Abstract
Introduction
The goal of total hip arthroplasty (THA) should be to reconstruct the acetabulum by positioning the hip center as close as possible to the anatomical hip center. However, the true position of the anatomic hip center can be difficult to determine during surgery on an individual basis. In 2005, we designed, produced an acetabular reaming guide, and clinically used to enable cup placement in the ideal anatomical position. This study was examined the accuracy the reaming guide for THA in prospective study.
Methods
This guide was applied consecutive 230 patients in primary THA. During planning, the distance from the acetabular edge to the reaming center and from the center to the perpendicular of the inter-teardrop line was measured on an anteroposterior (AP) X-ray. The reaming guide was adjusted depend on the reaming center by based planning. Acetabular reaming was performed with the process reamer.
Results
At planning, the position of the hip center was 18.1 mm in the vertical offset (VO) and 29.6 mm in the horizontal offset (HO). After surgery, the position of the hip center had a VO of 18.1 mm and an HO of 29.9 mm. The absolute error between planning and post-operation was a VO of 2.7 mm and an HO of 2.9 mm. Overall, 199 cases (86.5%) had an HO error of less than 5 mm and 204 cases (89.6%) had a VO error of less than 5 mm. The vertical height from the teardrop line to the inferior edge of the acetabular cup was 0.5 ± 3.5 mm.
Conclusion
The new reaming guide was closely reproduced the preoperative planning position in this prospective study. Our original acetabular reaming guide is a very useful tool for performing reaming during THA and for ensuring accurate cup placement at the anatomical hip center.
