| With the rapid development of China's economy and the aging of the population,the transportation and construction accidents even the athletic injuries,all of those can cause the distal radius fractures by high energy damage,which is becoming more and more common?Distal radius fracture is one of the most common types of bone fracture in orthopaedic and emergency department.Usually it refers to the radius fracture of 3 cm next to radiocarpal joint,which occurs easily in older population with osteoporosis.The increase of the fragility of distal radius in those people is the cause of unstable comminuted fracture after the falling.The treatment of distal radius fractures mainly divided into conservative treatment and surgical treatment at present.The stability of the conservative treatment is aimed at extra-articular fractures,which has the advantages of small trauma and economy.Fixed methods mainly include plaster,thermoplastic polymer materials and small splint fixation.But closed reduction prones to poor fracture alignment.Soft tissue injuries may occur around the fracture.Fracture malunion and traumatic arthritis may accompany the patient in the long convalescence.At the same time,general recovery period is longer than the conservative treatment,and long-term external fixation may limit the activities of the wrist and not conducive to the early functional exercise.In the process of recovery,adjust the firmness of the external fixation according to the swelling of fracture position timely.Fixed too loose to cause a decline in a fixed role.Fixed tightently prone to bone fascia room syndrome,carpal tunnel syndrome and skin pressure ulcer,etc.There are many kinds of surgical treatment for distal radius fractures,traditional methods mainly include orif locking and non-locking steel plate internal fixation and the needle plate internal fixation,the pique fixed,fixed external fixator and an intramedullary nail fixation,etc.Open reduction and internal fixation can obtain accurate force line and anatomical repositioning,joint consistency and stability,also can get a better protection.Strong internal fixation and complete anatomical reduction can allows early initiative of wrist function exercise,shorten the recovery time,thereby reducing the incidence of wrist joint stiffness.Now either surgical method,or a combination of the treatment of distal radius fractures,the result of the report is different,even contradictory.So far,no one more than any other surgical treatment effect is more prominent,how to choose the surgical method is still a hot discussion in the field of orthopaedics.The method of finite element analysis is applied to the femur biomechanics research for the first time.With valid discussion and analysis by many experts and scholars,finite element analysis have become a reliable research method in research of bone through decades of development.With the development of multiple disciplines including computer,software and materials,promote the finite element method(fem)simulation of the initial static model of the dynamic movement model for human body gradually;From a two-dimensional model of early gradually transformed to threedimensional finite element model;From single model further to include bone cartilage,meniscus,ligament,muscle and bone structure of the complex three-dimensional finite element model;more and more close to the real change in the human body.Currently in orthopaedic research,finite element method(fem)in the skeletal system model is established in this paper,fracture mechanism,aspects and so on,and the comparison of fracture fixation devices have been widely used,and reflects its validation and clinical practice of good results.Part One Volar locking plate versus external fixation with optional additional K-wire for treatment of AO type C2/C3 fractures: a retrospective comparative studyObjective: the aim of this study was to compare the radiographic and functional results of AO type C2/C3 fracture of distal radius between volar locking plate(VLP)and external fixation(EF).Methods:1.clinical case selection: It was a retrospective comparative study.Between January 2017 and March 2020,the patients who underwent EF or VLP fixation for AO type C2/C3 distal radius fractures were assessed.Exclusion criteria were old fracture,systematic skeletal diseases(e.g.,hyperparathyroidism)or local disorder(e.g.,tumors,Paget disease,or rheumatoid arthritis),treatment other than VLP or EF,patients lost to follow-up,or incomplete data.2.Data collection and measurement: The follow-up was at least 12 months.Gartland-Werley scale and the disabilities of the arm,shoulder,and hand(DASH)scale were used to evaluate the overall functional outcomes;wrist range of motion and grip strength were measured.The radiographic parameters included radial inclination,volar tilt,radial length,ulnar variance,and articular step-off.3.Statistics and data analysis: For comparison of continuous variables(age,surgical duration,volar tilt,radial inclination,radial length,ulnar variance,and articular step-off),Student's t test or Mann–Whitney U test was used,based on their data distribution status.As for categorical variables(gender,handedness,injury mechanism,complications),Pearson chi-square test or Fisher's exact test was used,if appropriate.A p value <0.05 was considered as statistically significant.All the analyses were performed using the SPSS 21.0 software(IBM,Armonk,NY,USA).Results:1.The mean follow-up time was 17.1 months.At final visit,VLP performed better in wrist flexion(69.7°vs 62.3°,P<0.001),forearm pronation(73.1°vs 64.8°,P=0.027)and supination(70.6°vs 63.1°,P=0.033)than EF,but non-significant for other motion parameters.2.No significant difference was found between two groups,in term of Gartland-Werley or DASH score(P>0.05).The ulnar variance and articular step-off was significantly more improved in VLP than EF group,being 0.6 vs1.6mm(P=0.002)and 0.5 vs 1.2mm(P=0.007).3.The overall rate of complications did not differ in both groups(28.2%vs 34.5%)(P=0.587).Conclusion:1.Compared to EF,VLP fixation showed better performance in wrist mobility,correction of ulnar variance and improving articular congruence.2.In terms of other imaging parameters,overall functional outcomes and complication rate,two fixed methods showed similar results.Part Two Curative effect observation of the minimally invasive treatment of distal radius fractures with auxiliary 3-dimensional printingObjective: To summarize the curative effect of minimally invasive treatment of distal radius fractures by 3-dimensional printing auxiliary plate/screw system externally.Methord:1.Screening into groups: the group standards:(1)type A,namely the extra-articular fractures and each subtype(2)type B,namely simple or part of intra-articular fractures of the subtype(3)C1,simple intra-articular fractures.Exclusion criteria:(1)the anatomical reattachment not serious comminuted fracture,such as C2 and C3 type;(2)the openness of severe soft tissue injury of the distal radius fracture;(3)Both rheumatoid arthritis and other carpal bone joint disease or systemic skeletal disease patients.2.Mold production and operation: According to the datas collected from preoperative CT scan and 3D reconstruction of the fracture and arteriovenous angiography of the lesion site,individually designed plate and external mould for fixation were made.Bone plate card slot in vitro fixed mold have been designed.3-dimensional printing help insert the screws accurately both at direction and orientation through the vitro reduction and plate/screw system fixation for the treatment of distal radius fractures.3.Postoperative follow-up: follow-up at 2 weeks,6 weeks,3 months,6months and 12 months after surgery,with a standard positive and lateral X ray examination.The wrist range of motion and grip strength were measured.The radiographic parameters included radial inclination,volar tilt,radial length.All postoperative patients with visual analogue scale(VAS)and wrist joint function score(Gartland-Werley score)are measured.Result:1.Satisfactory follow-up cases in 15 cases,9 cases of male,female 6cases;An average of 39.3 years old.A2 type 8 cases,5 cases of type A3,B2 of dorsal edge fracture of the distal part of the radius in 1 case,C1 type 1 case,all of these are closed fracture combining with wrist volar soft tissue injury.2.The postoperative follow-up for 12 ? 33 months,an average of 22.5months.At the follow-up of 2 weeks,12 weeks and 1 year after surgery,postoperative visual analogue scale(VAS)were 1.86±0.25,0.83±0.51 and0.31±0.05,wrist joint function score(Gartland-Werley score)were 6.54±1.71,2.72±0.53,2.05±0.29.Gartland-Werley score when the final follow-up:excellent 12 cases,good 2 cases and fair 1 case.3.At the time of the last follow-up: volar tilt for distal radius(13.1 ±3.2),radial inclination(21.9±4.6)°,radial shortening(2.0±1.1)mm,wrist flexion range(52.0±11.7),wrist back extension range(65.0±4.8),grip strength84.0%±4.2% for the healthy side.Conclusion1.The application of 3-dimensional printing auxiliary plate/screw system under external and minimally invasive treatment of distal radius fractures have many advantages.The plate/screw system can be individually designed before operation,precision auxiliary reset and guidance position Angle,minimally invasive and low requirement to the skin soft tissue condition,taking out easily.2.In the clinical study,the technology of fixed is reliable and recovery of joint function is good.Curative effect is satisfied in the short time of follow-up.Part Three Biomechanical Analysis of Non-locking Plate and Locking Plate for Fixation of Distal Radius Fractures in Normal and Osteoporotic HumansObjective: Distal radius fracture is a common fracture in clinical practice.With the aging of the population and the increase of high-energy injury accidents in China,the incidence of distal radius fracture in the elderly and adolescents has increased.The main treatments of distal radius fractures can include conservative treatment,pin internal fixation and open reduction and internal fixation.Distal radius fractures require restoration of normal palmar inclination,ulnar deviation,radial length,and anatomic position of the articular surface of the distal radius.Conservative treatment is difficult to achieve.In order to avoid complications such as radial malunion,wrist stiffness,limited mobility as well as arthritis,as well as shorten the recovery time and recover as soon as possible,open reduction and internal fixation is required for unstable fractures.At present,the commonly used surgical internal fixation devices include metacarpal locking plate and non-locking plate.The metacarpal plate is indicated for unstable fractures of the distal radius.Since patients with distal radius fractures mainly include the elderly population,the bone quality of patients with fractures includes osteoporotic and normal bones.The main purpose of this experiment was to analyze the biomechanical characteristics of non-locking plate versus locking plate fixation of distal radius fractures.Methods:1.A young healthy volunteer was recruited and underwent rapid thin-section CT scanning of his forearm.Three-dimensional data of the radius was created using mimics 20.0 software and stored as STL data,and imported into Geomagicstudio2013 software to smooth the surface,remove noise points,substantiate the radius model,and save in STEP format.The distal radius model was imported into UG10.0 software to create distal radius fractures;and the distal radius metacarpal plate and screw models were designed based on actual plate data.2.The model was then imported into Abaqus software to set load,boundary conditions,and the biomechanical characteristics of non-locking plates and locking plates for the fixation of distal radius fractures were analyzed,and the data such as stress and displacement were counted.Results:1.For the model of distal radius fixed with steel plate,the stress concentration site was mainly distributed in the steel plate.The maximum stress is 198 MPa and the maximum displacement is 1.157 mm for locking plate fixation of normal human distal radius fracture model;the maximum stress is 229.5MPa and the maximum displacement is 1.394 mm for non-locking plate fixation of normal human distal radius fracture model.2.The maximum stress is 181.4MPa and the maximum displacement is1.814 mm for locking plate fixation of osteoporotic human distal radius fracture model;the maximum stress is 244.1MPa and the maximum displacement is 2.178 mm for non-locking plate fixation of distal radius fracture mode The overall rate of complications did not differ in both groups(28.2% vs 34.5%)(P=0.587).Conclusion:Compared with non-locking plate,locking plate fixation of osteoporosis model and normal bone model has better stability and less stress peak value. |
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