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BACKGROUND:There is currently no anatomic locking plate suitable for the anteromedial platform,so the medial locking plate of the tibial plateau is usually placed forward to fix anteromedial compression fractures caused by hyperextension varus injury.Due to the inability of the locking screw to achieve vertical fixation of the fracture line,coupled with the influence of the patellar ligament,the clinical results are still unsatisfactory. OBJECTIVE:To compare the biomechanical performance of a new type of plate with traditional internal fixation methods in treating hyperextension varus tibial plateau fractures through finite element analysis. METHODS:CT data of 20 cases of hyperextension varus tibial plateau fractures were collected,and their morphological characteristics,such as medial posterior tibial slope,the medial articular fracture angle,surface area,and anterior cortical height were measured.A 24-year-old male volunteer with a height of 175 cm and a weight of 65 kg was selected,and his tibial CT data were imported into Mimics 21.0 software to generate a 3D model.Then,internal fixation models were imported into SolidWorks 2017 software.New type of plate,medial locking plate,posterior medial locking plate,and 6.5 mm hollow screws fixed data models were established based on the measured morphological data.Ansys 17.0 software was used to load stress on the four fixation models and compare their biomechanical performance. RESULTS AND CONCLUSION:(1)With the increase of axial load,the peak stresses of different internal fixation models approximately increased proportionally.At 500 N,the peak stress values were as follows:screw group(6.973 7 MPa)<new steel plate group(14.733 MPa)<medial locking plate group(16.445 MPa)<posterior medial locking plate group(25.199 MPa).(2)The peak stresses of the fracture block were as follows:at 500 N,screw group(3.657 9 MPa)<new steel plate group(4.510 8 MPa)<medial locking plate group(5.225 9 MPa)<posterior medial locking plate group(6.181 2 MPa).(3)With the increase of axial load,the displacement of the fracture block and internal fixation approximately increased proportionally,and the displacement distribution characteristics showed no significant changes.At 500 N,the steel plate displacement values were as follows:new steel plate group(1.030 7 mm)<medial locking plate group(1.503 mm)<screw group(2.096 5 mm)<posterior medial locking plate group(2.258 2 mm).At 500 N,the fracture block displacement values were as follows:new steel plate group(0.212 8 mm)<medial locking plate group(0.311 54 mm)<screw group(0.427 79 mm)<posterior medial locking plate group(0.454 98 mm).(4)It is concluded that in the treatment of hyperextension varus tibial plateau fractures,the stability and mechanics of the new steel plate are superior to traditional internal fixation methods.
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Objective: To summarize the progress in the treatment of hyperextension tibial plateau fractures.
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Objective To analyse the therapeutic effect of methylprednisolone combined with anterior decompression and internal fixation in the treatment of cervical spine hyperextension injury. Methods 42 patients who were diagnosed with cervical hyperextension injury in orthopaedics department of the First Hospital of Jiaxing were collected.All patients were randomly divided into experimental group and control group, 21 cases in each group.Patients in control group received anterior cervical decompression and internal fixation only , patients in experimental group received methylprednisolone combined with anterior decompression and internal fixation, after treatment, the serum levels of TNF-α, SOD and American Spinal Injury Association (ASIA) score were detected in all patients.Results After treatment, compared with control group, the serum levels of TNF-αwas lower, SOD was higher and ASIA score was higher in experimental group, and the differences were statistically significant (P<0.05).Conclusion The methylprednisolone combined with anterior decompression and internal fixation could significantly reduce the serum level of TNF-α, and increase the serum level of SOD and ASIA score in patients with cervical spine hyperextension injury, could reduce the inflammatory damage, improve the antioxidant capacity, which has a good clinical effect.
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The extension type locked metacarpophalangeal joint of the little finger is an extremely rare condition characterized by loss of flexion with little or no loss of extension. The most common cause for locking is entrapment of a strap of the ruptured palmar plate. We treated a locked metacarpophalangeal joint of the little finger due to a hyperextension injury. The mechanism of locking was a torn part of the palmar ligament that forcefully rides across the prominence of the radial condyle of the metacarpal bone together with the accessory collateral ligament. These dislocated parts of the ligament formed a constricting bundle that prevented closed reduction. Locking was released successfully by an open reduction using the dorsal approach of the metacarpophalangeal joint without complication.
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Collateral Ligaments , Fingers , Ligaments , Metacarpophalangeal Joint , Palmar PlateABSTRACT
Objective To discuss the degenerative factors, the spinal segment distribution, and the mechanism in hyperextension injury of cervical spine. Method Eighty-nine patients with hyperextension injury of cervical spine were retrospectively analyzed by observing the degenerativelesion, the spinal cord segment with high signal in T2WI, and the location of facial trauma. Results Fifty-eight cases showed the disc hemiation which was the most common lesion, followed by 8 cases showing the calcification of the posterior longitudinal ligament. Besides, 7 cases presented the developmental stenosis of spinal canal, and also, 6 cases showed disc hemiation combined with the yellow ligament hypertrophy. The intervertebral level of the spinal cord with high signal in T2WI were distributed as follows:4 cases were at C2/3, of which onesuffered the forehead trauma; 12 cases were at C3/ 4, of which 10 had the forehead trauma, and one had the zygomatic trauma; 12 cases were at C4/5, of which 5 had the forehead trauma, one had both the zygomatic and the forehead trauma, and one had both the forehead and with the lower jaw trauma; 11 cases were at CS/6,of which 3 had the forehead trauma, 3 had the zygomatic trauma, and 2 had the lower jaw trauma. The location of the spinal cord with single high signal in T2WI did not correspond with the intervertebral disc level in 4 cases. For 10 cases the high signal in T2WI was found at two discontinuous segments. For 2 cases the 1 high signal in T2WI was found at over two segments. For 6 cases the high signal in T2WI was found at over three segments. Conclusions Disc hemiation is the most common underlyding factor in cervical hyperextension injury. The spinal level with high signal in T2WI was correlative to the impacted facial site. The shear force at the inflection point with or without the anterior-posterior compression force accounted for the cervical hyperextension injury.
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[Objective]To investigate imaginological evidences of hyperxtensive injury of cervical spine and to evaluate its use in clinics.[Method]Seventy-eight patients with hyperextension injury at cervical spine by different cause were estimated by radiograph、CT and MRI.Fifty-seven cases(73.1%) appeared with widen of soft tissue of anteriorspine,including focal type(17.5%) and diffused type(82.5%). Thirty-six cases showed avulsion fracture of anterior edge in the cervical spine. Sixty-three cases showed degeneration and developmental spinal stenosis,twenty-one cases appeared integral vertebral canal. No contrast CT scan showed osteophyte of thirty-seven cases and intervertebral discs degeneration and protrusion of twenty-one cases.Sixty-one cases(78.2%) with both disc and anterior-longitudinal-ligament injury showed by MRI,fifty-seven cases showed haematoma and oedema at the anterior of the vertebral body. Sixty-four cases accompanied with different spinal cord injury.[Result]Obvious imaging feature for hyperextension injury of cervical spine,including anterior longitudinal ligament,intervertebral disc and spinal cord were found.There exists good relationship between spinal cord injury and imaging appearance. Clinically it showed typical central syndrome,but mostly showed us neuron-functional disturbance of different degree.[Conclusion]Combining of imaginological apperarance including radiograph,CT,MRI can provide evidences for diagnosis of hyperextension and help to treat acute hyperextension cervical injury.
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Objective To explore rational operative methods to treat hyperextension injuries of cervical spine. Methods 47 cases of hyperextension injury of cervical spine were treated in our department from September, 2000 to October, 2004. They were followed up and analyzed retrospectively. According to the operative methods, there were 3 groups: anterior approach, posterior approach, combined approach. Their therapeutic effects were compared respectively. Results After follow- ups for 6 to 12 months, preoperative and postoperative Frankel classifications and ASIA (American Spinal Injury Association) grades were compared between the 3 groups. It was found that neural function improved significantly in the 3 groups after operation. The anterior approach and combined approach groups had significantly better outcome in neural function than the posterior approach group ( P0.05) . Conclusions Anterior decompression- graft- internal fixation is the preferred consideration to treat hyperextension injury of cervical spine, and the posterior approach is only the secondary choice. The combined approach should be carefully selected under appropriate conditions
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The authors analized the 98 cases of cervical spine injuries without fracture or dislocation by hyperflexion/hyperextension of the neck. The peak incidence of the age was in the second to fourth decades(69.4%). There was a male preponderance with a sex ratio of. 1.8 : 1. Sources of trauma were motor vehicle accident, object falling on and motorcycle accident in the order of frequency. The common mechanisms of injury were flexion-extension, extension and flexion injury in the order of frequency. There were 10 cases of cervical cord injury without fracture or dislocation and operative management was given in 6 cases of them. The most common preexisting disease was congenital cervical stenosis. Surgical modality such as laminectomy, laminoplasty and anterior decompressive procedure made them improved. The authors discuss the mechanism of injury and surgical management of the patients with cervical cord injury in the absence of concomittent fracture or dislocation.