 310 of 1,367 spontaneously occurring tachycardias in which rate criterion only was not sufficient for arrhythmia diagnosis. In 78 episodes there was a double tachycardia, in 223 episodes SVT was detected in the VT or ventricular fibrillation zone, and in 9 episodes arrhythmia was detected outside the boundaries of the PR Logic functioning. In 100% of double tachycardias the VT was correctly diagnosed and received priority treatment. SVT was seen in 59 (19%) episodes diagnosed as VT. The causes of inappropriate detection were (1) algorithm failure (inability to fulfill the PR

Initial experience with mode switching in a dual sensor, dual chamber pacemaker in patients with paroxysmal atrial tachyarrhythmias.

Mode switching algorithms have been developed to avoid tracking of atrial fibrillation (AF) or flutter (AFL) during DDD(R) pacing. Upon recognition of AF or AFL, the mode is switched to a nontracking, sensor driven mode. The Vitatron Diamond model 800 pacemaker does this on a beat-to-beat basis. Atrial events occurring within a "physiological range" (+/- 15 beats/min) calculated from a running average of the atrial rate are tracked. When atrial events are not tracked the escape interval is either determined by the sensor(s) or by a fallback algorithm thereby preventing large increases in V-V interval during mode switching. Loss of atrioventricular (AV) synchrony by atrial premature beats and after an episode of AF or AFL is prevented by atrial synchronization pulses (ASP), which are delivered after a safe interval (timed out from the sensed premature atrial event) has expired and before delivery of the next ventricular stimulus. We implanted 26 such devices in 18 men and 8 women with symptomatic second- or third-degree AV block and paroxysmal AF or AFL. Their ages ranged from 18-84 years (mean 60), and the follow-up ranged from 2-13 months (mean 8). During pacemaker check-up, exercise testing or 24-hour Holter monitoring one or more episodes of mode switching was documented in 8 patients. In these 8 patients a smooth transition (ventricular rate) from sinus rhythm to AF or AFL was documented on one or more occasions, without inappropriate increase in ventricular rate in the DDDR mode. None of the patients complained of palpitations.(ABSTRACT TRUNCATED AT 250 WORDS)