The Animal Experimental Study Of Cartilage Changes After Patella Dislocation And Clinical Study Of Diagnosis And Treatment Of Patella Dislocation

Part one Animal Experimental Study of Cartilage Changes after Patella DislocationObjective:Distal dislocation of the patella is a common clinical condition in orthopaedics.The etiology of the patella includes dislocation of the periorbital bony structure or disorder of the soft tissue.The literature reports that dysplasia of the femur is one of the common manifestations of periorbital bony structure abnormalities and is one of the important causes of instability of the patellofemoral joint.However,our previous studies have broken the above conventional wisdom,and animal models have been used to demonstrate that early tibial instability can induce dysplasia of the femur.At the same time,we also proved that it is possible to obtain a trochlear dysplasia model by surgically,and to provide an ideal animal model for the study of femoral trochlear dysplasia.In recent years,the wnt/?-catenin pathway has been shown to regulate the formation and degeneration of articular cartilage by inhibiting cartilage formation and stimulating chondrocyte hypertrophy.However,the molecular mechanism of cartilage destruction and degeneration of articular cartilage in the early stages is unclear.In addition,it has not been reported whether the?-catenin pathway affects cartilage degeneration in the early stage of trochlear dysplasia.Therefore,in this study,the expression of?-catenin in the cartilage of rabbits and the cartilage in the control group was compared by immunohistochemistry,western blot and quantitative(q)RT-PCR,revealing the relationship between?-catenin and cartilage degeneration in the early stage of cartilage dysplasia.Methods:The experimental animals were 60 New Zealand white rabbits aged 1 month and weighing 290-320 g.Animals were randomly divided into two groups:experimental group(N=30)and control group(N=30).Animals in the experimental group received a dislocation of the patella at 0 weeks,whereas in the control group,we didn't dislocate patella at 0 weeks.The results were measured at 4 weeks after surgery.The postoperative findings mainly included 1)CT examination of femoral trochlear development,including femoral trochlear angulation,femoral trochlear width and depth;2)gross examination,assessment and recording of gross morphological changes of femoral trochlear cartilage;3)cartilage HE Staining;4)cartilage toluidine blue staining;5)Immunohistochemical staining of?-catenin;6)Western blot,detection of?-catenin and matrix metalloproteinase(MMP)-13;7)qRT-PCR,detection of?-catenin and Matrix metalloproteinase(MMP)-13 gene expression profile.Results:1.Femoral trochlear dysplasia caused by dislocation of the patella:CT results at 4 weeks postoperatively showed that the trochlear groove angle of the femur in the experimental group was greater than that of the control group.There was a statistically significant difference between the two groups(P<0.05).The femoral trochlear groove was found in the experimental group.The width was greater than that of the control group.The difference between the two groups was statistically significant(P<0.05).The depth of the femoral trochlear groove in the experimental group was greater than that of the control group.The difference between the two groups was statistically significant(P<0.05).In general terms,the rabbit femur trochlear groove in the experimental group was significantly wider and shallower than that in the control group,especially the lateral slope of the femoral trochlear was reduced,and the cartilage of the trochlear showed obvious rough changes.2.Cartilage degeneration occurred in the early stage of dysplasia of the femur trochlear:H&E staining of the femur cartilage in the control group showed that the four layers of the cartilage were clear and identifiable,and the cell size was uniform:the superficial cells were fusiform and arranged longitudinally.The cells of the transitional layer were round.Sparsely dispersed,the cells in the radiation layer are cylindrical,and the cells in the calcified layer are relatively large and loosely dispersed.There was no obvious damage to ECM toluidine blue staining.In the experimental group,the four layers of cartilage could not be identified,and the cell size was irregular when stained with H&E.The ECM toluidine blue stained unevenly.To determine cartilage degenerative changes in the femoral trochlear dysplasia model,we detected MMP-13(a marker of early cartilage degeneration)in articular cartilage from both groups by qRT-PCR and Western blot.The expression of MMP-13 mRNA was increased in the femoral trochlear dysplasia model group,which was significantly different from the control group(P<0.05).These results show that cartilage degenerative changes were observed early in the development of dysplasia of the femur.3.Increase in?-catenin mRNA expression in trochlear cartilage cells in dysplasia model of femur:In order to study the changes of?-catenin in cartilage of femoral trochlear dysplasia,we used immunohistochemistry,qRT-PCR and western blot to detect?-catenin expression.The results of immunohistochemistry showed that the expression of?-catenin increased in the experimental group at 4 weeks postoperatively.qRT-PCR results showed that the transcription level of?-catenin gene in chondrocytes was significantly increased(P<0.05),and Western blot results also showed that the expression of?-catenin protein increased in the experimental group.Therefore,the above results demonstrate that?-catenin is activated in cartilage with dysplasia of the femur.Given the increased mRNA expression of MMP-13 in this model,these results indicate that the activation of?-catenin may result in the early degeneration of chondrocytes.Conclusions:This experiment preliminary confirmed that after the dislocation of the patella,the cartilage beta-catenin pathway was activated,which resulted in the injury of femoral cartilage chondrocytes and cartilage matrix,and involved the changes of bone morphology.In addition,the experimental results provide a model and theoretical basis for further research on the mechanism of femur trochlear dysplasia.Part two Clinical Research on the alignment index of patella instabilityObjective:Patellofemoral instability is a common clinical disease in orthopedics,accounting for approximately 2%-3%of knee injuries.It has a high incidence in adolescents and the incidence rate is 10/year in 10-17 years old women.The incidence rate can reach 104/100000.Extensor knee line abnormality is one of the common clinically important causes of unstable patello-femoral joint.The indexes for assessing the patello-femoral joint force line mainly include the Q-angle,tibial tuberosity-femur trochlear groove spacing(TTTG)and so on.In recent years,the reliability and validity of the Q-angle and TTTG have been questioned.Therefore,the purpose of this study is to propose a new measurement method for the strength line of the patellofemoral joint to avoid the disadvantages of the Q-angle and TTTG and to accurately assess Patellofemoral instability.Methods:The study was divided into 2 groups.From 2014 to 2016,40patients with recurrent patellar dislocation(49 knees)who were treated in our department were included in the dislocation group.Patients with previous history of knee joint surgery were excluded;at the same time,we recruited 35volunteers as a control group,all volunteers had no history of patellofemoral instability.Measurement of Bone Angle Q:The patient was placed in a supine position for CT scans,the knee joint was fully extended,the quadriceps muscles were relaxed,and the feet were neutral.From the anterior superior iliac spine through the knee to the axial proximal humerus scan.CT scan images were saved in DICOM3 format,transferred to a personal computer,and reconstructed using the Mimics V17.0 3D image processing program software.We selected three bony markers on the image,namely the lowest point of the trochlear groove and the highest point of the tibial tubercle of the anterior superior iliac spine and the femoral condylar axis.Then connect the above three points.The angle between the two lines is the bony Q angle.Traditional Q-Angle Measurements:Patients were supine,knees fully extended,quadriceps loose,and neutral feet.Marker pens were used to mark the highest point of the anterior superior iliac spine,tibiofemoral center,and tibial tubercle on the patient's body surface.Finally,use a manual goniometer to measure the angle.Data were analyzed using SPSS13.0 software(IBM,Armonk,NY).Differences between the two groups were analyzed using the T test,P<0.05 considered statistically significant.Results:1.There was no significant difference in demographic data between the groups.In the dislocation group,14(28.5%)patients had dysplasia of femoral condyle,18(36.7%)patients had medial patello-femoral ligament dysfunction,5(10.2%)patients had high tibial and 9(18.4%)The patient developed early tendon arthritis.Six(15%)volunteers in the control group had mild femoral trochlear dysplasia(I/II),5(12.5%)had mild medial patellofemoral ligament dysfunction,and 1 had early patellofemoral arthritis.2.The diagnostic effectiveness of bony Q angle is better than that of traditional Q angle.The average Q-angle of the dislocation group was 16.2~o,and the mean value of the traditional Q-angle of the control group was 15~o.There was no significant difference between the two groups(P=0.102).The mean value of the skeletal Q-angle of the dislocation group was 28.6~o,while the mean value of the bony Q-angle of the control group was 21.1~o.There was a statistically significant difference between the two groups(P<0.001).3.There was no statistically significant difference in the angular measurements between the two observers.Conclusions:This study preliminarily proposed and validated a new evaluation index of the patellofemoral joint force-bony Q-angle.Based on our research data,we believe that the osseous Q-angle can embody the lateral vector force of the humerus without the interference of the soft tissues such as the quadriceps,which is an ideal evaluation index for the diagnosis and treatment effect of patellofemoral joint instability.Part three Clinical Study of Treatments of Patella Dislocation with Special Emphasis on the MPFL Injury PatternsObjective:Acute patella dislocation is one of the common knee injuries in adolescents and often involves the injury of Medial Patellofemoral Ligament(MPFL).However,its treatment is still controversial.At present,scholars believe that one of the important causes of controversy in the treatment of acute patella dislocation is the inability to correctly distinguish the type of injury of the medial patellofemoral ligament.In our previous study,the medial patellofemoral ligaments were divided into two functional subregions,overlapping and non-overlapping,based on the relationship between the medial patellofemoral ligament and the medial oblique muscle.Based on this functional subarea,the medial patellofemoral ligament injury types were divided into overlapping lesions,non-overlapping lesions,and joint injuries.Later,we demonstrated that conservative treatment can effectively treat the lesions in the medial iliac patella ligament overlap area and can provide patients with satisfactory clinical outcomes.Therefore,we believe that the lesions in the non-overlapping area of the medial patellofemoral ligament cannot achieve satisfactory clinical results through conservative treatment due to the loss of the attachment of the medial oblique muscle.The purpose of this study was to evaluate clinical treatment options based on a new medial patellofemoral ligament injury type of dislocation of the patella.The hypothesis of this study is that surgical treatment can improve the tibial stability and subjective patellofemoral joint function scores in the non-overlapping region of the medial patellofemoral ligament.Methods:This study retrospectively analyzed data from 62 patients who underwent surgical and non-surgical treatment of acute patella dislocation between October 2008 and November 2011.Patients were randomly divided into 3 groups according to their time of birth:30 cases in the surgical treatment group(born in odd years),and 32 cases in the conservative treatment group(even years in birth).Each patient underwent radiographic evaluation including anteroposterior and lateral knee radiographs on admission,and MRI examinations were used to determine MPFL lesion classification.All MRIs are analyzed by two experienced orthopedic surgeons and completed within 3 weeks after injury.If any dispute arises,the MRI will be reviewed by a sports medicine specialist and a final diagnosis will be made.Conservative treatment group:manual reduction of dislocation of the sacrum should pay special attention to secondary femoral or tibial cartilage injury.Before and after the reset,carefully observe the lateral x-ray film of the knee to eliminate the possibility of loose bodies in the joints.Once the joints are free,the arthroscopic surgery should be performed immediately.Intra-articular hematoma can be removed by joint puncture because it may cause pain and interfere with physical examination,and multiple joint punctures may be necessary if necessary.The knee brace is fixed for at least 3 weeks.During this period,the patient begins knee flexion and extension.The range of motion is limited to 60 degrees.In addition,the patient was allowed to load under the aid of the crutches;surgical treatment group:The patient was supine on the operating table,and after the onset of anesthesia,the motion of the tibia was first evaluated.At the beginning of the operation,a standard arthroscopic anterior and anterior medial approach was established to perform a diagnostic arthroscopic examination of the tibial and femoral trochlear articular cartilage injury,the tibia trajectory,and tibia motion.Examine and record the concomitant articular cartilage damage and treat the accompanying menisci and articular cartilage lesions.The midpoint of the medial condyle of the femur and the midpoint of the midpoint of the adductorium of the femur were initially selected as the femoral epithelial node.A 3 cm incision was made in the skin and the blunt dissection to the medial condyle was performed using a hemostat.Femoral ligaments are pointing and expose the broken ends.After that,the knee joint is placed in an extended position.The anchor is screwed into the highest point of the medial femoral condyle and slightly to the midpoint of the medial adductor muscle nodule.Hemostatic forceps are then used to clamp the broken end,and then the knee joint is flexed to perform dynamics.Observed.Evaluation methods:(1)Manipulation test to reconstruct the tension of the patellofemoral ligament;(2)Arthroscopic observation of the static involute relation of the patella tendon joint;(3)Arthroscopic dynamic observation of patellofemoral joint congruence and tibia trajectory.The tension of the graft tendon was adjusted according to the evaluation until a satisfactory patellofemoral relationship and medial and lateral soft tissue balance were obtained.Finally,the fractured medial patellofemoral ligament was firmly sutured using an anchor line.Rinse the wound and suture it layer by layer.Data was analyzed using SPSS 13.0 software(IBM,Armonk,NY).The Kolmogorov-Sminov test was used to test the normal distribution of the data.T test to analyze the parameter variables,Chi-square test to analyze the count data.P<0.05 considered statistically significant.Results:1.There was no significant difference in demographic data between the groups.All patients were diagnosed with acute patella dislocation,including a history of lateral displacement of the tibia.Physical examination revealed medial support with tenderness,knee effusion or hemarthrosis,and a positive tibia fear test.Of all 62 patients,two had severe femoral trochlear dysplasia,three were excluded due to a TT-TG greater than 20 mm,one patient was lost during follow-up,and the patient was followed up for a complete follow-up.There were 56 patients,including 26 conservative treatment groups and 30surgical treatment groups.In the conservative treatment group,6 patients(23.1%)and 5 patients in the surgical treatment group had osteochondral lesions.There was no statistically significant difference between the groups.In the conservative treatment group,1 patient(3.8%)and 1 patient in the surgical treatment group received free arthroscopic surgery for removal of free bodies.There was no statistical difference between the two groups.2.There was no significant difference in the subjective questionnaire between the conservative treatment group and the surgical treatment group.Conservative treatment group:excellent in 2 cases(7.7%),good in 8 cases(30.8%),good in 10 cases(38.5%),poor in 6 cases(23.1%);surgical treatment group:excellent in 10 cases(33.3%),good in 14 cases(46.7%),good in 4cases(13.3%),poor in 2 cases(6.7%),there was no significant difference between the two groups(P>0.05).3.There was no significant difference in the recurrence rate of patella instability in the conservative treatment group and the surgical treatment group.In the conservative treatment group,the rate of patella dislocation was11.5%,and the recurrence rate of the patella subluxation was 15.4%.The rate of re-dislocation of the patella in the surgical treatment group was 3.3%,and the recurrence rate of the patella subluxation was 6.7%.There was no statistical difference between the two groups(P>0.05).4.The Kujala score and CT evaluation in surgical treatment group were superior to conservative treatment group.The Kujala scores of the two groups were 80.19±5.07 and 93.57±4.03,respectively,with statistically significant differences between groups(P<0.001).Postoperatively,patients underwent knee CT scan with a knee flexion of 30°.The tibial tilt angle between the two groups was 8.96±1.64 and 6.83±1.44,respectively.There was a statistically significant difference between the groups(P<0.001);The degree of extroversion was 11.08±1.99 and 9.23±1.96,respectively.There was a statistically significant difference between groups(P=0.001).Conclusions:In this study,clinical follow-up was compared with surgery and conservative treatment combined with acute patella dislocation of medial patellofemoral ligament injury.It was pointed out that surgical treatment can reduce the incidence of postoperative tibial instability and improve knee function.This study proposes the principle of treating acute patella dislocation:routinely performing MRI of the knee joint after dislocation of the patella and determining whether there is a medial patellofemoral ligament injury and its type of injury.The acute patella dislocation combined with a non-overlapping lesion of the medial patellofemoral ligament should be treated timely by surgery.