Recurrent intra-articular osteoid osteoma of the hip after radiofrequency ablation: a case report and review of the literature

We present a case of a 53-year-old woman with recurrent intra-articular osteoid osteoma of the hip 6 months after initial treatment with percutaneous radiofrequency ablation. En bloc surgical excision of the osteoid osteoma and prophylactic internal fixation for impending stress fracture was performed. The patient is pain free, has returned to normal function and there is no sign of recurrence at the one-year follow-up. Intraarticular osteoid osteoma, present a diagnostic challenge and often they are misdiagnosed. Minimally invasive ablation techniques can fail in significant percentage and then surgical excision with histological confirmation remains the definitive treatment of choice

Vortex formation and recirculation zones in left anterior descending artery stenoses: computational fluid dynamics analysis

Flow patterns may affect the potential of thrombus formation following plaque rupture. Computational fluid dynamics (CFD) were employed to assess hemodynamic conditions, and particularly flow recirculation and vortex formation in reconstructed arterial models associated with ST-elevation myocardial infraction (STEMI) or stable coronary stenosis (SCS) in the left anterior descending coronary artery (LAD). Results indicate that in the arterial models associated with STEMI, a 50% diameter stenosis immediately before or after a bifurcation creates a recirculation zone and vortex formation at the orifice of the bifurcation branch, for most of the cardiac cycle, thus allowing the creation of stagnating flow. These flow patterns are not seen in the SCS model with an identical stenosis. Post-stenotic recirculation in the presence of a 90% stenosis was evident at both the STEMI and SCS models. The presence of 90% diameter stenosis resulted in flow reduction in the LAD of 51.5% and 35.9% in the STEMI models and 37.6% in the SCS model, for a 10 mmHg pressure drop. CFD simulations in a reconstructed model of stenotic LAD segments indicate that specific anatomic characteristics create zones of vortices and flow recirculation that promote thrombus formation and potentially myocardial infarction

Neurosteroid Dehydroepiandrosterone Interacts with Nerve Growth Factor (NGF) Receptors, Preventing Neuronal Apoptosis

The neurosteroid dehydroepiandrosterone (DHEA), produced by neurons and glia, affects multiple processes in the brain, including neuronal survival and neurogenesis during development and in aging. We provide evidence that DHEA interacts with pro-survival TrkA and pro-death p75NTR membrane receptors of neurotrophin nerve growth factor (NGF), acting as a neurotrophic factor: (1) the anti-apoptotic effects of DHEA were reversed by siRNA against TrkA or by a specific TrkA inhibitor; (2) [3H]-DHEA binding assays showed that it bound to membranes isolated from HEK293 cells transfected with the cDNAs of TrkA and p75NTR receptors (KD: 7.4±1.75 nM and 5.6±0.55 nM, respectively); (3) immobilized DHEA pulled down recombinant and naturally expressed TrkA and p75NTR receptors; (4) DHEA induced TrkA phosphorylation and NGF receptor-mediated signaling; Shc, Akt, and ERK1/2 kinases down-stream to TrkA receptors and TRAF6, RIP2, and RhoGDI interactors of p75NTR receptors; and (5) DHEA rescued from apoptosis TrkA receptor positive sensory neurons of dorsal root ganglia in NGF null embryos and compensated NGF in rescuing from apoptosis NGF receptor positive sympathetic neurons of embryonic superior cervical ganglia. Phylogenetic findings on the evolution of neurotrophins, their receptors, and CYP17, the enzyme responsible for DHEA biosynthesis, combined with our data support the hypothesis that DHEA served as a phylogenetically ancient neurotrophic factor

Open ankle dislocation without associated malleolar fracture

Open ankle dislocation without an associated fracture is an extremely rare injury. We present the case of a 24-year-old male athlete who had sprained his left ankle during volleyball playing. He sustained an open posteromedial dislocation of his left ankle, without an associated malleolar fracture. The treatment consisted of wound irrigation, debridement, reduction, and suture of the skin, followed by immobilization with a short leg cast. The ankle was immobilized in a neutral position for 8 weeks, and weight bearing was restricted for the first 6 weeks. At the 3-month follow-up visit, the patient reported that both ankle and feet had regained full, pain-free range of motion. At the 6-month follow-up visit, he returned to sports activities. At 9 months of follow-up, the patient participated in volleyball games at the same level as before his injury. At 2 years after the initial injury, he did not have any clinical complaints, and his ankle had no clinical or subjective signs of instability. © 2013 American College of Foot and Ankle Surgeons

Vanishing bone disease (gorham-stout syndrome): A review of a rare entity

Vanishing bone disease (Gorham-Stout syndrome) is a rare entity of unknown etiology, characterized by destruction of osseous matrix and proliferation of vascular structures, resulting in destruction and absorption of bone. Despite the extensive investigation of the pathogenetic mechanisms of the disease, its etiology hasn't been clarified and several theories exist. The syndrome can affect one or multiple bones of the patient, including the skull, the upper and lower extremities, the spine and pelvis. The clinical presentation of a patient suffering from vanishing bone disease includes, pain, functional impairment and swelling of the affected region, although asymptomatic cases have been reported, as well as cases in which the diagnosis was made after a pathologic fracture. In this short review we summarize the theories regarding the etiology as well as the clinical presentation, the diagnostic approach and treatment options of this rare disease. © 2014 Baishideng Publishing Group Inc

Early weight bearing after posterior malleolar fractures: An experimental and prospective clinical study

The distribution of axial load to the lower end of the tibia at different positions of the ankle joint for the anterior, middle, and posterior part of the joint was studied in both photoelastic models and fractured ankle joints in cadaveric specimens. Synthetic models were used to simulate both normal ankle joints and ankles with fractures of the posterior lip of the tibia. Tests were performed with the ankle at dorsiflexed, neutral-flexed, and plantarflexed positions of the ankle joint. The clinical portion of the study evaluated 15 patients with fracture of the posterior malleolus that comprised 0% to 33% of the articular surface. All patients had open reduction and internal fixation through a posterolateral or posteromedial approach, and were allowed full weight bearing in a cast within 7 days of surgery. In the simulated models, the posterior one fourth of the ankle joint remains unloaded in the majority of the cases. The stresses are greatly increased when the load is doubled and are mainly distributed to the 2 central quadrants. With additional axial load, the fourth quadrant sustained little increase in the load bearing. All patients have had an uneventful recovery. By the second postoperative month, they were able to walk normally and had a painless range of motion of the ankle. By the third month, all patients were able to undertake their daily activities, and all fractures were consolidated. The clinical relevance of this study is early weight bearing, after open reduction internal fixation of posterior malleolar fracture of the ankle joint, facilitates recovery, promotes fracture union, and allows the patient to assume normal activity by the third month after surgery. Copyright © 2003 by the American College of Foot and Ankle Surgeons