| BackgroundAccording to the types and the energy of violence, with or without rotation factors, as a common cervical spine injury in clinical,the dislocation of lower cervical spine (which is often refer to3-7cervical spine) can result in the total dislocation or semidislocation of cervical facet joints with unilateral or bilateral as well as the fracture of vertebral body, vertebral lamina, and spinous process; at the same time,it is often accompanied by different severity of spinal cord injury,and even life-threatening. Therefore early diagnosis and treatment,to shorten the time of compression of spinal cord and restoring the effective volume of the spinal canal are very important to create favorable conditions for the recovery of nerve function. Yet traction is an important means for relieving the compression of spinal cord, and most scholars believe that axial skull traction is the most simple, effective, safe and reliable device.From traction bow of Crutchfield to Gardner-wells,and scholars have improved or designed many new tools later such as modified Gardner-wells traction, bi-directional traction bed, Odebode-Agaja traction bow and so on. It is said that the skull traction is still an indispensable clinical means in the treatment of dislocation and fracture of lower cervical spine. It is also said that the skull traction is fast and efficient, cheap and easy. Whether the conservative treatment after unsuccessful closed reduction or the surgery after a failure of closed reduction,the skull traction is still plays an indispensable role in the treatment of dislocation and fracture of lower cervical spine, it’s worthwhile for us to continue to promote or improve.However, when the dislocation with interlocking,the traditional method is more or less disappointment. Now the traditional traction method is that the initial weight is4kg,and X-ray is executed per30min, if that failed,the2kg weight traction is increased and so on.If the weight is added to18kg or time over24hours not yet reset, a surgical reduction is required. This method is have so a lower success rate and need more time to consumed,many patients during the time for waiting a surgery result in death due to edema of spinal cord. Although the literature about the report of the large weight of skull traction combined with a variety of surgical procedures are many,but only the big hospital that have the advanced equipment,rich experience and technology of diagnosis and treatment can do it well,because it need electrophysiological equipment to monitor and also need an experienced doctor to judge the potential of neurological signs.If the traction is failed, the remedial measures can carry out by them.But the basic level hospitals can accept the most patients more easily, what have happened is that the condition of patients are increased or delayed,a waste of medical resources, increase the economic burden of patients, or even some of this avoidable tragedy because of the blind or inappropriate treatment for dislocation and fracture of lower cervical spine.To this end, our hospital developed an instant, safe and effective reduction tools, its prominent feature is stepless weight increased,fixed-length traction and adjustable three-dimensional angle. Before its clinical application, the theoretical research is followed bellow.First, we select the goats as experimental subjects, as compared with the other animals, the anatomy, biomechanics, and other aspects of goat cervical spine are similar to human cervical. As previous studies confirmed that the goat in flexion and extension, lateral bending and other biomechanical properties are similar to human and traction dependent on the the change of length and dynamics of goat cervical spine, so we made a research about the stretch ability of goat cervical spine.To confirme the existence of elastic creep and to prove the the variance of creep time and length in the state of normal and dislocation creep, the goat traction model is made. Third, the retrospective analysis was performed in our hospital which using a large weight traction combined with surgery in the treatment of cervical dislocation with fracture, indicating that the feasibility of traction with large weight,but it is no doubt that the success rate is low because of the fear of excessive traction. Fourth, in view of the feasible of instant and large weight and the fear of excessive traction, we developed such a new device that can increase in weight rapidly and prevent excessive traction and short-term follow-up confirmed in the preliminary clinical application of appropriate cases. Certainly it need to accumulation of a large sample of cases and long follow-up, and also need to further improvement of this device in clinical applications. Now the above research will be described below in detail.[Objective] To compare the tensile properties difference between goat and human cervical spines.[Method] Fourteen muscular and ligamentous C１-T１segments of adult male goats were obtained, in which4specimens was excarnated (Group A),12specimens still retain muscular and ligamentous (Group B) and8specimens were sectioned into a total of24functional spinal unit (a specimen can be sectioned for3units such as C1-3, C4-5and C6-7),then all the segments and units were conducted to a series of non-destructive progressive testing followed by tensile distraction tensile forceing to failure using a mini-Bionix MTS machine, and the recorded data of mean of maximum tensile force, maximum displacement and stiffness of cervical segments and maximum tensile force,of units was compared with the human cervical spine from reported literature whether the statistical difference were significant. At last the maximum tensile force-maximum displacement scatter diagram for cervical spine segment and the maximum tensile force-individual step scatter plot for functional spinal unit (FSU) was made respectively.[Results] Group A which compared to the Yoganandan etc’research that just retained ligament,there was no significant difference (P>0.05) in the mean of maximum tensile force, maximum displacement and stiffness. Compared to the Yliniemi etc’ research,group B had a significant difference (P>0.05) with respect to the maximum tensile force and maximum displacement, but the stiffness of both have significantly different (P<0.05). Goat FSU C4-5, compared with human research, the maximum tensile force was demonstrated to be no significant difference (P>0.05). From the the maximum tensile force-maximum displacement scatter diagram and the statistical analysis result from the table,it may be concluded that the resistance capacity fortension and deformation in human neck musle by comparison with goat neck musle and musle in contrast to ligament all was displayed more stronger.Compared with goat FSU,the maximum tensile force of human FSU which was illustrated by the he maximum tensile force-individual step scatter plot and the statistical analysis result from the table showed a discrete distribution and more larger fluctuation range.[Conclusion] The similarity may existence in the goat Cl-Tl segment and FSU C4-5compared to human cervical spine with respect to the maximum tensile force,at the same time, as far as the tensile properties,the individual differences of goat is not larger.Is is no doubt that it can be used as the corresponding segments of the human cervical spine biomechanical tensile test, but it must consider the difference of the resistance capacity for tension and deformation in human and goat cervical spine.[Objective] To establish the goat cervical spine creep model under normal and dislocation state and to compare the creep difference of two groups.[Methods] Sixteen healthy adult goats regardless of paroecious were randomly divided into the normal group and the dislocated group, immobilization of goats with a special traction device fixed, In1hour time relative axial displacement was recorded per30seconds in each group at5kg,10kg,15kg,20kg,25kg and30kg traction weight respectively, and then the relation curve of the weight,time,displacement was made. Finally, the comparison of displacement of two groups under the different tacation weight within and among groups was estimated with or without statistical significance.[Results] Within1hour in the statistics, with the weight increase and the passage of time,both the normal group and the dislocation group of rapid elastic creep of the time range was7min～28min and3min～13min respectly, followed by a slow creep, but the dislocation group had a long duration and eventually both groups ended in the elastic relaxation. The strain amplitude and relative strain amplitude (net increase of displacement) of two groups have significantly different (P<0.05), but at the traction weight of15kg, the strain amplitude of two groups had no significant difference (P>0.05).In the sate of dislocation,the great traction weight(15kg,25kg,30kg) displayed a faster creep rate and a larger relatively strain amplitude than small traction weight (5kg,10kg,15kg).Under sustained traction of different weights, the relative strain amplitude of normal group was progressively decreased, while the dislocation group was decreased first,then increased and lastly decreased.[Conclusion] An effective and reliable goat cervical spine creep model can be obtained from this traction device.Compared with the normal group, the dislocation group of goat cervical spine can be observed an more higher creep deformation,but it is more vulnerable to get a excessive traction.[Objective] To investigate the clinical effectiveness and feasibility of anterior approach in patients who had obtained successfhl high weight close reduction with skull traction and one-stage posterior-anterior approach in those who failed in closed reduction in the treatment of subaxial cervical fracture-dislocation with locked-facet.[Methods] From Jan.2000to Mar.2010,retrospective analysis was done on68cases of lower cervical fracture-dislocation with locked facet who were managed in our institution.Closed reduction was attempted in all patients using high weight Gardner-wells traction.If reduction was accomplished successfully,only anterior cervical fixation was performed(groupA).If reduction failed,one-stage posterior-anterior approach was performed (group B).[Results] Thirty seven patients were included in Group A and31patients in Group B.Success rate of closed reduction in all paitients, in patients with bilateral cervical locked facets and in patients with unilateral cervical locked facets was54.41percent,75.61percent and22.22percent respectively.These were statistically different between bilateral and unilateral group(P<0.05).No patient’s condition with spinal cord injury were aggravated after operation, Recovery of neurological function of five patients with complete spinal cord inury(SCI) was not improved at all.The average American Spinal Cord Injury Association (ASIA) neurological function scale improved1-2levels.The average score of ASIA sense and motor,Japanese Orthopaedics Association(JOA) were apparently improved respectively at final follow-up. There was no statistical difference between group A and group B in the recovery rate(p<0.05).All paitents were taken X-ray films disconnectedly at5days,and1,3,6,9,12mon after operation which displayed that these measurements of kyphosis (Cobb angle),vertebral body translation,vertebral body height and interbody fusion were mostly normal and no looseness or breakage was found in the fixation system for all but three patients developed prolapse of plate and screw.[Conclusion] Our study demonstrated that for reduction of bilateral cervical locked facets dislocation by high weight skull traction is more effective in comparison with unilateral cervical locked facet dislocation.Reasonably ASIA sensor score was increased after traction but motor score is of no avail. Anterior cervical fixation with successful reduction,compared to posterior-anterior approach with failed reduction, can reduce spinal cord injury and significantly improved the surgical results. All active and reasonable surgical strategy according to different severity of injury can get a practical and effective clinical results for subaxial cervical fracture-dislocation with locked facet.[Objective] To develop a new instant reduction device for lower cervical fracture-dislocation and report on its clinical effects.[Method] Forty seven cases of cervical fracture-dislocation were received. the treatment by a new type of cervical traction and reduction apparatus which is developed by the compositon of skull traction tong, slider, spring, ratchet wheel, bracket, rail and baseplate.After reduction then a flexible and reasonable operative approache should be adopted to treat fracture and dislocation of cervical spine according to the patient’s condition, and its follow-up was performed for observation of treatment effects.[Results] This new skull traction device can increase weight instantly, predetermined length and traction angle adjustable.47patients were all successful reducted, no case of nerve injury was aggravated, without a traction fixed screw loosed or prolapsed was found. The average traction weight,time and angle was25.6kg(10kg-60kg),8min(3～10min) and3.5degrees (5～35degrees),respectively. The follow-up lasted for average38mon(3～48mon) and all case got a satisfactory outcome of follow-up.[Conclusion] The new traction device for lower cervical fracture-dislocation have the characteristics of simple,practical, safe and efficient and have great clinical applications. |
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