Assessment of reproducibility and accuracy in templating hybrid total hip arthroplasty using digital radiographs

Abstract

In 20 patients undergoing hybrid total hip arthroplasty, the reproducibility and accuracy of templating using digital radiographs were assessed. Digital images were manipulated using either a ten-pence coin as a marker to scale for magnification, or two digital-line methods using computer software. On-screen images were templated with standard acetate templates and compared with templating performed on hard-copy digital prints. The digital-line methods were the least reliable and accuracy of sizing compared with the inserted prostheses varied between -1.6% and +10.2%. The hard-copy radiographs showed better reproducibility than the ten-pence coin method, but were less accurate with 3.7% undersizing. The ten-pence coin method was the most accurate, with no significant differences for offset or acetabulum, and undersizing of only 0.9%. On-screen templating of digital radiographs with standard acetate templates is accurate and reproducible if a radiopaque marker such as a ten-pence coin is included when the original radiograph is taken.

Acetate Templating on Digital Images Is More Accurate Than Computer-based Templating for Total Hip Arthroplasty

“…Intraobserver ICC values showed almost perfect agreement (ICC [ 0.8) for both acetabular and femoral components when using both templating methods, suggesting both methods are highly reproducible. Our ICC values correspond well to previous studies, which found ICC values ranging from 0.7 to 0.97 [6,10,15,21]. Our study showed that experience level did not have an effect on accuracy nor intraobserver variability.…”

“…However, values were lower than that quoted by Gamble et al [10], which found ICC values ranging from 0.8 to 0.94. We found moderate interobserver ICC value agreement for the acetate templating for the acetabular component, similar to the findings of Oddy et al (ICC, 0.43-0.47) [21]. Intraobserver ICC values showed almost perfect agreement (ICC [ 0.8) for both acetabular and femoral components when using both templating methods, suggesting both methods are highly reproducible.…”

“…Templating is an important aspect of preoperative planning for THA and can minimize both intraoperative and postoperative complications related to THA such as instability, leg length discrepancy, periprosthetic fracture, prosthetic loosening, and loss of bone stock [4,5,8,13,14,19,21,22]. Many surgeons use either standard radiographs with acetate templates or digital templating for preoperative planning for THA.…”

“…We have begun using a hybrid templating technique for THA, which involves templating directly over digital images on the liquid crystal display (LCD) monitor using acetate templates. This method has been described previously for use in templating for hybrid THA [21], but to our knowledge, its validity and reliability have yet to be studied in press-fit THA nor has it been compared with digital templating.…”

Digital templating in total knee and hip replacement: an analysis of planning accuracy

“…Different methods of scaling digital radiographs have been described and investigated to improve planning accuracy [17][18][19][20][21]. Accurate positioning of the reference ball at the level of the joint is crucial to achieving the greatest possible referencing reliability [17,22,23].…”