External Compartment Research Articles

Dynamic role of GlyT1 as glycine sink or source: Pharmacological implications for the gain control of NMDA receptors

Glycine transporter 1 (GlyT1) mediates the termination of inhibitory glycinergic receptor signaling in the spinal cord and brainstem, and is also present diffusely in the forebrain. Here, it regulates the ambient glycine concentration and influences the ‘glycine’ site occupancy of N-methyl-d-aspartate receptors (NMDARs). GlyT1 is a reversible transporter with a substantial, but not excessive, sodium-motive force for uphill transport. This study investigates its role as a potential source of glycine supply, either by reverse uptake or heteroexchange. Indeed, glutamate alone does not induce NMDAR current in “naive” oocytes co-expressing GluN1/GluN2A and GlyT1, a previously characterized cellular model. However, after substantial intracellular glycine accumulation, GlyT1 reverses its transport mode, and begins to release glycine into the external compartment, allowing NMDAR activation by glutamate alone. These uptake-dependent glutamate currents were blocked by ALX-5407 and potentiated by sarcosine, a specific inhibitor and substrate of GlyT1, respectively, suggesting a higher occupancy of the co-agonist site when GlyT1 functions as a glycine source either by reversed-uptake or by heteroexchange. These two glycine release mechanisms can be distinguished by their voltage dependence, as the reversed-uptake cycle decreases at hyperpolarized potentials, whereas heteroexchange electroneutrality preserves glycine efflux and NMDAR activation at these potentials. These results establish GlyT1-mediated efflux as a positive regulator of NMDAR coagonist site occupancy, and demonstrate the efficacy of sarcosine heteroexchange in enhancing coagonist site occupancy. Because NMDAR facilitation by GlyT1-inhibitors and sarcosine relies on different transport mechanisms, their actions may be a source of variability in reversing NMDAR hypofunction in schizophrenia.

Anatomical Safety Area for Periarticular Analgesic Infiltration through the Posterior Capsule in Total Knee Arthroplasty: Radiological Study in Magnetic Resonance.

Background: One of the main challenges of orthopedic surgery is adequate pain management after total knee arthroplasty. This work aimed to determine the anatomical safety area for infiltration through the posterior capsule of the knee in prosthetic surgery using Magnetic Resonance Imaging (MRI). Methods: A descriptive, observational, cross-sectional study was performed on 126 knee MRIs. The variables studied were age, sex, and distance between different neurovascular structures of the popliteal fossa (tibial nerve, common peroneal nerve, and vascular bundle). Data were analyzed for normality (Kolmogorov-Smirnov) and variance homogeneity (Levène). A value of p < 0.05 and a confidence interval of 9% were considered statistically significant for all comparisons. Student's t-test was used to compare the means between independent samples. Results: We observed statistically significant differences between the sexes regarding EP-EPS (external plateau-external popliteal sciatic nerve (common peroneal)), EP-IPS (external plateau-internal popliteal sciatic nerve (tibial)), and IP-PA (internal plateau-popliteal artery) measurements. The average distance between both nerves, EPS-IPS (external popliteal sciatic nerve and internal popliteal sciatic nerve), was 25.96 mm in females, while the value obtained in males was 29.93 mm, but this difference was not statistically significant. Conclusions: The average distance from the posterior capsule to the EPS and IPS nerves is greater in males than in females, despite no statistical differences. The presence of a lateralized arteriovenous bundle reduces the infiltration area of the external compartment. Regarding the safety area, infiltration of the internal compartment is safe since the volume diffuses into the muscle mass of the internal gastrocnemius upon injection. To infiltrate the external compartment, the needle must move at least 2 cm from the midline toward the external side (to exceed the maximum displacement of the neurovascular bundle established at 1.82 cm), and not advance beyond 0.76 cm (minimum distance at which we located the common peroneal nerve in the external compartment).

Prospective Observational Study of a Non-Arthroscopic Autologous Cartilage Micrografting Technology for Knee Osteoarthritis.

Autologous micrografting technology (AMT®) involves the use of autologous micrografts to stimulate/enhance the repair of damaged tissue. This study assessed the efficacy and safety of the AMT® procedure in patients with early stages of knee osteoarthritis. Briefly, the AMT® procedure involved extraction of auricular cartilage, disaggregation using the Rigeneracons® SRT in 4.0 mL of saline solution, and injection of the disaggregated micrografts into the external femorotibial compartment area of the affected knee. Ten patients (4 men, 6 women; age range: 37-84 years) were included in the study. In all patients, there was a steady improvement in knee instability, pain, swelling, mechanical locking, stair climbing, and squatting at 1- and 6-months post-procedure. Improvement in mobility was observed as early as 3 weeks post-procedure in 2 patients. Significant improvements were seen in mean scores of all five subscales of Knee Injury and Osteoarthritis Outcome Score (KOOS [KOOS symptoms, KOOS pain, KOOS ADL, KOOS sport and recreation, and KOOS quality-of-life]) between pre-procedure and 1- and 6-months post-procedure (all p ≤ 0.05). Autologous auricular cartilage micrografts obtained by AMT® procedure (using Rigenera® technology) is an effective and safe protocol in the treatment of early stage knee osteoarthritis. These encouraging findings need to be validated in a larger patient population and in a randomized clinical trial (RCT).

Conceptual Definition of A New Very-Light-Jet Aircraft Configuration

Israel Aircraft Industries (IAI) is a world leader in the design and manufacturing of business aircraft. IAI has developed and introduced to the market several biz-jets (Westwind I and II, Astra-AKA Gulfstream G-100, and Galaxy- AKA Gulfstream G-200). All these aircraft have been in the midsize and recently "super-midsize" category. During the last two years, IAI has been evaluating a new aircraft design, the ProJet that belongs to the new, emerging category of "very-light jets" (VLJ). This lightweight twin turbofan aircraft is characterized by its small size and low target price, compared to existing IAI designs. The ProJet will be certificated to FAR23 normal category requirements, including single pilot operation. The ProJet exploits newly developed technologies and capabilities, such as: new, small and efficient turbofan engines; advanced low cost and sophisticated avionic systems; advanced low cost mechanical and electrical systems; rapid and efficient development and production methods. All these attributes will provide the capability of introducing a very low cost aircraft into the emerging new VLJ market sector. The ProJet is a twin turbofan, low wing, T-tail airplane utilizing an all-metal airframe; designed in accordance with damage tolerance requirements. It features a comfortable pressurized cabin with optimized seating for 6 occupants, including 2 pilots, and excellent performance. The ProJet will have a VFR range of 1200nm, a cruise ceiling of 41,000ft, and a cruise speed of 365kt. It will take-off and land on runways shorter than 3000ft. Generous allowance for baggage stowage is provided in the pressurized internal baggage compartment, and in the external rear baggage compartment. The ProJet flight deck features an all-glass cockpit with an integrated avionics package, designed for ease of operation and reduced workload. Composite materials are utilized in flight control surfaces and secondary structures. Two FADEC controlled turbofan engines mounted on the upper aft fuselage supply the ProJet power. Each engine generates about 1300 pounds static installed thrust at ISA +10°C.

The bovine carbonic anhydrase promoted dehydration of bicarbonate to CO2 for the electrochemical production of syngas

The electrochemical reduction of CO2 into value-added products is a promising strategy for carbon footprint mitigation. Current research efforts are focused on combining this strategy with CO2 capture in bicarbonate-based solvents to build an efficient CO2 capture and utilization system. The primary challenge to address in this system is the development of a cost-effective CO2 regeneration method that will enable the CO2 gas feed to be continuously recovered from the bicarbonate capture medium for utilization. In this work, we studied systems for CO2 utilization, integrated with the bicarbonate dehydration activity of bovine carbonic anhydrase (BCA) to recover CO2 for the electrochemical production of syngas. Specifically, we investigated the generation of CO2 from bicarbonate catalyzed by BCA in the free form or immobilized on the electrode surface and the consequent Au-catalyzed electrochemical reduction of CO2 to CO. We showed that BCA functions efficiently in 2 M KHCO3 at pH 9 to promote the release of CO2 from an external compartment to the Au electrocatalyst in the CO2 reduction reaction electrolyzer, thereby achieving a significant faradaic efficiency of 27% for the CO product. This work demonstrates a sustainable and environmentally friendly approach for the electrochemical utilization of captured CO2.

Epidemiologic Survey of Myxofibrosarcoma Using Data from the Bone and Soft Tissue Tumor Registry in Japan.

Myxofibrosarcoma is a common sarcoma among older patients, with locally infiltrative behavior and a predilection for local postoperative recurrence. Some studies have reported the factors affecting prognosis, although only a few have mentioned the previous staging classification systems. This study investigated the clinical overview and prognosis of myxofibrosarcoma to determine the optimal treatment. This retrospective study analyzed the records of 349 patients with myxofibrosarcoma in the nationwide Bone and Soft Tissue Tumor Registry in Japan from 2006 to 2015. Clinical features, treatment options, and patient outcomes were investigated. Ultimately, 349 patients were identified. The overall survival rates were 93.1% at 2 years and 84.3% at 5 years. A multivariate analysis was performed using the Cox proportional hazards model. The study identified four significant prognostic factors for survival: tumor size, depth, compartment status, and location. The prognostic score was calculated by summing the scores of all the factors. The overall survival rate was 69.3% at 5 years for the patients with prognostic scores of 6 or higher. Conversely, the patients with prognostic scores of 2 or lower had a survival rate of 95.6% at 5 years. Among myxofibrosarcomas, those larger than 5 cm, deep-seated, invaded into the external compartment, or in axial body parts were associated with a significantly worse prognosis. Adjuvant radiotherapy and chemotherapy did not contribute significantly to a better prognosis. Previous staging classification systems are impractical for prognosis prediction. Therefore, new classifications are needed. Further research on new treatment methods for patients with a poor prognosis will be crucial in the future.

Insights into the Role of Electrolyte Ionophore on Electrochemical Reduction of CO2

Electrochemical reduction of carbon dioxide (CO2) to value-added chemicals and fuels offers a sustainable route to utilize CO2 by exploiting renewable energy source. The electrolyte plays a significant role by taking advantage of the interaction between electrocatalytic surface and electrolyte. In this work, we present a CO2 conversion flow cell with an external compartment for a reference electrode (AgCl/Ag) to investigate the effect of alkaline electrolyte composition on the direct conversion of CO2 to fuels and commodity chemicals under ambient conditions. In this flow cell, a catalytic Ag-based gas diffusion electrode (GDE) was employed for CO2 reduction reaction, while an anode electrode was prepared with a RuO2 catalytic GDE. The gaseous products generated from the cell were analyzed with a Gas Chromatography (GC), while the liquid products were analyzed with Nuclear Magnetic Resonance Spectroscopy (NMR). Electrolytes with various cations (Li+, Na+, K+) and anions (OH-, HCO3 -, CO3 2-) were investigated. With a KOH electrolyte (combination of the cation K+ and anion OH-), high faradaic efficiency (~ 97%) was achieved at -1.115 V vs SHE toward the formation of syngas (CO + H2) and ~ 60% faradaic efficiency was obtained toward the product of ethanol. The overall energy conversion efficiency could be up to ~ 45%. In consideration of faradaic efficiency, energy conversion efficiency, and the production of CO and ethanol, the preferable option of anions followed the order of OH- > HCO3 - > CO3 2-, while the option for cations was in the order of K+ > Na+ > Li+.

Emerging connections between gut microbiome bioenergetics and chronic metabolic diseases.

The conventional viewpoint of single-celled microbial metabolism fails to adequately depict energy flow at the systems level in host-adapted microbial communities. Emerging paradigms instead support that distinct microbiomes develop interconnected and interdependent electron transport chains that rely on cooperative production and sharing of bioenergetic machinery (i.e., directly involved in generating ATP) in the extracellular space. These communal resources represent an important subset of the microbial metabolome, designated here as the "pantryome" (i.e., pantry or external storage compartment), that critically supports microbiome function and can exert multifunctional effects on host physiology. We review these interactions as they relate to human health by detailing the genomic-based sharing potential of gut-derived bacterial and archaeal reference strains. Aromatic amino acids, metabolic cofactors (B vitamins), menaquinones (vitamin K2), hemes, and short-chain fatty acids (with specific emphasis on acetate as a central regulator of symbiosis) are discussed in depth regarding their role in microbiome-related metabolic diseases.

Nitrification and denitrification in recirculating aquaculture systems: the processes and players

AbstractOne of the major challenges in any sustainable aquaculture production systems is the accumulation of nitrogenous waste such as ammonia and its biological nitrification products viz nitrite and nitrate. Considering the bio‐security issues, amelioration of these wastes without water exchange can be accomplished only by way of establishing in situ nitrification and denitrification through biofilters/bioreactors activated with nitrifying/denitrifying bioaugmentors. In such systems, coexistence of aerobic denitrifiers, anaerobic ammonia oxidizers (Anammox) and complete ammonia oxidizers (Comammox) together with the autotrophic nitrifiers enhance the coupled nitrification–denitrification. This promotes total nitrogen removal without external carbon supplements or additional anerobic compartment in the system. Various recirculating aquaculture systems (RAS) comprise diverse nitrifying community in biofilters/bioreactors thereby imparting distinctive nitrogen conversion in the system. Meanwhile, the structure and population dynamics of the nitrifying/denitrifying consortia are influenced by the environmental factors forming the decisive factors of the success of the processes. Accordingly, understanding the complexity of nitrifying/denitrifying community composition turns out to be a requirement to facilitate its improvised performance. In this context, the review addresses different biological nitrogen removal systems, significance of nitrification–denitrification in RAS, genetic diversity of the key players in RAS, methods of analysis of their community structure, current application and prospects of the processes in RAS.

Evaluation of cartilage regeneration by arthroscopy after high tibial osteotomy

To evaluate the cartilage regeneration in the knee joint by arthroscopy after high tibial osteotomy. Eleven patients were included in the study who were treated with high tibial osteotomy and underwent microscopy when the internal fixation was unloaded from September 2017 to September 2019. Among them, there were 2 males and 9 females, aged from 55 to 64 years old. The internal and external compartment pictures of the knee were taken before and after surgery of removing the internal fixation and the International Cartilage Repair Society (ICRS) grading systerm was used to evaluate the degree of cartilage damage on the medial and lateral femoralcondyles and tibial plateau. The Westrn Ontarioand Mcmaster Universities osteoarthritis index (WOMAC) and the weight bearing line (WBL) were used to evaluate the function of the knee and the alignment of the lower limb. All 8 patients were followed up for more than 12 months, ranging from 12 to 22 months. The degenerated cartilage of the medial femoral condyle and medial tibial plateau was covered by newly regenerated cartilage. WOMAC score decreased from 102-127 to 41-52 and WBL was improved from 17%-34% to 58%-64%. All incisions healed in stageⅠ, and no complications such as internal fixation rupture and infection occurred during and after the operation. High tibial osteotomy can relieve the pain of the knee and the dysfunction by adjusting lower limb alignment, and the degenerated cartilage could be regenerated in the medial femoral condyle and medial tibial plateau.

Evaluation of proprioception and postural control at a minimum 1 year follow-up after ankle capsuloligamentous lateralplasty with Brostrom technique: A cohort study.

Recovery of postural control and proprioception in patients affected by chronic ankle instability (CAI) and operated on capsulo-ligaments reconstructive surgery lacks of objective assessment. The aim of this study was to evaluate long-term post-surgical postural and proprioceptive control through the DPPS device in a cohort of patients operated on ligaments reconstruction through the modified Brostrom procedure at a minimum follow up of 12 months.Eleven patients with post-traumatic lateral CAI, operated of external capsulo-ligamentous complex repair according to Brostrom technique at a minimum follow-up of 1 year were enrolled. Physical examination and American Orthopaedics Foot and Ankle Society (AOFAS) ankle-hindfoot score. Proprioceptive and postural stability was assessed by DPPS - Delos Postural Proprioceptive System, linked to a computer with a specific software and including a flat table, an electronic unstable proprioceptive board, a Delos Vertical Controller, a monitor and a horizontal bar fitted with an infra-red sensor for hand support.Patients were 5 males and 6 females, mean age of 38.4 ± 12 years. Mean BMI of the patients was 26.8 ± 4.4. Mean follow up was 13.4 ± 2.1. The mean value of (AOFAS) clinical score was 90.3/100. Mean Static Stability Index (SSI) with open eyes was 87.7% (±7.6) in the operated leg and 90.4% (±6.1) in the contra-lateral. SSI with closed eyes was 64.5% (±11.2) in the operated leg and 61.6% (±16.8) in the contra-lateral. Mean Dynamic Stability Index (DSI) without restrictions was 56.2% (±14.6) in the operated leg and 56.8% (±10.6) in the contra-lateral. DSI with restricted upper limbs, had a mean value of 56.3% (±11.4) in the operated leg and 58.1% (±11.9) in the contra-lateral.Re-tensioning capsular-ligamentous surgery of the external compartment for CAI allow to recovery proprioceptive and postural control on the operated side, comparable with data from the contralateral limb and from the healthy population of the same age and sex.

Popliteal artery transection associated with a minimally displaced tibial plateau fracture: a case report and review of the literature

BackgroundPoplital artery transection injury is potentially catastrophic, or even life-threatening. Severe traumas, including open fracture, gunshot, stabs, and knee dislocation and complex fracture of proximal tibia or distal femur, are the common causes of high rate of amputation due to popliteal artery trauma. No report mentions vascular injury associated with minimally displaced tibial plateau fracture in adult.Case presentationA 30-year-old male presented with popliteal artery transection injury associated with minimally displaced tibial plateau fracture. He presented to emergency department, 6 h after fall from ground into a 1-m height hole. Physical examination suggested acute ischemia, with signs of paleness, coldness, anesthesia, hemorrhagic bullae below the right knee level. There was severe swelling and ecchymosis in popliteal fossa and around the leg with significant calf tenderness and pedal edema. Tibialis posterior, dorsalis pedis, and popliteal arterial pulses were not palpable. Radiograph suggested minimally displaced tibial plateau fracture with no evidence of knee dislocation. The patient was taken up for emergency surgery after consultation with vascular surgeon. During the closed reduction external fixation and compartment decompression, popliteal artery trunk was found transected and end-to-end repair was performed. During the post-operational period, no complication was developed and the patient was followed-up for 1 year. At the one-year follow-up, he acquired good stability of his right knee with full range of motion.ConclusionSignificant swelling and ecchymosis should alert the surgeons to the possibility of vascular injury in knee joint injury, even if there is no fracture or dislocation, or fracture is minimally displaced.

Branching Stochastic Evolutionary Models of Cell Populations

This review paper surveys results on branching stochastic models with and without immigration published during the past nine years. Studies of this class of stochastic models were motivated by the quantitative analysis of the dynamics of population of cells of the central nervous system, called the terminally differentiated oligodendrocytes, and their progenitor cells. We focus on original ideasspecifically developed for Sevastyanov branching processes allowing the contribution of an external cellular compartment (e.g., stem cells) via anonhomogeneous Poisson immigration process. Limiting distributions are discribed in the subcritical, critical and supercritical cases for various immigration rates.

Critical performance assessment of a submerged hybrid forward osmosis - membrane distillation system

FO and MD have their drawbacks when employed as independent systems. To establish substantial superiority over single membrane process, an innovative FO and MD integration in a hybrid submerged module was introduced in this study. Initially, FO and MD were evaluated individually, using a conventional side-stream module. The stable-operation conditions of the hybrid module were estimated based on the results of the side-stream module: feed, DS, and distillate temperatures at 20, 40, and 20 °C, respectively. Sequentially, the actual stable-operation of the hybrid module was determined. The DS temperature found was higher than the one estimated by using the side-stream module (45 °C). This was related to lower fluxes in the submerged configuration, explained by significant polarization effects. Despite that, the hybrid is less energy-intensive compared to the side-stream since it is not necessary to pump the feed solution to an external compartment. The hybrid showed high rejection of TOC, TN, NH4, and TrOCs, which were 94.9%, 93.8%, 99.8%, and >97.5%, respectively. The results showed the potential of hybrid configuration in water treatment systems. The use of a single module allows the re-concentration of the DS and the production of distillate continuously, reducing the footprint of the processes.

Filling Tricompartmental Ligands with GdIII and ZnII Ions: Some Structural and MRI Studies

Here we report the synthesis and characterization of a mononuclear gadolinium complex (Gd) and two heteronuclear Zn-Gd complexes (ZnGd and Zn2Gd), which contain two similar three-armed ligands that display an external compartment suitable for lanthanoid ions, and two internal compartments adequate for zinc (II) ions [H3L′ = (2-(3-formyl-2-hydroxy-5-methyl phenyl)-1,3-bis[4 -(3-formyl-2-hydroxy-5-methylphenyl)-3-azabut-3-enyl]-1,3-imidazolidine; H3L = 2-(5-bromo-2-hydroxy-3-methoxyphenyl)-1,3-bis[4-(5-bromo-2-hydroxy-3-methoxyphenyl)-3-azabut-3-enyl]-1,3-imidazolidine]. The synthetic methods used were varied, but the use of a metalloligand, [Zn2(L)AcO], as starting material was the key factor to obtain the heterotrinuclear complex Zn2Gd. The structure of the precursor dinuclear zinc complex is mostly preserved in this complex, since it is based on a compact [Zn2Ln(L)(OH)(H2O)]3+ residue, with a µ3-OH bridge between the three metal centers, which are almost forming an isosceles triangle. The asymmetric spatial arrangement of other ancillary ligands leads to chirality, what contrasts with the totally symmetric mononuclear gadolinium complex Gd. These features were confirmed by the crystal structures of both complexes. Despite the presence of the bulky compartmental Schiff base ligand, the chiral heterotrinuclear complex forms an intricate network which is predominately expanded in two dimensions, through varied H-bonds that connect not only the ancillary ligands, but also the nitrate counterions and some solvated molecules. In addition, some preliminary magnetic resonance imaging (MRI) studies have been made to determine the relaxivities of the three gadolinium complexes, with apparently improved T1 and T2 relaxivities with increasing zinc nuclearity, since both transversal and longitudinal relaxivities appear to enhance in the sequence Gd &lt; ZnGd &lt; Zn2Gd.

Light-triggered enzymatic reactions in nested vesicle reactors

Cell-sized vesicles have tremendous potential both as miniaturised pL reaction vessels and in bottom-up synthetic biology as chassis for artificial cells. In both these areas the introduction of light-responsive modules affords increased functionality, for example, to initiate enzymatic reactions in the vesicle interior with spatiotemporal control. Here we report a system composed of nested vesicles where the inner compartments act as phototransducers, responding to ultraviolet irradiation through diacetylene polymerisation-induced pore formation to initiate enzymatic reactions. The controlled release and hydrolysis of a fluorogenic β-galactosidase substrate in the external compartment is demonstrated, where the rate of reaction can be modulated by varying ultraviolet exposure time. Such cell-like nested microreactor structures could be utilised in fields from biocatalysis through to drug delivery.

Elasticity Behaviour of a Healthy and Osteoarthritic Human Knee’s Fresh Cancellous Bone

The aim of this paper is to evaluate the elasticity modulus of fresh human cancellous bone from the internal and external compartments segments of osteoarthritic and non-osteoarthritic knees. Cancellous bone samples of young and old subjects from both genders were collected. The measurements of the elasticity modulus were made only few hours after the samples were taken in through compression tests. The results show that the average value of elasticity modulus of the internal compartment (IC) (84.92 MPa) was the double of the external one (EC) (40.12 MPa). These values were found regardless of the gender and age factors. In osteoarthritic knees only the values of the internal compartment (121.88 MPa) increased, without significant variation of those of the external compartment (42.91 MPa). The results of this work need to be confirmed by other series. If they are validated, they would explain that the preferential site of osteoarthritis on the inner compartment of the knees is not only due to a static disorder, but that there is a structural bone factor. The confirmation of this new parameter will invite us to a review our anatomical, physiological, biomechanical knowledge of cancellous bone. The study was approved by the ethics Committee of Rabta Tunis Hospital, and all participants provided informed consent indicating their conscious and voluntary participation.

Global Dynamics and Optimal Control of a Viral Infection Model with Generic Nonlinear Infection Rate

This paper is devoted to exploring the combined impact of a generic nonlinear infection rate and infected removable storage media on viral spread. For that purpose, a novel dynamical model with an external compartment is proposed, and the explanations of the main model assumptions (especially the generic nonlinear infection rate) are also examined. The existence and global stability of the unique equilibrium of the model are fully investigated, from which it can be seen that computer virus would persist. On this basis, a next-best approach to controlling the level of infected computers is suggested, and the theoretical analysis of optimal control of the model is also performed. Additionally, some numerical examples are given to illustrate the main results.

Vascular Complications in Arthroscopic Repair Of Posterior Cruciate Ligament

Introduction:Posterior cruciate ligament is the primary stabilizer of the knee. Among the potential complications in arthroscopic repair of this ligament, there are vascular lesions, due to laceration, thrombosis and injury of the intima of the popliteal artery. We used one case to show the vascular complications that may arise in arthroscopic repair of the posterior cruciate ligament, how to handle it and the results.Methods:One patient, 33 years old, with a history of traffic accident. In a physical exam the patient shows pain and swelling of the knee, positive posterior drawer test and positive Godfrey test. X-rays on the knee show posterior tibial translation and MRI a complete fibers rupture at the middle third of the posterior cruciate ligament. An arthroscopic repair surgery was scheduled three weeks after trauma, with PCL reconstruction using simple band technique.After surgical intervention, hemostatic cuff was released, no peripheral pulse, paleness and coldness of the member was confirmed. An arteriography was carried out, which confirmed absences of distal vascular filling in the popliteal artery. An urgent referral was carried out with Vascular Surgery Services, who had been informed of the surgery previously (a notification that is part of our routine for this kind of interventions). Arteriorrhaphy and venorrhaphy of the popliteal arteries was fulfilled 12 hours later, with a leg fasciotomy. Daily monitoring was performed, and after 72 hours, muscle necrosis is seen with wound drainage, analysis shows presence of gram-negative bacilli, Proteus Mirabilis-Pseudomonas spp and the lab results showed leukocytes: 8.700/ml, ESR: 58, CRP: 48. A new surgery is performed with complete resection of the anterior external compartment of the leg, and a system of continuous cleansing is applied with physiological saline solution and boric acid for 14 days until drainage is eliminated. Vancomycin and ceftazidime EV was indicated for 14 days and, after a good evolution of the wounds, patient is discharged from hospital with Sulfamethoxazole/trimethoprim 160mg/800mg to be taken orally for 14 days.Results:After treatment with oral antibiotic is completed, wounds progress positively. Foot in equinus position, has positive distal pulses with distal sensibility. Use of a thermoforming brace is indicated for movement. Vascular Surgery Services are currently following patient’s evolution. An ankle arthrodesis surgery is evaluated for the future.Conclusion:Combined injuries that result in a posterior tibial translation over 15 mm and, those that come along with injuries in the anterior cruciate ligament or posterior lateral structures of the knee, should be repaired through surgery. Vascular lesion caused by laceration, thrombosis or injury of the intima of the popliteal artery, mainly during perforation and preparation of tibial tunnel, is a serious lesion. Although these vascular lesions during arthroscopy are complications relatively rare, a potential risk should be considered, with consequences that could be fatal for the extremity and for patient’s life when bleeding is involved. In those cases, urgent treatment is imperative, that is the reason we believe it is safe to coordinate with Vascular Surgery Services before the surgery is carried out.

Juvenile Osteochondritis Dissecans of the Knee. About A Case

Introduction:Juvenile osteochondritis dissecans is a pathology that affects the superficial articular cartilage and subchondral bone in patients with open physes. Treatment of this disease is based on patient’s age and the stage of the disease.Methods:16-year-old patient, athlete, with a history of knee pain on the right side of acute onset, without traumatic history. A physical examination shows pain in the external compartment of the knee. MRI shows a stable lesion that involves the external femoral condyle, over a posterior area of 16 mm by 20mm. Crutches are indicate for walking without body burden. Symptoms continue for six months and there are no changes in MRI. It is decided to do a stabilization with a Herbert type screw. After the surgery, pain persists and in x-ray controls, osteointegration is not observed. Osteosynthesis material is extracted and mosaicplasty is performed. We used Guhl’s intraoperative classification.Results:In this case, for a young patient with Guhl’s lesion type III, the reduction with a Herbert type screw was indicated, as the lesion was stable, of a significant size and congruent. Lesion progressed to type IV in 6 months. Thus, mosaicplasty was performed, obtaining a good functional result according to the physical exam, with a complete range of flexion and extension. A second-look arthroscopic assessment was carried out 2 months after surgery, showing osteointegration and stability of the allogenic graft.Conclusion:The variable of stability of the fragment is very important when determining the treatment. Most of the stable lesions can be successfully treated with a conservative treatment. Also, it has been demonstrated that young patients have a higher rate of healing. Instead, unstable lesions require surgical treatment.