Analysis Of Correlation Factors Of Reset Infant DDH With Pelvic Osteotomy

Objective: To analysis the radiographic parameters of the X-ray films beforetreatment of those hips which need to pelvic surgery; To study potential radiologicpredictors of those that will require pelvic surgery；To guide the clinical application andbetter communicate with parents.Materials and Methods: Collect103cases of development displasia of the hip whowere treated in our hospital from March2006to February2012patients (aged12to36months). Dislocations secondary to neuromuscular causes or teratologic causes wereexcluded. There were54cases with complete clinical data and radiographic, a total of71hips. Divided the hips into two groups according to whether need pelvic osteotomy(PO)after they successfully relocated: group A(non-PO group); gropg B(PO group).Recordedall the patients’ sex, age, the side of dislocation. Measurements of the pelvic plainradiograph before the initial procedure in terms of distance from center of femoral headossific nucleus to midline(X1), distance from center of femoral head ossific nucleus toP-line(X2), distance from center of femoral head ossific nucleus to H-line(Y), width offemoral head ossific nucleus(D1), height of femoral head ossific nucleus(D2), distancefrom most medial proximal femoral metaphysis to midline(c), distance from most superiorproximal femoral metaphysis to H-line (h), modified Head-Tear drop distance (HT),distance from P-line to midline (b), acetabular length (A1), acetabular depth (A2),acetabular angle(T), the distance between the most medial borders of iliac bones in bothsides (A), the pelvic width(W), Smith’s c/b ratio and Smith’s h/b ratio. Univariate t testswere used to compared the first procedure age and all above radiographic measurements inthe two groups with SPSS17.0software, in order to check the statistical significance.Results: All patients were followed up for average35month（sfrom12to83months）.29hips(40.8%)later require a secondary pelvic osteotomy in all the71hips. X2, Y, h, theSmith’s c/b ratio and the Smith’s h/b ratio were significantly different between the2groups(higher in the OP group) with P. values of <0.005. The age at the first procedure, c, HT, b,A2were also found to be significantly higher in the PO group with P. values of <0.05. Conclusions：Based on our research, all measurements of lateralization (X2, c, HT,c/b ratio) and the superior migration measurements (Y, h, h/b ratio) may the potentialradiographic facors predicting the need for later pelvic osteotomy, and the distance fromcenter of femoral head ossific nucleus to P-line(X2), the c/b ratio and the h/b ratio may bethe best predictors.