Intraosseous Sites Research Articles

Prognostic factors of oral squamous cell carcinoma: the importance of recurrence and pTNM stage

BackgroundOral squamous cell carcinoma has a poor prognosis. Therefore, prognostic factors are important to increase the survival rate. This study assessed the survival rate and the prognostic factors for survival of patients with oral squamous cell carcinoma.MethodThis study included 168 patients who underwent surgery for oral squamous cell carcinoma between January 2006 and December 2021. The survival rate was analyzed with overall survival and disease-specific survival. The patient’s age, sex, pTNM stage, primary sites (lip, tongue, mouth of floor, mandibular gingiva, maxillary gingiva, mandibular vestibule, maxillary vestibule, retromolar trigone, palate, buccal mucosa, primary intra-osseous site), smoking and alcohol drinking habits, depth of invasion, perineural and lymphovascular invasion, cell differentiation, and postoperative radiotherapy were evaluated to analyze risk factors. Kaplan–Meier methods were used to estimate the survival rates. Cox regression methods were used to investigate the main independent predictors of survival in univariable and multivariable analysis.ResultsSixty-eight patients died of oral squamous cell carcinoma during follow-up periods. Their overall survival for 5 years was 51.2%, and the disease-specific survival was 59.2%. In univariable analysis, seven factors which are neck metastasis, depth of invasion, cell differentiation, lymphovascular invasion, postoperative radiotherapy, pTNM stage, and recurrence were significantly associated with survival. In multivariable analysis, pTNM stage and recurrence were significantly associated with survival.ConclusionIn patients with oral squamous cell carcinoma, pTNM stage and recurrence were significant prognostic factors. Neck metastasis, depth of invasion, cell differentiation, lymphovascular invasion, and postoperative radiotherapy were also prognostic factors. These factors serve as markers for obtaining prognosis information in oral squamous cell carcinoma.

The association of tibial vs. humeral intraosseous vascular access with patient outcomes in adult out-of-hospital cardiac arrests

AimHumeral and tibial intraosseous (IO) vascular access can deliver resuscitative medications for out-of-hospital cardiac arrest (OHCA), however the optimal site is unclear. We examined the association between IO tibia vs. humerus as the first-attempted vascular access site with OHCA outcomes. MethodsWe used prospectively-collected data from the British Columbia Cardiac Arrest registry, including adult OHCAs treated with IO humerus or IO tibia as the first-attempted intra-arrest vascular access. We fit logistic regression models on the full study cohort and a propensity-matched cohort, to estimate the association between IO site and both favorable neurological outcomes (Cerebral Performance Category 1–2) and survival at hospital discharge. ResultsWe included 1041 (43%) and 1404 (57%) OHCAs for whom IO humerus and tibia, respectively, were the first-attempted intra-arrest vascular access. Among humerus and tibia cases, 1010 (97%) and 1369 (98%) had first-attempt success, and the median paramedic arrival-to-successful access interval was 6.7 minutes (IQR 4.4–9.4) and 6.1 minutes (IQR 4.1–8.9), respectively. In the propensity-matched cohort (n = 2052), 31 (3.0%) and 44 (4.3%) cases had favourable neurological outcomes in the IO humerus and IO tibia groups, respectively; compared to IO humerus, we did not detect an association between IO tibia with favorable neurological outcomes (OR 1.44; 95% CI 0.90–2.29) or survival to hospital discharge (OR 1.29; 95% CI 0.83–2.01). Results using the full cohort were similar. ConclusionsWe did not detect an association between the first-attempted intra-arrest IO site (tibia vs. humerus) and clinical outcomes. Clinical trials are warranted to test differences between vascular access strategies.

Origens do carcinoma mucoepidermoide central: revisão sistemática

O carcinoma mucoepidermoide é um tumor maligno geralmente associado a glândulas salivares. Apenas de 2-4% de todos os carcinomas mucoepidermoides apresentam sítio primário intraósseo (carcinoma mucoepidermoide central), cuja etiogenia permanece obscura, justificando a importância de se pesquisar o assunto. Objetivo: Conhecer a(s) etiologia(s) mais provável(is) do carcinoma mucoepidermoide intraósseo. Método: revisão sistemática de acordo com as recomendações do PRISMA (Preferred Reporting itens for Systemstic Review and Meta-analysis Statement). As bases de dados consultadas foram: PubMed, Portal CAPES e Google acadêmico, e após aplicação dos critérios de inclusão e exclusão foram selecionados sete artigos que atenderam o objetivo da pesquisa, para os quais aplicaram-se a ferramenta Newcastle-Ottawa para análise de risco de viés e qualidade metodológica. A busca, seleção, extração e risco de viés foram feitas por três pesquisadores independentes Resultados: São duas as principais hipóteses etiológicas do carcinoma mucoepidermoide intraósseo: (1) derivado de um cisto odontogênico e (2) derivado de restos ectópicos. Conclusões: Ao que as evidências indicam o potencial pluripotente de células contidas nos cistos odontogênicos seria o responsável pela metaplasia e posterior carcinogênese. Nos casos derivados de restos ectópicos é clara a associação com a translocação t(11;19) e o transcrito de fusão CTRC1-MAML2 como um evento precoce ou etiológico.

Murine Models of Bone Sarcomas.

This chapter describes the procedures for inducing bone sarcoma in mice. Two models based on inoculation of cancer cells in paraosseous and intraosseous site will be described. In addition to providing technical aspects of anesthesia and surgical options, key information of cell preparation and postoperative follow-up will be discussed.

Intraosseous Needle Placement Confirmation by Doppler Ultrasonography

SESSION TITLE: Rapid Session: Bedside Imaging SESSION TYPE: Original Investigation Slide PRESENTED ON: Wednesday, November 1, 2017 at 07:30 AM - 08:30 AM PURPOSE: The 2015 guidelines for advanced cardiac life support (ACLS) recommend intraosseous (IO) access, if intravenous (IV) access is not readily attainable. The safety record for IO access is excellent. However, serious complications have been reported in the literature. In our institution, we experienced a limb threatening complication from a dislodged IO line despite standard confirmation. A properly placed IO line must be through the cortex of the bone and situated within the marrow cavity. Standard methods for confirmation of IO placement include aspiration of bone marrow, firm placement of the IO needle into the bone, and no evidence of extravasation. The traditional confirmation methods have as high as a 60% false positive rate for IOs that have incorrect penetrating placement, and a 10% false positive rate for incorrect subcutaneous placement. An alternative method to confirm IO placement is the use of color Doppler ultrasonography, which provides a noninvasive method for verification of correct IO placement. METHODS: Confirmation of correct IO placement was performed in a series of patients who received IO access during emergent resuscitation. Confirmation of IO placement with color Doppler was accomplished using a 7.5 MHz linear ultrasound probe placed adjacent to the IO site with the tomographic plane placed to intersect with the tip of the IO needle and the color Doppler map adjusted to target the needle tip area. Injection of 10 cc of agitated saline through the IO needle confirmed appropriate placement if the color signal showed subperiosteal color Doppler velocity pattern. The results of the color Doppler studies were compared to results of standard indices of IO placement. RESULTS: A total of 15 IO needle placements were studied. All were confirmed to be in appropriate subperiosteal position place using the three standard confirmation methods. The color Doppler technique confirmed placement in all 15 cases, indicating a perfect correlation between the methods. CONCLUSIONS: From this preliminary study, color Doppler ultrasonography may be a useful adjunct to standard confirmation techniques for intraosseous needle placement, as it allows for rapid identification of incorrect placement of IO lines, which in turn may prevent serious limb injury. The limitation of the technique is the requirement of operator training and machine availability. CLINICAL IMPLICATIONS: Using point-of-care color doppler ultrasonography helps quickly identify incorrect placement of IO lines. This, in turn, may help prevent serious, limb threatening injuries. DISCLOSURE: The following authors have nothing to disclose: Zubair Hasan, Karan Singh, Atul Palkar, Yonatan Greenstein, Paul Mayo No Product/Research Disclosure Information

Compartment syndrome- A rare complication of intraosseous access in adult patients

Background: Intraosseous (IO) access are being widely used in resuscitation of patients with difficult intra-venous (IV) access. The United Kingdom Resuscitation Council guidelines recommend the use of IO access, after two minutes of failed IV access in adult patients or two failed IV attempts in pediatric patients. There are various complications associated with IO access such as extravasation of the infusion fluid or medications, bleeding, infection and pain1. Compartment syndrome is a rare complication associated with IO access. This is reported commonly in children where in certain cases the affected limb required amputation. We report a case where an adult patient developed compartment syndrome secondary to IO access. Methods: A 52-year-old lady who was on dialysis for renal failure presented to the Emergency Department (ED) with septic shock. She was in peri-arrest and had a difficult IV access. Therefore an IO needle was inserted to her right tibia and resuscitation was carried out with fluids and medications. She required emergency intubation and ventilation and was later admitted to the Intensive Care Unit (ICU). The following day, it was found that she developed a compartment syndrome of the right lower leg where she had the IO access. Results: Patient was taken to the theatre for an urgent fasciotomy of the affected leg by the orthopedic surgeons with input from plastic surgeons. She made a steady but full recovery and was discharged home later. Conclusions: Compartment syndrome is a rare complication of IO access (0.6%) 1. Careful monitoring of the IO site is recommended. It is advisable to remove the IO needle once a definitive IV access is established. 1. Complication with Intraosseous Access: Scandinavian Users' Experience. Hallas et al. West J Emerg Med. 2013 Sep; 14(5): 440–443.

Excavating the Role of Aloe Vera Wrapped Mesoporous Hydroxyapatite Frame Ornamentation in Newly Architectured Polyurethane Scaffolds for Osteogenesis and Guided Bone Regeneration with Microbial Protection.

Guided bone regeneration (GBR) scaffolds are unsuccessful in many clinical applications due to a high incidence of postoperative infection. The objective of this work is to fabricate GBR with an anti-infective electrospun scaffold by ornamenting segmented polyurethane (SPU) with two-dimensional Aloe vera wrapped mesoporous hydroxyapatite (Al-mHA) nanorods. The antimicrobial characteristic of the scaffold has been retrieved from the prepared Al-mHA frame with high aspect ratio (∼14.2) via biosynthesis route using Aloe vera (Aloe barbadensis miller) extract. The Al-mHA frame was introduced into an unprecedented SPU matrix (solution polymerized) based on combinatorial soft segments of poly(ε-caprolactone) (PCL), poly(ethylene carbonate) (PEC), and poly(dimethylsiloxane) (PDMS), by an in situ technique followed by electrospinning to fabricate scaffolds. For comparison, pristine mHA nanorods are also ornamented into it. An enzymatic ring-opening polymerization technique was adapted to synthesize soft segment of (PCL-PEC-b-PDMS). Structure elucidation of the synthesized polymers is established by nuclear magnetic resonance spectroscopy. Sparingly, Al-mHA ornamented scaffolds exhibit tremendous improvement (175%) in the mechanical properties with promising antimicrobial activity against various human pathogens. After confirmation of high osteoconductivity, improved biodegradation, and excellent biocompatibility against osteoblast-like MG63 cells (in vitro), the scaffolds were implanted in rabbits as an animal model by subcutaneous and intraosseous (tibial) sites. Improved in vivo biocompatibilities, biodegradation, osteoconductivity, and the ability to provide an adequate biomimetic environment for biomineralization for GBR of the scaffolds (SPU and ornamented SPUs) have been found from the various histological sections. Early cartilage formation, endochondral ossification, and rapid bone healing at 4 weeks were found in the defects filled with Al-mHA ornamented scaffold compared to pristine SPU scaffold. Organ toxicity studies further confirm the absence of appreciable tissue architecture abnormalities in the renal hepatic and cardiac tissue sections. The entire results of this study manifest the feasibility of fabricating a mechanically adequate tailored nanofibrous SPU scaffold based on combinatorial soft segments of PCL, PEC, and PDMS by a biomimetic approach and the advantages of an Aloe vera wrapped mHA frame in promoting osteoblast phenotype progression with microbial protection for potential GBR applications.

On-Demand Guided Bone Regeneration with Microbial Protection of Ornamented SPU Scaffold with Bismuth-Doped Single Crystalline Hydroxyapatite: Augmentation and Cartilage Formation.

Guided bone regeneration (GBR) scaffolds are futile in many clinical applications due to infection problems. In this work, we fabricated GBR with an anti-infective scaffold by ornamenting 2D single crystalline bismuth-doped nanohydroxyapatite (Bi-nHA) rods onto segmented polyurethane (SPU). Bi-nHA with high aspect ratio was prepared without any templates. Subsequently, it was introduced into an unprecedented synthesized SPU matrix based on dual soft segments (PCL-b-PDMS) of poly(ε-caprolactone) (PCL) and poly(dimethylsiloxane) (PDMS), by an in situ technique followed by electrospinning to fabricate scaffolds. For comparison, undoped pristine nHA rods were also ornamented into it. The enzymatic ring-opening polymerization technique was adapted to synthesize soft segments of PCL-b-PDMS copolymers of SPU. Structure elucidation of the synthesized polymers is done by nuclear magnetic resonance spectroscopy. Sparingly, Bi-nHA ornamented scaffolds exhibit tremendous improvement (155%) in the mechanical properties with excellent antimicrobial activity against various human pathogens. After confirmation of high osteoconductivity, improved biodegradation, and excellent biocompatibility against osteoblast cells (in vitro), the scaffolds were implanted in rabbits by subcutaneous and intraosseous (tibial) sites. Various histological sections reveal the signatures of early cartilage formation, endochondral ossification, and rapid bone healing at 4 weeks of the critical defects filled with ornamented scaffold compared to SPU scaffold. This implies osteogenic potential and ability to provide an adequate biomimetic microenvironment for mineralization for GBR of the scaffolds. Organ toxicity studies further confirm that no tissue architecture abnormalities were observed in hepatic, cardiac, and renal tissue sections. This finding manifests the feasibility of fabricating a mechanically adequate nanofibrous SPU scaffold by a biomimetic strategy and the advantages of Bi-nHA ornamentation in promoting osteoblast phenotype progression with microbial protection (on-demand) for GBR applications.

A theoretical alternative intraosseous infusion site in severely hypovolemic children.

BackgroundStudies have shown that the venous system tends to collapse during hypovolemic shock. The use of the bone marrow space for infusions is an effective alternative, with the tibial insertion site being the norm.ObjectivesThis study was conducted to determine a quick intraosseous infusion method that could be an alternative to the tibial route in neonates during emergency situations.MethodA sample of 30 neonatal cadavers was dissected to explore a possible alternative to the tibial insertion site. The needle was inserted in the superolateral aspect of the humerus. The needle infusion site was then dissected to determine possible muscular and neurovascular damage that might occur during the administration of this procedure, with the greatest concern being the posterior circumflex humeral artery and axillary nerve exiting the quadrangular space. The distance of the needle insertion site was measured in relation to the soft tissue as well as to bony landmarks.ResultsThe calculated 95% confidence interval shows that the needle can be safely inserted into the intraosseous tissue at the greater tubercle of the humerus 9.5 mm – 11.1 mm from the acromion. This is about a little finger’s width from the acromioclavicular joint.ConclusionAnatomically, the described site is suggested to offer a safe alternative access point for emergency infusion in severely hypovolemic newborns and infants, without the risk of damage to any anatomical structures.

An Unusual Complication of Intraosseous Needle Use

Intraosseous (IO) needles are extremely useful tools to gain urgent access to the circulation when more conventional routes are unavailable or unsuccessful. As with any medical procedure, complications can occur. We review the indications for IO usage and illustrate an unusual complication of continued serous drainage following IO needle removal. The drainage was significant enough to require use of a drainage bag. This chronically ill patient developed septic shock, multi-system organ failure, renal failure and a high catabolic state. As he did not fully tolerate enteric tube feeds, it was not possible to maintain adequate serum albumin. The resultant lower colloid oncotic pressure contributed to the chronic serous leak from the IO site. Avoidance of such a complication relies on proper IO placement and the ability to maintain adequate nutrition to maintain plasma oncotic pressure. Other complications of IO use are reviewed. J Med Cases. 2015;6(2):98-100 doi: http://dx.doi.org/10.14740/jmc2080e

Relationships of intraosseous and systemic pressure waveforms in a Swine model.

Despite some focus on the use of intraosseous (IO) catheters to obtain laboratory samples, very little is known about the potential for obtaining other forms of clinical data. Largely unstudied is the relationship between IO pressures (IOPs) and systemic hemodynamic pressures such as mean arterial pressure (MAP) and central venous pressures (CVP). The objective was to explore the relationship between hemodynamic parameters (blood pressures) measured through an IO catheter and intravascular catheters placed in the arterial and central venous circulation. Eight pigs (Sus scrofa) weighing 30 to 45 kg were sedated with a short-acting agent, intubated with a cuffed endotracheal tube, and anesthetized with 2% to 3% isoflurane. Intravascular catheters were placed into the femoral or carotid artery and the femoral or jugular vein for MAP and CVP measurements. IO catheters, 15 mm for the sternum and 25 mm for the long bones, were placed percutaneously into the proximal tibia, proximal femur, proximal humerus, right proximal ulna, and/or sternum. Pressures were recorded during normotension, hypotension, and hypertension. Averaged across all eight animals, the means (ranges) for baseline systemic pressures were as follows: MAP = 66.5 (55.6 to 76.7) mm Hg, tibia IOP = 17.4 (9.3 to 34.5) mm Hg, femur IOP =18.4 (3.3 to 33.1) mm Hg, humerus IOP = 15.7 (2.8 to 28.9) mm Hg, ulna IOP = 16.0 (7.9 to 25.6) mm Hg, sternum IOP = 5.7 (-0.5 to 47.9) mm Hg, and CVP = 2.7 mm Hg (-3.3 to 7.9) mm Hg. The best median correlation occurred between femur IOP and mean MAP (r = 0.65). The four highest correlations between IOP and MAP were associated with mean femur IOP. Only one IO site had a correlation coefficient over 0.50 for CVP. The long bones tended to correlate better with the MAP and the sternum tended to correlate better with the CVP. Nonlinearity was observed in the actively rising pressure phases, which can be explained by a hysteresis model. The relationship between IOP and MAP or CVP is variable by site, with the MAP and CVP tending to be estimated by the femur and sternum, respectively. The relationship to actively rising pressures is nonlinear and a hysteresis model is proposed to explain the phase change. Further experimentation is needed to refine the IOP relationship to the MAP and CVP and assess the potential of these measurements to provide clinically relevant information.

Abstract 320: Decreasing Intraosseous Pressure and Increasing Respiratory Variability Track Fluid Volume Reduction in a Porcine Hypovolemia Model

Objectives: Central venous pressure (CVP) provides an invasive and imprecise but accepted method for estimating fluid volume status. Intraosseous (IO) pressure monitoring may provide an alternative to CVP. To investigate this possibility, we measured intraosseous pressure changes in a porcine model during a hemorrhagic shock protocol. Methods: Our preparation included placement of femoral artery and central venous pressure lines. IO access was obtained by standard technique (EZ-IO, Vidacare Corporation, San Antonio, TX) to monitor pressures in the femur, humerus and tibia. All pressure signals were transmitted to a data acquisition system (Dataq Instruments,Inc., Akron, OH). To create vascular fluid volume changes, 17% of each pig’s estimated total blood volume was bled every 10 minutes until physiologic signs of hemorrhagic shock were recorded (mean arterial pressure <50 mmHg; tachycardia >150/min). To estimate fluid volume status, we tracked changes in absolute arterial, venous and IO pressures. As increasing respiratory variability is an accepted indicator of developing hypovolemia, we evaluated pressure variability due to respiration in all pressures after each 10 minute bleed period using the following formula: Δsystolic pressure/pulse pressure. Results: A hypotensive state was achieved in all six animals after bleeding each animal to 66.1±11.7% (1706.57±210 ml) of their estimated baseline fluid volume. Arterial, CVP and all IO mean pressures decreased at a constant rate. The proportional decrease pre/post bleed (mmHg) was not statistically different among all pressures: arterial 78.5→ 34.0 (-57%), humerus 17.9 → 6.5 (-64%), femur 17.1 → 9.8 (-43%), tibia 14.8 → 8.4 (-43%), CVP 6.6→ -0.9. The respiratory variability ratio increased in arterial, CVP and IO pressures to a similar extent and rate from 0.2 to 0.8 as the hypovolemic state developed. Conclusions: IO pressure decreased consistently at each IO site in this hemorrhagic shock model, indicating IO pressures can be tracked as indicators of change in fluid volume status. Increasing variability in IO pressure during the respiratory cycle was also associated with decreasing vascular fluid volume. IO pressure appears to be equivalent to CVP as an indicator of fluid volume status.

253 Intraosseous Administration of CT Contrast in a Porcine Model: A Feasibility Study

Study Objectives: Obtaining rapid intravenous (IV) access is often difficult in patients who have sustained injuries due to major trauma. Intraosseous (IO) access is a safe and reliable alternative when peripheral IV access cannot be obtained quickly. For many trauma patients, contrast-enhanced computed tomography imaging is an important element of the initial diagnostic evaluation performed in the emergency department (ED). However, minimal information has been published regarding the injection of contrast material using IO access for the purpose of obtaining a contrast-enhanced computed tomography scan. This study was performed to evaluate IO administration of contrast material for a trauma-protocol computed tomography scan in an adult mini-swine model. Methods: Skeletally mature mini-swine were anesthetized and had peripheral IV and IO access established. IO access was obtained in the proximal humerus with fluoroscopic confirmation of correct needle placement. Each animal underwent contrast-enhanced trauma-protocol computed tomography scans using both routes of contrast administration. Contrast was administered using a MedRad® computerized power-injection system. computed tomography confirmation of contrast arterial phase wash-out between studies was established prior to administration of the second contrast injection. The order for route of administration (IV or IO) was randomized for each animal using block randomization. Images were evaluated for adequacy of vascular opacification by 2 board-certified radiologists. Results: All images obtained with both IV and IO contrast administration were judged to be adequately opacified to meet diagnostic criteria. One animal had partial extravasation of contrast after IO administration despite proper needle placement. Conclusion: In this swine model, injection of contrast material through a proximal humerus IO site resulted in adequate opacification of trauma-protocol computed tomography images in all animals. Our results suggest that intraosseous administration of contrast material may be a viable alternative in trauma patients when attempts at obtaining other vascular access are unsuccessful or would lead to unacceptable delays in diagnostic evaluation. Further study is warranted in human subjects to investigate the effectiveness of this methodology as well as the incidence and significance of contrast extravasation.

Analysis of intraosseous samples using point of care technology—An experimental study in the anaesthetised pig

BackgroundIntraosseous access is an essential method in emergency medicine when other forms of vascular access are unavailable and there is an urgent need for fluid or drug therapy. A number of publications have discussed the suitability of using intraosseous access for laboratory testing. We aimed to further evaluate this issue and to study the accuracy and precision of intraosseous measurements. MethodsFive healthy, anaesthetised pigs were instrumented with bilateral tibial intraosseous cannulae and an arterial catheter. Samples were collected hourly for 6h and analysed for blood gases, acid base status, haemoglobin and electrolytes using an I-Stat® point of care analyser. ResultsThere was no clinically relevant difference between results from left and right intraosseous sites. The variability of the intraosseous sample values, measured as the coefficient of variance (CV), was maximally 11%, and smaller than for the arterial sample values for all variables except SO2. For most variables, there seems to be some degree of systematic difference between intraosseous and arterial results. However, the direction of this difference seems to be predictable. ConclusionBased on our findings in this animal model, cartridge based point of care instruments appear suitable for the analysis of intraosseous samples. The agreement between intraosseous and arterial analysis seems to be good enough for the method to be clinically useful. The precision, quantified in terms of CV, is at least as good for intraosseous as for arterial analysis. There is no clinically important difference between samples from left and right tibia, indicating a good reproducibility.

Revascularization Process of the Bone–Patellar Tendon–Bone Autograft Evaluated by Contrast-Enhanced Magnetic Resonance Imaging 6 and 12 Months After Anterior Cruciate Ligament Reconstruction

Background: Contrast-enhanced magnetic resonance imaging (MRI) studies conducted on animal models have shown that the observed signal intensity changes are related to the degree of graft vascularity and its biomechanical properties. Purpose: To evaluate by contrast-enhanced MRI the revascularization process at 3 distinct sites discerned in relation to the surrounding microenvironment along the course of bone–patellar tendon–bone (BPTB) autograft in uncomplicated human anterior cruciate ligament (ACL)–reconstructed knees. Study Design: Case series; Level of evidence, 4. Methods: Thirty-two male patients were assessed with a 3-dimensional fast field echo/short tau inversion recovery (FFE/STIR) MRI sequence at the third postoperative day and at time intervals of 6 and 12 months after surgery. Signal-to-noise quotient (SNQ) was calculated for 3 specific graft sites (intra-articular site, intraosseous tibial tunnel site, and intraosseous juxta screw site) before and after gadolinium administration. Comparisons of the enhancement index (EI: SNQafter/SNQbefore gadolinium) were performed independently for each graft site and time interval. Results: Three days postoperatively, insufficient vascularization was noticed at the 3 sites. Six and 12 months after surgery, the enhancement index was significantly increased in all 3 sites (P < .001). The intra-articular site, 6 months postoperatively, achieved satisfactory contrast medium uptake (enhancement index >1), with significantly higher enhancement index values compared with the other 2 sites (P < .001). Twelve months after surgery, only the intraosseously enclosed sites displayed an increase of the enhancement index, although nonsignificant (P = .09 and P = .07, respectively). Conclusion: Revascularization of the graft occurs gradually along its length, with the intra-articular site being the first and the faster part to complete this phase, while both the intraosseous sites are still in progress throughout the first postoperative year. Revascularization is an important link at the intrinsic healing chain of the ACL graft. The surrounding microenvironment does seem to play a significant role in this process, and the differences in its composition along the graft course are reflected at the revascularization progress of the corresponding sites.

Resposta do tecido subcutâneo de camundongos à implantação de um novo biovidro à base de óxido de nióbio

O objetivo deste estudo foi avaliar a resposta biológica do tecido subcutâneo de camundongos à implantação de um novo biovidro à base de óxido de nióbio e óxido fosforoso. A morfologia do material foi analisada por microscopia eletrônica de varredura com espectroscopia de raios X por dispersão de energia (MEV/EDX) e a resposta tecidual foi avaliada após implantação de 30mg do biovidro no tecido subcutâneo da região dorsal de camundongos Balb/c (n=15), segundo ISO 10993-6. Após o período de 1, 3 e 9 semanas, os animais foram sacrificados e as necrópsias fixadas em formol tamponado pH 7,2 e submetidas ao processamento clássico para inclusão em parafina. Contudo, nenhum processo convencional de desmineralização de ossos e biomateriais cerâmicos foi capaz de desmineralizar o material. Alternativamente, o material obtido foi reprocessado e incluído em resina para corte em micrótomo de impacto. O estudo histopatológico considerou para análise: reação inflamatória (intensidade de células polimorfonucleares, mononucleares e células gigantes multinucledas das do tipo corpo estranho) e processo de reparo (tecido de granulação e fibrose). A análise do biomaterial no MEV/EDS demonstrou partículas irregulares com ampla variação dimensional e presença de nióbio, fósforo, cálcio, carbono e oxigênio. A análise histológica mostrou moderado infiltrado inflamatório composto de células mononucleares na semana 1, a qual desapareceu nos períodos subsequentes. Após 3 e 9 semanas, vasos sanguíneos foram observados com presença discreta de células gigantes multinucleadas tipo corpo estranho contendo partículas de biovidro de nióbio. Mesmo após 9 semanas, não se observou presença de cápsula fibrosa ao redor do material. Em nenhum momento, verificaram-se focos de necrose nem sinais de degradação das partículas. Baseado nestes resultados preliminares foi possível concluir que o material testado é biocompatível e não-bioabsorvível. A comparação deste biovidro contendo nióbio, especialmente implantado intra-ósseo, permitirá avaliar seu real potencial uso como enxerto ósseo.

Imaging the effects of castration on bone turnover and hormone‐independent prostate cancer colonization of bone

Tumor populations may selectively colonize bone that is being actively remodeled. In prostate cancer patients, androgen deprivation directly inhibits tumor growth initially, whilst induced bone loss may facilitate tumor colonization of bone by androgen-insensitive cells. We have tested this hypothesis using a xenograft model of early growth of prostate cancer in bone. PC3 cells transfected with Green fluorescent protein (GFP) were injected into castrated and non-castrated athymic mice via intrabial and intracardiac routes. In vivo tumor growth was monitored daily and animals sacrificed 6-9 days following initial GFP-based detection of tumors. Tumor bearing and contra-lateral non-tumor bearing tibias were analyzed extensively by micro-CT and histology/immunohistochemistry for the presence of tumor cells and the effects of tumor and/or castration on bone cells and bone structure evaluated. GFP-positive tumors in bone were visible from 12 days post-injection following intratibial injection, allowing tumors <1 mm diameter to be monitored in live animals. Castration did not affect tumor frequency, tumor volume, or time to initial appearance of tumors injected via intratibial or intracardiac routes. Castration decreased trabecular bone volume in all mice. Significant tumor-induced suppression of numbers of osteoblasts, coupled with increased numbers of activated osteoclasts, was evident in both intact animals and castrated animals. In vivo GFP imaging allows the detection of early tumor growth at intra-osseous sites. Castration induces bone loss, but PC3-GFP cells are also capable of inducing bone remodeling in intact animals at early time points, independently of pre-existing castration-induced alterations to bone.

Imaging of sacral tumours

All components of the sacrum (bone, cartilage, bone marrow, meninges, nerves, notochord remnants, etc.) can give rise to benign or malignant tumours. Bone metastases and intraosseous sites of haematological malignancies, lymphoma and multiple myeloma are the most frequent aetiologies, while primary bone tumours and meningeal or nerve tumours are less common. Some histological types have a predilection for the sacrum, especially chordoma and giant cell tumour. Clinical signs are usually minor, and sacral tumours are often discovered in the context of nerve root or pelvic organ compression. The roles of conventional radiology, CT and MRI are described and compared with the histological features of the main tumours. The impact of imaging on treatment decisions and follow-up is also reviewed.

Myeloid sarcoma: Case report with an unusual presentation in radicular cyst capsule

Myeloid sarcoma is a tumour mass of myeloblasts or immature myeloid cells occurring in an extra-medullary site or in a bone. The tumour may precede or occur concurrently with acute or chronic myeloid leukaemia or with other types of myeloproliferative disorders or myelodysplastic syndromes. Granulocytic sarcoma is a rare presentation in the oral and maxillofacial region, but has been reported in oral soft tissues as well as in intra-osseous sites. The majority of these cases occur in patients with known leukaemia or those who eventually develop the disease. Our report details the presentation of myeloid sarcoma in radicular cyst capsule, being also one of the unusual intra-osseous presentations of this rare tumour.

Acid-base status of blood from intraosseous and mixed venous sites during prolonged cardiopulmonary resuscitation and drug infusions.

a) To determine the relationship of acid-base balance (pH, PCO2) of blood samples from the intraosseous and the mixed venous route during prolonged cardiopulmonary resuscitation; b) to compare the effect of separate infusions of epinephrine, fluid boluses, or sodium bicarbonate through the intraosseous sites on the acid-base status of intraosseous and mixed venous blood during cardiopulmonary resuscitation; and c) to compare pH and Pco2 of intraosseous and mixed venous blood samples after sequential infusions of fluid, epinephrine, and sodium bicarbonate through a single intraosseous site. Prospective, randomized study. Animal laboratory at a university center. Thirty-two mixed-breed piglets (mean weight, 30 kg). Piglets were anesthetized and prepared for blood sampling and cardiopulmonary resuscitation. After anoxic cardiac arrest, ventilation was resumed and chest compression was resumed. Blood gas samples from the pulmonary artery and both intraosseous sites were obtained simultaneously at baseline, at cardiac arrest, and at 5, 10, 15, 20, and 30 mins of cardiopulmonary resuscitation for group 1 (control group) and after drug (epinephrine and sodium bicarbonate) and saline infusions via one of the intraosseous cannulas in groups 2 through 5. We found no differences between intraosseous and mixed venous pH and Pco2 during periods of <15 mins of cardiopulmonary resuscitation. However, this relationship was not maintained during prolonged cardiopulmonary resuscitation and after bicarbonate infusion. After large volume saline infusion, the pH and Pco2 of mixed venous and intraosseous blood were similar. During epinephrine infusion, the relationship between intraosseous and mixed venous pH and Pco2 was similar to that found in the control group. The intraosseous blood sample could be used to assess central acid-base balance in the early stage of arrest and cardiopulmonary resuscitation of <15 mins. However, during cardiopulmonary resuscitation of longer duration, drug infusions may render the intraosseous site inappropriate for judging central acidosis.