Influence to the curative effect of THA with different methods to reconstruct limb length for Crowe IV type developmental dysplasia of the hip

Objective To explore the differences of the joint function and the patient's satisfaction between two different methods to reconstruct limb length for unilateral Crowe Ⅳ developmental dysplasia of the hip (DDH).Methods The clinical controlled study were used.21 cases with unilateral DDH Crowe Ⅳ treated with total hip arthroplasty were divided into 2 groups randomly.The patients in the first group were reconstructed the limb with the compensatory length and those in the second group were did with the real length.The patients were followed up 10 years.Two independent sample t-test was used to compare these two operations.Harris scores and SF-36 scores were used in the test.Survival analysis with Kaplan-Meier method was involved in the survival of the prosthesis and then test with Log-rank test.X-ray films of different period were compared to confirm the prosthetic loosening.Results Seventeen patients were followed up 8-10 years.There were no significant differences both in Harris score and most of the SF-36 scores at the median follow-up of 10 years.The item mental healthy of SF-36 expressed significant difference.Five patients required revision.There were 10 cases suffered with polyethylene wear,6 cases with severe osteoporosis in greater trochanter,and 3 cases with osteolytic reaction.Conclusion There are no significant differences between the two surgical method in the survival rate of prosthesis and the joint function in the median follow up.The satisfaction of the control groups is lower than the trial groups both at the early stage after the operation and the median follow up.The revision rate between the two groups is similar but the reason is different. Key words: Hip dislocation, congenital;  Arthroplasty, replacement, hip;  Follow-up studies