Outcome of Percutaneous Tenotomy in the Management of Congenital Talipes Equino Varus by Ponseti Method.

Congenital talipes equino varus (CTEV) is a common complex congenital anomaly affecting approximately 1 per 900 live births in Bangladesh. Current trends in the treatment of idiopathic clubfoot have shifted from extensive surgical release to more conservative techniques. The Ponseti method that includes manipulation, serial casting, percutaneous tenotomy and bracing has recently become very popular for the management of CTEV with reported excellent outcomes. The purpose of this study was to evaluate the outcomes of Percutaneous Tenotomy in the treatment of equinus deformity of idiopathic clubfoot. Between June 2012 and November 2013 we treated 47 feet in 34 children by the Ponseti method. The standard protocol described by Ponseti was used. Percutaneous tenotomy of the Achilles tendon was performed under local anaesthesia in the outpatient department of Dhaka Medical College Hospital. The Pirani score was used for assessment and mean follow up time was 12 months. The compliance of percutaneous tenotomy among the 47 feet was recorded and 40(85.1%) were good, 4(8.5%) were fair and 3(6.4%) were poor. The rating of final outcome of percutaneous tenotomy after one year follow-up periods among 47 feet, 36(76.6%) were good, 11(23.4%) were fair and zero (0%) were poor. This study permits to conclude the percutaneous tenotomy in Ponseti method as a safe, effective outdoor procedure to correct the residual equinus deformity of club foot after serial casting.

Correction: First principles study of electronic and optical properties and photocatalytic performance of GaN-SiS van der Waals heterostructure.

[This corrects the article DOI: 10.1039/D1RA06011B.].

Correction: Theoretical prediction of the electronic structure, optical properties and photocatalytic performance of type-I SiS/GeC and type-II SiS/ZnO heterostructures.

[This corrects the article DOI: 10.1039/D3RA01061A.].

Theoretical prediction of the electronic structure, optical properties and photocatalytic performance of type-I SiS/GeC and type-II SiS/ZnO heterostructures.

Nowadays, it would be ideal to develop high-performance photovoltaic devices as well as highly efficient photocatalysts for the production of hydrogen via photocatalytic water splitting, which is a feasible and sustainable energy source for addressing the challenges related to environmental pollution and a shortage of energy. In this work, we employ first-principles calculations to investigate the electronic structure, optical properties and photocatalytic performance of novel SiS/GeC and SiS/ZnO heterostructures. Our results indicate that both the SiS/GeC and SiS/ZnO heterostructures are structurally and thermodynamically stable at room temperature, suggesting that they are promising materials for experimental implementation. The formation of SiS/GeC and SiS/ZnO heterostructures gives rise to reduction of the band gaps as compared to the constituent monolayers, enhancing the optical absorption. Furthermore, the SiS/GeC heterostructure possesses a type-I straddling gap with a direct band gap, while the SiS/ZnO heterostructure forms a type-II band alignment with indirect band gap. Moreover, a red-shift (blue-shift) has been observed in SiS/GeC (SiS/ZnO) heterostructures as compared with the constituent monolayers, enhancing the efficient separation of photogenerated electron-hole pairs, thereby making them promising candidates for optoelectronic applications and solar energy conversion. More interestingly, significant charge transfers at the interfaces of SiS-ZnO heterostructures, have improved the adsorption of H, and the Gibbs free energy ΔH* becomes close to zero, which is optimal for the hydrogen evolution reaction to produce hydrogen. The findings pave the path for the practical realization of these heterostructures for potential applications in photovoltaics and photocatalysis of water splitting.

A Modified Approach for Harvesting Non Vascularized Fibular Graft for Pediatric Age Group.

The conventional technique of harvesting free non-vascularized fibular grafting is associated with different scale of morbidity and usually a long scar. We follow a technique that causes minimum interference to the surrounding soft tissues to harvest the desired length of fibula. This prospective study was performed at Department of Orthopaedics, Dhaka Medical College Hospital from January 2018 to December 2018. Thirty patients of average age 10.5 years (range 8 to 14 years) were taken up for the study. The fibula was harvested by two separate incisions, 1 cm each at proximal and distal extent of proposed length of graft after elevating the periosteum circumferentially using a periosteum elevator. Compression bandage and above knee plaster immobilization was applied that help to reduce hematoma formation. The mean follow up is 12 months. The patients were evaluated clinically and by radiology. Twenty nine patients showed good results. One patient had delayed wound healing resulting in fair result. This modified approach of harvesting fibula reduces donor site morbidity and is safer and easier than conventional approach.

Outcomes of Varus Derotation Femoral Osteotomy By Angle Blade Plate in Legg-Calve-Perthes Disease for Patient Above Eight Years of Age in The Lateral Pillar B or B/C Group.

Legg-Calve-Perthes disease (LCPD) that starts after 8 years (late onset) usually follow more aggressive course and the long-term outcome is also poor. Treatment method of LCPD that will produce best results is controversial particularly if the patients are with late-onset presentation. This prospective study was conducted from January 2015 to January 2019 at Dhaka Medical College Hospital and Health N Hope Hospital, Dhaka, Bangladesh. We evaluated the radiographic outcomes for patients who had varus derotation femoral osteotomy (VDRO). We followed up 16 patients who had femoral varus osteotomy. All patients were above 8 years of age at clinical onset. The involvement of femoral epiphysis was in either in B or B/C in lateral pillar classification. All patients had MRI done to confirm radiological diagnosis and classification. The mean age was 9.5 years (range, 8 to 12 years). Final outcome was evaluated by using the Stulberg classification which was radiological. Important exclusion criteria were patient with bilateral involvement and requirement of femoral varus >30 degree. We had 81.25% of our patient with satisfactory outcomes. Among them there were Stulberg grade I, 0 cases; Stulberg grade II, 13 cases (81.25%); Stulberg III, 3 cases (18.75%), Stulberg IV and V both 0 case each. The surgical outcomes for varus derotation femoral osteotomy in late onset LCPD patients over 8 years old were showing the good results than other modalities of non surgical and surgical methods.

A first principles study of a van der Waals heterostructure based on MS2 (M = Mo, W) and Janus CrSSe monolayers.

The strategy of stacking two-dimensional materials for designing van der Waals heterostructures has gained tremendous attention in realizing innovative device applications in optoelectronics and renewable energy sources. Here, we performed the first principles calculations of the geometry, optoelectronic and photocatalytic performance of MS2-CrSSe (M = Mo, W) vdW heterostructures. The mirror asymmetry in the Janus CrSSe system allows the designing of two models of the MS2-CrSSe system by replacing S/Se atoms at opposite surfaces in CrSSe. The feasible configurations of both models of the MS2-CrSSe system are found energetically, dynamically and thermally stable. The studied heterobilayers possess an indirect type-I band alignment, indicating that the recombination of photogenerated electrons and holes in the CrSSe monolayer is hence crucial for photodetectors and laser applications. Remarkably, a red-shift in the optical absorption spectra of MS2-CrSSe makes them potential candidates for light harvesting applications. More interestingly, all heterobilayers (except W(Mo)S2-CrSSe of model-I(II)) reveal appropriate band edge positions of the oxidation and reduction potentials of the photocatalysis of water dissociation into H+/H2 and O2/H2O at pH = 0. These results shed light on the practical design of the MS2-CrSSe system for efficient optoelectronic and photocatalytic water splitting applications.

First principles study of electronic and optical properties and photocatalytic performance of GaN-SiS van der Waals heterostructure.

The vertical stacking of two-dimensional materials via van der Waals (vdW) interaction is a promising technique for tailoring the physical properties and fabricating potential devices to be applied in the emerging fields of materials science and nanotechnology. The structural, electronic and optical properties and photocatalytic performance of a GaN-SiS vdW heterostructure were explored using first principles calculations. The most stable stacking configuration found energetically stable, possesses a direct staggered band gap, which is crucial for separating photogenerated charged carriers in different constituents and is efficacious for solar cells. Further, the charge transfer occurred from the SiS to GaN layer, indicating that SiS exhibits p-type doping in the GaN-SiS heterobilayer. Interestingly, a systematic red-shift was observed in the optical absorption spectra of the understudy heterobilayer system. Moreover, the conduction band edge and valence band edge of the monolayers and corresponding heterostructure were located above and below the standard redox potentials for photocatalytic water splitting, making these systems promising for water dissociation for hydrogen fuel production. The results provide a route to design the GaN-SiS vdW heterostructure for the practical realization of next-generation light detection and energy harvesting devices.

Core Decompression with Non Vascularized Fibular Graft as Modern Surgical Treatment of Early Hip Avascular Necrosis.

Cellular death of bone due to impairment of the blood supply leading to collapse resulting in pain, and loss of joint function is known as avascular necrosis (AVN). The head of femur is the most common bone affected by avascular necrosis followed by talus and scaphoid. We evaluate the results of core decompression with non-vascularized fibular graft in avascular necrosis of femoral head. This quasi experimental study was done at Mymensingh Medical College Hospital, Dhaka Medical College Hospital and some other private hospitals of Bangladesh. The study includes patients who underwent core decompression and non-vascularized fibular grafting in avascular necrosis of femoral head from January 2017 to December 2018. In this study we evaluated total 20 patients and majority of the patients belongs to the group of 20-30 years. Out of 20 patients, 8 of them were unilaterally involved rest 12 had bilateral involvement. Out of 24 hips of bilateral involvement 4 were grade III and IV (Ficat and Arlet classification) therefore not included in the study. So, we study 28 hips only. The average success rate was 90% after core decompression and non-vascularized fibular bone grafting. Harris hip score of 60 on presentation had poorer outcome. Patients with less than 80 degrees of flexion had poorer outcome.

Evaluation of Outcome of Exchange Nailing with Autogenous Bone Graft for Treating Aseptic Nonunion of Femoral Shaft Fracture.

Femoral shaft fractures are severe injuries and challenging for both, the patient and the surgeon. This study has been designed to assess the success rate of exchange nailing with autogenous cancellous bone graft for the treatment of non united femoral shaft fractures previously treated by ORIF with intramedullary nail. This quasi experimental study was carried out in the Department of Orthopaedics & Traumatology of Dhaka Medical College Hospital and NITOR from July 2007 to December 2008. Thirteen patients were followed up regularly for at least 1 (one) year after each operation to assess the functional outcome as well as union time according to the prescribed scoring system. Final outcome was analyzed by SPSS-18 version. Level of significance was set at 0.05 (p<0.05). In this study exchange nailing with autogenous cancellous bone graft were done for femoral shaft fracture with nonunion in 13 patients. Mean±SD age was 39.08±5.780 years; Male: Female = 9:4. Among 13 nonunion fractures, all (100%) were united after exchange nailing with autogenous cancellous bone graft in aseptic condition. Mean union time was 26.97±2.976 weeks in static mode of fixation. Union time was highest in atrophic type of fracture and lowest in hypertrophic type of fracture. Final outcome according to modified Thoresen's score was satisfactory 92.29%; according to modified Silvia's score was 10.77±0.832. Exchange nailing with autogenous cancellous bone graft is an effective method of treatment in femoral shaft fracture with nonunion after intramedullary nailing. It provides a good scope to reinforce the optimum mechanical stability by a larger diameter nail and locked if necessary; as well as biological stimulation by reaming and bone grafting.

New Delhi metallo-ß-lactamase (NDM-1): an update.

New Delhi metallo-ß-lactamase (NDM-1) is a novel broad spectrum carbapenemase with ability to inactivate all ß-lactams except aztreonam. However, most of the NDM-1-producers also produce aztreonam hydrolysing-ß-lactamases thereby making these pathogens absolutely resistant to all ß-lactams. The bla(NDM-1) gene encodes a 27.5 kDa protein of 269 amino acids. It shares very little identity with other metallo-ß-lactamases. Maximum identity has been observed to VIM-1/VIM-2 (32.4%). This mini-review is an update of the scientific literature for the said enzyme. Following the recommendation of David livermore, we further propose to combine "aztreonam" and "inhibitor of the most frequently encountered aztreonam hydrolysing-ß-lactamases in a given setting" as a possible strategy against NDM-1-producers. The inhibitor should be 'versatile' as well, i.e. it should have the ability to inhibit most of the variants of aztreonam hydrolysing-ß-lactamases prevalent in the concerned setting. We strongly recommend surveillance studies using aztreonam/NXL-104-combination against NDM-1-producing pathogens in different geographical regions across the globe.