The Comparison Of 4 Types Of Patellar Side Fixation Of Medial Patellofemoral Ligament Reconstruction-A Meta-analysis Of Complications And Efficacy

Background:Recurrent patellar dislocation is defined as twice or more dislocation after the first dislocation of the patella,or the symptoms of patellar instability more than three months after the first dislocation.The longer course of RPD,the more serious damage caused by dislocation,which can cause a series of complications,such as synovial hypertrophy,patellar cartilage injury,osteoarthritis,loose bodies,etc.Decreased motor function of the affected limb,resulting in muscle atrophy around the joint.Current surgical procedures for the treatment of RPD include distal rearrangement,proximal rearrangement,lateral retinaculum release,tibial tuberosity osteotomy,trochlear plasty,and several types of combined surgery.The purpose of RPD surgery is to correct dislocation and prevent recurrence of dislocation,prevent further damage of the patellar cartilage,and delay the degeneration of the patellofemoral j oint.There are different reports about the method of MPFL reconstruction.There are still different opinions on the types of graft,the graft tension,the fixation method and the choice of fixed position.The patellar side fixation in the treatment of RPD with MPFL reconstruction was divided into four categories:bone tunnel fixation,suture anchoring,suture fixation and interference screw fixation.The eff-icacy,complications and surgical adaptation of the four types patellar side fixation methods were compared.Aim to analyze the advantages and disadvantages of patellar side fixation in MPFL reconstruction,to help surgeons and patients to choose the most appropriate fixation methods.Objective:A meta-analysis of complications and efficacy of 4 types of patellar side fixation of medial patellofemoral ligament reconstruction for patellar dislocation.Methods:A search was performed to find literature including randomized controlled studies and non-randomized controlled studies studies published from the time of database built to March 2017 about medial patellofemoral ligament reconstruction for patellar dislocation.Including randomized controlled studies and non-randomized controlled studies.Subsequently,evidence-based medical meta-analysis was used to evaluate the efficacy and complications of patellofemoral ligament reconstruction in the treatment of recurrent patellofemoral dislocation.The complication rate of the 4 typess patellar fixation methods was compared.The efficacy indicators were preoperative Kuj ala score,postoperative Kuj ala score,and Kujala score change.The extracted data was entered into MetaAnalyst 3.13 software for comprehensive analysis of the data.Results:A total of 1424 patients(1454 knees)were included in 44 articles.There were 662 patients(673knees)in the bone tunnel group,460 patients(471 knees)in the suture anchoring group,285 patients(291 knees)in the suture group and 17 patients(19 knees)in the interference screw group.There were 8 studies have control group,of which 4 were random control trail.4 random control trial use Cochrane collaboration’s tool for assessing risk of bias and the remaining 40 studies were evaluated by MINORS entry.Several different patellar side fixation methods for MPFL reconstruction were analyzed in 44 studies.The Kuj ala score of 1454 cases of knee j oint preoperative and postoperative was counted in 44 studies.According to the different methods of patellar side fixation,they were divided into 4 groups for analysis.Since there is only one study in the interference screw group,it is not included in the calculation of heterogeneity within the group,and is included in the study only when inter-group heterogeneity is calculated.Test of heterogeneity within and among groups(I2=90.1%,P=0.00001;I2=98%,P=0.0001;I2=97%,P=0.00001;I2=93%,P=0.00001).Homogeneity Test of Variance for the change of Kujala score among groups(P=0.3 5).There was significant difference among 4 types patellar side fixation on the change of Kuj ala score.The difference between bone tunnel fixation group and suture fixation group was significant,but there was no significant difference among other groups(P<0.1).The suture fixation group had the highest change in Kuj ala score.The complication rate of bone tunnel group,suture anchor group,suture group and interference screw group were 15%,3%,3%and 5%respectively.The most common complications were stiffness of the knee j oint followed by pain,patellofem oral joint instability is also more common.Patellar fracture only in the bone tunnel fixation group.Patellar redislocation was more common in the bone tunnel group,but only in 2 knees in the suture anchor group.All patients in the study received satisfactory results after MPFL reconstruction and the Kujala score was significantly improvedConclusionsOur study does not recommend the bone tunnel fixation method because of its high incidence of complications and the suture method is the best fixation for MPFL reconstruction.The clinical decision should be made according to the patient’s gender,patella size,compliance,amount of exercise,economic situation and pathological changes of the patella in order to grasp the surgical indications of MPFL reconstruction and the choice of patellar side fixation.