ALEXANDRE LEME GODOY DOS SANTOS
Projetos de Pesquisa
Unidades Organizacionais
Instituto de Ortopedia e Traumatologia, Hospital das Clínicas, Faculdade de Medicina
LIM/41 - Laboratório de Investigação Médica do Sistema Músculoesquelético, Hospital das Clínicas, Faculdade de Medicina
LIM/41 - Laboratório de Investigação Médica do Sistema Músculoesquelético, Hospital das Clínicas, Faculdade de Medicina
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- Biomechanical comparison of plantar-to-dorsal and dorsal-to-plantar screw fixation strength for subtalar arthrodesis(2020) CHAUDHARI, Nileshkumar; GODOY-SANTOS, Alexandre Leme; NETTO, Cesar de Cesar; RODRIGUEZ, Ramon; DUN, Shouchen; HE, Jun Kit; CKISSACK, Haley; FLEISIG, Glenn S.; NEE, Eduardo Araujo; SHAH, AshishObjective: To compare screw fixation strength for subtalar arthrodesis. Methods: Eight matched pairs of cadaver feet underwent subtalar joint arthrodesis with two 7.3mm cannulated screws. Randomization was used to assign screw orientation, such that one foot in each pair was assigned dorsal to plantar screw orientation (DP Group), and the other foot, plantar to dorsal orientation (PD Group). Standard surgical technique with fluoroscopy was used for each approach. Following fixation, each specimen was loaded to failure with a Bionix (R) 858 MTS device, applying a downward axial force at a distance to create torque. Torque to failure was compared between DP and PD Groups using Student's t test, with p=0.05 used to determine statistical significance. Results: Statistical analysis demonstrated that the mean torque to failure slightly favored the DP Group (37.3Nm) to the PD Group (32.2Nm). However, the difference between the two groups was not statistically significant (p = 0.55). Conclusion: In subtalar arthrodesis, there is no significant difference in construct strength between dorsal-to-plantar and plantar-to-dorsal screw orientation. The approach chosen by the surgeon should be based on factors other than the biomechanical strength of the screw orientation.
- Soft Tissue Structures at Risk With Percutaneous Posterior to Anterior Screw Fixation of the Talar Neck(2018) ROBERTS, Lauren E.; PINTO, Martim; STAGGERS, Jackson R.; GODOY-SANTOS, Alexandre; SHAH, Ashish; NETTO, Cesar de CesarBackground: Fractures of the talar neck and body can be fixed with percutaneously placed screws directed from anterior to posterior or posterior to anterior. The latter has been found to be biomechanically and anatomically superior. Percutaneous guidewire and screw placement poses anatomic risks for posterolateral and posteromedial neurovascular and tendinous structures. The objective of this study was to determine the injury rate to local neurovascular and tendinous structures using this technique in a cadaveric model. In addition, we aimed to determine the number of attempts at passing the guidewires required to achieve acceptable placement of 2 parallel screws. Methods: Eleven fresh frozen cadaver limbs were used. Two 2.0-mm guidewires were placed under fluoroscopic guidance, posterior to anterior centered within the talus. The number of attempts required was recorded. A layered dissection was then performed to identify injury to any local anatomic structure. The shortest distance between the closest guidewire and the soft tissue structures was measured. Results: The mean total number of guidewires passed to obtain optimal placement of 2 parallel screws was 2.9 +/- 0.7. Direct contact between the guidewire and the sural nerve was seen in 100% of the specimens, with the nerve impaled by the guidewire in 3 of 11 (27.2%) cases. The peroneal tendons were impaled in 1 of 11 (9%) specimens and the Achilles tendon was in contact with the guidewire in 8 of the 11 (72.7%) specimens, and impaled at its most lateral border with the guidewire in 2 specimens (18.2%). Conclusion: The placement of posterior to anterior percutaneous screws for talar neck fixation is technically demanding, and multiple guidewires are needed. Our cadaveric study showed that important tendinous and neurovascular structures were in proximity with the guidewires and that the sural nerve was injured in 100% of the cases. Clinical Relevance: Given the risk of injury to these structures, we recommend a formal posterolateral incision for proper visualization and retraction of the anatomic structures at risk.
- ER PvuII and XbaI polymorphisms in postmenopausal women with posterior tibial tendon dysfunction: a case control study(2018) PONTIN, P. A.; NOGARA, P. R. B.; FONSECA, F. C. P.; NETTO, C. Cesar; CARVALHO, K. C.; SOARES JUNIOR, J. M.; BARACAT, E. C.; FERNANDES, T. D.; MAFFULLI, N.; SANTOS, M. C. L.; GODOY-SANTOS, A. L.BackgroundPosterior tibial tendon (PTT) insufficiency is considered as the main cause of adult acquired flat foot and is three times more frequent in females. High estrogen levels exert a positive effect on the overall collagen synthesis in tendons. We have previously demonstrated the association between some genetic single-nucleotide polymorphism (SNP) and tendinopathy. In the present study, we investigated the association of PvuII c454-397T>C (NCBI ID: rs2234693) and XbaI c454-351A>G (NCBI ID: rs9340799) SNPs in estrogen receptor alfa (ER-) gene with PPT dysfunction.MethodsA total of 92 female subjects with PTT dysfunction, with histopathological examination of the tendon and magnetic resonance image (MRI) evidence of tendinopathy, were compared to 92 asymptomatic females who presented an intact PPT at MRI for PvuII and XbaI SNPs in the ER- gene. Genomic DNA was extracted from saliva and genotypes were obtained by polymerase chain reaction restriction fragment length polymorphism.ResultsThe analysis of PvuII SNPs showed no significant differences in the frequency of alleles and genotypes between control and PTT dysfunction groups. The XbaI SNPs in the ER- gene showed significant differences in the frequency of genotypes between control and test groups (p=0.01; OR 95% 1.14 (0.55-2.33).ConclusionsThe XbaI SNP in the ER gene may contribute to tendinopathy, and the A/A genotype could be a risk factor for PTT tendinopathy in this population. The PvuII SNP studied was not associated with PTT tendinopathy.
- Incidence and Predictive Factors for Amputations Derived From Charcot's Neuroarthropathy in Persons With Diabetes(2023) BANDEIRA, Mariana A.; SANTOS, Alexandre L. G. dos; WOO, Kevin; GAMBA, Monica A.; SANTOS, Vera L. C. de GouveiaCharcot's neuroarthropathy (CN) is the progressive destruction of the bones and joints of the feet, as a consequence of severe peripheral neuropathy, which predisposes patients to amputations. The purpose of this study was to measure the cumulative incidence of amputations resulting from CN and risk factors among amputated people with diabetes mellitus (DM). This was an epidemiological, observational, and retrospective study of 114 patients with DM who had an amputation involving the lower limbs. Data were collected from 2 specialized outpatient clinics between 2015 and 2019, including socio-demographic and clinical variables (cause of amputation: CN, peripheral arterial disease [PAD], infected ulcers, fracture, osteomyelitis, and others; body mass index [BMI]; 1 or 2 DM, time since DM diagnosis, insulin treatment, glycated hemoglobin; creatinine; smoking and drinking; systemic arterial hypertension, diabetic retinopathy, diabetic kidney disease, diabetic peripheral neuropathy, acute myocardial infarction, PAD, and stroke; characteristics of amputation [level and laterality], in addition to the specific variables related to CN [time of amputation in relation to the diagnosis of CN, diagnosis of CN in the acute phase, and treatment implemented in the acute phase]). We compared socio-demographic and clinical characteristics, including types of amputation, between patients with and without CN. Statistical analyses were performed using the 2 sample t-test or Wilcoxon-Mann-Whitney test, for quantitative variables, and the Pearson's chi(2) test or Fisher's exact test for categorical variables. The investigation of the possible association of predictive factors for a CN amputation was carried out through logistic regression. The amputation caused by CN was present in 27 patients with a cumulative incidence of 23.7% in 5 years. There was a statistically significant association between BMI and the occurrence of CN (odds ratio: 1.083; 95% confidence interval: 1.001-1.173; P = .048); higher values of BMI were associated with a higher occurrence of amputations secondary from CN.
- FLEXOR HALLUX TENDON TRANSFER: COMPARATIVE STUDY THROUGH DOUBLE OR SINGLE APPROACH(2014) SAKAKI, Marcos Hideyo; GODOY-SANTOS, Alexandre Leme; ORTIZ, Rafael Trevisan; ARAUJO, Antonio; FERNANDES, Tulio DinizObjective: To quantify the FHL length difference obtained through a single approach and by a double combined approach. Methods: 16 fresh cadavers, a total of 32 feet, were used to measure the FHL graft length. With the cadaver positioned in ventral decubitus, a posteromedial incision in the ankle and a second incision in the plantar cavus were performed. Results: The average gain of tendon's length (GTL) was of 42.43 mm, the lowest value being 32 mm and the largest 48 mm. The comparative analysis of the GTL on the right and left sides through the paired ""t"" Test does not show statistical differences, with a p-value = 0.463 and a statistical power of 0.1443. The height analysis of the sample and the right and left GTL performed through linear regression do not show statistically significant differences, with a p-value of 0.38311 and 0.82640, respectively. Conclusion: Harvesting the FHL graft using a double combined approach yields a 42.43 mm length gain in comparison to harvesting using the single approach.
- Risks of injury in distal metatarsal minimally invasive osteotomy when comparing standard and modified techniques: A cadaveric study(2022) AUCH, Elijah; MANSUR, Nacime Salomao Barbachan; LALEVEE, Matthieu; MALY, Connor; MARTINS, Fernando; GIAROLA, Ivan; LI, Shuyuan; GODOY-SANTOS, Alexandre Leme; NETTO, Cesar de CesarBackground: The objectives of the study were to evaluate the structures at risk in distal metatarsal mini -invasive osteotomy (DMMO) and to compare standard and intraosseous approaches. Methods: DMMO was performed on the second and fourth metatarsals of 11 fresh-frozen cadaveric spe-cimens. The standard technique was performed in 11 metatarsals. It was then compared to a modified intraosseous technique that entails starting inside the bone in 11 other metatarsals. The cadavers were dissected to identify unintentional injury to soft tissue structures. Results: In the standard group the most injured structures were the metatarsal joint capsules (MJC) (27%), extensor digitorum longus (EDL) (18%), and extensor digitorum brevis (EDB) (9%). The modified intraosseous group injured the EDL (27%), not the MJC (0%) and the EDB (0%). Distances between osteotomies and the dorsal metatarsal head articular surface (DMHAS) were 6.08 +/- 3.99 mm in the standard and 9.92 +/- 3.42 mm in the modified (p = 0.02). Conclusion: The DMMO techniques most frequently injured the EDL. Intra-articular positioning of the os-teotomy was more observed in the standard. Overall, it appears the modified method could be an alter-native to the standard DMMO. Clinical relevance: The modified minimally invasive DMMO has a comparable rate of potential iatrogenic in-juries. This intraosseous procedure may present as an option when planning surgery to the lesser metatarsals. Level of Evidence: Level III. Comparative Cadaveric Study.
- Charcot neuroarthropathy: realignment of diabetic foot by means of osteosynthesis using intramedullary screws – case report,(2014) SANTOS, Alexandre Leme Godoy dos; ALBINO, Rômulo Ballarin; ORTIZ, Rafael Trevisan; SAKAKI, Marcos Hideyo; CORSATO, Marcos de Andrade; FERNANDES, Tulio DinizDiabetes mellitus is a serious disease that affects a large portion of the population. Charcot neuroarthropathy is one of its major complications and can lead to osteoarticular deformities, functional incapacity, ulcers and ankle and foot infections. Realignment of the foot by means of arthrodesis presents a high rate of implant failure due to weight-bearing on an insensitive foot. The aim of this report was to describe successful use of intramedullary osteosynthesis with compression screws to stabilize the deformed foot, in a diabetic patient with neuroarthropathy.
- Surgical management of displaced talus neck fractures: single vs double approach, screw fixation alone vs screw and plating fixation-systematic review and meta-analysis(2021) GIORDANO, Vincenzo; LIBERAL, Bauer Ramos; RIVAS, Daniela; SOUTO, Danilo Baia; YAZEJI, Henrique; SOUZA, Felipe Serrao; GODOY-SANTOS, Alexandre; AMARAL, Ney PecegueiroPurpose: To provide a direct comparison between two important aspects related to talar neck fractures management - surgical approaches and fixation strategies. Data sources: A systematic review and meta-analysis was performed using PubMed, SciELO, and gray literature databases. The keyword ""talus fracture"" and the combined terms ""talus neck fracture AND surgical approach"" and ""talus neck fracture AND fixation strategy"" were used. Study selection: Study selection, data extraction, and the risk of bias assessment were performed following the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. Searches were limited to human studies and the English and Portuguese. Inclusion criteria were articles in full text that reported on any aspect of surgical approach and fixation strategy for talus neck fractures. Exclusion criteria were skeletally immature patients, mean follow-up of less than 12 months, studies that did not use the Hawkins classification system, primary treatment of arthrodesis, studies published before year 2000, and studies published in languages other than English and Portuguese. Data extraction: Basic information was collected including journal, author(s), year published, level of evidence, number of fractures, and follow-up. Specific information was collected including fracture classification, surgical approach, fixation strategy, complication rate, type of complication(s), and outcome measurement(s). Data synthesis: Fixed-effects model was used for meta-analysis. The choice for surgical approach(es) and fixation strategy was stratified based on fracture classification. Complication rate, type of complication(s), and outcome measurement(s) were calculated for all studies and delineated by fracture classification. Conclusion: There is a significant correlation between poor scores and poor fracture reduction, but not with the modified Hawkins classification, surgical approach, and fixation strategy. The presence of an open talus neck fracture-dislocation jeopardizes the functional outcome, increasing the risk of complications. The overall avascular necrosis and post-traumatic osteoarthritis event rate was 0.279 and 0.400, respectively. Both complications were highly correlated to higher energy fracture patterns and to the use of combined approaches, but not to fixation strategy.
- The use of polyvinyl alcohol hydrogel implants in the lesser metatarsal heads. Is it safely doable? A cadaveric study(2020) NETTO, Cesar de Cesar; GODOY-SANTOS, Alexandre Leme; CABE, Taylor N.; ROBERTS, Lauren E.; HARNROONGROJ, Thos; DELAND, Jonathan; DRAKOS, MarkBackground: The use of synthetic polyvinyl alcohol hydrogel (PVAH) implants for treatment of lesser toe metatarsophalangeal joint (MTPJ) arthritis is promising and currently limited by the size of implants available. The primary objective of this cadaveric study was to investigate the maximum drilling size and largest PVAH implant dimension that could be safely introduced while still preserving an intact bone rim of the lesser metatarsal heads. Methods: Height and width of all lesser metatarsals were measured on CT and during anatomic dissection. Sequential reaming of the second to fourth metatarsals was performed. Maximum reaming size, largest implant inserted, and failure of the metatarsal head were recorded. Metatarsal head sizes were compared and a multiple regression analysis evaluated measurements that influenced maximum drilling and implant size. Results: CT and anatomical measurements demonstrated significant correlation (ICC range, 0.-0.85). Mean values for height and width of the metatarsal heads were respectively: second (14.9 mm and 9.9 mm), third (14.8 mm and 8.8 mm), fourth (14.0 mm and 8.7 mm) and fifth (12.3 mm and 9.3 mm). All the second, third and fourth metatarsal heads could be safely drilled up to 7.5 mm, preserving an intact bone rim. At 80% of the time, the heads could be safely drilled up to 8.0 mm. Height of the metatarsal heads was the only factor to significantly influence the size of maximum reaming and implant introduced. In respectively 20%, 40% and 50% of the second, third, and fourth metatarsal heads, neither 8 mm nor 10 mm PVAH implants could be used. Conclusions: Our cadaveric study found that the even though the majority of the lesser metatarsal heads could be safely drilled up to 8 mm, the smallest PVAH implant size currently available in most countries (8 mm) could be inserted in most of the second, but only in about half of the third and fourth metatarsal heads. The remaining bone rim around inserted implants was considerably thin, usually measuring less than 1 mm. In order to optimize the use PVAH in lesser metatarsal heads, smaller implant options are needed.
- Epidemiological study on talus fractures(2014) SAKAKI, Marcos Hideyo; SAITO, Guilherme Honda; OLIVEIRA, Rafael Garcia de; ORTIZ, Rafael Trevisan; SILVA, Jorge dos Santos; FERNANDES, Túlio Diniz; SANTOS, Alexandre Leme Godoy dosObjective: To analyze the characteristics of patients with talus fractures and the injuries that they present. Methods: Retrospective analysis on patients hospitalized in the Institute of Orthopedics and Traumatology, Hospital das Clínicas, School of Medicine of the University of São Paulo, between 2006 and 2011, with talus fractures. Patient profile parameters, risk factors, fracture characteristics, treatment data and acute complications were analyzed. Results: Analysis on 23 cases showed that men were more affected than women, with a ratio of 4.8:1. The most frequent trauma mechanism was traffic accidents, followed by falls from a height. The most frequent type of fracture was at the neck of the talus, with 17 cases. Among the 23 cases, seven had peritalar dislocation at the time of presentation, four had exposed fractures and 11 presented other associated fractures. The mean length of time between the trauma and the definitive treatment was six days, while the mean length of hospital stay was 11 days. Three patients presented acute postoperative complications. Conclusion: Talus fractures occurred most commonly in the region of the talar neck and most frequently in young males who suffered high-energy trauma. In almost half of the cases, there were other associated fractures. The length of hospital stay was 11 days.