MISMARPE protocol: minimally invasive surgical and miniscrew-assisted rapid palatal expansion.

OBJECTIVE: The purpose of this article is to present the MISMARPE technique, a new minimally invasive surgical procedure to treat maxillary transverse atresia in adult patients under local anesthesia and on an outpatient basis. TECHNIQUE DESCRIPTION: The technique consists of miniscrew-assisted rapid palatal expansion (MARPE) associated with a minimally invasive approach using maxillary osteotomies, latency and activation periods until the desired expansion is achieved. The present MISMARPE technique was performed in 25 consecutive cases with a success rate of 96%, yielding good skeletal outcomes with minimal trauma. The expander appliances, with their anchorage types, and a description of the surgical steps of the MISMARPE technique are presented. CONCLUSION: MISMARPE is a new and effective alternative for less invasive treatment of maxillary transverse deficiency in adults, compared to conventional surgery. Emphasis is placed on the importance of systematic and well-established protocols, for executing the procedures safely and predictably.

Miniscrew-assisted rapid palatal expansion (MARPE): Factors influencing planning.

OBJECTIVE: This cross-sectional study evaluated the bone thickness on mini-implants insertion site, the factors that influence the digital planning of MARPE appliance (miniscrew-assisted rapid palatal expansion), and its different designs. METHODS: A total of 135 plannings were assessed regarding the size of the expander screw used, the positioning and the type of the mini-implant rings, and their location in relation to the teeth. Bone thickness measurements were assessed in the region of the mini-implants' trajectory. Differences between the sexes was verified using the ANOVA test (5% significance). RESULTS: 73 cases were planned with 4 mini-implants and 62 cases, with 6 mini-implants. In 90% of cases, teeth #16 and #26 were used as supports, and the most used expander screw was 13mm (64.1% of cases). The anterior mini-implants of conventional MARPE showed more pronounced insertion in bone in males (5.9 ± 2mm; p= 0.025). The extra mini-implants (anterior region) were inserted with greater bone thickness in males (11.1 ± 2.3mm) compared to females (9.9 ± 1.8mm; p=0.041). A greater bone thickness was observed in males (10.1 ± 2.1 mm) when using mini-implants in the paramedian region. CONCLUSION: Additional rings allow more pronounced bone insertion. Male patients had greater bone thickness, which may be related to greater difficulty in opening the sutures. The alveolar process region seems to be a satisfactory site for mini-implants to those patients with reduced bone thickness in the paramedian posterior region. MARPE appliance must be customized for each patient, due to bone thickness and anatomical variations.

A Randomized Controlled Study on the Efficacy of Different Approaches of Intramedullary Nailing with Blocking Screws for Proximal Tibial Fractures

SUMMARY: The objective of this study was to compare and analyze the clinical efficacy of different approaches of intramedullary nailing with blocking screws for proximal tibial fractures. One hundred cases of proximal tibial fractures treated in the orthopedic department from April 2021 to September 2023 were included in the study and divided into control and treatment groups using a random number table. A control group (n=50) treated with infrapatellar intramedullary nailing with blocking screws, and a treatment group (n=50) treated with suprapatellar intramedullary nailing with blocking screws. We observed the excellent and good rates in both groups, compared various perioperative indicators, changes in joint range of motion (ROM), Visual Analog Scale (VAS) pain scores, Lysholm knee joint function scores, changes in inflammatory factors, and various bone markers before and after treatment, and analyzed postoperative complications. There were no significant differences in baseline data such as age, sex, body mass index, fracture site, concomitant fibular fractures, time from fracture to surgery, injury mechanism, and AO/OTA fracture classification between the two groups (P>0.05). The excellent and good rate in the treatment group after treatment was 90.00 % (45/50), significantly higher than 72.00 % (36/50) in the control group (P0.05). However, the treatment group had shorter surgical times and fewer fluoroscopy times than the control group (P<0.05). After treatment, both groups showed increased ROM and Lysholm scores, as well as decreased VAS scores. Moreover, compared to the control group, the treatment group had higher ROM and Lysholm scores and lower VAS scores (P<0.05). Inflammatory factors including interleukin-1β (IL-1β), C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), osteocalcin (BGP), and calcitonin (CT) increased in both groups after treatment, while total n- terminal propeptide of type I procollagen (Total-PINP) and b-C-terminal telopeptide of type I collagen (β-CTX) decreased. Compared to the control group, the treatment group exhibited greater increases in inflammatory factors and lower levels of Total-PINP and β-CTX, but higher BGP and CT levels (P<0.05). The incidence of postoperative complications was 8.00 % (4/50) in the treatment group and 24.00 % (12/50) in the control group, with statistically significant differences (P=4.762, X2=0.029). In the treatment of proximal tibial fractures, intramedullary nailing with blocking screws using the suprapatellar approach achieves significant clinical efficacy. It reduces surgical time, minimizes radiation exposure to healthcare workers and patients, improves knee joint range of motion and function, decreases postoperative pain and complication rates, suppresses inflammatory reactions, and promotes the improvement of bone markers related to fracture healing.

El objetivo de este estudio fue comparar y analizar la eficacia clínica de diferentes abordajes de clavo intramedular con tornillos de bloqueo para las fracturas de tibia proximal. Se incluyeron en el estudio 100 casos de fracturas de tibia proximal tratados en el departamento de ortopedia desde abril de 2021 hasta septiembre de 2023 y se dividieron en grupos de control y de tratamiento mediante una tabla de números aleatorios. Un grupo control (n=50) tratado con clavo intramedular infrapatelar con tornillos de bloqueo, y un grupo tratamiento (n=50) tratado con clavo intramedular suprapatelar con tornillos de bloqueo. Observamos excelentes y buenas tasas en ambos grupos, comparamos varios indicadores perioperatorios, cambios en el rango de movimiento articular (ROM), puntuaciones de dolor en la escala visual analógica (EVA), puntuaciones de función Lysholm de la articulación de la rodilla , cambios en factores inflamatorios y varios marcadores óseos, antes y después del tratamiento, y se analizaron las complicaciones postoperatorias. No hubo diferencias significativas en los datos iniciales como edad, sexo, índice de masa corporal, sitio de fractura, fracturas de fíbula concomitantes, tiempo desde la fractura hasta la cirugía, mecanismo de lesión y clasificación de fractura AO/OTA entre los dos grupos (P>0,05). La tasa de excelente y buena en el grupo con tratamiento después del tratamiento fue del 90,00 % (45/50), significativamente mayor que el 72,00 % (36/50) en el grupo control (P0,05). Sin embargo, el grupo con tratamiento tuvo tiempos quirúrgicos más cortos y menos tiempos de fluoroscopía que el grupo control (P <0,05). Después del tratamiento, ambos grupos mostraron un aumento de las puntuaciones de ROM y Lysholm, así como una disminución de las puntuaciones de VAS. Además, en comparación con el grupo control, el grupo con tratamiento tuvo puntuaciones ROM y Lysholm más altas y puntuaciones EVA más bajas (P <0,05). Los factores inflamatorios que incluyen interleucina-1β (IL-1β), proteína C reactiva (CRP), factor de necrosis tumoral-α (TNF-α), osteocalcina (BGP) y calcitonina (CT) aumentaron en ambos grupos después del tratamiento, mientras que el total disminuyó el propéptido n-terminal del procolágeno tipo I (Total-PINP) y el telopéptido β-C-terminal del colágeno tipo I (β-CTX). En comparación con el grupo control, el grupo con tratamiento mostró mayores aumentos en los factores inflamatorios y niveles más bajos de Total-PINP y β-CTX, pero niveles más altos de BGP y CT (P <0,05). La incidencia de complicaciones postoperatorias fue del 8 % (4/50) en el grupo de tratamiento y del 24 % (12/50) en el grupo control, con diferencias estadísticamente significativas (P=4,762, X2=0,029). En el tratamiento de las fracturas de tibia proximal, el clavo intramedular con tornillos de bloqueo mediante el abordaje suprapatelar logra una eficacia clínica significativa. Reduce el tiempo quirúrgico, minimiza la exposición a la radiación de los trabajadores de la salud y los pacientes, mejora el rango de movimiento y la función de la articulación de la rodilla, disminuye el dolor postoperatorio y las tasas de complicaciones, suprime las reacciones inflamatorias y promueve la mejora de los marcadores óseos relacionados con la curación de las fracturas.

Thermographic analysis of perforations in polyurethane blocks performed with experimental conical drill bit in comparison to conventional orthopedic drill bit: a preliminary study.

OBJECTIVE: Conical orthopedic drill bits may have the potential to improve the stabilization of orthopedic screws. During perforations, heat energy is released, and elevated temperatures could be related to thermal osteonecrosis. This study was designed to evaluate the thermal behavior of an experimental conical drill bit, when compared to the conventional cylindrical drill, using polyurethane blocks perforations. RESULTS: The sample was divided into two groups, according to the method of drilling, including 25 polyurethane blocks in each: In Group 1, perforations were performed with a conventional orthopedic cylindrical drill; while in Group 2, an experimental conical drill was used. No statistically significant difference was observed in relation to the maximum temperature (MT) during the entire drilling in the groups, however the perforation time (PT) was slightly longer in Group 2. Each drill bit perforated five times and number of perforations was not correlated with a temperature increase, when evaluated universally or isolated by groups. The PT had no correlation with an increase in temperature when evaluating the perforations universally (n = 50) and in Group 1 alone; however, Group 2 showed an inversely proportional correlation for these variables, indicating that, for the conical drill bit, drillings with longer PT had lower MT.

The efficiency of a customized distalizer with Variety SP® screws anchored on palatal miniscrews for upper molar distalization.

OBJECTIVE: To assess the effectiveness of a customized distalizer with Variety SP® screws anchored on palatal miniscrews for upper molar distalization. METHODS: Seventeen patients aged between 12.5 and 24 years underwent distalization with a customized distalizer. Lateral cephalogram and cast analysis were performed before and after distalization. Linear and angular parameters of the upper first molar, first premolar, and central incisor were assessed. RESULTS: Distalization with the force passing near the center of resistance (CRes) of the upper first molars resulted in distal movement, with minimal distal tipping (2.8 ±â€Š0.45°, p< 0.05). However, distalization passing occlusal to the CRes led to greater distal tipping (13.6 ±â€Š1.63°, p< 0.05). Statistically significant spontaneous distal tipping and distal movement of the upper first premolars occurred, with a mean of 6.2 ±â€Š1.24° (p< 0.05) and 0.68 ±â€Š0.34 mm (p< 0.05), respectively. The positional change of the upper central incisors presented a mean of -0.23 ±â€Š0.1 mm (p> 0.05) and 2.65 ±â€Š1.1° (p< 0.05). Upper first molar intrusion was statistically significant, with a mean of 0.88 ±â€Š0.2 mm (p< 0.05). Upper right and left first molars rotation towards palatal midline presented mean of 4.1 ±â€Š0.19° (p< 0.05) and 3.4  ±â€Š0.1° (p< 0.05), respectively. Additionally, the distance between upper right and left first molars increased significantly, with a mean of 2.54 ±â€Š0.01 mm (p< 0.05). CONCLUSION: The study successfully demonstrated the efficiency of molar distalization without anchorage loss using a customized distalizer anchored on palatal miniscrews.

Femoral neck osteosynthesis using interfragmentary compression or position screw in synthetic bones. What are the mechanical differences?

PURPOSE: We aim to compare interfragmentary compression with the position osteosynthesis in the fixation of different femoral neck fractures (FN) in synthetic bones subjected to vertical load. METHODS: Forty-two synthetic femurs were subjected to neck fractures and separated into 3 groups according to the Pauwels classification: Pauwels I had 6 units (PI); Pauwels II, 24 units, with and without comminution (PII); and Pauwels III, 12 units, with and without comminution (PIII). After, they were fixed with 2 different ways: three 7, 0 mm cannulated lag screws (CSs) versus three 6, 5 mm solid fully threaded screws (SSs). Screws positioning was oriented by the Pauwels classification: inverted triangle or crossed screws. All specimens were submitted to vertical loading until failure. RESULTS: The average force was 79.4 ± 22.6 Kgf. The greatest one was recorded in model 1 (135.6 Kgf), and the lowest in model 41 (39.6 Kgf). CSs and SSs had similar resistance until failure (p = 0.2). PI showed heightened resistance and PIII showed a worse response (p < 0,01). CSs had better performance in PIII (p = 0.048). Comminution and screws orientation caused no difference on peak force (p = 0.918 and p = 0.340, respectively). CONCLUSIONS: In synthetic bones, the resistance of a femoral neck fracture osteosynthesis using a 7, 0 mm cannulated lag screw or 6, 5 mm solid fully threaded screw are similar. There was no loss of efficiency with comminution in the femoral neck. Osteosynthesis resistance decreased with the verticalization of the fracture line and, in the more vertical ones, interfragmentary compression with CSs was more resistant than positional osteosynthesis with SSs.

Minimally invasive hallux valgus surgery using 3D printed patient specific instrumentation.

In this technical report study, we describe technique for performing the osteotomy and screw passage in minimally invasive fourth-generation hallux valgus surgery with transverse and akin extra-articular metaphyseal osteotomy (META) using a 3D-printed patient-specific surgical instrumentation guide. In an effort to minimize the learning curve and address the variability associated with technical corrections and screw placement, we have initiated the creation of personalized patient-specific instrumentation guides using 3D printing. Our hypothesis is that this approach will enhance safety, precision, decrease surgical time, and reduce exposure to radiation. Level of Evidence: Level V, expert opinion.

Minimally invasive Chevron-Akin (MICA) osteotomies without Akin fixation in hallux valgus correction: a case series with 2-year follow-up.

PURPOSE: The minimally invasive Chevron-Akin (MICA) is considered the third generation of minimally invasive hallux valgus (HV) surgery, and its original description included fixation of the Akin osteotomy with a screw. The aim of this study is to evaluate a series of patients undergoing HV correction using the MICA technique without screw fixation of the Akin osteotomy. METHODS: We retrospectively evaluated 58 consecutive patients who underwent surgical correction for HV between August 2018 and March 2020. A total of 69 feet were evaluated with a minimum follow-up of 2 years. Clinical outcomes such as pain (VAS), function (AOFAS), range of movement, criteria personal satisfaction and complications were evaluated. RESULTS: The AOFAS score (mean ± standard deviation) significantly improved from 57.0 ± 8.6 preoperatively to 93.9 ± 8.7 postoperatively (p < .001) with a minimum follow-up of 2 years. The VAS score improved from 6.0 ± 1.8 preoperatively to 0.6 ± 1.4 at 2-year follow-up (p < .001), and the hallux valgus angle reduced from 39.7 ± 6.9 to 8.9 ± 9.0 (p < .001). The majority of patients (95.6%) reported the result as excellent or good, and the most common complication was the need to remove the screw (7.2%). CONCLUSIONS: The use of MICA without Akin osteotomy fixation resulted in successful correction of hallux valgus with improvements in clinical and radiographic parameters. LEVEL OF EVIDENCE: IV, case series.

Hot isostatic pressing as an alternative thermo-mechanical treatment for metallic full-arch implant-supported frameworks obtained by additive and subtractive manufacturing technology: Vertical and horizontal fit, screw removal torque, and stress analysis.

PURPOSE: To assess vertical and horizontal fit, screw removal torque, and stress analysis (considered biomechanical aspects) of full-arch implant frameworks manufactured in Ti-6Al-4V through milling, and additive manufacturing Direct Metal Laser Sintering (DMLS) and Electron Beam Melting (EBM), and the effect of the thermo-mechanical treatment Hot Isostatic Pressing (HIP) as a post-treatment after manufacturing. MATERIAL AND METHODS: Maxillary full-arch implant frameworks were made by milling, DMLS, and EBM. The biomechanical assessments were screw removal torque, strain-gauge analyses, and vertical and horizontal marginal fits. The vertical fit was assessed by the single-screw test and with all screws tightened. All frameworks were submitted to a standardized HIP cycle (920°C, 1000 bar pressure, 2 h), and the tests were repeated (α = 0.05). RESULTS: At the initial time, milled frameworks presented higher screw removal torque values, and DMLS and EBM frameworks presented lower levels of strain. Using the single-screw test, milled and DMLS frameworks presented higher vertical fit values, and with all screws tightened and horizontally, higher fit values were found for milled frameworks, followed by DMLS and EBM. After HIP, milling and EBM frameworks presented higher screw removal torque values; the lowest strain values were found for EBM. Using the single-screw test, milled and DMLS frameworks presented higher vertical fit values, and with all screws tightened and horizontally no differences were found. CONCLUSIONS: DMLS and EBM full-arch frameworks presented adequate values of screw removal torque, strain, and marginal fit, although the worst values of marginal fit were found for EBM frameworks. The HIP cycle enhanced the screw removal torque of milled and EBM frameworks and reduced the strain values of milled frameworks. The HIP represents a reliable post-treatment for Ti-6Al-4V dental prostheses produced by milling and EBM technologies.

Comparison of maxillary transversal changes between auxiliary beta-titanium expansion arch and miniscrew-assisted rapid palatal expansion.

OBJECTIVE(S): This study compared buccal bone thickness, dental inclinations and maxillary transverse width dimensions changes between auxiliary beta-titanium expansion arch (AEA) and miniscrew-assisted rapid palatal expansion (MARPE). MATERIALS AND METHODS: The sample consisted of 29 patients, aged between 18 and 40 years, with transverse maxillary deficiency and treated without extractions, divided into two groups: group AEA: comprised 13 individuals (initial mean age: 29.23 ± 9.13 years) treated using auxiliary beta-titanium expansion arch; group MARPE: comprised 16 patients (initial mean age: 24.92 ± 7.60 years) treated with miniscrew-assisted rapid palatal expansion. Buccal bone thickness, dental inclinations and transverse width dimensions (dental, nasal base and jugular) were measured in cone-bean computed tomographies at pre- and post-treatment stages. The variables were compared using the independent t-test. RESULTS: The buccal bone thickness was similar for both groups at the post-treatment stage. The second premolars were significantly more buccal inclined in the AEA group and the right maxillary first molars in the MARPE group. The intercanine and intermolar distances were statistically significantly greater in the MARPE group. Changes in dental arch transverse dimensions were significantly greater for the MARPE group. CONCLUSION: Both treatment protocols corrected the maxillary transverse discrepancy; however, MARPE provided greater correction.

Evaluation of mechanical properties and morphology of miniscrews Ti6Al4V cold worked versus annealed in artificial bones.

PURPOSE: This study aimed to evaluate the influence of different manufacturing procedures (Eli annealed - hot work versus cold worked - cold work) of the raw material under mechanical properties and morphological characteristics of orthodontic miniscrews (MS). MATERIAL AND METHODS: Thirty MS were randomly separated into 3 types (n=10) according to manufacturer and manufacturing process of the raw material: type A - SIN® annealed (control group); type B - Dentfix® annealed; and, type C - Dentfix® cold worked. MI were inserted in artificial bone blocks, through the manufacturer's specific manual key attached to the digital torquemeter stabilized via custom device. Data of fracture's occurrence was performed using Fisher's exact test. Comparisons between the other two types regarding insertion torque and removal torque were performed using the Mann-Whitney test. Data of fracture torque, shear stress, normal stress and torque ratio was submitted to Kruskal Wallis and Dunn tests (α=0.05). Representative images of surface morphology and fractures were selected. RESULTS: Type C showed statistically the lowest fracture torque (N.cm) (26.11±0.41) (P=0.0012) and highest torque ratio (%) (98.74±0.85) (P=0.0007). Type C showed statistically higher calculated shear (MPa) (2,432.73±508.41) and normal stress (MPa) (1,403.86±293.39) than type B and type A, showing that they differed in relation to the mechanical strength of the material with which they were made (P=0.0007). CONCLUSION: Type A fractured completely inside the most apical bone. Type B and type C fractured closer to the transmucosal profile. Cold worked process should be more prone to fractures than those annealed raw manufactured.

Screws versus plate with screws for osteosynthesis of the posterior malleolus: a systematic review and meta-analysis.

INTRODUCTION: fractures involving the posterior malleolus (PM) of the ankle can have significant functional and clinical implications if not properly treated. The optimal treatment approach for these fractures remains uncertain. This review aims to compare the use of cannulated screws versus plate with screw fixation in terms of their impact on the development of postoperative ankle osteoarthritis and functional outcomes in patients with PM fractures. MATERIAL AND METHODS: a comprehensive search was conducted in PubMed, EMBASE, and Cochrane Library databases to identify studies directly comparing cannulated screws versus plate with screw fixation for PM fractures and their association with the development of postoperative osteoarthritis and functional outcomes. The quality of the included studies was assessed using appropriate assessment tools. The data on osteoarthritis development and functional outcomes were extracted and analyzed. RESULTS: a total of 691 articles were screened, and several studies were included for analysis. The findings revealed no statistically significant difference in the development of postoperative ankle osteoarthritis between the cannulated screws and plate with screw fixation groups. Similarly, there was no significant difference in functional outcomes between the two treatment approaches. CONCLUSION: based on the available evidence, there is no significant difference in the development of postoperative ankle osteoarthritis or functional outcomes between cannulated screws and plate with screw fixation for PM fractures. However, further research is needed to strengthen these findings and provide more conclusive evidence.

INTRODUCCIÓN: las fracturas que involucran el maléolo posterior (MP) del tobillo pueden tener importantes implicaciones funcionales y clínicas si no se tratan adecuadamente. El enfoque de tratamiento óptimo para estas fracturas sigue siendo incierto. El objetivo de esta revisión es comparar el uso de tornillos canulados versus placa con fijación de tornillos en cuanto a su impacto en el desarrollo de la osteoartrosis de tobillo postoperatoria y los resultados funcionales en pacientes con fracturas del MP. MATERIAL Y MÉTODOS: se realizó una búsqueda exhaustiva en las bases de datos de PubMed, EMBASE y Cochrane Library para identificar estudios que compararan directamente tornillos canulados versus placa con fijación de tornillos para fracturas de MP y su asociación con el desarrollo de osteoartrosis postoperatoria y los resultados funcionales. La calidad de los estudios incluidos se evaluó utilizando herramientas de evaluación adecuadas. Los datos sobre el desarrollo de osteoartrosis y los resultados funcionales se extrajeron y analizaron. RESULTADOS: se revisaron un total de 691 artículos y se incluyeron varios estudios para su análisis. Los hallazgos revelaron que no hay una diferencia estadísticamente significativa en el desarrollo de osteoartrosis de tobillo postoperatoria entre los grupos de tornillos canulados y placa con fijación de tornillos. Del mismo modo, no hubo una diferencia significativa en los resultados funcionales entre los dos enfoques de tratamiento. CONCLUSIÓN: según la evidencia disponible, no hay una diferencia significativa en el desarrollo de osteoartrosis de tobillo postoperatoria o en los resultados funcionales entre los tornillos canulados y la placa con fijación de tornillos para las fracturas del MP. Sin embargo, se necesita más investigación para fortalecer estos hallazgos y proporcionar evidencia más concluyente.

Busch-Hoffa fracture: A systematic review.

BACKGROUND: Accomplish a thorough review on the existing biomechanical and clinical studies about coronal plane fractures of the distal femur. METHODS: We performed an electronic search of PubMed/MEDLINE database from April to June, 2023. The terms for the database search included "Hoffa fractures," OR "Busch-Hoffa fractures" OR "coronal plane fractures of the distal femur." RESULTS: The search identified 277 potentially eligible studies. After application of inclusion and exclusion criteria, 113 articles were analyzed in terms of the most important topics related to coronal plane fractures of the distal femur. CONCLUSION: Lateral coronal plane fractures of the distal femur are more frequent than medial, present a more vertical fracture line, and usually concentrate on the weight bearing zone of the condyle. The Letenneur system is the most used classification method for this fracture pattern. Posterior-to-anterior fixation using isolated lag screws (for osteochondral fragments-Letenneur type 2) or associated with a posterior buttressing plate (when the fracture pattern is amenable for plate fixation-Letenneur types 1 and 3) is biomechanically more efficient than anterior-to-posterior fixation. Anterior-to-posterior fixation using lag screws complemented or not by a plate remains a widely used treatment option due to the surgeons' familiarity with the anterior approaches and lower risk of iatrogenic neurovascular injuries. There is no consensus in the literature regarding diameter and number of screws for fixation of coronal plane fractures of the distal femur.

A standard canulated screw may not fit up to 1/3 of the patients treated percutaneously for anterior column acetabular fractures-A pilot study.

A proper evaluation of the narrowings and length of the anterior acetabular column would offer better predictability and precision for implant insertion in the case of an acetabular fracture. OBJECTIVE: To determine the diameter and length of the safety corridor of the anterior column of the acetabulum in patients with available pelvic computed tomography (CT), analyze the obtained measurements against those of a standard 6.5-mm implant, and verify possible sex differences regarding these measurements. A secondary aim was to develop a method for measurement of the anterior column of the acetabulum based on CT images. MATERIALS AND METHODS: In 200 CT scans of hemipelvises we measured the diameter of two areas of narrowing and the length of the safety corridor of the anterior column. The images were submitted to multiplanar reformatting adjusted to a plane orthogonal to the bone corridor, drawn at the level of the superior pubic ramus. RESULTS: Measurement #1 had a mean value of 8.12 (2.27) mm in the overall sample and median values of 9.03 (7.76-10.48) mm in men and 6.77 (5.44-7.19) mm in women. Measurement #2 had a mean value of 7.29 (2.19) mm and median values of 8.23 (7.18-9.82) mm in men and 5.9 (4.65-7.19) mm in women. Measurement #3 had a mean value of 109.53 (13.66) mm in the overall sample and median values of 117.17 (112.9-122.9) mm in men and 100.91 (90.95-111.17) mm in women (p<0.001 all three measurements). Measurement #1 was smaller than 6.5 mm in 22.5% of the patients (of whom 90% were women). Measurement #2 was smaller than 6.5 mm in 35% of the patients (of whom 80% were women). CONCLUSIONS: This study proposed an anatomic evaluation of the anterior column of the acetabulum using conventional CT images The areas of narrowing in the anterior column had an average of 8.12 mm at the level of the pubic tubercle and 7.29 mm at the level of the acetabular fossa. The mean length of the safety corridor was 109.53 mm. In 35% of the cases, a 6.5 mm percutaneous screw would have violated the cortical bone of the safety corridor.

Antegrade posterior column screw fixation for acetabular fractures: It's time to standardize the surgical technique.

Antegrade fixation of posterior column fractures of the acetabulum is challenging due to the narrow corridor and risk of screw misplacement. Although both antegrade and retrograde lag screws have been previously described for posterior column fracture fixation, the literature lacks a standardized technique for correct and safe screw placement, especially in an antegrade fashion. This technical note aims to optimize intraoperative images during posterior screw insertion using the antegrade technique, according to predetermined landmarks to save surgical time, decrease radiation exposition, and prevent surgical complications.

[Clinical and radiographic factors associated with failure of the dynamic hip screw system]. / Factores clínicos y radiográficos asociados a la falla del sistema del tornillo dinámico de cadera.

Background: The most widely used fixation system for transtrochanteric fractures is the dynamic hip screw system, which has a failure prevalence of 10 to 17% and it is associated with the presence of clinical and radiographic factors. Objective: To evaluate the association of clinical and radiographic factors with the failure of the screw system in post-operative patients for transtrochanteric hip fracture. Material y methods: A case-control study was carried out. The inclusion criteria were: patients > 18 years, who underwent surgery due to transtrochanteric fracture, were treated with the hip screw system, and who attended the Trauma Service. The patient with failure of the hip screw system was selected as the case and the patient without failure of the system as control. The variables analyzed in these groups were: age, gender, body mass index and radiographic variables. Statistical analysis was performed with chi-squared and Mann-Whitney U. Results: 163 patients (median 73 years), 20 cases and 143 controls, were included. The radiographic factors with a significant association with hip screw system failure were the AO classification of fractures (p < 0.001), the tip apex distance (p = 0.03), the calcar-referenced tip apex (p = 0.02), the position of the screw (p < 0.001), and quality of reduction (p < 0.003). Clinical factors did not show a significant association. Conclusions: Radiographic factors are associated with failure in the hip screw system in patients in post-operative care due to transtrochanteric fracture.

Introducción: el sistema de fijación más usado para fracturas transtrocantéricas es el sistema del tornillo dinámico de cadera, el cual tiene una prevalencia de falla del 10 al 17% y se asocia a la presencia de factores clínicos y radiográficos. Objetivo: evaluar la asociación de los factores clínicos y radiográficos con la falla del sistema del tornillo en pacientes postoperados de fractura transtrocantérica de cadera. Material y métodos: se hizo un estudio de casos y controles. Los criterios de inclusión fueron: pacientes > 18 años, postoperados de fractura transtrocantérica, tratados con el sistema del tornillo de cadera, que acudieron a la consulta de Traumatología. Se seleccionó como caso al paciente con falla del sistema del tornillo de cadera y como control al paciente sin falla de este. Las variables analizadas en los grupos fueron la edad, el género, el índice de masa corporal y las variables radiográficas. El análisis estadístico se hizo con chi cuadrada y U de Mann-Whitney. Resultados: se incluyeron 163 pacientes (mediana de 73 años), 20 casos y 143 controles. Los factores radiográficos con asociación significativa con la falla del sistema del tornillo de cadera fueron la clasificación AO de la fractura (p < 0.001), la distancia punta-ápex (p = 0.03), punta ápex calcar (p = 0.02), la posición del tornillo (p < 0.001) y la calidad de la reducción (p < 0.003). Los factores clínicos no mostraron asociación significativa. Conclusiones: los factores radiográficos se asocian con la falla en el sistema del tornillo de cadera en pacientes postoperados de fractura transtrocantérica.

Comparative Assessment of Contact Osteogenesis at the Titanium Implant-Bone Junction in Male Rabbits with Dissimilar Femoral Defects / Evaluación Comparativa de la Osteogénesis de Contacto en la Unión entre el Hueso y el Implante de Titanio en Conejos Macho con Defectos Femorales Diferentes

SUMMARY: Traumatized bone tissue has the capacity to repair itself so that it eventually regains its almost original form, even in the case of artificially inserted implants. The process that stays at the base of the regeneration is represented by osteogenesis or remote osteogenesis. The major difference between the two types of bone formation is the location of the cement line, which is located on the surface of the implant for contact osteogenesis and on the surface of the bone defect for remote osteogenesis. The aim of the present study was to assess the contact osteogenesis in the case of inserted titanium screws in holes with diameters of 1.8 mm and 1 mm respectively. The obtained results show, in the case of the groove with 1.8 mm that the newly proliferated bone represents 73.85 % of the total area, while in the case of the groove with 1 mm in diameter the value of the newly proliferated bone is 26.15 %. In conclusion, the insertion of titanium screws by self-tapping into the hole smaller than the core of the screw is accompanied by bone proliferation by contact osteogenesis much more modest than in the case of insertion into the hole larger than the core of the screw.

El tejido óseo traumatizado tiene la capacidad de reparar en forma espontánea, de modo que eventualmente recupera su forma casi original, incluso en el caso de implantes insertados artificialmente. El proceso que queda en la base de la regeneración está representado por la osteogénesis u osteogénesis a distancia. La principal diferencia entre los dos tipos de formación ósea es la ubicación de la línea de cemento, que se encuentra en la superficie del implante para la osteogénesis de contacto y en la superficie del defecto óseo para la osteogénesis remota. El objetivo del presente estudio fue evaluar la osteogénesis de contacto en el caso de tornillos de titanio insertados en forámenes con diámetros de 1,8 mm y 1 mm respectivamente. Los resultados obtenidos muestran, en el caso del surco de 1,8 mm que el hueso neoproliferado representa el 73,85 % del área total, mientras que en el caso del surco de 1 mm de diámetro el valor del hueso neoproliferado es del 26,15 %. En conclusión, la inserción de tornillos de titanio por autorroscantes en el foramen menor que el núcleo del tornillo se acompaña de una proliferación ósea por osteogénesis de contacto mucho más modesta que en el caso de la inserción en el foramen mayor que el núcleo del tornillo.

Analysis of the Mechanical Behavior of Porcine Graft Fixation in a Polyurethane Block Using a 3D-printed PLA Interference Screw / Análise do comportamento mecânico da fixação do enxerto suíno em um bloco de poliuretano usando um parafuso de interferência PLA impresso em 3D

Abstract Objective The interest in using 3D printing in the healthcare field has grown over the years, given its advantages and potential in the rapid manufacturing of personalized devices and implants with complex geometries. Thus, the aim of the present study was to compare the mechanical fixation behavior of a 3D-printed interference screw, produced by fused deposition modeling of polylactic acid (PLA) filament, with that of a titanium interference screw. Methods Eight deep flexor porcine tendons, approximately 8 mm wide and 9 cm long, were used as graft and fixed to a 40 pounds-per-cubic-foot (PCF) polyurethane block at each of its extremities. One group was fixed only with titanium interference screws (group 1) and the other only with 3D-printed PLA screws (BR 20 2021 018283-6 U2) (group 2). The tests were conducted using an EMIC DL 10000 electromechanical universal testing machine in axial traction mode. Results Group 1 (titanium) obtained peak force of 200 ± 7 N, with mean graft deformation of 8 ± 2 mm, and group 2 (PLA) obtained peak force of 300 ± 30 N, and mean graft deformation of 7 ± 3 mm. Both the titanium and PLA screws provided good graft fixation in the polyurethane block, with no slippage or apparent deformation. In all the samples, the test culminated in graft rupture, with around 20 mm of deformation in relation to the initial length. Conclusion The 3D-printed PLA screw provided good fixation, similar to that of its titanium counterpart, producing satisfactory and promising results.

Resumo Objetivo O interesse em utilizar a impressão 3D na área da saúde tem crescido ao longo dos anos, dadas as suas vantagens e o seu potencial na rápida fabricação de dispositivos e implantes personalizados com geometrias complexas. Assim, o objetivo do presente estudo foi comparar o comportamento de fixação mecânica de um parafuso de interferência impresso em 3D, produzido pela modelagem fundida de deposição do filamento de ácido polilático (PLA), com o de um parafuso de interferência de titânio. Métodos Oito tendões suínos flexores profundos, de aproximadamente 8 mm de largura e 9 cm de comprimento, foram utilizados como enxerto e fixados em um bloco de poliuretano de 40 PCF em cada uma de suas extremidades. Um grupo foi fixado apenas com parafusos de interferência de titânio (grupo 1) e o outro apenas com parafusos PLA impressos em 3D (BR 20 2021 018283-6 U2) (grupo 2). Os testes foram realizados utilizando uma máquina de teste universal eletromecânica EMIC DL 10.000 no modo de tração axial. Resultados O grupo 1 (titânio) obteve força máxima de 200 ± 7 N com deformação média do enxerto de 8 ± 2 mm, e a força máxima do grupo 2 (PLA) foi de 300 ± 30 N e deformação média do enxerto de 7 ± 3 mm. Ambos os parafusos de titânio e PLA forneceram boa fixação de enxerto no bloco de poliuretano, sem deslizamento ou deformação aparente. Em todas as amostras o teste culminou na ruptura do enxerto, com cerca de 20 mm de deformação em relação ao comprimento inicial. Conclusão O parafuso PLA impresso em 3D proporcionou boa fixação, semelhante à de sua contraparte de titânio, produzindo resultados satisfatórios e promissores.

Manejo y presentación de las fracturas transtrocantéricas de cadera durante la pandemia de COVID-19 en un hospital de tercer nivel de atención.

BACKGROUND: The prevalence of intertrochanteric hip fractures is approximately 30%. The usual management of hip fractures is performed by dynamic hip screw (DHS) or central medullary nailing (CMN). The COVID-19 pandemic has changed medical treatment guidelines in all specialties around the world. OBJECTIVE: To recognize the prevalence and management of unstable trochanteric hip fractures during the COVID-19 pandemic. METHOD: An observational study was conducted in a third-level care hospital in patients with fractures of type AOOTA 31A2.1 and A2.2 managed with CMN or DHS. The management trends by orthopedic surgeons were analyzed. RESULTS: The prevalence during 2019 was 38%, in 2020 it was 21.3% and in 2021 it was 32.6%. The male-to-female ratio found was 1:1.7. The age was 66.48 ± 21.6 years (range: 17-92). Of orthopedic surgeons surveyed, 80.4% preferred CMN. CONCLUSIONS: The prevalence decreased during 2020. The treatment trend during the pandemic was higher for the DHS system; the use of CMN decreased by 86%. The treatment of intertrochanteric hip fractures was influenced due to the COVID-19 pandemic towards a cheaper method.

ANTECEDENTES: La prevalencia de las fracturas transtrocantéricas se sitúa alrededor del 30%. El tratamiento se realiza mediante sistema de tornillo deslizante (STD) o clavo centromedular (CCM). La pandemia de COVID-19 ha modificado las pautas de tratamiento médico en todas las especialidades en todo el mundo. OBJETIVO: Reconocer la prevalencia y el manejo de las fracturas transtrocantéricas inestables durante la pandemia de COVID-19. MÉTODO: Se realizó un estudio observacional en un hospital de tercer nivel de atención en pacientes con fracturas de tipo AOOTA 31A2.1 y A2.2 manejados con CCM o STD, y se analizaron las tendencias de manejo por parte de los cirujanos ortopedistas. RESULTADOS: La prevalencia durante el año 2019 fue del 38%, en 2020 fue del 21.3% y en 2021 fue del 32.6%. La proporción encontrada hombre-mujer fue de 1:1.7. La edad fue de 66.48 ± 21.6 años (rango: 17-92). De los cirujanos ortopedistas encuestados, el 80.4% prefieren el CCM. CONCLUSIONES: La prevalencia disminuyó durante el año 2020. La tendencia de tratamiento durante la pandemia fue superior para el sistema STD y el uso de CCM disminuyó un 86%. El tratamiento de estas fracturas fue influenciado por la pandemia de COVID-19 hacia un método más económico.

Fatigue life estimation of dental implants using a combination of the finite element method and traditional fatigue criteria.

Failure by fatigue can be sudden and catastrophic. Therefore, ensuring that dental implants, which are under constant cyclic loading, do not fail to fatigue is imperative. The majority of the studies about the topic only performed in vitro tests, which are expensive and time-consuming. The Finite Element (FE) method is less costly and it allows the simulation of several different loading scenarios. Nonetheless, there are only a few studies analysing fatigue in dental prostheses using FE models, and the few available did not include all the relevant parameters, such as geometry effect, surface finishing, etc. Therefore, this study aimed to analyse the fatigue behaviour of a single-unit dental implant with two screws using a combination of the numerical results and the traditional fatigue criteria - a combination that was not yet fully and correctly explored. A finite element model comprising a single implant, one abutment, one abutment screw, one fixation screw and one prosthetic crown was developed. Material properties were assigned based on literature data. A 100 N load was applied to mimic the mastication forces and fatigue analysis was conducted using the Gerber, Goodman and Soderberg fatigue criteria. The fatigue analysis demonstrated that the abutment screw could fail in less than 1 year, depending on the criteria, while the fixation screw exhibits an infinite life. The results illustrated the importance of analysing the fatigue behaviour of dental implants and highlighted the potential of finite element models to simulate the biomechanical behaviour of dental implants.