Clinical Study On Intervention Of Splint To Ulnar Column In The Treatment Of Type Frykman? Fracture Of The Distal Radius And Related Finite Element Analysis

BackgroundAs a flash part of traditional Chinese medicine,small splint elastic fixation is a simple and inexpensive treatment for distal radius fractures with satisfactory results.However,it is regrettable that it has being maintained in the stage of"experience",lack of scientific exploration and reorganization.Its characteristics and advantages have not been systematically interpreted and clarified.At present,the proportion of internal fixation surgery was increasing year by year in the treatment of the distal radius fractures which caused a very substantial increase in patients,trauma,economic and mental burden.In the meanwhile,the proportion of the splints was compressed rapidly,and it has a tendency to be buried or even lost unwittingly.Based on the above situation,we need to sort out,excavate and improve this traditional technology with modern methods,and inherit and innovate it.This is also the most urgent task for Chinese medical practitioners of bone injury.According to literature,it was about fifty-one percent to sixty-five percent of the distal radius fractures combined with the ulnar styloid fracture.The occurrence ratio of type Frykman? fracture of the distal radius proposed by Frykman in 1967,which was characterized by fracture involving the radiocarpal joint and the distal ulnar radial joint(DRUJ),combined with the ulnar styloid fracture,was increasing year by year.There was a controversy that whether the fracture of the ulna styloid process requireded surgical treatment or not,since the fracture fragment was too small to be fixed easily.In the treatment of type Frykman? fracture of the distal radius with open reduction and internal fixation,most of the clinicians only fixed the distal radius fracture,but the ulnar styloid fracture was not fixed.The patients were encouraged to perform functional exercises in early stage after operation according to the AO guidelines.In this way,the damage of the ulnar side column was not able to be repaired well,or even worse,during the recovery process.The related literature also reported that the wrist joint function was significantly different after the simple distal radius internal fixation of the distal radius fracture combined with or without ulnar structure injury.The wrist joint function recovery was poor,and the incidence of complications of the ulnar column is higher after combined.Through clinical observation,we found that the outcomes of manipulative reduction and splint fixation for treating type Frykman? fracture of the distal radius without intra-articular comminuted fracture were satisfactory.Compared with the simple distal radius internal fixation,the splint was better for the wrist joint function recovery and the incidence of the ulnar column complications was lower.We deemed that the wrist joint was treated as a whole in the treatment cycle,the splint as elastic fixation could provide the relative stability of the distal radioulnar joint and the ulnar side structure of the wrist.It is necessary to design related clinical control studies for analysis.In addition,we intend to use the finite element method to further verify the hypothesis from the biomechanical point of view.The main characteristic of finite element analysis method is to establish the corresponding bone and joint simulation model by microcomputer,and carry out simulation analysis under certain special conditions to get the research results which are difficult to obtain in objective entity experiment.One of the features of type Frykman? fracture of the distal radius is combined with ulnar styloid fracture,ligaments and structures attached to the ulnar styloid which plays an important role in maintaining the stability of the distal radioulnar joint.The normal tension of these ligaments and structures will be affected by the fracture of the ulna styloid process,which involves more ligaments when the base of the ulna styloid process is broken.For the above reasons,we will establish and verify the finite element model of the normal wrist joint,On this basis,four finite element models of wrist joint with and without splint fixation for ulnar styloid process type ? and ? fracture will be established respectively,and we will analyze the effect of splint fixation on the stability of the distal radioulnar joint and the ulnar side structure of the wrist after the ulnar styloid fracture which the related finite element analysis is not reported for the time being.In the finite element research,besides the traditional splint location assembly model,we will also extend the distal part of the ulnar splint to the base of the fifth metacarpal bone with finite element software.Compared with the traditional splint,we will analyze whether the lengthening of the ulnar splint can provide greater stability to the distal radioulnar joint in order to provide reference for clinical improvement of traditional splint in treatment of type Frykman? fracture of the distal radius.Objective1.To designe a non-randomized control study for patients with type Frykman?fracture of the distal radius without intra-articular comminuted fracture;To compare the curative effect and the the incidence of the ulnar column complications of the treatment with the manipulation splint external fixation and the simple distal radius internal fixation in the short term;To analyse whether the splint fixation therapy has a positive effect on the recovery of the injury of the ulnar column of this type of fracture.2.To explore the biomechanical mechanism of splint intervention on the ulnar column after ulnar styloid fracture by finite element analysis,to verify the hypothesis that the splint as elastic fixation can provide the relative stability of the distal radioulnar joint and the ulnar side structure of the wrist.3.Through the finite element analysis,to analyse whether the lengthening of the ulnar splint can provide greater stability to the distal radioulnar joint and provide reference for clinical improvement of traditional splint in treatment of type Frykman? fracture of the distal radius.Methods1.The clinical study of splint intervention on the ulnar column in the treatment of type Frykman? fracture of the distal radius.We designed a non-randomized control study for patients by type Frykman?fracture of the distal radius without intra-articular comminuted fracture,the test group was treated with the manipulation splint external fixation,and the control group was treated with the simple distal radius internal fixation.Matching requirements included the same gender,the similar age,the same type of ulnar styloid fracture and the same anatomical distal radius grade after treatment.According to the results of the sample measurement,34 pairs(68 cases)were completed,including 18 pairs of type I fractures of the ulnar styloid and 16 pairs of type ?.After 12 weeks of follow-up,the incidence of complications of ulnar column were recorded,the imaging evaluation was performed according to the anatomical reduction standard for the distal radius fracture proposed by Bunger,and wrist function was evaluated by Gartland-Werley wrist score system,wrist active mobility,hand grip strength and kneading force.At last,the difference between the two groups were compared.2.Finite element analysis on intervention of splint fixation treating for ulnar styloid fractureA three-dimensional finite element model of normal wrist joint was established based on the forearm and wrist CT images of a healthy volunteer.After debugging the model,Von Mises stress of the distal radius was obtained by loading the 100N stress in the axial direction,and the validity of the model was verified by comparing with the experimental data in the literature.On this basis,four wrist joint finite element models with and without splint fixation for ulnar styloid type ? and type ?fractures were established.Under axial compression,lateral extension,pronation and supination 4 working conditions,we analysed the change of the stress distribution of the distal radioulnar joint,and the relative displacement of the distal radioulnar joint as well as the ulnar styloid fracture broken end.We extended the distal part of the ulnar splint to the base of the fifth metacarpal bone in the fracture model with splint fixation by using finite element software to analyse whether it can provide greater stability to the distal radioulnar joint.Results1.The clinical study of splint intervention on the ulnar column in the treatment of type Frykman? fracture of the distal radiusAll distal radius fractures healed well at the follow-up period to 12 weeks after treatment.Ulnar column complications occurred in 9 patients(26.5%)in the test group and 24 patients(70.6%)in the control group(P<0.05).According to the anatomical reduction standard for the distal radius fracture proposed by Bunger in test group and the control group at the end of the follow-up,the results were 3 and 7 cases in excellence,24 and 26 cases in good,4 and 1 cases in fair and 3 and 0 cases in poor with excellence and good rate of 79.4%and 97.1%,there is significant difference between 2 groups(Z=-2.354,P=0.019).According to the Gartland-Werley score in test group and the control group,the results were 12 and 7 cases in excellence,19 and 15 cases in good,2 and 9 cases in fair and 1 and 3 cases in poor with excellence and good rate of 91.2%and 64.7%,showing significant difference between 2 groups(Z=-2.330,P=0.020).The range of flexion and extension of the injured wrist was 81.7%±7.5%of the contralateral side in the test group,and 60%of the control group,the difference was not statistically significant(P=0.453);The range of activities of the wrist radial ulnar deviation,pronation and supination were contralateral 81.4%±6.8%,80.3%±10.2%in the test group,and 76.8%±8.0%,71.4%±8.5%in the control group that the differences were statistically significant(P=0.013,P=0.000).The hand grip strength of the injured wrist was 73.5%±7.1%of the contralateral side in the test group,and 72.0%±7.4%in the control group that the difference was not statistically significant(P=0.400).The hand pinching force of the injured wrist was 73.1%±6.5%of the contralateral side in the test group,and 69.8%±6.4%in the control group that the difference was statistically significant(P=0.036).2.Finite element analysis on intervention of splint fixation treating for ulnar styloid fractureA three-dimensional finite element model of normal wrist joint was established and validated,and the other four models were established based on this model.This study showed that the stress values of the ulnolunate ligament,ulnotriquetral ligament,the palmar radioulnar ligaments and the dorsal radioulnar ligament in type I fracture model all reduced after splint fixation in the lateral tension,pronation and supination conditions.In the pronation and supination conditions,the relative displacement values of the distal radioulnar joints in the ulnar styloid type I and II fracture models were greater than those in the normal wrist joint model,of which in the type I fracture model were smaller than in the type II fracture model.The orthotopic transplantation were significantly reduced after the intervention on the two fracture models by the splint.The displacement values of the ulnar styloid fracture end in the ulnar styloid type I fracture model were smaller than the type II fracture model,which were significantly reduced after the intervention by the splint.Under the remaining conditions,the change of the above values was not obvious or has no practical clinical significance.After extending the distal part of the ulnar splint to the base of the fifth metacarpal bone in the type I and II fracture models with splint fixation by using finite element software.We found that the relative displacement of the distal radioulnar joint decreased further under the rotating condition.Conclusion1.Clinical researchFor treating type Frykman? fracture of the distal radius without intra-articular comminuted fracture,the anatomic score of distal radius in the test group is less than the one in the contorl group after 12 weeks,but it obtains more satisfactory wrist function,especially in the range of radial ulnar deviation,pronation and supination of wrist joint were better than the latter.The related complications due to ulnar column injury are lower than the latter.2.Finite element researchThe finite element study shows that distal radioulnar joint stability becomes worse after ulnar styloid fracture,which occures in type ? fracture model is more obvious.In the finite element model of ulna styloid process fracture,the relative stability of the distal radioulnar joint and the ulnar structure of the wrist will increase after the splint fixation.Compared with the traditional splint,we find that the lengthening of the ulnar splint could provide greater stability to the distal radioulnar joint through the finite element analysis,which can provide reference for clinical improvement of traditional splint in treatment of type Frykman? fracture of the distal radius.