| Pronation-Abduction Ⅲ degree ankle fracture is an unstable intra-articular fracture that requires surgery to restore ankle function.Precise anatomical reduction of the fracture block maximizes the function of the ankle joint.The occurrence of ankle arthritis is associated with poor articular surface reduction.The poor recovery of ankle joint function will greatly affect the quality of life of patients.ORIF is one of the main treatment methods for pronation-abduction Ⅲ-degree ankle fracture,but it is not suitable for internal fixation for open,comminuted and soft-tissue ankle fractures.Open reduction further aggravates the skin and other soft tissue damage,fracture anatomy reduction in terms of external fixation,although less than the internal fixation,but the external fixation of the soft tissue well protected,postoperative ankle function score has an advantage.The external fixator has the advantages of simple operation,low cost,satisfactory recovery of ankle function and no need for secondary surgery in the treatment of pronation-abduction Ⅲ-degree ankle fracture.However,there is a lack of external fixator in the treatment of pronation-abduction Ⅲ basic experimental study of ankle fractures.For this purpose,we will complete the design of partial external fixation of the anterior and external third-degree ankle fractures.The three-dimensional finite-angle pronation-abduction type Ⅲ ankle fractures that have been established in the early stage of the study group Based on the meta-model,the finite element analysis method was used to analyze the mechanics of the local transfixation external fixation method.Then the cadaver specimen experiment was used to verify the partial transfixation external fixation method,and the basic experimental study of the external fixation method was perfected.1.Pronation-Ⅲ of abduction ankle fracture partially pinning and external fixation design1.1.PurposeTo design a method for external fixation of a fixed pronation-ablation lateral ankle fracture.1.2.Object and Methodmaterial:Combined rod type external fixator;Software:Solidworks2016.method:Inner ridge to 2 φ2.0mm olive thread pin parallel fixed.Insert a φ3.0mm Kirschner into the iliac bone to fix the axis of the patella from the tip of the lateral malleolus.A(p2.5 mm olive needle was inserted through the patella from the lateral malleolus at the distal humerus of the 2-3 cm section of the joint,and the lower jaw was fixed.The external fixation was installed after the perspective reduction was satisfactory.A φ4.5mm thread half-pin is fixed at a radius of 15-20° from the posterior to the anterior to the tibial axis at a point 5-7cm from the distal tibial articular surface of the tibia to strengthen the stability of the external frame.1.3.ResultsA method of external fixation with a fixed pronation-abduction lateral ankle joint fracture was designed.1.4.ConclusionsThe fixation method achieves local needle insertion,fine needle fixation,and non-trans-articular external fixation in the treatment of pronation-abduction III degree ankle fractures and provides an important reference for the external fixation of intra-articular and peri-articular fractures.2.Finite Element Analysis of External Puncturing Techniques for pronation-abduction III degree ankle fractures2.1.PurposeA three-dimensional finite element model was established to visualize the"complete" pre-and-outside third-degree fractures of the sacroiliac joint through external fixation of the ankle and external fixation of the prosthetic-abduction degree III ankle fracture.2.2.0bject and MethodBased on the "complete" three-dimensional finite element model of the anterior and abduction Ⅲ-degree ankle fractures of the bones already completed in the early stage of the study group,use Kirschner wire and external fixator to reset the fracture end according to the reverse displacement mechanism.Through finite element analysis of local needles outside the solid method.2.3.Results(1)The complete pre-pronation-abduction Ⅲ-degree finite element model of ankle fracture was established.(2)The finite element method was used to analyze the method of external fixation of the needle through the needle.It was found that the fixation method can achieve a good reduction and fixation of the fractured end.2.4.ConclusionsAfter finite element analysis,the local needle-to-needle external fixation method can achieve a good reduction and fixation of the anterior-abduction degree III ankle fracture.3.Experimental study on cadaveric specimens with external fixation3.1.Study on the effect of the new external fixation in the reduction of ankle joint fracture in Pronation-abduction Ⅲ degree3.1.1.PurposeTo verify the effect of external fixation with partial needles on the reduction effect of pronation-abduction Ⅲ degree ankle fractures.3.1.2.Object and MethodA typical pronation-abduction Ⅲ-degree ankle fracture Pronation-abduction tients X-ray measurements of fracture line height and shape,through the closed osteotomy bones made full bones of the Pronation-abduction Ⅲ degree fracture body model.The fracture model was divided into two groups using the crossover interchange principle.One group was fixed with a new external fixation scheme(experimental group),one group was fixed with an internal fixation scheme(control group),and immediately after the fixation was fixed,specimens were taken to record the reduction effect.Fracture reduction was evaluated according to the Buewell-Charnley Fracture Radiological Assessment Criteria.3.1.3.ResultsIn the aspect of excellent and good rate,the excellent external fixation group was 3,good10and poorl,the excellent and good rate was 92.9%;the internal fixation group was 4,good 10 and poor0,the excellent and good rate was 100%.In the experimental group,the lateral malleolus displacement was2.41±1.57mm,the medial malleolus displacement was2.80±1.46mm,the medial malleolus s Pronation-abduction ce was 4.07 ± 1.32mm,the talus tilt was1.57±2.95mm and the talus shift was2.12±1.34mm.Ankle displacement2.0±1.33mm.In the control group,the lateral malleolus displacement was 1.59±1.01 mm,the medial malleolus displacement was2.37±1.90mm the medial malleolus s Pronation-abduction ce was4.59±1.85mm,the talus tilt was2.50±4.54mm,the talus displacement wasl.89±0.787mm,the lateral radiographs was 1.8 8 ± 1.11 mm.Statistic results lateral shift:P>0.05,internal shift P>0.05,intemal space P>0.05,talus tilt P>0.05,talus shift P>0.05,posterior temporal shift P>0.05.3.1.4.ConclusionsIn pronation-abduction III degree ankle fracture reduction effect,the partialneedle external fixation method has a reset effect equivalent to the internal fixation.3.2.Experimental Study on Rotational Stability of Partially Inserted Needle External Solid Method3.2.1.PurposeTo study the rotational stability of the fixation of the pronation-abduction III degree ankle fracture after internal and external fixation of fracture end fracture resistance violence experiment to better guide the external fixation of ankle fracture.After the functional exercise.3.2.2.Object and MethodWith a multidimensional mechanical measuring instrument and a specimen fixed platform,10Nm,15Nm,and20Nm torques were applied to the ankle joint specimens after internal and external fixation.The relevant mechanical Pronation-abduction rameters were recorded by the sensor,and immediately after the corresponding torsional loading,the ankle joint was taken laterally and the X-ray film was taken.The lateral malleolus,medial malleolus,the shift of talus and other conditions were assessed by Buewell-Charnley radiographic evaluation criteria.The data were analyzed using statistical methods.3.2.3.ResultsWhen 10N M torsional force was applied to internal and external fixed sputum specimens,there was no statistical difference in the displacement index between the two fractures(P>0.05),suggesting that the anti-rotation ability of the two was com Pronation-abduction rable.When the torque ofl5NM was applied to the ankle with internal and external fixation,the size of the medial malleolus was statistically significant(P<0.05),which indicated that the external fixator had better stability.The other indexes were not statistically significant and the stability was com Pronation-abduction rable.20N M torque on the internal and external fixation of ankle specimens,the size of the medial malleolus shift was statistically significant(P<0.05),suggesting that the external fixator has better stability,the remaining indicators were not statistically significant,the stability is quite.3.2.4.ConclusionsThe method of local needle transfixation relying on the overall space structure of the external fixator has better anti-rotational force,suggesting that the local transfix needle external fixation method has better postoperative stability.4.Study ConclusionsThe method of local needle transfixation achieved localized transfixion,fine needle fixation,and non-trans-articular external fixation for pronation-abduction type III degree ankle fractures.After finite element analysis and cadaveric specimen experimental verification,the reduction of the pronation-abduction degree III ankle fracture using a partial needle external fixation method has a reduction effect comparable to that of internal fixation,and the partial needle external fixation method shows better Anti-rotation ability,better postoperative stability. |
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