IS THERE A CORRELATION BETWEEN SEVERITY OF HIP DYSPLASIA AND SOCKET LOOSENING IN CEMENTED THR?

Abstract

To determine socket survivorship in DDH based on the severity of hip dysplasia, we carried out a retrospective study of 283 cemented total hip replacements carried out at Wrightington. The hips were classified according to the Crowe and Hartofilakidis classifications. Revision was used as the end point for prosthetic survivorship. The results were analysed statistically using SPSS for Windows

The mean age at time of surgery was 42.6 years with a mean follow-up of 15.7 years. The acetabulum was grafted in 46 cases. The commonest cause for revision was aseptic loosening of the acetabular component (88.3%). 254 procedures were carried out through a transtrochanteric approach with a direct lateral approach used for the remaining mildly dysplastic hips. At 10 years 5.3% of dysplastic, 14.8% of low dislocation and 51.1 % of high dislocation hips were revised.. At 10years 6% of Crowe Type1, 8.5% of Type2, 25.5% of Type3 and 39.2% of Type4 hips were revised. At 20 years 24% of dysplastic, 45% of low dislocation and 88% of high dislocation hips were revised. At 20years 27.3% of Crowe Type1, 29.3% of Type2, 63.3% of Type3 and 84.4% of Type4 hips were revised. The 20 year survival of patients less than 50 years of age at the time of surgery was 61% as compared to 92% survival in patients more than 50 years of age. The mean age of patients in the revised group was 35 years as compared to 45 years in the non-revised group.

Conclusion: This study demonstrates satisfactory results in dysplastic hips following cemented total hip replacements. With increasing severity of hip dysplasia there is a higher rate of premature failure of the acetabular component. There is adverse correlation between age and survival of the acetabular component. There is a dramatic increase in cup failure between 10 and 20 years.