How to use chest radiographs and ECGs in children with pacemakers.

A child with pacemaker is an uncommon presentation to the general paediatric ward, and most clinicians without previous experience may not feel confident in assessing these patients. This article provides an overview of paediatric pacemakers and commonly found radiological and electrophysiological correlates along with clinical consideration.

Epicardial Pacemaker Causing Cardiac Strangulation.

Cardiac strangulation is a rare but potentially lethal complication of epicardial pacemaker insertion. We present the case of a 9-year-old girl who was identified as having cardiac strangulation on routine follow-up for an epicardial pacemaker inserted on day 1 of life for congenital complete heart block (CCHB). The potential clinical presentations and risk factors for pacemaker strangulation are then discussed.

First Tarsometatarsal Joint Fusion in Foot-A Biomechanical Human Anatomical Specimen Analysis with Use of Low-Profile Nitinol Staples Acting as Continuous Compression Implants.

Background and Objectives: The aim of this study was to investigate under dynamic loading the potential biomechanical benefit of simulated first tarsometatarsal (TMT-1) fusion with low-profile superelastic nitinol staples used as continuous compression implants (CCIs) in two different configurations in comparison to crossed screws and locked plating in a human anatomical model. Materials and Methods: Thirty-two paired human anatomical lower legs were randomized to four groups for TMT-1 treatment via: (1) crossed-screws fixation with two 4.0 mm fully threaded lag screws; (2) plate-and-screw fixation with a 4.0 mm standard fully threaded cortex screw, inserted axially in lag fashion, and a 6-hole TMT-1 Variable-Angle (VA) Fusion Plate 2.4/2.7; (3) CCI fixation with two two-leg staples placed orthogonally to each other; (4) CCI fixation with one two-leg staple and one four-leg staple placed orthogonally to each other. Each specimen was biomechanically tested simulating forefoot weightbearing on the toes and metatarsals. The testing was performed at 35-37 °C under progressively increasing cyclic axial loading until construct failure, accompanied by motion tracking capturing movements in the joints. Results: Combined adduction and dorsiflexion movement of the TMT-1 joint in unloaded foot condition was associated with no significant differences among all pairs of groups (p ≥ 0.128). In contrast, the amplitude of this movement between unloaded and loaded foot conditions within each cycle was significantly bigger for the two CCI fixation techniques compared to both crossed-screws and plate-and-screw techniques (p ≤ 0.041). No significant differences were detected between the two CCI fixation techniques, as well as between the crossed-screws and plate-and-screw techniques (p ≥ 0.493) for this parameter of interest. Furthermore, displacements at the dorsal and plantar aspects of the TMT-1 joint in unloaded foot condition, together with their amplitudes, did not differ significantly among all pairs of groups (p ≥ 0.224). Conclusions: The low-profile superelastic nitinol staples demonstrate comparable biomechanical performance to established crossed-screws and plate-and-screw techniques applied for fusion of the first tarsometatarsal joint.

Sore knee - why and when to call a cardiologist.

A young girl received a diagnosis of septic arthritis of the knee unresponsive to standard medical and surgical treatment. We report the patient's clinical journey with clinical commentary throughout, underlying the importance of differential diagnosis that may open several scenarios and a different final diagnosis accordingly. Finally, we will discuss the treatment and management of the patient's final diagnosis.

Midfoot Trauma: Let's Get It Right the First Time.

Lisfranc injuries represent a wide variety of injury patterns, from stable midfoot sprains to grossly displaced fractures and fracture-dislocations. Obtaining and maintaining an anatomic reduction is critical in the treatment of these injuries. Considerable controversy remains as to the optimal method of treatment. Beyond the type and severity of the injury pattern, treatment decisions may ultimately be defined by activity-specific criteria and patient demographics.

Medial talar resection: how much remains stable?

PURPOSE: Pathologies of the medial talus (e.g., fractures, tarsal coalitions) can lead to symptomatic problems such as pain and nonunion. Bony resection may be a good solution for both. It is unclear how much of the medial talus can be taken before the subtalar joint becomes unstable. The aim of this study was to evaluate the effect a limited resection of the medial talar facet and the anteromedial portion of the posterior talar facet has on subtalar stability. METHODS: Eight fresh-frozen human cadaveric lower limbs were mounted in a frame for simulated weight-bearing. Computed tomography scans were obtained under 700 N single-legged stance loading, with the foot in neutral, 15° inversion, and 15° eversion positions. A sequential resection of 10, 20, and 30% of the medial facet and the anteromedial portion of the posterior talar facet to the calcaneus, based on the intact talus width, was performed. Measurements of subtalar vertical angulation, talar subluxation, coronal posterior facet angle and talocalcaneal (Kite) angle in the anteroposterior and lateral view were performed. RESULTS: Gross clinical instability was not observed in any of the specimens. No significant differences were detected in the measurements between the resected and intact states (P ≥ 0.10) as well as among the resected states (P ≥ 0.11). CONCLUSION: In a biomechanical setting, resecting up to 30% of the medial facet and anteromedial portion of the posterior facet based on the intact talus width-does not result in any measurable instability of the subtalar joint in presence of intact ligamentous structures. LEVEL OF EVIDENCE: V.

Macrodystrophia Lipomatosa of the Foot: A Case Report of MRI and Histologic Findings Including Pacinian Corpuscle Abnormalities.

CASE: A 37-year-old man presented with pain and macrodactyly of a toe. Imaging and histology demonstrated findings consistent with macrodystrophia lipomatosa (MDL). We compared our findings with control tissue obtained from an identical site of a fresh-frozen cadaveric foot from the same anatomical site. Pacinian corpuscles (PCs) in the MDL tissue were increased in number, size, and shape compared with the control tissue and demonstrated edematous interstitial lamellae and vacuolar degenerative change. We also document the magnetic resonance imaging findings of the PCs. CONCLUSION: Peculiar abnormalities of PCs in MDL underline nerve damage and may be a contributing factor in the pain associated with this unusual condition.

Exercise prescription improves exercise tolerance in young children with CHD: a randomised clinical trial.

OBJECTIVE: The main objective of this study was to ascertain if a structured intervention programme can improve the biophysical health of young children with congenital heart disease (CHD). The primary end point was an increase in measureable physical activity levels following the intervention. METHODS: Patients aged 5-10 years with CHD were identified and invited to participate. Participants completed a baseline biophysical assessment, including a formal exercise stress test and daily activity monitoring using an accelerometer. Following randomisation, the intervention group attended a 1 day education session and received an individual written exercise plan to be continued over the 4-month intervention period. The control group continued with their usual level of care. After 4 months, all participants were reassessed in the same manner as at baseline. RESULTS: One hundred and sixty-three participants (mean age 8.4 years) were recruited, 100 of whom were male (61.3%). At baseline, the majority of the children were active with good exercise tolerance. The cyanotic palliated subgroup participants, however, were found to have lower levels of daily activity and significantly limited peak exercise performance compared with the other subgroups. One hundred and fifty-two participants (93.2%) attended for reassessment. Following the intervention, there was a significant improvement in peak exercise capacity in the intervention group. There was also a trend towards increased daily activity levels. CONCLUSION: Overall physical activity levels are well preserved in the majority of young children with CHD. A structured intervention programme significantly increased peak exercise capacity and improved attitudes towards positive lifestyle changes.

Cardiac strangulation after epicardial pacing: the importance of non-specific symptoms and a low index of suspicion.

Cardiac strangulation is a rare and potentially deadly complication of epicardial pacemaker implantation. A young boy presenting with chest pain and tiredness almost 7 years after pacemaker implantation was found to have cardiac strangulation. Literature review revealed 22 cases reported to date with a worrying rise in the number of reports over the past 3 years. Strangulation is associated with implantation of leads at a young age and appears to be related to somatic growth. Serial assessment with chest X-ray and echocardiogram is recommended, at least until full adult growth is attained with further coronary artery imaging reserved for symptoms or suspicious echocardiographic findings. If cardiac strangulation is diagnosed prompt replacement of the offending system is needed.

Biomechanical analysis of peri­implant fractures in short versus long cephalomedullary implants following pertrochanteric fracture consolidation.

INTRODUCTION: Pertrochanteric femur fracture fixation with use of cephalomedullary nails (CMN) has become increasingly popular in recent past. Known complications after fracture consolidation include peri­implant fractures following the use of both short and long nails, with fracture lines around the tip of the nail or through the interlocking screw holes, resulting in secondary midshaft or supracondylar femur fractures, respectively. Limited research exists to help the surgeon decide on the use of short versus long nails, while both have their benefits. The aim of this biomechanical study is to investigate in direct comparison one of the newest generations short and long CMNs in a human anatomical model, in terms of construct stability and generation of secondary fracture pattern following pertrochanteric fracture consolidation. METHODS: Eight intact human anatomical femur pairs were assigned to two groups of eight specimens each for nailing using short or long CMNs. Each specimen was first biomechanically preloaded at 1 Hz over 2000 cycles in superimposed synchronous axial compression to 1800 N and internal rotation to 11.5 Nm. Following, internal rotation to failure was applied over an arc of 90° within one second under 700 N axial load. Torsional stiffness as well as torque at failure, angle at failure, and energy to failure were evaluated. Fracture patterns were analyzed. RESULTS: Outcomes in the study groups with short and long nails were 9.7 ± 2.4 Nm/° and 10.2 ± 2.9 Nm/° for torsional stiffness, 119.8 ± 37.2 Nm and 128±46.7 Nm for torque at failure, 13.5 ± 3.5° and 13.4 ± 2.6° for angle at failure, and 887.5 ± 416.9 Nm° and 928.3 ± 461.0 Nm° for energy to failure, respectively, with no significant differences between them, p ≥ 0.17. Fractures through the distal locking screw holes occurred in 5 and 6 femora instrumented with short and long nails, respectively. Fractures through the lateral entry site of the head element were detected in 3 specimens within each group. For short nails, fractures through the distal shaft region, not interfacing with the implant, were detected in 3 specimens. CONCLUSION: From a biomechanical perspective, the risk of secondary peri­implant fracture after intramedullary fixation of pertrochanteric fractures is similar when using short or long CMN. Moreover, for both nail versions the fracture pattern does not unexceptionally involve the distal locking screw hole.

Finding NEEMO: towards organizing smart digital solutions in orthopaedic trauma surgery.

There are many digital solutions which assist the orthopaedic trauma surgeon. This already broad field is rapidly expanding, making a complete overview of the existing solutions difficult.The AO Foundation has established a task force to address the need for an overview of digital solutions in the field of orthopaedic trauma surgery.Areas of new technology which will help the surgeon gain a greater understanding of these possible solutions are reviewed.We propose a categorization of the current needs in orthopaedic trauma surgery matched with available or potential digital solutions, and provide a narrative overview of this broad topic, including the needs, solutions and basic rules to ensure adequate use in orthopaedic trauma surgery. We seek to make this field more accessible, allowing for technological solutions to be clearly matched to trauma surgeons' needs. Cite this article: EFORT Open Rev 2020;5:408-420. DOI: 10.1302/2058-5241.5.200021.

32 year follow up of patients following atrial redirection surgery for transposition of the great arteries.

OBJECTIVE: A significant body of patients who have undergone Mustard or Senning procedure require lifelong follow up. In this retrospective review, we examined the cohort of such patients currently attending our center. DESIGN: Patients who had undergone either Mustard or Senning procedure were identified. We retrospectively reviewed medical records, recorded demographic information and data regarding the clinical state, NHYA class, cardiopulmonary exercise testing, NT-proBNP measurement, and recent cardiac MRI findings. RESULTS: Forty-six patients were identified, the mean age was 32.2 years (± 6.1 years), 67.4% were male. Thirty-two patients (69.6%) had undergone a Senning procedure. The median length of the follow-up was 32 years. Thirty-two patients (69.6%) were NHYA class 1. The mean VO2max achieved was 24.2 ± 5.8 mL/min/kg. The mean NT-proBNP was 266.4 pg/mL (± 259.9 pg/mL). The mean right ventricular end-diastolic volume (RVEDV) was 212.4 mL ± 73.1 mL (indexed 114.2 mL/m2  ± 34.4 mL/m2 ). The mean right ventricular ejection fraction (RVEF) was 53.7% ± 7.9%. The mean left ventricular end-diastolic volume (LVEDV) was 161.5 mL ± 73.7 mL (indexed 87.8 mL/m2  ± 41.1 mL/m2 ). The mean left ventricular ejection fraction (LVEF) was 59.8% ± 5.7%. There was a significant correlation between right ventricular (RV) size on MRI and NT-proBNP level. CONCLUSIONS: We present a relatively well cohort of patients with overall favorable long-term outcome. The majority of patients are NHYA class 1 and the systemic right ventricular function appears to be well preserved as assessed by MRI. The exercise tolerance is reduced, with the majority of patients achieving around 60% of the estimated VO2max . Regular specialist follow-up and assessment with advanced imaging at regular intervals remain important for this group.

Acute and Chronic Syndesmotic Injury: The Authors' Approach to Treatment.

Ankle injuries are a common traumatic injury. Rupture to the syndesmosis may occur as a result of these injuries. Strategies for the treatment of both acute and chronic syndesmotic repair are reviewed in detail. Significance of Chaput, Wagstaffe, and posterior malleolus fractures on syndesmotic stability are reviewed. Treatment considerations for total ankle arthroplasty are discussed, and correction of coronal plane deformity as a result of late syndesmotic injury at the time of ankle arthroplasty is outlined.

Axial and shear pullout forces of composite, porcine and human metatarsal and cuboid bones.

OBJECTIVES: The varying mechanical properties of human bone have influence on the study results. Pullout and shear forces of human bone were compared to different substitutes to evaluate their suitability for biomechanical studies. METHODS: After bone mineral density (BMD) determination, axial pullout tests were performed with cortical 3.5 mm nonlocking (NL) and 2.7 mm head locking (HL) screws on human, porcine and polyurethane composite bones. Porcine and human constructs were additionally loaded in shear direction. RESULTS: Apparent BMD was significantly lower in osteoporotic (159 mgHA/ccm ± 56) and nonosteoporotic (229 mgHA/ccm ± 25) human bone than that in porcine bone (325 mgHA/ccm ± 42; p < 0.01). Axial construct stiffness and ultimate pullout force of porcine bone (NL: 666N/mm ± 226, 910N ± 140; HL: 309N/mm ± 88, 744N ± 185) was significantly different from composite bone (NL: 1284N/mm ± 161; 1175N ± 116; HL: 1241N/mm ± 172, 1185N ± 225) and osteoporotic human bone (NL: 204N/mm ± 121, 185N ± 113; HL: 201N/mm ± 65; 189N ± 58) but not from nonosteoporotic human bone (NL: 620N/mm ± 205, 852N ± 281; HL: 399N/mm ± 224; 567N ± 242). Porcine bone exhibited an ultimate shear force (NL: 278N ± 99; HL: 431N ± 155) comparable to nonosteoporotic human bone (NL: 207 ± 68: HL: 374N ± 137). CONCLUSION: Screw pullout and shear forces of porcine bone are close to nonosteoporotic human bone. THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE: Human bone specimens used in biomechanical studies are predominantly of osteoporotic bone quality. Conclusions on nonosteoporotic human bone behaviour are difficult. Alternatives such as porcine bone and composite bone were investigated, and it could be shown that screw pullout and screw shear forces of porcine bone are close to nonosteoporotic human bone.

Retrospective UK multicentre study of the pregnancy outcomes of women with a Fontan repair.

BACKGROUND: The population of women of childbearing age palliated with a Fontan repair is increasing. The aim of this study was to describe the progress of pregnancy and its outcome in a cohort of patients with a Fontan circulation in the UK. METHODS: A retrospective study of women with a Fontan circulation delivering between January 2005 and November 2016 in 10 specialist adult congenital heart disease centres in the UK. RESULTS: 50 women had 124 pregnancies, resulting in 68 (54.8%) miscarriages, 2 terminations of pregnancy, 1 intrauterine death (at 30 weeks), 53 (42.7%) live births and 4 neonatal deaths. Cardiac complications in pregnancies with a live birth included heart failure (n=7, 13.5%), arrhythmia (n=6, 11.3%) and pulmonary embolism (n=1, 1.9%). Very low baseline maternal oxygen saturations at first obstetric review were associated with miscarriage. All eight women with saturations of less than 85% miscarried, compared with 60 of 116 (51.7%) who had baseline saturations of ≥85% (p=0.008). Obstetric and neonatal complications were common: preterm delivery (n=39, 72.2%), small for gestational age (<10th percentile, n=30, 55.6%; <5th centile, n=19, 35.2%) and postpartum haemorrhage (n=23, 42.6%). There were no maternal deaths in the study period. CONCLUSION: Women with a Fontan circulation have a high rate of miscarriage and, even if pregnancy progresses to a viable gestational age, a high rate of obstetric and neonatal complications.

Removal of scatter radiation in paediatric cardiac catheterisation: a randomised controlled clinical trial.

OBJECTIVE: This study sought to determine if DNA integrity was compromised by ionising radiation from paediatric cardiac catheterisations and if dose optimisation techniques allowed DNA integrity to be maintained. MATERIALS AND METHODS: Children were imaged using either: (i) an anti-scatter grid (current departmental protocol), (ii) no anti-scatter grid or, (iii) no anti-scatter grid and a 15 cm air-gap between the child and the x-ray detector. Dose area product and image quality were assessed, lifetime attributable cancer risk estimates were calculated and DNA double-strand breakages quantified using the γH2AX assay. RESULTS: Consent was obtained from 70 parents/guardians/children. Image quality was sufficient for each procedure performed. Removal of the anti-scatter grid resulted in dose reductions of 20% (no anti-scatter grid) and 30% (15 cm air-gap), DNA double-strand break reductions of 30% (no anti-scatter grid) and 20% (15 cm air-gap) and a reduction of radiation-induced cancer mortality risk of up to 45%. CONCLUSION: Radiation doses received during paediatric cardiac catheterisation procedures resulted in a significant increase in DNA damage while maintaining acceptable image quality and diagnostic efficacy. It is feasible to remove the anti-scatter grid resulting in a reduction in DNA damage to the patient. The γH2AX assay may be used for assessment of dose optimisation strategies in children.

Late Treatment of Syndesmotic Injuries.

Normal syndesmosis anatomy and alignment are essential to ankle function. Although injuries to the syndesmosis are common with ankle injuries, accurate diagnosis and reduction continue to be a challenge. Late reconstruction for syndesmosis is reviewed. A surgical technique for late reconstruction is outlined in detail.

Dystrophin Exon 29 Nonsense Mutations Cause a Variably Mild Phenotype.

BACKGROUND: Nonsense mutations in the dystrophin gene usually result in a severe Duchenne muscular dystrophy phenotype. FINDINGS: We describe a 7-year-old boy with a rare pathogenic mutation in exon 29 c.3940C>T p.(Arg1314Ter) resulting in exon skipping, in turn rescuing the phenotype from a severe Duchenne type to a milder Becker muscular dystrophy type. No adults have been described with this mutation to date. CONCLUSIONS: Exon skipping of exon 29 results in a higher level of functional dystrophin. Some cases of muscular dystrophy may still require muscle biopsy to determine optimal management and pharmaceutical treatment options.