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.
- 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.
- Effect of Peritalar Subluxation Correction for Progressive Collapsing Foot Deformity on Patient-Reported Outcomes(2023) CESAR NETTO, Cesar de; MANSUR, Nacime Salomao Barbachan; LALEVEE, Matthieu; CARVALHO, Kepler Alencar Mendes de; GODOY-SANTOS, Alexandre Leme; KIM, Ki Chun; LINTZ, Francois; DIBBERN, KevinBackground: Peritalar subluxation (PTS) is part of progressive collapsing foot deformity (PCFD). This study aimed to evaluate initial deformity correction and PTS optimization in PCFD patients with flexible hindfoot deformity undergoing hindfoot joint-sparing surgical procedures and its relationship with improvements in patient-reported outcome measures (PROMs) at latest follow-up. We hypothesized that significant deformity/PTS correction would be observed postoperatively, positively correlating with improved PROMs.Methods: A prospective comparative study was performed with 26 flexible PCFD patients undergoing hindfoot joint-sparing reconstructive procedures, mean age 47.1 years (range, 18-77). We assessed weightbearing computed tomography (WBCT) overall deformity (foot and ankle offset [FAO]) and PTS markers (distance and coverage maps) at 3 months, as well as PROMs at final follow-up. A multivariate regression model assessed the influence of initial deformity correction and PTS optimization in patient-reported outcomes.Results: Mean follow-up was 19.9 months (6-39), and the average number of procedures performed was 4.8 (2-8). FAO improved from 9.4% (8.4-10.9) to 1.9% (1.1-3.6) postoperatively (P < .0001). Mean coverage improved by 69.6% (P = .012), 12.1% (P = .0343) and 5.2% (P = .0074) in, respectively, the anterior, middle, and posterior facets, whereas the sinus tarsi coverage decreased by an average 57.1% (P < .0001) postoperatively. Improvements in patient-reported outcomes were noted for all scores assessed (P < .03). The multivariate regression analysis demonstrated that improvement in both FAO and PTS measurements significantly influenced the assessed PROMs.Conclusion: This study demonstrated significant improvements in the overall 3D deformity, PTS markers, and PROMs following hindfoot joint-sparing surgical treatment in patients with flexible PCFD. More importantly, initial 3D deformity correction and improvement in subtalar joint coverage and extraarticular impingement have been shown to influence PROMs significantly and positively. Addressing these variables should be considered as goals when treating PCFD.Level of Evidence: Level II, prospective cohort study.
- Ankle Osteoarthritis(2021) GODOY-SANTOS, Alexandre Leme; FONSECA, Lucas Furtado; CESAR NETTO, Cesar de; GIORDANO, Vincenzo; VALDERRABANO, Victor; RAMMELT, StefanAbstract Osteoarthritis (OA) is characterized by a chronic, progressive and irreversible degradation of the joint surface associated with joint inflammation. The main etiology of ankle OA is post-traumatic and its prevalence is higher among young and obese people. Despite advances in the treatment of fractures around the ankle, the overall risk of developing posttraumatic ankle OA after 20 years is almost 40%, especially in Weber type B and C bimalleolar fractures and in fractures involving the posterior tibial border. In talus fractures, this prevalence approaches 100%, depending on the severity of the lesion and the time of follow-up. In this context, the current understanding of the molecular signaling pathways involved in senescence and chondrocyte apoptosis is fundamental. The treatment of ankle OA is staged and guided by the classification systems and local and patient conditions. The main problems are the limited ability to regenerate articular cartilage, low blood supply, and a shortage of progenitor stem cells. The present update summarizes recent scientific evidence of post-traumatic ankle OA with a major focus on changes of the synovia, cartilage and synovial fluid; as well as the epidemiology, pathophysiology, clinical implications, treatment options and potential targets for therapeutic agents.
- Anatomic Evaluation of Percutaneous Achilles Tendon Lengthening(2018) PHILLIPS, Sierra; SHAH, Ashish; STAGGERS, Jackson Rucker; PINTO, Martim; GODOY-SANTOS, Alexandre Leme; NARANJE, Sameer; NETTO, Cesar de CesarBackground: The objective of the study was to evaluate the accuracy of percutaneous Achilles tendon lengthening (TAL) using a triple hemisection technique and the improvement in ankle dorsiflexion. Methods: Ten fresh-frozen above-knee cadaveric specimens were used. A percutaneous triple hemisection of the Achilles tendon (proximal, intermediate, and distal) was performed. Maximum ankle dorsiflexion was evaluated pre- and postprocedure with a digital goniometer. After proper dissection, the relative width of the cuts was noted. Following forced ankle dorsiflexion, displacement in the tensile gaps was measured in all 3 cuts with a precision digital caliper. Results: The overall relative width of the percutaneous cut was 51.3% 16.3% of the Achilles tendon diameter, 44.3% 13.6% for the proximal cut, 50.3% +/- 15.6% for the intermediate cut, and 59.3% +/- 18.4% for the distal cut. Tendon excursion averaged 13.0 +/- 3.8 mm for the proximal cuts, 12.5 +/- 4.7 mm for the intermediate cuts, and 8.2 +/- 3.7 mm for the distal cuts. One cadaver had a complete rupture of the Achilles tendon and was excluded from the excursion data analysis. The mean range of motion for ankle dorsiflexion was 8.1 +/- 3.9 degrees preprocedure and 27.6 +/- 5.3 degrees postprocedure. The dorsiflexion angle significantly increased (P < .0001) at an average of 19.5 +/- 5.0 degrees following TAL. Conclusion: Our cadaveric study demonstrated that the percutaneous triple hemisection of the Achilles was an accurate technique that provided successful lengthening of the tendon and increased ankle dorsiflexion. Complete ruptures are possible complications. Clinical Relevance: Our cadaveric study showed that in a clinical situation, triple hemisections of the Achilles tendon can be performed reliably, with significant improvement of the ankle dorsiflexion, mainly through increased tendon excursion at the proximal and intermediate cuts, and with low risk of complete ruptures.
- Primary Arthrodesis for High-Energy Lisfranc Injuries(2020) GODOY-SANTOS, Alexandre Leme; NETTO, Cesar de CesarThe reported incidence of Lisfranc injuries is 9.2/100.000 person-years; two-thirds of the injuries are nondisplaced. Tarsometatarsal injuries range from minor sprains and isolated ligamentous injuries to grossly unstable and multiligamentous lesions. High-energy injuries are usually linked with mechanical energy dissipation through the soft tissues. Operative treatment options include open reduction and internal fixation, open reduction with hybrid internal and external fixation, closed reduction with percutaneous internal or external fixation, and primary arthrodesis. Treatment goals are to obtain a painless, plantigrade, and stable foot. Anatomic reduction is a key factor for improved outcomes and decreased rates of post-traumatic arthritis.
- Kager's fat pad inflammation associated with HIV infection and AIDS: MRI findings(2014) GODOY-SANTOS, Alexandre Leme; BORDALO-RODRIGUES, Marcelo; ROSEMBERG, Laercio; FERNANDES, Tulio Diniz; LIMA, Ana Lucia Lei Munhoz; CAMANHO, Gilberto Luis; MAFFULLI, NicolaTo describe magnetic resonance imaging (MRI) features of Kager's fat pad inflammation in HIV-positive patients with lipodystrophy due to protease inhibitor treatment and posterior ankle pain. A case-control, cross-sectional study; group 1 included 14 HIV-positive patients using protease inhibitors, presenting lipodystrophy syndrome and having posterior ankle pain; group 2 (CGHIV-) included 112 HIV-negative patients without lipodystrophy syndrome who were being evaluated for posterior ankle pain; group 3 (CGHIV + 1) included 23 HIV-positive patients not using a protease inhibitor, without lipodystrophy syndrome and with posterior ankle pain; group 4 (CGHIV + 2) comprised 18 HIV-positive patients who were being treated with a protease inhibitor and had lipodystrophy syndrome but did not have posterior ankle pain. Images were evaluated for the presence of edema by two radiologists who were blinded to clinical features. Fisher's exact test was used to evaluate differences among the groups. Interobserver variation was tested using Cohen's kappa (kappa) statistic. The presence of edema within Kager's fat pad was strongly associated with symptoms in HIV-positive patients who had lipodystrophy (p a parts per thousand currency signaEuro parts per thousand 0.0001). Concordance between observers was excellent (kappa > 0.9). MRI findings of Kager's fat pad inflammation related to HIV/AIDS is a source of symptoms in HIV patients with posterior ankle pain using protease inhibitors and having lipodystrophy syndrome.
- Biomechanical Efficacy of Three Methods for the Fixation of Posterior Malleolar Fractures: A Three-Dimensional Finite Element Study(2023) GIORDANO, Vincenzo; BABINSKI, Marcio Antonio; FREITAS, Anderson; PIRES, Robinson Esteves; SOUZA, Felipe Serrao de; FARIA, Luiz Paulo Giorgetta de; LABRONICI, Pedro Jose; GODOY-SANTOS, AlexandreIntroduction: We investigated the biomechanical behaviour of different fixations of the tibial posterior malleolus (TPM), simulating distinct situations of involvement of the tibiotalar articular surface (TTAS) through a finite element model (FEM). Material and methods: A 3D computer-aided design model of the left ankle was obtained. The materials used were divided according to their characteristics into ductile and non-ductile, and all materials were assumed to be linear elastic, isotropic, and homogenous. Three different fracture lines of the TPM were defined, with sagittal angles of 10 degrees, 25 degrees, and 45 degrees. For biomechanical comparison, different constructions using a trans-syndesmotic screw (TSS) only (Group T), a one-third tubular plate only with (Group PT) and without (Group PS) a TSS, and a locked compression plate with (Group LCPT) and without (Group LCPS) a TSS were tested. FEM was used to simulate the boundary conditions of vertical loading. Load application regions were selected in the direction of the 700 N Z-axis, 90% on the tibia and 10% on the fibula. Data on the displacement and stress in the FEM were collected, including the total principal maximum (MaxT) and total principal minimum (MinT) for non-ductile materials, total displacement (desT), localized displacement at the fragment (desL), localized displacement at syndesmosis (desS), and Von Mises equivalent stress for ductile materials. The data were analysed using ANOVA and multiple comparison LSD tests were used. Results: For TPM fractures with sagittal angles 10 degrees and 25 degrees, desL in the PT and LCP groups was significantly lower, as well as Von Mises stress in Group LCPT in 10 degrees, and PT and LCPT groups in 25 degrees. For TPM fractures with a sagittal angle of 45 degrees, desL in the LCP group and Von Mises stress in Group LCPS and LCPT were significantly lower. We found that any TPM fracture may indicate instability of the distal tibiofibular syndesmosis, even when the fragment is small. Conclusion: Our study showed that in fragments involving 10% of the TTAS, the use of a TSS is sufficient, but when the involvement is greater than 25% of the TTAS, either a non-locked or locked plate must be used to buttress the TPM. In posterior fragments affecting 45% or more of the TTAS, the use of a locking plate is recommended.