First aid and treatment for cervical spinal cord injury with fracture and dislocation

<b>Background: </b> Traumatic cervical spinal cord injury with subaxial fracture and dislocation not only indicates a highly unstable spine but can also induce life-threatening complications. This makes first aid critically important before any definitive operative procedure is undertaken. The present study analyzes the various first aid measures and operative procedures for such injury. <b> Materials and Methods: </b> Two hundred and ninety-five patients suffered from cervical spinal cord injury with fracture and dislocation. The average period between injury and admission was 4.5 days (range 5 h-12 weeks). The injury includes burst fractures (<i> n </i> = 90), compression fractures with herniated discs (<i> n</i> = 50), fractures and dislocation (<i> n</i> = 88) and pure dislocation (<i> n</i> = 36). Other injuries including developmental spinal canal stenosis and/or multi-segment spinal cord compression associated with trauma (<i> n</i> = 12), lamina fractures compressing the spinal cord (<i> n</i> = 6), ligament injuries (<i> n</i> = 7) and hematoma (<i> n</i> = 6) were observed in the present study. The injury level was C4 (<i> n</i> = 17), C5 (<i> n</i> = 29), C6 (<i> n</i> = 39), C7 (<i> n</i> = 35), C4-5 (<i> n</i> = 38), C5-6 (<i> n</i> = 58), C6-7 (<i> n</i> = 49), C4-6 (<i> n</i> = 16) and C5-7 (<i> n</i> = 14). According to the Frankel grading system, grade A was observed in 20 cases, grade B in 91, grade C in 124 and grade D in 60. One hundred and eighteen (40&#x0025;) patients had a high fever and difficulty in breathing on presentation. First aid measures included early reduction and immobilization of the injured cervical spine, controlling the temperature, breathing support,and administration of high-dose methylprednisolone within eight hours of the injury (<i> n</i> = 12) and administration of dehydration and neurotrophy medicine. Oxygen support was given and tracheotomy was performed for patients with serious difficulty in breathing. Measures were taken to prevent bedsores and infections of the respiratory and urological systems. Two hundred and thirty six patients were treated with anterior decompression, 31 patients were treated by posterior approach surgery and combined anterior and posterior approach surgery was performed in a single sitting on 28 patients. <b> Results: </b> All patients were followed for 0.5-18 years (mean 11.8 years). At least one Frankel grade improvement was observed in 178 (60.3&#x0025;) patients. In the anterior surgery group, the best results were observed in the cases with slight compressive fracture with disc herniation (44/50 patients, 88.0&#x0025;). In the posterior surgery group, one Frankel grade improvement was observed in the cases with developmental spinal canal stenosis with trauma, lamina fractures, ligament injuries and hematoma (27/31, 87.1&#x0025;). Most of the patients in the Frankel D group recovered normal neurological function after surgery. The majority of the patients with Frankel C neurological deficit (102/124) had the ability to walk postoperatively, while most of the seriously injured patients (Frankel A and B) had no improvement in their neurological function. Radiolographic fusion of the operated segments occurred in most patients within three months. Loss of intervertebral height and cervical physiological curvature was observed to varying degrees in 30.1&#x0025; (71/236) of the cases in the anterior surgery group. <b> Conclusion:</b> First aid measures of early closed reduction or realignment and immobilization of the cervical spine, breathing support and high-dose methylprednisolone were most important in the treatment for traumatic spinal cord injury. Surgery should be performed as soon as the indications of spinal injury appear. The choice of the approach-anterior, posterior or both, should be based on the type of the injury and the surgeon&#x2032;s experience. Any complications should be actively prevented and treated

Effect of natural carbonation on chloride binding behaviours in OPC paste investigated by a thermodynamic model

The combined effects of carbonation and chloride attack can accelerate the degradation of reinforced concrete (RC) structures. In this study, the effect of natural carbonation on the chloride binding behaviours in Ordinary Portland cement (OPC) paste was investigated. The phase-equilibrium model for the dissolution/precipitation reactions and the surface complexation model for the ionic adsorption of C–S–H were adopted. An experiment from the literature was used as the benchmark. The results indicate that Kuzel's salt is produced when OPC paste is exposed to a mild chloride attack. During the natural carbonation process, Kuzel's salt is converted into Friedel's salt. As the carbonation continues, the Friedel's salt disappears. Complete natural carbonation results in a total loss of chemical binding capacity, and only a partial loss of the physical binding capacity in cement-based materials. This completely differs from the accelerated carbonation commonly used in the laboratory, which can cause complete loss of both chemical and physical binding capacity. Therefore, the durability design of RC structures vulnerable to the combined attack of chloride and carbonation based on the results of the accelerated carbonation is conservative.Materials and Environmen

Impressed current cathodic protection of chloride-contaminated RC structures with cracking: A numerical study

Impressed current cathodic protection (ICCP) is an effective and direct method for controlling the corrosion of reinforced concrete (RC) structures. However, few investigations related to ICCP in cracked RC structures have been reported. In this study, the effect of cracks in concrete cover on ICCP of chloride-contaminated RC structures was investigated through a numerical model including steel polarisation, electrode reactions, and ionic migration. In the developed numerical model, cracked concrete cover is assumed to consist of sound concrete and cracks, and cracks have their own ionic diffusion coefficients. The results indicate that the ICCP can maintain its ability to remove Cl− if concrete cover does not completely crack. Once the complete cracking in concrete cover occurs, the Cl− removal ability of ICCP would decrease or even disappear. Cracking does not cause any adverse effect on the pH improvement of ICCP. In this case, a stronger cathodic polarisation is recommended.Materials and Environmen