Clinical Orthopaedics and Related Research: June 2011 - Volume 469 - Issue 6 - p 1554–1559 doi: 10.1007/s11999-010-1701-1 Symposium: Update on Hard-on-Hard Bearings in Hip Arthroplasty

Intraoperative Radiographs for Placing Acetabular Components in Hip Resurfacing Arthroplasty

Gross, Thomas, P., MD1; Liu, Fei, PhD1, a; Webb, Lee, NP1
Hip

Background Various clinical and biomechanical studies suggest certain acetabular positions may be associated with higher wear and failure rates in modern metal-on-metal hip resurfacing arthroplasties. However, there are no widely available, reliable, and cost-effective surgical techniques that ensure surgeons are able to place an acetabular component within the safe range of inclination angles after hip resurfacing surgeries.

 

Questions/purposes We investigated the accuracy of intraoperative radiographs to determine the acetabular inclination angle in resurfacing arthroplasty procedures.

 

Patients and Methods The study group included the first 100 resurfacing arthroplasties performed after we started routinely checking the intraoperative acetabular inclination angles. The acetabular component was repositioned if the intraoperative acetabular inclination angle was out of the target range of 30° to 50°. The control group included the previous 100 resurfacing arthroplasties performed without the benefit of intraoperative radiographs. A posterior minimally invasive surgical approach was used in both groups. Demographics and diagnoses were similar in both groups.

 

Results The average (± SD) difference between the intraoperative and 6-week radiographs was 2.7° ± 2.5°. The acetabular inclination angles at 6-week followup were within the targeted range more frequently in the study group than in the control group (outliers: 4% versus 29%).

 

Conclusions These data suggest a single intraoperative radiograph is a quick, reliable, and cost-effective method for ensuring the acetabular inclination angle is within the targeted range.

 

Level of Evidence Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.


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