Study On The Short-term Effect Of Periacetabular Osteotomy For Hip Dysplasia And Cartilage In Acetabular Weight-bearing Area

Background:Nowadays,developmental dysplasia of the hip（DDH）in children and adolescents has gradually attracted extensive attention.How to treat this series of diseases more reasonably and effectively is the direction of orthopaedic doctors and relevant scientific researchers.With more and more attention focused on how to detect and treat DDH early,how to better ensure the best curative effect of DDH has become a difficulty and focus.Developmental hip dysplasia refers to a disease in which the femoral head is gradually sublated,cartilage degeneration in weight-bearing area,focal necrosis of femoral head and severe osteoarthritis due to the poor coverage of the femoral head caused by the acetabulum development defect,resulting in long-term biomechanical abnormalities of the hip joint.The injury of acetabulum and femoral cartilage of hip joint can lead to hip pain,decreased range of motion and even painful stiffness of hip joint.Therefore,the acetabular weight-bearing area and cartilage changes can be used as an indicator of hip dysplasia in the study of the efficacy of surgical treatment,so it is important to conduct clinical analysis.Periacetabular osteotomy（PAO）is an effective method for the treatment of adolescent hip dysplasia,and has a high long-term hip preservation rate.The so-called Pao surgical treatment is to rearrange the acetabulum through rotation,so as to improve the coverage of acetabulum and femoral head,so as to improve hip function,relieve pain and prevent secondary diseases.Therefore,it has a good hip preservation effect.Although the femoral head has been well covered after PAO,due to the reduction of acetabular lunate cartilage before operation,the weight-bearing area of the femoral head can-not be completely covered by acetabular cartilage,which may be one of the factors leading to poor long-term effect after operation.Short-term functional outcomes and radiographic changes during this procedure are important in assessing the success of PAO.The research on the cartilage changes of acetabular weight-bearing area in patients with DDH has gradually aroused everyone’s interest,and may be one of the main factors for the unsatisfactory effect after PAO.Postoperative improvement of dysplastic hip plays an important role in postoperative recovery and prevention of postoperative hip arthritis and even delay its development.The acetabular cartilage is known to play an important role in the hip joint.Currently,there are many studies on the thickness of the acetabular cartilage,but there are few studies on the size,area and morphology of the acetabular cartilage,especially the changes in the morphology of the acetabular cartilage before and after PAO in DDH patients.Changes in the morphology of the acetabular cartilage play an important role in the treatment of developmental hip dysplasia.This study evaluated the short-term outcome and the weight-bearing area of the acetabular cartilage after PAO in patients with Crowe type I hip dysplasia.Method:1.Patients with Crowe-I DDH undergoing PAO surgery were selected,and the corresponding Harris and VAS scores were obtained before and after operation.The preoperative and postoperative X-ray,CT and MRI imaging examinations were compared,and CE angle,HASA,PASA,VCA,AI and Sharp angle were measured.2.We determining the cartilage ROI area of acetabular weight-bearing area by MRI,and measure the length and area of acetabular cartilage in the same ROI area before and after operation,and observe the imaging changes of patients after operation.3.The data were statistically analyzed to observe the short-term curative effect and imaging changes of patients after operation,and to evaluate the changes and amplification of cartilage in acetabular weight-bearing area.Result:According to all imaging examination indicators,patients with DDH experienced significant improvement in Harris and VAS pain scores after PAO,as well as significant improvement in the coverage of the femoral head,CE Angle,Sharp Angle,AI Angle,and VCA.According to the relevant measurements of CT examination,HASA PASA and AASA were improved,and the acetabular inclusion was increased after operation.In addition,the normal anatomical status of the Shenton line was observed,and the increased length of the glabellar arch and the increase of the weight-bearing area were observed on the X-ray,which may assist in the evaluation of the postoperative changes in the biomechanics of the acetabulum.It is known that the eyebrow arch of the hip joint can refer to the change of acetabular force when the hip joint space is normal and there is no secondary severe arthritis.Its extension can be considered that the weight-bearing area of the acetabulum of the femoral head is increased and the mechanical environment is improved.With the extension of the eyebrow arch,there is no clear stenosis of the joint space and no progress of arthritis,it is speculated that the increased acetabular coverage area is also covered by cartilage,which is the acetabular cartilage may expand to the inner or outer edge.To verify this,we divide the cartilage in the MRI weight-bearing area of the hip joint into ROI zones,and take the maximum sequence of the central coronal plane of the femoral head,the sequence of the first two layers and the sequence of the last layer were taken to measure the width of ROI cartilage in the weight-bearing area of the acetabulum,obtained the average to reduce the measurement error,and visible difference,statistical analysis was statistically significant.It can be considered that the width of cartilage in acetabular weight-bearing area has been improved.Three-dimensional imaging was performed on the ROI of the hip joint cartilage in the weight-bearing area,and the area of the cartilage was measured and statistically analyzed.The results showed statistical significance,indicating that the cartilage in the acetabular weightbearing area of the hip joint was improved.It can be seen that in the short-term postoperative efficacy of DDH patients,their pain was significantly relieved,joint function was improved,and acetabular cartilage in the acetabular weight-bearing area may be enlarged and morphologic changes.Conclusion:For patients with Crowe-I DDH who underwent PAO surgery,this study evaluated the short-term postoperative efficacy in more details according to a variety of evaluation data.It was observed that the short-term postoperative efficacy was significantly improved.It can be seen that PAO is an effective method for the treatment of adolescent and adult hip dysplasia.The short-term postoperative followup results are satisfactory,and the postoperative function of patients was significantly improved,which can improve the acetabular coverage rate,reduce cartilage damage,and prevent the progression of osteoarthritis.But the long-term efficacy needs more detailed observation.The length of osseous acetabular sourcil was significantly prolonged,the length of acetabular cartilage in the weight-bearing area increased,and the three-dimensional reconstruction of ROI showed that the cartilage area in the weight-bearing area is increased.There may be "amplification" of cartilage in the weight-bearing area,and the mechanical environment of cartilage was improved,reducing the probability of cartilage injury,but more detailed imaging data are needed for evaluation.