Hip Revision With Leg Length Discrepancy:Influencing Factors And Treatment

Objective:Leg length discrepancy(LLD)has become a major factor in patients with dissatisfaction,and been the main reason for the complaint of patients after total hip arthroplasty(THA),Most of patients before revision hip surgery appear LLD,so solving this problem is one of the most important purposes of revision hip surgery.We analyze the origin of the LLD from the revision hip surgery,and explore the treatability and treatment of each factor.As a reference in clinical,we can improve the consistency of the leg length better.Methods: Through the medical system and imaging system,we collected the clinical and radiographic records of patients who had undergone revision hip surgery at our institution with LLD from October 2014 to October 2016.We divided the source of LLD into the acetabular side,the femoral side and the joint space,futhermore,divided them into many factors and evaluation index including the abduction angle,the anteversion angle,the diameter of the acetabulum,the distance from the lowest point of the acetabulum to the punctate connection vertical,the eccentric moment of the hip prosthesis,etc.The total difference of the leg length and the factors was analyzed according to the statistical data.The Harris score of hip and each factor were analyzed by t test to analyze the difference,the relationship between the total difference of leg length and each factor were analyzed by multiple linear regression.Through the result,We can analyze the origin of the LLD,and explore the proportion,treatability and treatment of each factor.The patients be divided into two groups by used to traditional Chinese manipulation or not,The Harris score of hip after two weeks were statistical analyzed.Result:In this study,35 patients were screened and followed up,the average duration of follow-up was 25.9 months(14-47 months).The Harris score preoperatively was 12-57(36.9 ± 3.2),and 72-95(90.3 ± 3.5)postoperatively.Between the preoperative and postoperative,the statistical analysis showed that there were statistically significant in the total difference of leg length,in all factors except the abduction angle and anteversion angle(p>0.05).The proportion of femoral factors is large than other(There are 27 patients with the distance from the FCR to the horizontal line of small trochanter midpoint connection vertical is difference from the preoperative to postoperative).Through the result of multiple linear regression,there is a liner between the distance from the FCR to the horizontal line of small trochanter midpoint connection vertical and the total difference of leg length.There were statistically significant in the Harris score of hip before and after traditional Chinese manipulation.Conclusions: The method of dividing the source of LLD into the acetabular side,the femoral side,the joint space and many factors can help us to analyze the causes of LLD in clinical.In order to improve the consistency of the leg length better in revision hip surgery,we should to focus on this main factors including the distance from the lowest point of the acetabulum to the punctate connection vertical,the eccentric moment of the hip prosthesis and the distance from the femoral head rotation center to the horizontal line of small trochanter midpoint connection vertical.Among the factors,the factors of femoral side occurs in higher amounts,better treatability,which should be the main factor of consideration of adjusting the leg length in revision hip surgery.The traditional Chinese manipulation has a good clinical effect.