Masquelet technique in military practice:specificities and future directions for combat-related bone defect reconstruction

Because of its simplicity,reliability,and replicability,the Masquelet induced membrane technique(IMT)has become one of the preferred methods for critical bone defect reconstruction in extremities.Although it is now used worldwide,few studies have been published about IMT in military practice.Bone reconstruction is particularly challenging in this context of care due to extensive soft-tissue injury,early wound infection,and even delayed management in austere conditions.Based on our clinical expertise,recent research,and a literature analysis,this narrative review provides an overview of the IMT application to combat-related bone defects.It presents technical specificities and future developments aiming to optimize IMT outcomes,including for the management of massive multi-tissue defects or bone reconstruction performed in the field with limited resources.

Inverted internal limiting membrane flap technique for very large macular hole

AIMTo assess the anatomical and visual outcome of idiopathic macular holes greater than 1000 µm using the inverted internal limiting membrane flap technique.METHODSThis retrospective case series included 5 eyes of 5 patients with idiopathic macular hole with base diameter greater than 1000 µm who underwent inverted internal limiting membrane flap technique along with standard 23G pars plans vitrectomy with posterior hyaloid detachment and fluid gas exchange with 12%-14% perfluoropropane (C3F8). Preoperative and postoperative visual acuity and spectral domain optical coherence tomography images were evaluated. The main outcome measures were visual outcome and macular hole closure.RESULTSMean age was 63.2±8.4y with all 5 subjects being females. Mean duration of symptoms was 11±14mo with a mean postoperative follow up of 13.2±13mo. The mean base diameter of the macular holes was 1420±84.8 µm (1280-1480 µm). Type 1 closure was achieved in four out of five patients, while one patient had type 2 closure using the inverted internal limiting membrane (ILM) flap technique. Median baseline BCVA was 0.79 logMAR (Snellen’s equivalent 20/120) and median final BCVA 0.6 logMAR (Snellen’s equivalent 20/80) with mean visual improvement of approximately three lines improvement. No complications related to surgical procedure were noted.CONCLUSIONThe inverted internal limiting membrane flap technique may be promising for very large macular holes with high rate of macular closure and good visual outcome.

Remove volatile organic compounds(VOCs) with membrane separation techniques

Membrane separation, a new technology for removing VOCs including pervaporation, vapor permeation, membrane contactor, and membrane bioreactor was presented. Comparing with traditional techniques, these special techniques are an efficient and energy saving technology. Vapor permeation can be applied to recovery of organic solvents from exhaust streams. Membrane contactor could be used for removing or recovering VOCs from air or wastewater. Pervaporation and vapor permeation are viable methods for removing VOCs from wastewater to yield a VOC concentrate which could either be destroyed by conventional means, or be recycled for reuse.

Application of extracorporeal membrane oxygenation techniques in heart transplantation operations

Objective To investigate clinical results of extracorporeal membrane oxygenation ( ECMO ) technique during peri - operative heart transplantation.

Ilizarov bone transport combined with the Masquelet technique for bone defects of various etiologies (preliminary results)

BACKGROUND The Ilizarov bone transport(IBT)and the Masquelet induced membrane technique(IMT)have specific merits and shortcomings,but numerous studies have shown their efficacy in the management of extensive long-bone defects of various etiologies,including congenital deficiencies.Combining their strong benefits seems a promising strategy to enhance bone regeneration and reduce the risk of refractures in the management of post-traumatic and congenital defects and nonunion that failed to respond to other treatments.AIM To combine IBT and IMT for the management of severe tibial defects and pseudarthrosis,and present preliminary results of this technological solution.METHODS Seven adults with post-traumatic tibial defects(subgroup A)and nine children(subgroup B)with congenital pseudarthrosis of the tibia(CPT)were treated with the combination of IMT and IBT after the failure of previous treatments.The mean number of previous surgeries was 2.0±0.2 in subgroup A and 3.3±0.7 in subgroup B.Step 1 included Ilizarov frame placement and spacer introduction into the defect to generate the induced membrane which remained in the interfragmental gap after spacer removal.Step 2 was an osteotomy and bone transport of the fragment through the tunnel in the induced membrane,its compression and docking for consolidation without grafting.The outcomes were retrospectively studied after a mean follow-up of 20.8±2.7 mo in subgroup A and 25.3±2.3 mo in subgroup B.RESULTS The“true defect”after resection was 13.3±1.7%in subgroup A and 31.0±3.0%in subgroup B relative to the contralateral limb.Upon completion of treatment,defects were filled by 75.4±10.6%and 34.6±4.2%,respectively.Total duration of external fixation was 397±9.2 and 270.1±16.3 d,including spacer retention time of 42.4±4.5 and 55.8±6.6 d,in subgroups A and B,respectively.Bone infection was not observed.Postoperative complications were several cases of pin-tract infection and regenerate deformity in both subgroups.Ischemic regeneration was observed in two cases of subgroup B.Complications were corrected during the course of treatment.Bone union was achieved in all patients of subgroup A and in seven patients of subgroup B.One non-united CPT case was further treated with the Ilizarov compression method only and achieved union.After a follow-up period of two to three years,refractures occurred in four cases of united CPT.CONCLUSION The combination of IMT and IBT provides good outcomes in post-traumatic tibial defects after previous treatment failure but external fixation is longer due to spacer retention.Refractures may occur in severe CPT.

Sprayed separation membranes: A systematic review and prospective opportunities

Membrane separation technology has been taken up for use in diverse applications such as water treatment,pharmaceutical,petroleum,and energy-related industries.Compared with the design of membrane materials,the innovation of membrane preparation technique is more urgent for the development of membrane separation technology,because it not only affects physicochemical properties and separation performance of the fabricated membranes,but also determines their potential in industrialized application.Among the various membrane preparation methods,spray technique has recently gained increasing attention because of its low cost,rapidity,scalability,minimum of environmental burden,and viability for nearly unlimited range of materials.In this Review article,we summarized and discussed the recent developments in separation membranes using the spray technique,including the fundamentals,important features and applications.The present challenges and future considerations have been touched to provide inspired insights for developing the sprayed separation membranes.

Chemodynamics of heavy metals in long-term contaminated soils:Metal speciation in soil solution

The concentration and speciation of heavy metals in soil solution isolated from long-term contaminated soils were investigated. The soil solution was extracted at 70% maximum water holding capacity （MWHC） after equilibration for 24 h. The free metal concentrations （Cd^2＋, Cu^2＋, Pb^2＋, and Zn^2＋） in soil solution were determined using the Donnan membrane technique （DMT）. Initially the DMT was validated using artificial solutions where the percentage of free metal ions were significantly correlated with the percentages predicted using MINTEQA2. However, there was a significant difference between the absolute free ion concentrations predicted by MINTEQA2 and the values determined by the DMT. This was due to the significant metal adsorption onto the cation exchange membrane used in the DMT with 20%, 28%, 44%, and 8% mass loss of the initial total concentration of Cd, Cu, Pb, and Zn in solution, respectively. This could result in a significant error in the determination of free metal ions when using DMT if no allowance for membrane cation adsorption was made. Relative to the total soluble metal concentrations the amounts of free Cd^2＋ （3%-52%） and Zn^2＋ （11%-72%） in soil solutions were generally higher than those of Cu^2＋ （0.2%-30%） and Pb^2＋ （0.6%-10%）. Among the key soil solution properties, dissolved heavy metal concentrations were the most significant factor governing free metal ion concentrations. Soil solution pH showed only a weak relationship with free metal ion partitioning coefficients （Kp） and dissolved organic carbon did not show any significant influence on Kp.

Role of the Ilizarov non-free bone plasty in the management of long bone defects and nonunion: Problems solved and unsolved

BACKGROUND Ilizarov non-free bone plasty is a method of distraction osteogenesis using the Ilizarov apparatus for external fixation which originated in Russia and was disseminated across the world. It has been used in long bone defect and nonunion management along with free vascularized grafting and induced membrane technique. However, the shortcomings and problems of these methods still remain the issues which restrict their overall use.AIM To study the recent available literature on the role of Ilizarov non-free bone plasty in long bone defect and nonunion management, its problems and the solutions to these problems in order to achieve better treatment outcomes.METHODS Three databases(Pub Med, Scopus, and Web of Science) were searched for literature sources on distraction osteogenesis, free vascularized grafting and induced membrane technique used in long bone defect and nonunion treatment within a five-year period(2015-2019). Full-text clinical articles in the English language were selected for analysis only if they contained treatment results,complications and described large patient samples(not less than ten cases for congenital, post-tumor resection cases or rare conditions, and more than 20 cases for the rest). Case reports were excluded.RESULTS Fifty full-text articles and reviews on distraction osteogenesis were chosen.Thirty-five clinical studies containing large series of patients treated with this method and problems with its outcome were analyzed. It was found that distraction osteogenesis techniques provide treatment for segmental bone defects and nonunion of the lower extremity in many clinical situations, especially in complex problems. The Ilizarov techniques treat the triad of problems simultaneously(bone loss, soft-tissue loss and infection). Management of tibial defects mostly utilizes the Ilizarov circular fixator. Monolateral fixators are preferable in the femur. The use of a ring fixator is recommended in patients with an infected tibial bone gap of more than 6 cm. High rates of successful treatment were reported by the authors that ranged from 77% to 100% and depended on the pathology and the type of Ilizarov technique used. Hybrid fixation and autogenous grafting are the most applicable solutions to avoid after-frame regenerate fracture or deformity and docking site nonunion.CONCLUSION The role of Ilizarov non-free bone plasty has not lost its significance in the treatment of segmental bone defects despite the shortcomings and treatment problems encountered.

Inverted Internal Limiting Membrane Flap Technique for Repair of Large Macular Holes： A Short-term Follow-up of Anatomical and Functional Outcomes

Background：Inverted internal limiting membrane （ILM） flap technique has recently been reported in a limited number of studies as an effective surgical technique for the management of large macular holes （MHs） with fair MH closure rates as well as gains in visual acuity.In the current study,longitudinal changes in multi-focal electroretinogram （mfERG） responses,best-corrected visual acuity （BCVA） and spectral-domain optical coherence tomography （SD-OCT） were evaluated in eyes with large MHs managed by this technique.Methods：A prospective noncontrolled interventional study of eight patients （eight eyes） with large MHs （minimum diameter 〉400 μm） was conducted.All MHs were treated with pars plana vitrectomy and indocyanine green-assisted inverted ILM flap technique.SD-OCT images were used to assess the anatomical outcomes of surgery while BCVA and mfERG were used to evaluate the functional outcomes during a 3-month follow-up.Results：All patients underwent successful intended manipulation and translocation of the ILM flap without flap dislocation and achieved complete anatomical closure.Partial microstructural reconstruction,demonstrated on SD-OCT as restoration of the external limiting membrane and the ellipsoid zone,was observed in all cases as early as 1 month after surgery.Functionally,as compared to baseline,all patients showed improvements in BCVA and all but one in mfERG response during follow-up.However,Pearson＇s test revealed no significant correlations between BCVA and mfERG responses of the fovea and of the macular area at each evaluation time point.Conclusions：Inverted ILM flap technique appeares to be a safe and effective approach for the management of large idiopathic MHs with favorable short-term anatomical and functional results.Postoperative reconstruction of the microstructure generally shows good consistency with improvements in both BCVA and mfERG response,of which the latter might be a supplement for the former in postoperative functional follow-up.