Chemogenetic ablation of dopaminergic neurons leads to transient locomotor impairments in zebrafish larvae.

To determine the impact of a controlled loss of dopaminergic neurons on locomotor function, we generated transgenic zebrafish, Tg(dat:CFP-NTR), expressing a cyan fluorescent protein-nitroreductase fusion protein (CFP-NTR) under the control of dopamine transporter (dat) cis-regulatory elements. Embryonic and larval zebrafish express the transgene in several groups of dopaminergic neurons, notably in the olfactory bulb, telencephalon, diencephalon and caudal hypothalamus. Administration of the pro-drug metronidazole (Mtz) resulted in activation of caspase 3 in CFP-positive neurons and in a reduction in dat-positive cells by 5 days post-fertilization (dpf). Loss of neurons coincided with impairments in global locomotor parameters such as swimming distance, percentage of time spent moving, as well as changes in tail bend parameters such as time to maximal bend and angular velocity. Dopamine levels were transiently decreased following Mtz administration. Recovery of some of the locomotor parameters was observed by 7 dpf. However, the total numbers of dat-expressing neurons were still decreased at 7, 12, or 14 dpf, even though there was evidence for production of new dat-expressing cells. Tg(dat:CFP-NTR) zebrafish provide a model to correlate altered dopaminergic neuron numbers with locomotor function and to investigate factors influencing regeneration of dopaminergic neurons.

Single-cell transcriptomic atlas of lung microvascular regeneration after targeted endothelial cell ablation.

We sought to define the mechanism underlying lung microvascular regeneration in a model of severe acute lung injury (ALI) induced by selective lung endothelial cell ablation. Intratracheal instillation of DT in transgenic mice expressing human diphtheria toxin (DT) receptor targeted to ECs resulted in ablation of >70% of lung ECs, producing severe ALI with near complete resolution by 7 days. Using single-cell RNA sequencing, eight distinct endothelial clusters were resolved, including alveolar aerocytes (aCap) ECs expressing apelin at baseline and general capillary (gCap) ECs expressing the apelin receptor. At 3 days post-injury, a novel gCap EC population emerged characterized by de novo expression of apelin, together with the stem cell marker, protein C receptor. These stem-like cells transitioned at 5 days to proliferative endothelial progenitor-like cells, expressing apelin receptor together with the pro-proliferative transcription factor, Foxm1, and were responsible for the rapid replenishment of all depleted EC populations by 7 days post-injury. Treatment with an apelin receptor antagonist prevented ALI resolution and resulted in excessive mortality, consistent with a central role for apelin signaling in EC regeneration and microvascular repair. The lung has a remarkable capacity for microvasculature EC regeneration which is orchestrated by newly emergent apelin-expressing gCap endothelial stem-like cells that give rise to highly proliferative, apelin receptor-positive endothelial progenitors responsible for the regeneration of the lung microvasculature.

Zebrafish Parla- and Parlb-deficiency affects dopaminergic neuron patterning and embryonic survival.

Many genes associated with familial Parkinson's disease contribute to mitochondrial morphology and function. Some of these genes, for example, Pink1 and Parkin, are part of a common pathway. The presenilin-associated rhomboid-like (PARL) gene was recently linked to familial Parkinson's disease. The PARL gene product is found in the inner mitochondrial membrane and cleaves the optic atrophy 1 protein, involved in mitochondrial morphology and apoptosis. In Drosophila, the PARL-related rhomboid-7 gene acts upstream of pink1 and parkin. However, such a genetic relationship is still unknown in vertebrates. Here, we show that the zebrafish genome comprises two parl paralogs: parla and parlb. Morpholino-mediated loss of parla and/or parlb function resulted in mild neurodegeneration, as evidenced by a lower density of dopaminergic neurons. Patterning of dopaminergic neurons was also perturbed in the ventral diencephalon. Morphants exhibited extensive cell death throughout the entire body as well as increased larval mortality. The morphant phenotype could be rescued by injection of human PARL mRNA, but not catalytically inactive PARL, suggesting functional conservation between the human and zebrafish proteins. More importantly, the zebrafish pink1 mRNA as well as the human PINK1 mRNA, but not kinase-dead nor Parkinson's disease-linked mutant PINK1 mRNA, also rescued the morphant phenotype, providing evidence that Parl genes may function upstream of Pink1, as part of a conserved pathway in vertebrates.

Transgenic zebrafish expressing green fluorescent protein in dopaminergic neurons of the ventral diencephalon.

We have generated a line of transgenic zebrafish, Tg(dat:EGFP), in which the green fluorescent protein (GFP) is expressed under the control of cis-regulatory elements of the dopamine transporter (dat) gene. In Tg(dat:EGFP) fish, dopamine (DA) neurons are labeled with GFP, including those in ventral diencephalon (vDC) clusters, amacrine cells in the retina, in the olfactory bulb, in the pretectum, and in the caudal hypothalamus. In the vDC, DA neurons of groups 2-6 are correctly labeled with GFP, based on colocalization analyses. MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) treatments induced a modest but significant loss of DA neurons in groups 2-6 of the vDC. This transgenic line will be useful for the study of DA neuron development and in models of DA neuron loss.

Single-cell transcriptomic analysis of neuroepithelial cells and other cell types of the gills of zebrafish (Danio rerio) exposed to hypoxia.

The fish gill is a multifunctional organ involved in numerous physiological processes, such as gas exchange and sensing of hypoxia by respiratory chemoreceptors, called neuroepithelial cells (NECs). Many studies have focused on zebrafish (Danio rerio) to investigate the structure, function and development of the gills, yet the transcriptomic profile of most gill cells remains obscure. We present the results of a comprehensive transcriptomic analysis of the gills of zebrafish using single-cell RNA sequencing (scRNA-seq). Gill cells from ETvmat2:EGFP zebrafish were individually labelled before scRNA-seq library construction using 10× Genomics Chromium technology. 12,819 cells were sequenced with an average depth of over 27,000 reads per cell. We identified a median of 485 genes per cell and 16 cell clusters, including NECs, neurons, pavement cells, endothelial cells and mitochondrion-rich cells. The identity of NECs was confirmed by expression of slc18a2, encoding the vesicular monoamine transporter, Vmat2. Highly differentially-expressed genes in NECs included tph1a, encoding tryptophan hydroxylase, sv2 (synaptic vesicle protein), and proteins implicated in O2 sensing (ndufa4l2a, cox8al and epas1a). In addition, NECs and neurons expressed genes encoding transmembrane receptors for serotonergic, cholinergic or dopaminergic neurotransmission. Differential expression analysis showed a clear shift in the transcriptome of NECs following 14 days of acclimation to hypoxia. NECs in the hypoxia group showed high expression of genes involved in cell cycle control and proliferation. The present article provides a complete cell atlas for the zebrafish gill and serves as a platform for future studies investigating the molecular biology and physiology of this organ.

Right Ventricular Maladaptation to Pressure Overload in Fischer Rats Is Associated With Profound Deficiency in Adenylate Kinase 1 and Impaired Ventricular Energetics.

BACKGROUND: We explored the mechanism of maladaptive right ventricular (RV) remodeling in Fischer compared with Sprague-Dawley (SD) rats exposed to pressure overload. METHODS: Pulmonary hypertension was induced by injection of the VEGFR antagonist, SU5416, followed by a 3-week exposure to hypoxia (Sugen chronic hypoxia). In vivo oxidative metabolism was assessed by RV/left ventricle ratio of [11C]acetate positron emission tomography clearance (kmono). Unbiased, global transcriptional and proteomic profiling was performed in Fischer and SD rats at baseline and after Sugen chronic hypoxia. RESULTS: All Fischer rats succumbed to RV failure by 5 weeks, whereas SD rats showed preserved RV function and 88% survival beyond 9 weeks (P<0.0001). Fischer rats exhibited increased oxidative metabolism at 4 weeks (P<0.05) and impaired RV efficiency compared with SD (work metabolic index: 52±10 versus 91±27 mmHg·mL/cm2, respectively; P<0.05), but no differences in mitochondrial complex activity. AK1 (adenylate kinase 1) was among the top 10 differentially expressed genes between Fischer and SD rats, with markedly lower RV expression in Fischer rats (FC: 3.36, P<0.05), confirmed by proteomic analysis and validated by Western blotting (>10-fold reduction, P<0.001). While whole-genome sequencing failed to reveal any coding region mutations in Fischer rats, there was a unique variant in a highly conserved upstream flanking region likely involved in the regulation of AK1 expression. CONCLUSIONS: Therefore, Fischer rats exhibit profound AK1 deficiency and inefficient cardiac energetics likely related to reduced adenosine triphosphate shuttling from the mitochondria to the contractile fibers. This represents a novel mechanism for RV failure in response to chronic increases in afterload.

Effects of low-dose methylcyclopentadienyl manganese tricarbonyl-derived manganese on the development of diencephalic dopaminergic neurons in zebrafish.

Fuel additive methylcyclopentadienyl manganese tricarbonyl (MMT) is counted as an organic manganese (Mn)-derived compound. The toxic effects of Mn (alone and complexed) on dopaminergic (DA) neurotransmission have been investigated in both cellular and animal models. However, the impact of environmentally relevant Mn exposure on DA neurodevelopment is rather poorly understood. In the present study, the MMT dose of 100 µM (about 5 mg Mn/L) caused up-regulation of DA-related genes in association with cell body swelling and increase in the number of DA neurons of the ventral diencephalon subpopulation DC2. Furthermore, our analysis identified significant brain Mn bioaccumulation and enhancement of total dopamine levels in association with locomotor hyperactivity. Although DA levels were restored at adulthood, we observed a deficit in the acquisition and consolidation of memory. Collectively, these findings suggest that developmental exposure to low-level MMT-derived Mn is responsible for the selective alteration of diencephalic DA neurons and with long-lasting effects on fish explorative behaviour in adulthood.

Dopaminergic neurons regenerate following chemogenetic ablation in the olfactory bulb of adult Zebrafish (Danio rerio).

Adult zebrafish have the ability to regenerate cells of the central nervous system. However, few neuronal regeneration studies in adult zebrafish addressed their ability to regenerate specific types of neurons following cell specific ablation. We show here that treatment of transgenic Tg(dat:CFP-NTR) adult zebrafish with the prodrug metronidazole (Mtz) according to our administration regimen predominantly ablates dopamine (DA) neurons within the olfactory bulb (OB) of adult fish. Loss of DA neurons was accompanied by an impaired olfaction phenotype, as early as 1-week post-treatment, in which fish were unable to sense the presence of the repulsive stimulus cadaverine. The olfactory impairment was reversed within 45 days and coincided with the recovery of DA neuron counts in the OB. A multi-label pulse-chase analysis with BrdU and EdU over the first seventeen days-post Mtz exposure showed that newly formed DA neurons were recruited within the first nine days following exposure and led to functional and morphological recovery of the OB.

Comparison of macular thickness by optical coherence tomography measurements after uneventful phacoemulsification using ketorolac tromethamine, nepafenac, vs a control group, preoperatively and postoperatively.

PURPOSE: To analyze, using optical coherence tomography, the macular thickness values of patient groups using nonsteroidal anti-inflammatory drug (NSAID) eye drops or artificial tears during uncomplicated cataract surgery. METHODS: A total of 77 eyes from 42 patients were analyzed. The patients were divided into three groups, each using one of the following ophthalmic sterile suspensions: nepafenac (21 eyes), propylene glycol (24 eyes), or ketorolac tromethamine (32 eyes). RESULTS: The mean macular thicknesses of the nepafenac group, preoperatively as well as at 1, 7, and 45 days postoperatively, were 216.42, 216.61, 222.47, and 218.28, respectively; those of the propylene glycol control group were 218.29, 214.50, 219.37, and 228.45, respectively; and those of the ketorolac tromethamine group were 217.46, 220.71, 225.25, and 228.46, respectively. There were no significant differences between groups at any time, with p-values of 0.971, 0.6742, 0.6711, and 0.327, respectively. CONCLUSION: During the study period, no significant differences in macular thickness were observed between the patient groups using two types of NSAIDs or between those groups and the control group that used propylene glycol, indicating that neither drug was superior to the other or the placebo. However, a slight macular thickening, without reduction of visual acuity, was observed in all groups.

Occult macular dystrophy: brief literature review / Distrofia macular ocular: breve revisão da literatura

ABSTRACT Occult macular dystrophy is characterized by a slowly progressive bilateral reduction of visual acuity in patients with normal fundus and fluorescein angiography. We describe a case of a 36-year-old male patient diagnosed with this condition, after extensive investigation with multimodal imaging, electrophysiology tests, and systemic screening.

RESUMO A distrofia macular oculta é caracterizada por perda visual, lentamente progressiva, em pacientes com fundoscopia e angiografia fluoresceínica normais. Relatamos o caso de um paciente de 36 anos do sexo masculino diagnosticado com essa condição após extensa investigação com exames de imagem multimodais, eletrofisiológicos e rastreio de doenças sistêmicas.

BONE TUNNEL ENLARGEMENT WITH NON-METALLIC INTERFERENCE SCREWS IN ACL RECONSTRUCTION.

OBJECTIVE: To compare the widening of bone tunnels between poly-etheretherketone (PEEK), absorbable polylactic acid DL (PLDL) and tricalcium phosphate (TCP) interference screws in anterior cruciate ligament (ACL) reconstruction. METHODS: Three groups of patients undergoing ACL reconstruction with at least 1 year of follow-up using the out-in drilling technique and hamstring as a graft were assessed. The patients were divided according to the type of interference screw used (PEEK, PLDL and TCP). Computed tomography (CT) was performed to measure the greatest femoral and tibial tunnel widening regarding to the initial tunnel, and then it was compared between groups. RESULTS: Mean widening in group 1 (PEEK) was 39.56% (SD 16%) in the femoral tunnel and 33.65% (SD 20%) in the tibia. In group 2 (PLDL) mean widening was 48.43% in the femoral tunnel (SD 18%) and 35.24% (SD 13%) in the tibial tunnel. In group 3 (TCP) mean widening was 44.51% in the femur (SD 14%) and 36.83% in the tibia (SD 14%). The comparison between groups (PLDL-PEEK, PLDL-TCP, PEEK-TCP) shows no statistically significant difference. CONCLUSION: Bone tunnel enlargement values after ACL reconstruction with the use of different types of materials (bioinert and biomaterials) of interference screws (PEEK, PLDL and TCP) were similar. Level of Evidence III, Comparative retrospective study.

OBJETIVO: Comparar o alargamento dos túneis ósseos entre parafusos de interferência de poli-éter-etil-cetona (PEEK), ácido poli lático (PLDL) absorvível e tricálcio fosfato (TCP) na reconstrução do ligamento cruzado anterior (LCA). MÉTODOS: Foram avaliados três grupos de pacientes submetidos à reconstrução do LCA com ao menos um ano de acompanhamento, com perfuração de fora para dentro, tendões flexores quádruplos como enxerto, que foram divididos de acordo com o parafuso de interferência utilizado (PEEK, PLDL e TCP). Realizou-se tomografia computadorizada (TC) para aferição do maior alargamento do túnel tibial e femoral em relação ao túnel inicial, e foi comparado o alargamento entre os grupos. RESULTADOS: O alargamento médio no grupo 1 (PEEK) foi 39,56% (DP = 16%) no túnel femoral e 33,65% (DP = 20%) na tíbia. No grupo 2 (PLDL) o alargamento médio do túnel femoral foi 48,43% (DP = 18%) e 35,24% (DP = 13%) na tíbia. No grupo 3 (TCP) 44,51% (DP = 14%) foi o alargamento médio no fêmur e 36.83% (DP = 14%) na tíbia. Na comparação entre os grupos (PLDL-PEEK, PLDL-TCP, PEEK-TCP) não houve diferença estatisticamente significante. CONCLUSÃO: O alargamento dos túneis ósseos após a reconstrução do LCA com a utilização de diferentes tipos de materiais (bioinertes e biomateriais) de parafusos de interferência (PEEK, PLDL e TCP) foi semelhante. Nível de Evidencia III, Estudo retrospectivo comparativo.

Terrible triad of the elbow: evaluation of surgical treatment.

OBJECTIVE: This study aims at analyzing retrospectively the clinical-functional and radiographic results of surgical treatment of the terrible elbow triad, with at least 12 months of postoperative follow-up evaluating elbow function. METHODS: A group of patients for retrospective analysis from 2004 to 2015 was defined, in which 12 patients were studied. They underwent surgery due to fracture of the radial head, coronoid fracture, and elbow dislocation; they were evaluated by the Disabilities of the Arm, Shoulder and Hand (DASH) score, the degree of patient satisfaction, the degree of trauma energy, radiographic images, range of motion, and complications. RESULTS: There was a higher incidence of Regan and Morrey type II coronoid process fractures; in relation to the injuries, nine patients had deinsertion of the brachialis. Half of the patients suffered a fall from their own height as the mechanism of trauma. The extent of elbow flexion and extension averaged 126.6 and 24.1 degrees, respectively; the averages for pronation and supination were 64.1 and 62.0 degrees, respectively. All patients presented muscle strength of grade IV or V. The mean DASH score was 14.3, the mean pain score was 2.5, and a majority of the patients were satisfied with the treatment. CONCLUSION: Despite the total loss of range of motion of the elbow, especially in extension, the treatment was satisfactory for most patients.

OBJETIVO: Este estudo tem o objetivo de analisar, retrospectivamente, os resultados clínico- funcionais e radiográficos do tratamento cirúrgico da tríade terrível do cotovelo, com no mínimo doze meses de acompanhamento pós-operatório, avaliando a função do cotovelo. MÉTODOS: Definimos um grupo de pacientes para avaliação retrospectiva no período de 2004 a 2015, no qual foram estudados 12 pacientes, submetidos a procedimento cirúrgico devido a fratura da cabeça do rádio, fratura do processo coronoide e luxação do cotovelo; sendo avaliados pelo escore Disabilities of the Arm, Shoulder and Hand (DASH), grau de satisfação do paciente, grau de energia do trauma, radiografias, arco de movimento e complicações. RESULTADOS: Observou-se maior incidência de fraturas do processo coronoide do tipo II de Regan e Morrey; em relação às lesões, nove pacientes apresentaram desinserção do músculo braquial. Metade dos pacientes apresentou queda da própria altura como mecanismo de trauma. Os graus de flexão e extensão do cotovelo tiveram respectivamente as médias: 126,6 e 24,1 graus; e as médias em graus de pronação e supinação foram respectivamente: 64,1 e 62,0 graus. Todos os pacientes apresentaram grau de força muscular IV ou V. Obtivemos escore DASH médio de 14,3, a escala de dor teve média de 2,5, e a maioria dos pacientes se disse satisfeita com o tratamento. CONCLUSÃO: Apesar da perda de amplitude total de movimento do cotovelo, principalmente em extensão, o tratamento mostrou-se satisfatório para a maioria dos pacientes.

Delayed effects of methylmercury on the mitochondria of dopaminergic neurons and developmental toxicity in zebrafish larvae (Danio rerio).

Methylmercury (MeHg) is a known neurotoxicant affecting the central nervous system but effects on dopaminergic (DA) neurons are not well understood. Wild-type zebrafish (Danio rerio) and two transgenic lines: Tg(dat:eGFP) expressing enhanced green fluorescent protein (eGFP) in DA neuron clusters and Tg(dat:tom20 MLS-mCherry) expressing red fluorescence (mCherry) targeted to mitochondria of DA neurons were used to evaluate the effects of micromolar MeHg exposure on DA neuron and whole animal motor function during early development. Three-day-old larvae were exposed to micromolar concentrations of MeHg (0.03, 0.06, and 0.3µM) in system water. Exposure to 0.3µM MeHg caused mortality and significant morphological abnormalities including edema, curvature of the spine, and hemorrhages in zebrafish larvae after a 48h exposure period. At 0.06µM MeHg, the appearance of morphological abnormalities was delayed for 72h and far less severe, whereas 0.03µM MeHg did not cause any morphological defects or mortalities. A delayed but significant reduction in locomotor ability and mCherry fluorescence in specific brain regions in the 0.06µM MeHg exposed larvae suggests that DA neuron function rather than neuron numbers was compromised. Double immunolabeling with tyrosine hydroxylase and pan neural staining showed no effect of MeHg exposure. We have established Tg(dat:tom20 MLS-mCherry) zebrafish larvae as a model which can be used to assess MeHg neurotoxicity and that exposure to low dose MeHg (0.06µM) during development may predispose DA neurons to impairment caused by changes in mitochondrial dynamics.

Transgenic Zebrafish Expressing mCherry in the Mitochondria of Dopaminergic Neurons.

Genetic mutations and environmental toxins are known to affect mitochondrial health and have been implicated in the progressive degeneration of dopaminergic neurons in Parkinson's disease. To visualize mitochondria in dopaminergic neurons of live zebrafish, we used the regulatory elements of the dopamine transporter (dat) gene to target a reporter, mCherry, after fusion with the mitochondrial localizing signal (MLS) of Tom20. Immunoblot analysis of mitochondrial and cytosolic fractions from Tg(dat:tom20 MLS-mCherry) larvae shows that mCherry is efficiently targeted to the mitochondria. Confocal imaging of live fish was carried out from 1 day postfertilization (dpf) to 9 dpf. We also colocalized dat mRNA expression with the mCherry protein in the olfactory bulb (OB), subpallium (SP), pretectum (Pr), diencephalic clusters 2 and 3 (DC2/3), caudal hypothalamus (Hc), locus coeruleus (LC), anterior preoptic area (POa), retinal amacrine cells (RAC), caudal hypothalamus (Hc), and preoptic area (PO). Treating Tg(dat:tom20 MLS-mCherry) larvae with the dopaminergic neurotoxin MPTP (1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine) at 2 or 3 dpf resulted in a decrease in mCherry fluorescence in the pretectum, olfactory bulb, subpallium, diencephalic clusters 2 and 3, and the caudal hypothalamus. Labeling of mitochondria in nigrostriatal dopaminergic neurons of zebrafish could allow their visualization in vivo following genetic or pharmacological manipulations.

Terrible triad of the elbow: evaluation of surgical treatment / Tríade terrível do cotovelo. Avaliação do tratamento cirúrgico

ABSTRACT Objective: This study aims at analyzing retrospectively the clinical-functional and radiographic results of surgical treatment of the terrible elbow triad, with at least 12 months of postoperative follow-up evaluating elbow function. Methods: A group of patients for retrospective analysis from 2004 to 2015 was defined, in which 12 patients were studied. They underwent surgery due to fracture of the radial head, coronoid fracture, and elbow dislocation; they were evaluated by the Disabilities of the Arm, Shoulder and Hand (DASH) score, the degree of patient satisfaction, the degree of trauma energy, radiographic images, range of motion, and complications. Results: There was a higher incidence of Regan and Morrey type II coronoid process fractures; in relation to the injuries, nine patients had deinsertion of the brachialis. Half of the patients suffered a fall from their own height as the mechanism of trauma. The extent of elbow flexion and extension averaged 126.6 and 24.1 degrees, respectively; the averages for pronation and supination were 64.1 and 62.0 degrees, respectively. All patients presented muscle strength of grade IV or V. The mean DASH score was 14.3, the mean pain score was 2.5, and a majority of the patients were satisfied with the treatment. Conclusion: Despite the total loss of range of motion of the elbow, especially in extension, the treatment was satisfactory for most patients.

RESUMO Objetivo: Este estudo tem o objetivo de analisar, retrospectivamente, os resultados clínico- funcionais e radiográficos do tratamento cirúrgico da tríade terrível do cotovelo, com no mínimo doze meses de acompanhamento pós-operatório, avaliando a função do cotovelo. Métodos: Definimos um grupo de pacientes para avaliação retrospectiva no período de 2004 a 2015, no qual foram estudados 12 pacientes, submetidos a procedimento cirúrgico devido a fratura da cabeça do rádio, fratura do processo coronoide e luxação do cotovelo; sendo avaliados pelo escore Disabilities of the Arm, Shoulder and Hand (DASH), grau de satisfação do paciente, grau de energia do trauma, radiografias, arco de movimento e complicações. Resultados: Observou-se maior incidência de fraturas do processo coronoide do tipo II de Regan e Morrey; em relação às lesões, nove pacientes apresentaram desinserção do músculo braquial. Metade dos pacientes apresentou queda da própria altura como mecanismo de trauma. Os graus de flexão e extensão do cotovelo tiveram respectivamente as médias: 126,6 e 24,1 graus; e as médias em graus de pronação e supinação foram respectivamente: 64,1 e 62,0 graus. Todos os pacientes apresentaram grau de força muscular IV ou V. Obtivemos escore DASH médio de 14,3, a escala de dor teve média de 2,5, e a maioria dos pacientes se disse satisfeita com o tratamento. Conclusão: Apesar da perda de amplitude total de movimento do cotovelo, principalmente em extensão, o tratamento mostrou-se satisfatório para a maioria dos pacientes.

Bone tunnel enlargement with non-metallic interference screws in acl reconstruction / Alargamento dos túneis ósseos na reconstrução do lca com parafusos de interferência não metálicos

ABSTRACT Objective: To compare the widening of bone tunnels between poly-etheretherketone (PEEK), absorbable polylactic acid DL (PLDL) and tricalcium phosphate (TCP) interference screws in anterior cruciate ligament (ACL) reconstruction. Methods: Three groups of patients undergoing ACL reconstruction with at least 1 year of follow-up using the out-in drilling technique and hamstring as a graft were assessed. The patients were divided according to the type of interference screw used (PEEK, PLDL and TCP). Computed tomography (CT) was performed to measure the greatest femoral and tibial tunnel widening regarding to the initial tunnel, and then it was compared between groups. Results: Mean widening in group 1 (PEEK) was 39.56% (SD 16%) in the femoral tunnel and 33.65% (SD 20%) in the tibia. In group 2 (PLDL) mean widening was 48.43% in the femoral tunnel (SD 18%) and 35.24% (SD 13%) in the tibial tunnel. In group 3 (TCP) mean widening was 44.51% in the femur (SD 14%) and 36.83% in the tibia (SD 14%). The comparison between groups (PLDL-PEEK, PLDL-TCP, PEEK-TCP) shows no statistically significant difference. Conclusion: Bone tunnel enlargement values after ACL reconstruction with the use of different types of materials (bioinert and biomaterials) of interference screws (PEEK, PLDL and TCP) were similar. Level of Evidence III, Comparative retrospective study.

RESUMO Objetivo: Comparar o alargamento dos túneis ósseos entre parafusos de interferência de poli-éter-etil-cetona (PEEK), ácido poli lático (PLDL) absorvível e tricálcio fosfato (TCP) na reconstrução do ligamento cruzado anterior (LCA). Métodos: Foram avaliados três grupos de pacientes submetidos à reconstrução do LCA com ao menos um ano de acompanhamento, com perfuração de fora para dentro, tendões flexores quádruplos como enxerto, que foram divididos de acordo com o parafuso de interferência utilizado (PEEK, PLDL e TCP). Realizou-se tomografia computadorizada (TC) para aferição do maior alargamento do túnel tibial e femoral em relação ao túnel inicial, e foi comparado o alargamento entre os grupos. Resultados: O alargamento médio no grupo 1 (PEEK) foi 39,56% (DP = 16%) no túnel femoral e 33,65% (DP = 20%) na tíbia. No grupo 2 (PLDL) o alargamento médio do túnel femoral foi 48,43% (DP = 18%) e 35,24% (DP = 13%) na tíbia. No grupo 3 (TCP) 44,51% (DP = 14%) foi o alargamento médio no fêmur e 36.83% (DP = 14%) na tíbia. Na comparação entre os grupos (PLDL-PEEK, PLDL-TCP, PEEK-TCP) não houve diferença estatisticamente significante. Conclusão: O alargamento dos túneis ósseos após a reconstrução do LCA com a utilização de diferentes tipos de materiais (bioinertes e biomateriais) de parafusos de interferência (PEEK, PLDL e TCP) foi semelhante. Nível de Evidencia III, Estudo retrospectivo comparativo.