Ângelo Ribeiro Vaz de Faria
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Ângelo Ribeiro Vaz de Faria has a total of 15 co-authors. Here are the top co-authors by number of shared publications:
- Jefferson Soares Leal
Universidade Federal de Minas Gerais, Brazil
3 shared publications - Rogério Lúcio Chaves de Resende
Universidade Federal de Minas Gerais, Brazil
3 shared publications - Renato de Mello Guimarães
Universidade Federal de Minas Gerais
2 shared publications - Carlos Bauer Namem Lopes Junior
Rede Mater Dei, Brazil
1 shared publication - Fernando Magalhães Gosende
Universidade Federal de Minas Gerais, Brazil; Rede Mater Dei, Brazil
1 shared publication - Igor Guedes Nogueira Reis
Departamento do Aparelho Locomotor, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
1 shared publication
Latest Publications
- Open Access
- 1 January 2026
- Published by FapUNIFESP (SciELO) in Acta Ortopedica Brasileira
- Vol. 34 (spe2) , e297893
BIOMECHANICAL STUDY OF PULLOUT RESISTANCE OF CORTICAL SCREWS IN SWINE LUMBAR VERTEBRAE
Introduction: This study aimed to evaluate the mechanical resistance to pullout of the lumbar cortical bone trajectory (CBT) screw with and without transfixation of the second cortical in a biomechanical assay in swine vertebrae. Methods: A pullout test was performed in 16 swine vertebrae (L5 and L6) fixed with 32 CBT screws using the same protocol. Of these, 16 were inserted in a monocortical manner according to the original technique and 16 through a modified technique which included the transfixation of the second cortical bone. Results: The average maximum load value for pulling out the inserted screws with the modified technique including the transfixation of the second cortical bone was 140.50 Kgf (± 56.56), while in the original technique it was 95.69 Kgf (± 42.19) (p = 0.004). Conclusion: The biomechanical tests applied to the studied sample showed that the pullout resistance of the CBT screws inserted with the bicortical technique was, on average, 46% higher than the screws inserted according to the original monocortical technique. Level of Evidence II; Experimental study.
- 1 January 2026
- Published by FapUNIFESP (SciELO) in Acta Ortopedica Brasileira
- Vol. 34 (spe2) , e297893
Open AccessBIOMECHANICAL STUDY OF PULLOUT RESISTANCE OF CORTICAL SCREWS IN SWINE LUMBAR VERTEBRAE
Introduction: This study aimed to evaluate the mechanical resistance to pullout of the lumbar cortical bone trajectory (CBT) screw with and without transfixation of the second cortical in a biomechanical assay in swine vertebrae. Methods: A pullout test was performed in 16 swine vertebrae (L5 and L6) fixed with 32 CBT screws using the same protocol. Of these, 16 were inserted in a monocortical manner according to the original technique and 16 through a modified technique which included the transfixation of the second cortical bone. Results: The average maximum load value for pulling out the inserted screws with the modified technique including the transfixation of the second cortical bone was 140.50 Kgf (± 56.56), while in the original technique it was 95.69 Kgf (± 42.19) (p = 0.004). Conclusion: The biomechanical tests applied to the studied sample showed that the pullout resistance of the CBT screws inserted with the bicortical technique was, on average, 46% higher than the screws inserted according to the original monocortical technique. Level of Evidence II; Experimental study.
- Open Access
- 1 March 2021
- Published by FapUNIFESP (SciELO) in Coluna/Columna
- Vol. 20 (1) , 8-13
INTEROBSERVER REPRODUCIBILITY ASSESSMENT OF THE NEW AOSPINE CLASSIFICATION FOR SUBAXIAL CERVICAL LESIONS
Objective: To evaluate the interobserver agreement of the new AOSpine classification for subaxial cervical fractures. Methods: A descriptive study, which11 traumatic lesions of the subaxial cervical spine (through radiographic and tomographic images), were evaluated by 16 observers being: 6 senior surgeons, 4 fellows in spinal surgery and 6 physicians residents in Orthopedics and Traumatology by the new AOSpine classification, with subsequent statistical analysis of the results. An agreement analysis was performed using the Kappa coefficient, both individually and in combination, with an interpretation of the index performed using the standardized model for Landis and Koch. To determine the level of significance of the analyzes, values less than 0.05 were considered statistically significant. Results: In general, the level of agreement among the examiners was considered reasonable. The lesions “A0 (F3)”, “A4 (F3)”, “B1”, “B3”, “B3 (F3)”, “C”, “C (F3)” and “F3”showed a low level of agreement between the examiners. The level of reasonable agreement was obtained between fractures “A0”, “A1”, “A4”, “B2” and “C (F4)”. The only fracture that presented a moderate level of agreement was the “C (F4 BL)” lesion. This result indicates that the referred injury was the fracture of the subaxial column that presented the best level of agreement among the 16 examiners in the present study. Conclusions: The results of the study indicate an intermediate agreement of the new AOSpine classification for subaxial cervical lesion and point to the need to carry out studies that seek to evaluate this new classification in order to better evaluate its strengths and weaknesses, contributing for its improvement. Level of evidence III; Diagnostic study - investigation of a diagnostic test.
- 1 March 2021
- Published by FapUNIFESP (SciELO) in Coluna/Columna
- Vol. 20 (1) , 8-13
Open AccessINTEROBSERVER REPRODUCIBILITY ASSESSMENT OF THE NEW AOSPINE CLASSIFICATION FOR SUBAXIAL CERVICAL LESIONS
Objective: To evaluate the interobserver agreement of the new AOSpine classification for subaxial cervical fractures. Methods: A descriptive study, which11 traumatic lesions of the subaxial cervical spine (through radiographic and tomographic images), were evaluated by 16 observers being: 6 senior surgeons, 4 fellows in spinal surgery and 6 physicians residents in Orthopedics and Traumatology by the new AOSpine classification, with subsequent statistical analysis of the results. An agreement analysis was performed using the Kappa coefficient, both individually and in combination, with an interpretation of the index performed using the standardized model for Landis and Koch. To determine the level of significance of the analyzes, values less than 0.05 were considered statistically significant. Results: In general, the level of agreement among the examiners was considered reasonable. The lesions “A0 (F3)”, “A4 (F3)”, “B1”, “B3”, “B3 (F3)”, “C”, “C (F3)” and “F3”showed a low level of agreement between the examiners. The level of reasonable agreement was obtained between fractures “A0”, “A1”, “A4”, “B2” and “C (F4)”. The only fracture that presented a moderate level of agreement was the “C (F4 BL)” lesion. This result indicates that the referred injury was the fracture of the subaxial column that presented the best level of agreement among the 16 examiners in the present study. Conclusions: The results of the study indicate an intermediate agreement of the new AOSpine classification for subaxial cervical lesion and point to the need to carry out studies that seek to evaluate this new classification in order to better evaluate its strengths and weaknesses, contributing for its improvement. Level of evidence III; Diagnostic study - investigation of a diagnostic test.
- Open Access
- 1 June 2020
- Published by FapUNIFESP (SciELO) in Coluna/Columna
- Vol. 19 (2) , 127-132
MORPHOMETRY OF THE POSITIONING OF CORTICAL TRAJECTORY PEDICLE SCREWS IN BRAZILIANS
Objective Morphometric study of the positioning of the cortical trajectory pedicle screw in the lumbar spine of Brazilian patients of different sexes and ages, through the use of computed tomography images, in order to obtain more reliable data about cortical screw insertion and the variations observed, providing assistance for a safer, more effective approach with fewer complications. Methods Selection of 100 patients from a database, alternating by sex, measuring the length, diameter, cephalic angulation, and lateral angulation of the vertebrae from L1 to L5. Results Statistically significant measurements were obtained for the four different parameters in relation to sex. The mean age was 56, with a minimum of 20 and a maximum of 87 years. The L4 and L5 screws showed a reduction in relation to the other levels, while the width showed a progressive increase starting at L3. Lateral angulation was the parameter with the least variation among the levels, while there was greater variation and a reduction from L4 to L5 in cephalic angulation. Conclusion Statistically significant results were obtained for length, diameter, lateral and cephalic angulation. Sex was a significant factor in spine surgery instrumentation using the cortical trajectory pedicle screw technique. Level of evidence I; Diagnostic study (investigation of an examination for diagnosis).
- 1 June 2020
- Published by FapUNIFESP (SciELO) in Coluna/Columna
- Vol. 19 (2) , 127-132
Open AccessMORPHOMETRY OF THE POSITIONING OF CORTICAL TRAJECTORY PEDICLE SCREWS IN BRAZILIANS
Objective Morphometric study of the positioning of the cortical trajectory pedicle screw in the lumbar spine of Brazilian patients of different sexes and ages, through the use of computed tomography images, in order to obtain more reliable data about cortical screw insertion and the variations observed, providing assistance for a safer, more effective approach with fewer complications. Methods Selection of 100 patients from a database, alternating by sex, measuring the length, diameter, cephalic angulation, and lateral angulation of the vertebrae from L1 to L5. Results Statistically significant measurements were obtained for the four different parameters in relation to sex. The mean age was 56, with a minimum of 20 and a maximum of 87 years. The L4 and L5 screws showed a reduction in relation to the other levels, while the width showed a progressive increase starting at L3. Lateral angulation was the parameter with the least variation among the levels, while there was greater variation and a reduction from L4 to L5 in cephalic angulation. Conclusion Statistically significant results were obtained for length, diameter, lateral and cephalic angulation. Sex was a significant factor in spine surgery instrumentation using the cortical trajectory pedicle screw technique. Level of evidence I; Diagnostic study (investigation of an examination for diagnosis).
- Open Access
- 22 April 2020
- Published by Springer Nature in Patient Safety in Surgery
- Vol. 14 (1) , 1-7
The hidden risk of ionizing radiation in the operating room: a survey among 258 orthopaedic surgeons in Brazil
Background: This study aims to assess orthopaedic surgeon knowledge in Brazil about ionizing radiation and its health implications on surgical teams and patients. Methods: A 15-question survey on theoretical and practical concepts of ionizing radiation was administered during the 23rd Brazilian Orthopaedic Trauma Association annual meeting. The survey addressed issues within orthopedic surgery, such as radiation safety concepts, protection, exposure, as well as the participant gender. Participants were either orthopedic surgeons or orthopedic surgery residents working at institutions in Brazil. Results: One thousand surveys were distributed at the moment of the meeting registration, and 258 were answered completely (25.8% response rate). Only 5.8% of participants used basic radiation protection equipment; 47.3% used a dosimeter; 2.7% reached the annual maximum permissible radiation dose; 10.5% knew the period of increased risk to fetal gestation; 5.8% knew the maximum permissible radiation dose during pregnancy; 58.5% knew that the hands, eyes, and thyroid are the most exposed areas and at greater risk of radiation-related lesions; 25.2% knew the safe distance from a radiation-emitting tube is 3 m or more; 44.2% knew the safest positioning of the radiation-emitting tube; 25.2% knew that smaller tubes emit greater radiation at the entrance dose to magnify the image; and 55.4% knew that the surgery team receives more scattered radiation in surgical procedures performed on obese patients. Conclusion: This study revealed inadequate theoretical and practical knowledge about radiation exposure among orthopaedic surgeons in Brazil. Only a minority of orthopaedic surgeons used basic radiation protection equipment. No significant differences in knowledge were found when comparing all orthopedic surgery specialties. Our findings indicate an urgent need for education to increase knowledge among orthopaedic surgeons about the hazards of ionizing radiation. Personal protection and implementation of the ALARA (as low as reasonably achievable) protocol in daily practice are important behaviors to prevent the harmful effects of ionizing radiation.
- 22 April 2020
- Published by Springer Nature in Patient Safety in Surgery
- Vol. 14 (1) , 1-7
Open AccessThe hidden risk of ionizing radiation in the operating room: a survey among 258 orthopaedic surgeons in Brazil
Background: This study aims to assess orthopaedic surgeon knowledge in Brazil about ionizing radiation and its health implications on surgical teams and patients. Methods: A 15-question survey on theoretical and practical concepts of ionizing radiation was administered during the 23rd Brazilian Orthopaedic Trauma Association annual meeting. The survey addressed issues within orthopedic surgery, such as radiation safety concepts, protection, exposure, as well as the participant gender. Participants were either orthopedic surgeons or orthopedic surgery residents working at institutions in Brazil. Results: One thousand surveys were distributed at the moment of the meeting registration, and 258 were answered completely (25.8% response rate). Only 5.8% of participants used basic radiation protection equipment; 47.3% used a dosimeter; 2.7% reached the annual maximum permissible radiation dose; 10.5% knew the period of increased risk to fetal gestation; 5.8% knew the maximum permissible radiation dose during pregnancy; 58.5% knew that the hands, eyes, and thyroid are the most exposed areas and at greater risk of radiation-related lesions; 25.2% knew the safe distance from a radiation-emitting tube is 3 m or more; 44.2% knew the safest positioning of the radiation-emitting tube; 25.2% knew that smaller tubes emit greater radiation at the entrance dose to magnify the image; and 55.4% knew that the surgery team receives more scattered radiation in surgical procedures performed on obese patients. Conclusion: This study revealed inadequate theoretical and practical knowledge about radiation exposure among orthopaedic surgeons in Brazil. Only a minority of orthopaedic surgeons used basic radiation protection equipment. No significant differences in knowledge were found when comparing all orthopedic surgery specialties. Our findings indicate an urgent need for education to increase knowledge among orthopaedic surgeons about the hazards of ionizing radiation. Personal protection and implementation of the ALARA (as low as reasonably achievable) protocol in daily practice are important behaviors to prevent the harmful effects of ionizing radiation.