Publications by authors named "Gilberto Nakama"

 To evaluate the clinical and functional outcomes of the pharmacological block of the genicular nerves as a modality in the therapeutic arsenal for knee osteoarthritis, since it is simple, safe, and minimally invasive.  The pharmacological block of the genicular nerves was performed in 20 patients with grades 3 and 4 knee osteoarthritis per the Kellgren-Lawrence classification. We assessed their clinical and functional outcomes one, three, and six months after the procedure.

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Modern advances in molecular medicine have led to the reframing of osteoarthritis as a metabolically active, inflammatory disorder with local and systemic contributing factors. According to the 'inflammatory theory' of osteoarthritis, immune response to an initial damage is the key trigger that leads to progressive joint destruction. Several intertwined pathways are known to induce and govern articular inflammation, cartilage matrix degradation, and subchondral bone changes.

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Background: Bone marrow stimulation (BMS) via microfracture historically has been a first-line treatment for articular cartilage lesions. However, BMS has become less favorable because of resulting fibrocartilage formation. Previous studies have shown that angiogenesis blockade promotes cartilage repair.

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Recent efforts have focused on customizing orthobiologics, such as platelet-rich plasma (PRP) and bone marrow concentrate (BMC), to improve tissue repair. We hypothesized that oral losartan (a TGF-β1 blocker with anti-fibrotic properties) could decrease TGF-β1 levels in leukocyte-poor PRP (LP-PRP) and fibrocytes in BMC. Ten rabbits were randomized into two groups (N = 5/group): osteochondral defect + microfracture (control, group 1) and osteochondral defect + microfracture + losartan (losartan, group 2).

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Background: Microfracture or bone marrow stimulation (BMS) is often the first choice for clinical treatment of cartilage injuries; however, fibrocartilage, not pure hyaline cartilage, has been reported because of the development of fibrosis in the repair tissue. Transforming growth factor β1 (TGF-β1), which can promote fibrosis, can be inhibited by losartan and potentially be used to reduce fibrocartilage.

Hypothesis: Blocking TGF-β1 would improve cartilage healing in a rabbit knee BMS model via decreasing the amount of fibrocartilage and increasing hyaline-like cartilage formation.

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Background: Transtibial pull-out repair of the medial meniscal posterior root (MMPR) has been largely assessed through biomechanical studies. Biomechanically comparing different suture types would further optimize MMPR fixation and affect clinical care.

Purpose/hypothesis: The purpose of this study was to determine the optimal suture material for MMPR fixation.

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Background: Although posterior medial meniscal root (PMMR) repairs are often successful, postoperative meniscal extrusion after a root repair has been identified as a potential clinical problem.

Purpose/hypothesis: The purpose was to quantitatively evaluate the tibiofemoral contact mechanics and extent of meniscal extrusion after a PMMR repair. It was hypothesized that the addition of a centralization suture (into the posterior medial tibial plateau) would help restore normal joint load-bearing characteristics and restore the native amount of meniscal extrusion after a root tear.

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Background: Given the variety of suturing techniques for bucket-handle meniscal repair, it is important to assess which suturing technique best restores native biomechanics.

Purpose/hypothesis: To biomechanically compare vertical mattress and cross-stitch suture techniques, in single- and double-row configurations, in their ability to restore native knee kinematics in a bucket-handle medial meniscal tear model. The hypothesis was that there would be no difference between the vertical mattress and cross-stitch double-row suture techniques but that the double-row technique would provide significantly improved biomechanical parameters versus the single-row technique.

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Background: A flattened posterior tibial slope may cause excessive unwanted stress on the posterior cruciate ligament (PCL) reconstruction graft and place patients at risk for PCL reconstruction graft failure. To date, there is a paucity of biomechanical studies evaluating the effect of posterior tibial slope on the loading properties of single-bundle (SB) and double-bundle (DB) PCL grafts.

Purpose/hypothesis: The purpose of this study was to quantify the effect of sagittal plane tibial slope on PCL reconstruction graft force at varying slopes and knee flexion angles for SB and DB PCL reconstructions.

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Background: Previous work has reported that increased tibial slope is directly correlated with increased anterior tibial translation, possibly predisposing patients to higher rates of anterior cruciate ligament (ACL) tears and causing higher rates of ACL graft failures over the long term. However, the effect of changes in sagittal plane tibial slope on ACL reconstruction (ACLR) graft force has not been well defined.

Purpose/hypothesis: The purpose of this study was to quantify the effect of changes in sagittal plane tibial slope on ACLR graft force at varying knee flexion angles.

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Meniscal root tears are defined as radial tears located within 1 cm from the meniscal attachment or a bony root avulsion. This injury is biomechanically comparable to a total meniscectomy, leading to compromised hoop stresses resulting in decreased tibiofemoral contact area and increased contact pressures in the involved compartment. These changes are detrimental to the articular cartilage and ultimately lead to the development of early osteoarthritis.

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Background: Ramp lesions were initially defined as a tear of the peripheral attachment of the posterior horn of the medial meniscus at the meniscocapsular junction. The separate biomechanical roles of the meniscocapsular and meniscotibial attachments of the posterior medial meniscus have not been fully delineated.

Purpose: To evaluate the biomechanical effects of meniscocapsular and meniscotibial lesions of the posterior medial meniscus in anterior cruciate ligament (ACL)-deficient and ACL-reconstructed knees and the effect of repair of ramp lesions.

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The posterior cruciate ligament (PCL) is the largest and strongest ligament in the human knee, and the primary posterior stabilizer. Recent anatomy and biomechanical studies have provided an improved understanding of PCL function. PCL injuries are typically combined with other ligamentous, meniscal and chondral injuries.

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Background: It is not clear which fixation of total knee arthroplasty obtains the best clinical, functional and radiographic results in people with osteoarthritis and other non-traumatic diseases, such as rheumatoid arthritis.

Objectives: To assess the benefits and harms of cemented, cementless and hybrid knee prostheses fixation techniques in participants with primary osteoarthritis (osteoarthritis following trauma was not included) and other non-traumatic diseases, such as rheumatoid arthritis.

Search Methods: We searched CENTRAL (2011, issue 10), MEDLINE via PubMed, EMBASE, Current Controlled Trials, LILACS, The Cumulative Index to Nursing and Allied Health Literature, SPORTDiscus, Health Technology Assessment Database and the Database of Abstracts of Reviews of Effectiveness, all from implementation to October 2011, along with handsearches of high-yield journals and reference lists of articles.

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Objective: To analyze the most common methods for measuring patellar height and the impact of observer experience in correlations with the other observers using digital radiography.

Methods: Sixty digital radiographs of the knee in lateral view were analyzed by four observers: a physician in the second year of medical residence in orthopedics (R2); a physician in the third year of medical residence in orthopedics (R3); an orthopedic surgeon who was a specialist in knee surgery (SK); and a radiologist who was a specialist in musculoskeletal radiology (SR). The indices used were: Insall-Salvati (IS), Blackburne-Peel (BP), Caton-Deschamps (CD) and modified Insall-Salvati (ISM).

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Unlabelled: Acute lateral ankle sprain (ALAS) is a common injury, but its treatment has yet to be firmly established. The purpose of this study was to investigate how Brazilian Orthopedists (including residents) manage the diagnosis, classification, treatment and complications of ALAS.

Methods: A multiple-choice questionnaire was developed with the aim of addressing the main aspects of the treatment of ALAS.

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Surgical procedures for double-bundle reconstruction of anterior cruciate ligament, which currently use semitendinous and gracilis tendon grafts, have been described in the last decade. Most of the techniques utilize twice the hardware used in single-bundle reconstructions. We report an original anterior cruciate ligament double-bundle reconstruction technique using semitendinous and gracilis tendon grafts, maintaining their tibial bone insertions with two tibial and two femoral tunnels.

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In this article, an original double-bundle anterior cruciate ligament reconstruction technique is described. The procedure is developed using hamstring tendon grafts while maintaining tibial osseous insertion. Two tibial tunnels are drilled and a simplified and precise outside-in double tunnel femoral drilling technique is utilized.

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Background: Exercise is one of the most common triggers of asthmatic symptoms. Many factors, including hyperventilation, determine the prevalence and severity of exercise-induced bronchospasm (EIB). However, the influence of time of day has not been adequately described.

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