Browsing by Author "Carmona, Maximiliano"
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- ItemDo corticosteroids affect lumbar spinal fusion? A rabbit model using high-dose methylprednisolone(SPRINGER TOKYO, 2011) Urrutia, Julio; Carmona, Maximiliano; Briceno, JorgeThe effect of corticosteroids on spinal fusion healing has not yet been determined. To evaluate the effect of corticosteroids on lumbar spinal fusion we designed a randomized, placebo-controlled animal study using high-dose methylprednisolone sodium succinate, which is widely used in patients with spinal cord injury who are undergoing spinal fusion.
- ItemEffect of a single dose of pamidronate administered at the time of surgery in a rabbit posterolateral spinal fusion model(2010) Urrutia, Julio; Briceno, Jorge; Carmona, Maximiliano; Olavarria, Fernando; Hodgson, FelipeSpinal fusion is usually performed on patients who receive bisphosphonates (BP); however, limited data on their action on spinal fusion are available. Previous studies in animal models have shown that chronic administrations of BP reduced spinal fusion rates, and only one study has shown that a single dose administration of zolendronic acid increased fusion rate. The objective of the present study was to evaluate if pamidronate (PA), which was previously demonstrated to reduce spinal fusion rate when administered continuously for 8 weeks, would increase the spinal fusion rate if administered in a single dose at the time of surgery in a rabbit model. Thirty-two New Zealand rabbits underwent an L5-L6 posterolateral intertransverse fusion with iliac crest autograft. Animals were randomized to receive either PA 3 mg/kg in a single dose immediately after surgery, or normal saline. Animals were killed 8 weeks after surgery and fusion was determined by manual palpation and radiographic analysis. Fusion healing was obtained in eight rabbits (50%) in the PA group and in four animals (25%) in the control group, p = 0.137. In a rabbit model, a single dose of PA did not decrease lumbar spinal arthrodesis consolidation rates, but it obtained a nonsignificant higher spinal fusion rate.
- ItemPeriprosthetic Hip Fracture due to Ballistic Injuries(2024) Sandoval, Felipe; Valenzuela, Joaquin; Carmona, Maximiliano; Guiloff, Benjamin; Salgado, MartinPeriprosthetic hip fractures are a common cause for revision. To date, however, there are no reports of periprosthetic fractures (PFs) in total hip arthroplasty caused by ballistic injury (BI). There are no current recommendations on the management of this pathology in the literature. The objective of this paper is to report on 2 successfully treated cases of PF caused by BIs. Additionally, a brief review of the literature regarding open fracture secondary to BIs is carried out. What we consider appropriate initial and definitive management for these patients is outlined. According to our clinical results and current evidence, adequate management for a BI Vancouver B1 femoral PF consists of early antibiotic therapy, surgical debridement, osteosynthesis with variable angle locking plate, structural allograft, cerclage wires, and negative pressure wound therapy. (c) 2024 The Authors. Published by Elsevier Inc. on behalf of The American Association of Hip and Knee Surgeons. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/).
- ItemRadiographic Assessment of Bone Quality Using 4 Radiographic Indexes: Canal Diaphysis Ratio Is Superior(2024) Faundez, Jorge; Carmona, Maximiliano; Klaber, Ianiv; Zamora, Tomas; Botello, Eduardo; Schweitzer, DanielBackground: Osteoporosis increases the risk of periprosthetic fracture and loosening in hip arthroplasty. Many methods have been proposed to assess bone quality in X-rays, including both qualitative such as the Dorr classification and quantitative such as the Calcar-Canal Ratio (CCR) and Cortical -Thickness index/Canal-Bone ratio (CTI/CBR). The Canal-Diaphysis ratio (CDR) has been described as a predictor for hip fragility fractures; however, its relationship with bone mineral density (BMD) has not been described. The purpose of this study was to evaluate the correlation of the Dorr classification, CCR, CTI/CBR, and CDR with BMD of the proximal femur in patients without hip fracture. Methods: Forty-seven patients over 45 years of age who had less than 6 months between radiographs and dual -energy X-ray absorptiometry were evaluated. Measurements of CCR, CBR, CDR, and Dorr classification were performed in all radiographs by 2 independent observers. Results: The CDR had a high correlation (r = 0.74, P=<0.01) with BMD, whereas the CTI/CBR had a moderate correlation (r = 0.49, P=<0.01), and the CCR had no correlation with BMD (r = 0.06, P = .96). When evaluating the receiver operating characteristic curve, CDR showed the best performance (area under curve [AUC] = 0.75) followed by CBR (AUC = 0.73) and CCR (AUC = 0.61). The optimal cutoff value for the CDR was 0.49, with 100% sensitivity and 58% specificity. The inter- and intra-observer variability was good for all methods. No differences were found between Dorr classification of patients who had or did not have osteoporosis. Conclusion: Of all the analyzed methods, the CDR was found to have the best correlation with BMD. This study proposes the use of CDR as a tool for assessing bone quality when deciding the implant fixation method in hip arthroplasty. (c) 2023 Elsevier Inc. All rights reserved.
- ItemTibial subchondral trabecular bone micromechanical and microarchitectural properties are affected by alignment and osteoarthritis stage(2020) Renault, Jean-Baptiste; Carmona, Maximiliano; Tzioupis, Chris; Ollivier, Matthieu; Argenson, Jean-Noel; Parratte, Sebastien; Chabrand, PatrickAt advanced knee osteoarthritis (OA) stages subchondral trabecular bone (STB) is altered. Lower limb alignment plays a role in OA progression and modify the macroscopic loading of the medial and lateral condyles of the tibial plateau. How the properties of the STB relate to alignment and OA stage is not well defined. OA stage (KL scores 2-4) and alignment (HKA from 17 degrees Varus to 8 degrees Valgus) of 30 patients were measured and their tibial plateau were collected after total knee arthroplasty. STB tissue elastic modulus, bone volume fraction (BV/TV) and trabecula thickness (Tb.Th) were evaluated with nanoindentation and mu CT scans (8.1 mu m voxel-size) of medial and lateral samples of each plateau. HKA and KL scores were statistically significantly associated with STB elastic modulus, BV/TV and Tb.Th. Medial to lateral BV/TV ratio correlated with HKA angle (R = -0.53, p = 0.016), revealing a higher ratio for varus than valgus subjects. STB properties showed lower values for KL stage 4 patients. Tissue elastic modulus ratios and BV.TV ratios were strongly correlated (R = 0.81, p < 0.001). Results showed that both micromechanical and microarchitectural properties of STB are affected by macroscopic loading at late stage knee OA. For the first time, a strong association between tissue stiffness and quantity of OA STB was demonstrated.
- ItemTraction images heavily influence lateral wall measurement in trochanteric hip fractures. A prospective study(2023) Carmona, Maximiliano; Gonzalez, Nicolas; Segovia, Javier; de Amesti, Martin; Zamora, Tomas; Schweitzer, DanielIntroduction: hip fracture represents a global health problem, with a high morbidity and mortality rate and an increasing incidence. The treatment of trochanteric fractures is reduction and osteosynthesis, and implant selection depends mainly on the stability of the fracture and lateral wall competence. Lateral wall competence has gained relevance in recent years, which led to the modification of the AO/OTA classification. However, determination of lateral wall integrity is difficult from plain radiographs; the influence of images with traction on its measurement has not been evaluated.
- ItemValidación de medidas de resultados informados por los pacientes en ortopedia y traumatología(2022) Vidal Olate, Catalina Victoria; Lira Salas, María Jesús; Besa, Pablo; Carmona, Maximiliano; Irarrazaval Dominguez, SebastianEn los últimos años, ha habido un aumento en la aplicación de cuestionarios diseñados para la medición de resultados (o desenlaces) clínicos en la práctica médica. Para aplicar un cuestionario en una población distinta a la cual fue originalmente creado y diseñado, es necesario llevar a cabo un proceso riguroso de adaptación, con una determinada metodología. El objetivo de esta guía metodológica es describir el proceso de traducción, adaptación transcultural y validación de medidas de resultados informados por los pacientes (MRIPs) en Ortopedia y Traumatología.