A Series Of Clinical Studies About Acetabular Labrum Of Adult Developmental Dysplasia Of Hip

Objective: Developmental dysplasia of hip(DDH)is the most common cause of adult hip osteoarthritis,and peripheral acetabular osteotomy(PAO)is the preferred treatment at present.PAO surgery can improve the location of the acetabulum,delay the development of hip osteoarthritis.However,some postoperative cases have poor hip function,in which preoperative acetabular labrum lesions may be an important factor.At present,we are lack of the understanding about the acetabular labrum.This study includes four parts.the first one is we measured the normal acetabular labrum correctly,the second one is we observed and measured the acetabular labrum of DDH patients,the third one is we studied some special acetabular labrum lesions of DDH patients histologically,and the last one is we maked a case-control study on the treatment of DDH patients weather disposed the acetabular labrum lesions.This study systematically revealed DDH patients with the diagnosis and treatment of acetabular lesions,will help the clinical doctors to diagnose and treat such patients.Methods:(1)?We selected 15 fresh frozen adult body specimens from which we cut the 30 complete acetabulum and labrum.According to the clock mode,a reliable anatomical landmark has been set to measure the labrum accurately.We measured the width and thickness of normal labrum at different points.(2)?We selected 148 cases of DDH from the image database,which all have MRA and pelvic anteroposterior radiographs.Using the measurement tool,the labrum shapes were measured accurately on the MRA image,compared with the control of normal labrum(data provided by the first part),and observed the labrum lesions at the same time.The measurement point was chosen to correspond to the normal labrum measurement point.The margin of the lateral CE,the angle of the acetabular angle and the coverage of the acetabulum were measured in the pelvic anteroposterior plate,and the correlation between the angle and the labrum lesions was analyzed.(3)?We studied 15 DDH patients with tissue embedment in hip joints.Embedded tissues in theacetabulum were excised during surgery and intra-articular changes were observed.Another 5 patients with avascular necrosis of the femoral head were also included in the study.Normal acetabular labrum,acetabular cartilages,and ligamentum teres of the femur were harvested from patients during surgery.All the specimens were labeled and stained by HE and observed using microscopy.(4)? A series of 65 developmental dysplasia of the hip(DDH)cases who underwent PAO was observed retrospectively.At least 1.5 cm size labrum injury was detected by MRI.Labrum repaired group included 47 cases who underwent periacetabular osteotomy and labral repair.Mean follow up was at least 1 years.Control group included 18 cases who underwent periacetabular osteotomy without labral repair.Mean followup was at least1 years.Results:(1)? The upper part of the normal labrum is wider than the front.The maximum width at 9 o'clock is 6.06 ± 2.54 mm,the 1 point is the smallest,3.82 ± 0.78 mm.the thickness of 3-point are the largest,3.79 ± 0.95 mm,4-point are the smallest,2.89 ± 0.61 mm.(2)?The labrum of the DDH group was wider than the normal labrum at anterosuperior quadrant,and was thickened at anterosuperior and posterosuperior quadrants of the acetabulum.The phenomenon of labrum tear in adults with DDH were very common(43.2%),which occurred most at 1 point and negatively correlated with LCE angle.The labrum varus was not uncommon(10.8%),which occurred mostly at 12 o'clock,and negatively correlated with LCE and EI,but positively correlated with AI.(3)? HE staining of all 15 embedded tissues were consistent with those of normal acetabular labrum,which were composed of fibrous cartilage.Normal acetabular cartilage and ligamentum teres of the femur were characterized as hyaline cartilage and fibrous connective tissue,respectively.Significant degeneration of the acetabular cartilage at the original sites of tissue embedment were observed after removal of the embedded tissues in all 15 DHH patients.(4)?We compared the result between two groups according to the Harris hip score and iHOT-12 score.There is no significant difference in Harris score between the two groups.However,better iHOT-12 score was seen in labrum repaired group.One of the indicator in iHOT-12 score "abdominal inguinal region pain" in significantly higher in labrum repaired group than in control group(P<0.05).Conclusion:1? According to the clock mode,the length are the widest at 9 points and the thickest at 3 points in the normal labrum.The upper part of the normal labrum is wider than the front.2?the width and thickness of labrum in Adult DDH patients were larger than the normal labrum,especially at the upper quadrant.The phenomenon of labrum tear in adults with DDH were very common(43.2%),which negatively correlated with LCE angle.The labrum varus was not uncommon(10.8%),and negatively correlated with LCE and EI,but positively correlated with AI.3?These data suggest that embedded tissues in the hip joint of DDH patients are fibrous cartiage,which are the same with the normal labrum.4?For the adult DDH patients with labrum injury larger than 1.5cm,labrum repair as well as PAO should be performed.