Article Abstract

A preliminary evaluation of raising the center of rotation in total hip arthroplasty for the patients with developmental dysplasia of the hip

Authors: Jiandong He, Yi Wang, Liang Du, Ming Ni, Xiang Li, Guoqiang Zhang, Jiying Chen, Wei Chai

Abstract

Background: Total hip arthroplasty is an effective treatment for developmental dysplasia of the hip (DDH). However, there are still debated issues in total hip arthroplasty (THA) for DDH patients. Placing the acetabular cup according to the anatomic center of rotation (COR) in THA is not always the perfect choice for the DDH patients. We raised the COR in THA in order to get better press fit and coverage for the acetabular cup. This study aims to evaluate the clinical results of raising the COR in total hip arthroplasty for the patients with developmental dysplasia of the hip.
Methods: A retrospective analysis was carried out in 16 DDH patients (19 hips) who received THA in our department from March 2015 to January 2016. The COR was raised in THA for all the 19 hips. We evaluated the vertical distance between COR of acetabular cup and anatomic COR, horizontal distance between COR of acetabular cup and anatomic COR, coverage for acetabular cup, preoperative Harris hip score and postoperative Harris hip score.
Results: The mean follow-up time of 16 cases (19 hips) DDH was 16 months (range, 4–22 months). The mean vertical distance between COR of acetabular cup and anatomic COR was 1.07±0.26 cm (range, 0.68–1.48 cm). The mean horizontal distance between COR of acetabular cup and anatomic COR was 0.24±0.11 cm (range, 0.10–0.51 cm). The mean coverage for acetabular cup was 88.3% (range, 79.8–97.7%). The mean preoperative Harris hip score was 51.9±13.9 (range, 36.4–75.8), and the mean postoperative Harris hip score was 85.5±6.5 (range, 75.6–95.8), and there is significant difference between the two groups (P<0.01).
Conclusions: Raising the COR in THA for DDH patients is a feasible option when the coverage for acetabular cup was poor. A detailed preoperative plan is the crucial step to get good coverage for acetabular cup and minor limb length discrepancy.