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

Abstract

Background Templating is an important aspect of preoperative planning for total hip arthroplasty and can help determine the size and positioning of the prosthesis. Historically, templating has been performed using acetate templates over printed radiographs. As a result of the increasing use of digital imaging, surgeons now either obtain additional printed radiographs solely for templating purposes or use specialized digital templating software, both of which carry additional cost. Questions/purposes The purposes of this study was to compare acetate templating of digitally calibrated images on an LCD monitor to digital templating in terms of (1) accuracy; (2) reproducibility; and (3) time efficiency.Methods Acetate onlay templating was performed directly over digital radiographs on an LCD monitor and was compared with digital templating. Five separate observers participated in this study templating on 52 total hip arthroplasties. For the acetate templating, the digital images were magnified to the scaled reference on the templates provided by the manufacturer (ratio 1.2:1) before templating using a 25-mm marker as a reference. Both the acetate and digital templating results were then compared with the actual implanted components to determine accuracy. Interobserver and intraobserver variability was determined by an intraclass correlation coefficient. Observers recorded time to complete templating from the time of complete upload of patients' imaging onto the system to completion of templating. Conclusions Acetate onlay templating on digitally calibrated images can be a reliable substitute for digital templating using specialized software. It is quicker to

Templating in uncemented total hip arthroplasty—on intra- and interobserver reliability and professional experience

“…An increasing number of studies aim to evaluate the accuracy, precision and reliability of preoperative templating in THA, and the results are predominantly reported in favour of templating (10)(11)(12)(13)(14)(15). Most publications follow the example of Knight and Atwater, who used a ±1 size approximation of the component sizes in their evaluation.…”

“…The results are predominantly reported as favourable, and the recommendation to utilize the method is strong (15). However, most studies report on at least partially cemented prostheses, which is less dictated by anatomical constraints than uncemented prostheses.…”

Accuracy and Reliability of Preoperative On-screen Templating Using Digital Radiographs for Total Hip Arthroplasty

“…Preoperative on-screen templating methods have been described in several earlier papers1314151617). Petretta et al17) compared acetate templating of digitally calibrated images on an liquid crystal display (LCD) monitor to digital templating in their 52 THAs, and concluded that acetate onlay templating on digitally calibrated images can be a reliable substitute for digital templating.…”

“…Petretta et al17) compared acetate templating of digitally calibrated images on an liquid crystal display (LCD) monitor to digital templating in their 52 THAs, and concluded that acetate onlay templating on digitally calibrated images can be a reliable substitute for digital templating. Krishnamoorthy et al13) also studied the accuracy and reliability of templating the acetabular cup size using conventional acetate templates on digital radiographs, and they reported 90% prediction rate for the acetabular cup size within ±1 size.…”

“…Although digital templating was less accurate than acetate templating in many studies, some studies reported no differences between the two templating methods, and concluded that digital templating was safe and reliable128926). But one recent study comparing acetate templating on an LCD monitor to digital templating reported the superiority of the acetate onlay templating in terms of accuracy, reproducibility and time efficiency17).…”