Degeneracy and Photon Trapping in a Dissipationless Two-Mode Optomechanical Model.

In this work, we theoretically study a finite and undamped two-mode optomechanical model consisting of a high quality optical cavity containing a thin, elastic, and dielectric membrane. The main objective is to investigate the precursors of quantum phase transition in such a model by studying the behavior of some observables in the ground state. By controlling the coupling between membrane and modes, we find that the two lowest energy eigenstates become degenerate, as is indicated by the behavior of the mean value of some operators and by other quantifiers as a function of the coupling. Such degenerate states are characterized by a coherent superposition of eigenstates describing one of the two modes preferentially populated and the membrane dislocated from its equilibrium position due the radiation pressure (Schrödinger's cat states). The delocalization of the compound system photons+membrane results in an increase in fluctuations as measured by Robertson-Schrödinger uncertainty relations.

The optimized tourniquet versus no tourniquet in total knee arthroplasty. Analysis of muscle injury, functional recovery, and knee strength.

Background: Tourniquet is widely used in total knee replacement surgery because it reduces intraoperative hemorrhage and provides a comfortable surgical area for the surgeon. It's possible that its use could lead to impaired postoperative functional and motor recovery, as well as local and systemic complications. Our goal was to compare the outcomes of total knee replacement without ischemia using an optimized protocol, consisting of tourniquet inflation before skin incision and deflation after cementing, with a pressure of one hundred millimeters above systolic blood pressure and without postoperative articular suction drains.). We believed that tourniquet effectively would result in no additional muscle damage and no functional or knee strength impairment compared to no tourniquet. Methods: In a prospective and randomized study, 60 patients with osteoarthritis were evaluated for total knee replacement, divided in two groups: 'without tourniquet' and 'optimized tourniquet'. Outcomes were mean creatine phosphokinase levels, Knee Society Score and knee isokinetic strength. Data were considered significant when p < 0.05. Results: Creatine phosphokinase levels and functional score were similar between groups. There were no differences between groups regarding knee extension strength on the operated limbs, although the knee flexors' peak torque in the operated limb in the optimized tourniquet group was significantly higher at 6 months relative to preoperative and 3 months assessments. Conclusions: The optimized tourniquet protocol use in total knee replacement combines the benefits of tourniquet use without compromising functional recovery and without additional muscle damage and strength deficits compared to surgery without its use.

Continuous Vertical Inside-Out Versus Traditional Vertical Inside-Out Meniscal Repair: A Biomechanical Comparison.

Background: Biomechanical assessment of meniscal repairs is essential for evaluating different meniscal suturing methods and techniques. The continuous meniscal suture technique is a newer method of meniscal repair that may have biomechanical differences compared with traditional techniques. Purpose: To evaluate the displacement, stiffness after cyclical loading, and load to failure for a continuous vertical inside-out meniscal suture versus a traditional vertical inside-out meniscal suture in a porcine medial meniscus. Study Design: Controlled laboratory study. Methods: A total of 28 porcine knees were acquired and divided into 2 test groups of 14 medial meniscus each. A 2.0-cm longitudinal red-white zone cut was made in the body of the medial meniscus for each knee. The continuous suture (CS) group received 4 vertical stitches performed with a continuous vertical meniscal suture technique, and the inside-out suture (IO) group received a traditional vertical suture with 4 stitches. Two traction tapes were passed between the sutures and positioned in the biomechanical testing fixture device. Each specimen underwent load-to-failure testing at 5 mm/s, and displacement, system stiffness, and maximum load to failure were compared between the groups. Results: The displacement after the cyclic test was 0.53 ± 0.12 and 0.48 ± 0.07 mm for the CS and IO groups, respectively. There was no significant difference between the groups (P = .2792). The stiffness at the ultimate load testing was 36.3 ± 1.9 and 35.3 ± 2.4 N/mm for groups CS and IO, respectively, with no significant difference between the groups (P = .2557). In the load-to-failure test, the ultimate load was 218.2 ± 63.9 and 238.3 ± 71.3 N in the CS and IO groups, respectively, with no significant group differences (P = .3062). Conclusion: A continuous vertical meniscal suture created a configuration for treating longitudinal meniscal lesions that was beneficial and biomechanically similar to a traditional vertical suture technique. Clinical Relevance: The study findings indicate that use of the continuous vertical inside-out meniscal suture technique is a possible therapeutic option.

Diagnosis by Manual Maneuver of Medial Meniscus Ramp Lesions.

The intra-articular injury most often associated with a chronic anterior cruciate ligament tear involves the posterior horn of the medial meniscus. A specific type of medial meniscal injury, called a ramp lesion, has received greater attention for identification and treatment because of its considerable incidence and diagnostic difficulty. Based on their location, these lesions may be arthroscopically "hidden" during traditional anterior visualization. The purpose of the present Technical Note is to describe the Recife maneuver. This maneuver diagnoses injuries to the posterior horn of the medial meniscus using additional arthroscopic management through a standard portal. The Recife maneuver is performed with the patient in the supine position. A 30° arthroscope is inserted through the anterolateral portal, and the posteromedial compartment is accessed according to the transnotch view (modified Gillquist view). In the proposed maneuver, with the knee in 30° of flexion, a valgus stress with internal rotation is performed, followed by palpation of the popliteal region and digital pressure on the joint interline. This maneuver allows a greater visualization of the posterior compartment, allowing the diagnostic evaluation of the integrity between the meniscus and the capsule, in a safer way, being able to identify ramp tears without the need to create a posteromedial portal. We recommend that the addition of the diagnostic visualization step of the posteromedial compartment as described by the Recife maneuver be performed to assess the meniscal status in routine anterior cruciate ligament reconstruction.

Combined All-Inside Anterior Cruciate Ligament Reconstruction With Semitendinosus Plus Anterolateral Ligament Reconstruction With Intact Gracilis Tibial Insertion and Transtibial Passage.

The indications for combining anterior cruciate ligament reconstruction with anterolateral ligament reconstruction have increased considerably in recent years since several anatomical, clinical, and biomechanical studies have proven the importance of the anterolateral periphery in knee rotational stability. Much is still being discussed on how to combine these techniques in terms of which grafts and fixation options to use, as well as avoiding tunnel convergence. This study aims to describe anterior cruciate ligament reconstruction with a triple-bundle semitendinosus tendon graft all-inside technique combined with an anterolateral ligament reconstruction maintaining the gracilis tendon insertion on the tibia, using independent anatomical tunnels. With this, we were able to reconstruct both using only hamstring autografts, reducing morbidity in other possible donor areas, in addition to allowing stable fixation of both grafts without tunnel convergence.

Single Femoral Tunnel for Anterior Cruciate Ligament Reconstruction With Bone-Patellar Tendon-Bone Graft and Lemaire's Extra-Articular Tenodesis as a Good Alternative for Combined Anterior Cruciate Ligament and Anterolateral Ligament Revision Surgeries.

The literature has shown a significant decrease in failure rates when the anterior cruciate ligament (ACL) reconstruction was associated with an extra-articular reinforcement technique such as the anterolateral ligament (ALL) or the iliotibial band tenodesis (ITBT) using the modified Lemaire technique. As much as there is a progressive decrease in the failure rates of ACL reconstructions when the ALL reconstruction technique is associated, there are still and will be cases that will result in graft rupture. These cases will require more alternatives for revision, which are always challenging for the surgeon, where the lateral approaches represent complicating factors, especially because of the distortion of the lateral anatomy (by the previous approach for ALL reconstruction), previous reconstruction tunnels, and the presence of fixation materials. We present here a safe technique that offers great stability to the fixation of the graft and is easy to perform, using a single tunnel for the passage of the ACL and ITBT grafts, allowing a single fixation for both. In this way, we performed a lower-cost surgery, with a lower risk of lateral condyle fracture and tunnel confluence. This technique is indicated to be used in cases of revision after failure of combined ACL reconstruction with ALL.

Onlay Technique for Posterior Cruciate Ligament Reconstruction: The Paccola's Technique.

The primary function of the posterior cruciate ligament (PCL) is to restrict the posterior translation of the tibia, and its secondary function is to limit the tibial external rotation, mainly at 90° and 120° of knee flexion. The prevalence of PCL rupture ranges between 3% and 37% of patients with knee ligament tears. This ligament injury often is associated with other ligament injuries. Surgical treatment is recommended for acute PCL injuries associated with knee dislocations or when stress radiographs show a tibial posteriorization greater than or equal to 12 mm. The techniques classically described for the surgical treatment are inlay and transtibial, which can be performed in a single- or double-bundle fashion. Biomechanical studies suggest that the double-bundle technique is superior to the single femoral bundle, suggesting less postoperative laxity. However, such superiority has not yet been proven in clinical studies. This paper will describe the step-by-step technique for PCL surgical reconstruction. The tibial fixation of the PCL graft is performed by using a screw and spiked-washer, and the femoral fixation can be done with a single- or double-bundle technique. We will explain the surgical steps in detail, with tips to perform them simply and safely.

Predictive and protective factors for allogenic blood transfusion in total knee arthroplasty. A retrospective cohort study.

Background: This study aimed to identify the predictive and protective factors of blood transfusion in patients undergoing total knee arthroplasty (TKA) and therefore determine the profile of patients with low and high risk of blood transfusion after arthroplasty. Methods: We conducted a retrospective study with all patients who underwent primary TKA between January 2017 and December 2019 (n = 1.028 patients) in our institution. Information about allogenic transfusion was collected from medical records to determine the incidence, the predictive and protective factors of blood transfusion. All cases of blood transfusions were documented as well the number of units and the moment of each transfusion. We performed univariate and multivariate logistic regression analyses to identify the independent risk and protective factors. Results: The total transfusion rate was 11%, 1.1% at intraoperative and 9,9% at postoperative period. The independent risk factors for transfusion were female gender (OR 1.64), older age (>55yo, OR > 2) higher surgical risk (ASA III, OR 3.07), lower preoperative hemoglobin levels (p = 0.024), post-traumatic arthritis (OR 4.11) and use of postoperative drains (OR 1.81) The protective factors for transfusion were male gender (OR 0.60), obesity (IMC >30, OR 0.60) and use of intravenous tranexamic acid intraoperatively (OR 0.40). Conclusions: We conclude that in addition to the well-established risk factors for blood transfusion such as advanced age, low hemoglobin levels and high surgical risk, we can add post-fracture arthroplasty, non-use of tranexamic acid and the use of postoperative joint drain.

AMP kinase activation by Omega-3 polyunsaturated fatty acid protects the retina against ischemic insult: An in vitro and in vivo study.

PURPOSE: To investigate the possible beneficial effects of omega-3 polyunsaturated fatty acids (ω3-PUFAs) in ischemic retinal angiogenesis and whether AMP-activated protein kinase (AMPK) is involved. METHODS: Human retinal microvascular endothelial cells (hRMECs) were exposed to dimethyloxalylglycine (DMOG), a hypoxia-inducible factor hydroxylase inhibitor, in the presence or absence of docosahexaenoic acid (DHA) and small interfering RNA (siRNA) for AMPKα for 24 h. Ischemic factors, endothelial mesenchymal transition marker, endothelial barrier integrity, cell migration, and tube formation were evaluated. Neonatal AMPKα2-/- and control wild-type (WT) mice were submitted to an oxygen-induced retinopathy (OIR) protocol; their nursing mother mice were either fed ω3-PUFAs or not. In the end, ischemic markers and endothelial cell proliferation were evaluated in neonatal mouse retinal tissue through immunohistochemical or immunofluorescent assays among all studied groups. RESULTS: Cells exposed to DMOG displayed increased expressions of hypoxic and endothelial mesenchymal transition (vimentin) markers and barrier disarrangement of Zonula Occludens-1 compared to the control, accompanied by increased cellular migration and tube formation (p < 0.05). AMPK activity was significantly decreased. Supplementation with DHA restored the mentioned alterations compared to DMOG (p<0.05). In siRNAAMPKα-treated cells, the beneficial effects observed with DHA were abolished. DHA upregulated G-protein receptor-120 (GPR120), which promptly increased intracellular levels of calcium (p ≤ 0.001), which consequently increased Calcium/calmodulin-dependent protein kinase kinase ß expression (CaMKKß) thus phosphorylating AMPKThr172. AMPKα2-/- and wild-type (WT) OIR mice exhibited similar retinal ischemic changes, and the oral supplementation with ω3-PUFA efficiently prevented the noticed ischemic alterations only in WT mice, suggesting that AMPKα2 is pivotal in the protective effects of ω3-PUFA. CONCLUSIONS: ω3-PUFAs protect the retina from the effects of ischemic conditions, and this effect occurs via the GPR120-CaMKKß-AMPK axis. A better understanding of this mechanism might improve the control of pathological angiogenesis in retinal ischemic diseases.

Optimized Tourniquet Use in Primary Total Knee Arthroplasty: A Comparative, Prospective, and Randomized Study.

BACKGROUND: The results of recent studies investigating tourniquet (TNQ) use for knee arthroplasty are controversial. Therefore, this study aimed to compare patients undergoing total knee arthroplasty who did not have a TNQ to those in whom an optimized TNQ protocol was applied. METHODS: We prospectively evaluated 127 patients who had knee osteoarthritis who had undergone total knee arthroplasty and randomized them into two groups: "without TNQ" and "optimized TNQ" (TNQ inflation before skin incision, deflation after cementing, with pressure one hundred millimeters of mercury above the systolic blood pressure, and without articular suction drain usage). The means of surgery and TNQ duration, blood loss, number of blood transfusions, degree of pain, edema, range of motion (ROM), functional score over time, and postoperative complications were compared between the groups. Statistical significance was set at P < .05. RESULTS: No significant differences were found in terms of surgical timing, blood loss, thigh and knee pain, edema, ROM, functional scores, and complications between the "without TNQ" and "optimized TNQ" groups. CONCLUSION: The use of an optimized TNQ in primary total knee arthroplasty presents similar clinical results to surgery without a TNQ and did not increase the incidence of postoperative complications. Its use allowed surgery to occur with the benefits of a clean and dry surgical field provided by TNQ without increasing procedure-related comorbidities.

Osteochondral Allograft Transplant for Combined Medial and Lateral Patellar Cartilage Lesions: The Osteochondral Wide Lesion (OWL) Technique.

Symptomatic articular cartilage injuries are often seen in young active patients and athletes. Magnetic resonance imaging screening examinations have frequently identified such lesions in athletic patients. Patellofemoral chondral defects were previously identified as the most common knee cartilage lesion in high-level athletes. Chondral defects measuring 2 cm2 or greater and complex cartilage defects involving bone loss are ideally replaced with fresh osteochondral allograft. We describe a technique indicated for patients with symptomatic and recurrent anterior knee pain associated with osteochondral patellar defects including the lateral and medial patellar facets. Patients who have undergone previous interventions, including membrane techniques, microfracture, or autologous chondral transplantation, without clinical benefit are also eligible to undergo osteochondral allograft transplantation for combined medial and lateral patellar cartilage lesions, that is, the osteochondral wide lesion (OWL) technique.

Treatment of Distal Patellar Tendon Chronic Rupture: The X-Wave Technique.

Injuries to the patellar tendon (PT) are associated with knee function deterioration and loss of the capacity to perform daily and sports activities. Patellar tendon injury is often misdiagnosed at emergency rooms, leading to chronic proximal retraction and a challenging clinical scenario. Proximal PT injuries are more common, while distal ones, which can involve tibial bone avulsion fractures or direct tendon avulsion, are rarer. The low incidence of distal PT rupture and the variety of injury patterns make a personal approach reasonable when based on the intraoperative findings and the surgeon's experience. Our purpose is to describe a surgical technique to restore the knee extensor mechanism after chronic distal PT rupture using two kinds of graft, one as a waveform augmentation of the native tendon and the other as reinforcement in a letter X aspect.

Posterior-Medial Meniscal Root Repair Through Lateral Tibial Tunnel Combined With Medial Opening Osteotomy and Homologous Graft.

When there is a rupture in the meniscal roots or close to them, the menisci suddenly and considerably reduce their capacity to absorb the axial mechanical load that passes through the knee, quickly leading to the development of a process of chondral degeneration. The varus deformity of the lower limb (when the mechanical axis crosses the medial compartment of the knee) favors this type of injury owing to the overload in the medial compartment. When the patient has both varus deformity and medial meniscal posterior root injury, there is a clear indication for surgical realignment of the affected lower limb. There is still not a consensus regarding combining meniscal root repair with corrective osteotomy, although there is a tendency to perform both procedures aiming at long-term joint preservation. We present a safe alternative technique for simultaneous medial meniscal posterior root repair using a lateral tibial transosseous tunnel associated with a valgus-producing high tibial osteotomy with homologous bone grafting, allowing a full return to daily activities and sports.

Renal protection induced by physical exercise may be mediated by the irisin/AMPK axis in diabetic nephropathy.

In patients with diabetes, it has been suggested that physical exercise may reduce albuminuria and the progression of renal disease. However, the molecular mechanism by which physical exercise protects the kidney in diabetes remains poorly understood. The aim of the present study was to determine the contribution of muscle irisin secretion induced by aerobic physical exercise with the subsequent activation of AMPK for kidney protection under diabetic conditions. Aerobic physical exercise in rats protected the kidney in streptozotocin-induced diabetes. It reduced albuminuria, glomerular hypertrophy, and glomerular expression of collagen IV and fibronectin, as well as markers of kidney inflammation, when compared to sedentary diabetic rats. These effects were associated with elevation in muscle FNDC5/irisin and activity of AMPK in the diabetic kidney. However, the beneficial effects of exercise were lost when the diabetic rats were treated with CycloRGDyK, that in the bone it has been described as an irisin receptor blocker. In cultured human tubular (HK-2) cells, treatment with recombinant irisin counteracted the effect of high glucose in a dose-dependent manner. Irisin, per se, also activated AMPK in HK-2 cells. It is concluded that in diabetes, the renal protective effect of exercise may be mediated by the irisin/AMPK pathway.

Meniscal Root Repair Alone or Combined with Different Procedures After at Least 6 Months of Follow-Up: A Series of Cases.

Purpose: To analyze clinical and functional outcomes of patients submitted to posterior meniscal root repair of the medial or lateral meniscus in different settings, with at least 6 months of follow-up. Patients and Methods: Retrospective multicentric study assessing epidemiological characteristics and clinical-functional results of 22 patients who underwent meniscal root reinsertion (MRR) by transtibial technique. This study addressed different settings: isolated medial root repair, medial root repair associated with high tibial osteotomy (HTO) and lateral root repair associated with anterior cruciate ligament (ACL) reconstruction. Results: Twelve patients had an isolated tear of the posterior root of the medial meniscus and underwent MRR alone. Six patients had a varus axis >5°, undergoing MRR in addition to HTO in the same surgical procedure. Four patients underwent repair of the posterior root of the lateral meniscus associated with simultaneous reconstruction of the ACL. The main results of the study were observed in the improvement of the IKDC score from 27.7% preoperatively to 69.8% in the postoperative period (p < 0.0001) and the Lysholm score of 44.4 points preoperatively to 88.4 points in the postoperative period (p < 0.0001). Significant clinical and subjective improvements were also reported. Conclusion: Medial meniscal root repair, associated or not with valgus tibial osteotomy (when indicated) and lateral meniscal root repair associated with ACL reconstruction, improved clinical, functional, and subjective results of the patients presented in this case series in the short term.

Doença de Madelung: abordagem cirúrgica combinada de lipectomia e lipoaspiração / Madelung's disease: combined surgical approach of lipectomy and liposuction

A doença de Madelung (DM) ou lipomatose simétrica múltipla é uma patologia caracterizada pelo acúmulo de tecido adiposo não encapsulado e depositado simetricamente ao redor do pescoço e tronco superior (tipo I - forma mais comum). Sua etiologia ainda é pouco esclarecida, porém apresenta evidente associação com o consumo crônico excessivo de bebidas alcoólicas. As deformidades físicas são o que levam o paciente a buscar serviço médico, juntamente com eventuais sintomas de acometimento cervical como redução de mobilidade e afecções respiratórias. O diagnóstico da lipomatose simétrica múltipla é clínico, podendo ser complementado com exame de imagem para afastar demais hipóteses diagnósticas e avaliar a extensão do acometimento. O tratamento pode ser realizado por duas modalidades: clínico ou cirúrgico (lipectomia ou lipoaspiração). Relata-se o caso de paciente com lipomatose simétrica múltipla tipo I abordado cirurgicamente com ambas as técnicas: lipectomia cervical e lipoaspiração abdominal. Paciente evoluiu de maneira satisfatória, com redução de queixas e sem recidivas até o presente momento.

Madelung's disease or Multiple Symmetric Lipomatosis is a condition characterized by the accumulation of unencapsulated adipose tissue deposited symmetrically around the neck and upper trunk (type I - most common form). Its etiology is still unclear, but it is clearly associated with chronic excessive consumption of alcoholic beverages. Physical deformities lead the patient to seek medical care, along with possible symptoms of cervical involvement such as reduced mobility and respiratory disorders. Multiple Symmetric Lipomatosis diagnosis is clinical and can be complemented with imaging to rule out other diagnostic hypotheses and assess the extent of involvement. Treatment can be performed in two ways: clinical or surgical (lipectomy or liposuction). We report the case of a patient with Multiple Symmetric Lipomatosis type I surgically treated with both techniques: cervical lipectomy and abdominal liposuction. The patient evolved satisfactorily, with a reduction in complaints and no recurrences so far.

Modified Pulvertaft on Weave Technique Restores Full Active Knee Extension in Patients With Large Chronic Quadriceps Tendon Rupture: A Case Series.

PURPOSE: We aimed to investigate the clinical and functional outcomes, including maximal and explosive strength, after chronic quadriceps tendon rupture repair with Modified Pulvertaft on Weave (MPW) technique METHODS: Knee joint range of motion (ROM), patella height, thigh circumference, and Lysholm and International Knee Documentation Committee (IKDC) scores were assessed preoperatively and postoperatively. The knee extensors maximal (isokinetic peak torque and isometric maximal voluntary contraction (MVC) torque) and explosive strength-rate of torque development (RTD) early [RTD50 and RTD100] and late [RTD250]-were performed. We assessed the thigh circumference and vastus lateralis muscle thickness (MT) as indicators of quadriceps muscle mass, and the voluntary quadriceps activation using surface electromyography (EMG50). RESULTS: Nine patients (mean age: 53 ± 11 years) took part in the study. We observed a significant increase in the knee active ROM and a decreased extension deficit (both, P < .001), but not for pain (P = .07), IKDC (P = .07), and Lysholm (P = .21) after the surgery. We did not observe a difference between involved (n = 8) and uninvolved (n = 10) limbs for ROM, thigh circumference, and MT. We observed differences for extensors peak torque, MVC torque, and late RTD (all, P < .05). However, we did not observe differences for early RTD and EMG50. Significant positive correlations were observed for RTD50 (ρ = .80) and RTD100 (ρ = .81) vs EMG50. Both the IKDC and Lysholm were better correlated with the early than with later RTD. CONCLUSIONS: The MPW reestablished the active knee extension. The same level of quadriceps muscle mass was observed in both limbs, suggesting a lack of hypotrophy due to the injury. Although the involved limb had demonstrated lower knee extensors maximal strength, they demonstrate an equivalent early RTD when compared to the uninvolved limb. The early RTD seems to be better correlated with the patient's functionality than the later RTD and maximal strength. LEVEL OF EVIDENCE: IV, case series.

Controlled Double Gradual Opening Osteotomy for the Treatment of Severe Varus of the Knee-Blount's Disease.

Varus deformity of the knee can lead to early degeneration of the medial tibiofemoral joint. Pediatric patients can be pathologically affected with this deformity known as Blount disease. The cause of this pathology is still uncertain, but some risk factors are well established, such as obesity and family history. The diagnosis is made through clinical history, physical examination, and the radiographic analysis after the age of 2.5 years. The analysis of the metaphyseal-diaphyseal angle, described by Levine and Drennan, is also commonly used for prognosis. When this angle is greater than 16°, it is considered to be grossly abnormal. Possible options for correcting the generated angular deformity are epiphysiodesis, osteotomy (acute or gradual correction), and gradual correction by distraction of the physis. In this surgical technique, we performed a double tibial osteotomy with controlled gradual opening using monolateral external fixator (Orthofix, Verona, Italy). Our technique proved to be an effective way to correct the adolescent tibia vara and is practical and reproducible. Moreover, the use of gradual opening osteotomy allowed a more accurate outcome.

Continuous Meniscal Suture in Radial Meniscal Tear: The Hourglass Technique.

The key to preventing early knee osteoarthritis is meniscal preservation. The main functions of the meniscus are impact absorption, mechanical load transmission, lubrication, joint stability, and proprioception. Radial lesions that extend to the joint capsule are called complete radial tears. This type of injury compromises 2 of the main meniscal functions, which are impact absorption and load distribution, which is equivalent, from a biomechanical perspective, to a total meniscectomy. In the recent past, the treatment of choice for this type of injury was partial meniscectomy. However, several studies have observed progressive joint degeneration after this type of treatment. Recently, different types of meniscal sutures involving radial lesions of the meniscus have been developed. It is believed that such repairs may bring a decrease in future osteoarthritis in this patient profile. The purpose of this article is to describe the steps of continuous meniscal suture for the treatment of radial tears of the medial and lateral menisci.

How to Create an Arthroscopy Training Laboratory Using a Bovine Knee Model.

Orthopaedic surgeries by video arthroscopy have become increasingly popular, as they allow joint treatment through small incisions and minimal tissue damage. However, their execution requires specific skills from the surgeon, different from open surgery, which can only be achieved through practical training. These skills would be ideally performed on human cadaveric anatomical pieces which, however, can be difficult to access for different reasons. Animal anatomical models for surgical skills training have been used for years in medicine, and we observed that the bovine knee has anatomical characteristics quite similar to that of the human knee. In this study, we explain, step by step, the installation and creation of an arthroscopy laboratory with a bovine model, in an effort to contribute to several training centers in arthroscopic surgery around the world, assisting and guiding such centers to install arthroscopy laboratories and facilitating the improvement of more surgeons.