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.
- 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.
- 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.
- Changes in cartilage, synovial cells and synovial fluid after malleolar fractures: What its importance for post-traumatic ankle osteoarthitis?(2019) GODOY-SANTOS, A.L.; LOPES, D.; GIAROLA, I.; CESAR NETTO, C. de; RAMMELT, S.Background: Despite advances in malleolar fractures treatment, the overall risk to develop posttraumatic ankle osteoarthritis after 20 years is almost 40%, especially bimalleolar Weber type B and C fractures and fractures involving the posterior tibial rim. Methods: We performed a systematic literature review of clinical studies targeting the changes in cartilage, synovial cells and synovial fluid after malleolar fractures. Results: The acute ankle injury initiates a sequence of biological events potentially leading to progressive articular surface damage resulting from inflammatory changes in cartilage, synovial tissue and synovial fluid. Conclusion: A better understanding of the molecular and histological changes induced by acute trauma may potentially lead to novel, targeted treatment of malleolar fractures besides anatomical reduction and adequate stabilization. © 2019
- The use of three-dimensional biometric Foot and Ankle Offset to predict additional realignment procedures in total ankle replacement(2022) NETTO, Cesar de Cesar; DAY, Jonathan; GODOY-SANTOS, Alexandre Leme; RONEY, Andrew; MANSUR, Nacime S. Barbachan; LINTZ, Francois; ELLIS, Scott J.; DEMETRACOPOULOS, Constantine A.Background: Decision to perform associated corrective alignment procedures in patients undergoing total ankle replacement (TAR) is commonly made intraoperatively. The Foot and Ankle Offset (FAO) can evaluate multiplanar deformity and be an effective instrument in surgical planning. This study objective was to assess the ability of this tool to predict the need for additional realignment procedures at the time of TAR.Methods: In this retrospective study, we enrolled 21 patients who underwent TAR and had preoperative WBCT studies. Two independent and blinded observers calculated the preoperative FAO using dedicated software. FAO measurements were compared between the different alignment groups (physiological alignment, valgus and varus). A multivariate regression analysis was used to assess the correlation between performed realignment procedures and FAO values.Results: Mean preoperative FAO was 4.4% (95%CI = 1.4-7.5). The number of osseous realignment procedures needed was found to correlate positively and significantly with FAO (p = .001). The number of osseus procedures needed was significantly higher in patients with valgus malalignment (p = .009). Patients with valgus malalignment needing a medial column procedure had a relative risk of 6.3 when compared to varus malalignment patients (p = .02).Conclusion: The number of additional bony realignment procedures performed at the time of TAR sig-nificantly correlated with preoperative FAO and that the number of osseus procedures needed was sig-nificantly higher in patients with valgus malalignment. Such biometric tools may enhance the preoperative assessment and surgical planning for patients undergoing TAR, with the potential to optimize surgical outcomes.(c) 2022 European Foot and Ankle Society.
- FOOT ALIGNMENT IN SYMPTOMATIC NATIONAL FOOTBALL LEAGUE (NFL) ATHLETES: A WEIGHTBEARING CT ANALYSIS(2021) BERNASCONI, Alessio; NETTO, Cesar de Cesar; ROBERTS, Lauren; LINTZ, Francois; GODOY-SANTOS, Alexandre Leme; O'MALLEY, Martin JosephObjective: Our aim was to describe the foot alignment in National Football League (NFL) players with different symptomatic foot and ankle pathologies using weightbearing cone-beam computed tomography (WBCBCT), comparing them to normally aligned feet as control group. Methods: 41 feet (36 active NFL players) were assessed using WBCBCT and compared to 20 normally aligned controls from a normal population. Measurements included: Foot and Ankle Offset (FAO); Calcaneal Offset (CO); Hindfoot Alignment Angle (HAA); angle between inferior and superior facets of the talus (Inftal-Suptal); angle between inferior facet of the talus and the horizontal/floor (lnftal-Hor); Forefoot Arch Angle (FAA); navicular- and medial cuneiform-to-floor distance. Results: NFL athletes showed a neutrally aligned hindfoot when compared to controls (FAO: 1% vs 0.5%; CO: 2.3 mm vs 0.8 mm; HAA: 2.9 degrees vs 0.8 degrees in two groups, with all p > 0.05) and a normal morphology of the subtalar joint (no difference in Inftal-Suptal and Inftal-Hor angles). Conversely, in athletes we found a decreased medial longitudinal arch (FAA: 15 degrees vs 18.3 degrees, p = 0.03) with smaller navicular (38.2 mm vs 42.2 mm, p = 0.03) and medial cuneiform (27 mm vs 31.3 mm, p = 0.01) mean distances to the floor when compared to controls. Conclusion: In our series, NFL players presented a lower medial longitudinal arch than controls but a neutrally aligned hindfoot. WBCBCT may help shed light on anatomical risk factors for injuries in professional players.
- Extensive Synovial Chondromatosis Involving All Flexor Tendons in the Tarsal Tunnel: A Case Report(2019) PINTER, Zachariah; SHAH, Ashish; CESAR NETTO, Cesar de; SMITH, Walter; O’DALY, Andres; GODOY-SANTOS, Alexandre LemeAbstract Synovial chondromatosis is a rare condition characterized by benign chondrogenic metaplasia of extra-articular synovial tissue. It usually affects a single tendon sheath of the hand or foot. This report describes a rare case with extensive synovial chondromatosis affecting all flexor tendons in the tarsal tunnel, its radiological features, surgical treatment, and clinical outcome. The authors present a unique case of extensive synovial chondromatosis in a 48-year-old male involving the tendon sheaths of the flexor hallucis longus, flexor digitorum longus, and posterior tibialis tendons, at the level of the tarsal tunnel, with extension into the plantar aspect of the foot. The patient initially presentedwith symptoms of tarsal tunnel compression and was found to have a 4-cm mass in the posteromedial aspect of the ankle. The presumptive diagnosis of synovial chondromatosiswasmadebased on radiographic and magnetic resonance imaging evidence. The patient underwent surgical resection of the tumor, aswell as tarsal tunnel releaseandgastrocnemius recession. The diagnosiswas confirmed postoperatively by surgical histopathology. The postoperative course of the patient was uncomplicated and his tarsal tunnel symptoms resolved. This represents a case of extensive synovial chondromatosis involving all flexor tendons in the tarsal tunnel that was correctly diagnosed by clinical and imaging findings, which required early surgical resection to avoid long-term neurovascular complications.
- What Are the Updates on Epidemiology of Progressive Collapsing Foot Deformity?(2021) GODOY-SANTOS, Alexandre Leme; SCHMIDT, Eli L.; CHAPARRO, Felipe