A Comparison of Acetate vs Digital Templating for Preoperative Planning of Total Hip Arthroplasty: Is Digital Templating Accurate and Safe?

doi:10.1016/j.arth.2007.11.019

The Journal of Arthroplasty

Volume 24, Issue 2, February 2009, Pages 175-179

https://doi.org/10.1016/j.arth.2007.11.019 Get rights and content

Abstract

The purposes of this study were to compare the accuracy of acetate and digital templating for primary total hip arthroplasty (THA) and to determine if digital templating is safe. Preoperative planning was performed on 50 consecutive preoperative radiographs during 2005. Templating results were compared with the actual hip implants used. Interrater reliability of acetate templating and accuracy of acetate and digital templating were recorded. Digital measurement overestimated acetabular size (P < .001) and underestimated the femoral size (P = .03). The absolute errors were larger for digital compared with acetate templating; however, mean absolute errors did not differ significantly (acetabulum, P = .090; femur, P = .114). Acetate and digital templating can accurately predict the size of THA implants. Digital templating was determined to be acceptably safe for preoperative planning of primary THA operations.

Section snippets

Materials and Methods

Preoperative templating for THA requires standardized radiographs with consistent magnification and matching templates. Traditional pelvic and hip radiographs are performed with the x-ray tube at a standardized distance from the x-ray table 1, 2, 3, 12. The magnification of the images is proportional to the distance between the pelvis and the film. This distance can be affected by the size of the patient [1].

Traditional acetate templating uses a fixed magnification of the overlaid implant [1].

Results

Acetate templating predicted acetabular cup size within one size in 196 (78%) of 250 cases. Digital templating predicted acetabular cup size within one size in 30 (60%) of 50 cases. Acetate templating predicted femoral stem size within one size in 192 (77%) of 250 cases. Digital templating predicted femoral stem size within one size in 37 (74%) of 50 cases. Digital measurements significantly overpredicted cup size (negative error values, P < .001) (Table 1). Digital measurements significantly

Discussion

In this study, preoperative planning for THA was accurate and safe with acetate and digital templating. Digital templating, which represents a technologic innovation for reconstructive surgeons, was not more accurate than acetate templating. However, preoperative digital measurement was found to be acceptably safe for planning primary total hip arthroplasty operations. Preoperative acetate templating of appropriately magnified analog films demonstrated good to excellent interrater reliability.

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Cited by (97)

Comparison of three-versus two-dimensional pre-operative planning for total hip arthroplasty
2024, Journal of Orthopaedics
A successful clinical outcome for total hip arthroplasty (THA) depends on accurate sizing and positioning of the implants. Using three-dimensional (3-D) pre-operative planning with a computerized tomography (CT) scan has many potential advantages over conventional 2-D planning using radiographs, including potentially more accurate assessments of the size and anteversion of the acetabulum, as well as lateral femoral offset. The purpose of this study was to compare the accuracy of 3-D to 2-D templating with respect to acetabular and femoral size, as well as lateral femoral offset.
Pre-operative templating data was collected prospectively from a consecutive series of 290 primary THAs (acetabulum on all, femoral component on 255 of the cases using one specific stem). All cases were initially templated on a digital imaging picture archiving and communication (PACS) system with calibrated images to estimate the acetabular size, femoral size, and lateral femoral offset. The 3-D templating was then performed with software based on a CT scan, and the results were compared to what was surgically implanted.
The 3-D templating for the acetabulum was accurate 99.7% of the time based on the final implanted component. The 2-D templating for the acetabulum was accurate 39% of the time, with 46% templating larger and 15% templating smaller than the final implanted component. The 3-D templating of the femoral component was accurate 63% of the time, and within one size of final implant in 96% of cases. The 2-D templating of the femoral component was accurate 53% of the time and within one size of final implant in 94% of cases. Lateral femoral offset consistently matched the 3-D plan, with a 100% match rate. The 2-D templated femoral offset was accurate 87% of the time and was changed in 13% of cases after 3-D templating.
The CT-based 3-D preoperative planning was superior to 2-D planning for THA with respect to acetabular size, femoral size, and lateral femoral offset. Precise acetabular component sizing conserves bone and allows for a more predictable press fit, while facilitating efficient inventory management. Lateral femoral offset is often difficult to measure on 2-D images, and 3-D templating consistently allows for accurate offset restoration, which is important for normal hip function and stability.
Free Hip Arthroplasty Templating Software - Does it Work?
2023, Arthroplasty Today
Preoperative planning is important for successful total hip arthroplasty (THA) and has been historically performed using acetate templates. Digital software templating has been adopted for evaluating implant size, position, and alignment. Commercial software can be expensive, but free programs exist. Detroit Bone Setter (detroitbonesetter.com, Detroit, MI) is a freely available templating program, but hasn’t been validated. Our study reports this program’s accuracy for templating THA.
Sixty-five patients undergoing THA between 2017 and 2022 at 2 hospitals were included. All cases were templated by the senior author or orthopaedic trauma fellow prospectively or retrospectively in a blinded fashion. Direct anterior or posterior approaches were used based on attending surgeon’s preference. A student's t-test was used to compare means of templated vs actual implant sizes of femoral and acetabular components.
There was no significant difference between implanted (mean [M] = 6.4, standard deviation [SD] = 2.0) and templated femoral component sizes (M = 5.7, SD = 2.1). There was a significant difference between implanted (M = 57.0, SD = 3.9) and templated acetabular component sizes (M = 53.4, SD = 3.0). Bland-Altman testing demonstrated femoral components with positive measurement bias of 0.62, indicating slight overestimation of implant size. Acetabular component size was overestimated with positive measurement bias of 3.6 mm.
Detroit Bone Setter is advantageous as it is freely available and supports most major company implants. It accurately templated femoral component size but consistently overestimated acetabular component size by 3.6 mm. Further studies are needed prior to recommending its routine use for templating THA when other validated methods exist. It could be used with caution when no other methods are available.
Under viral attack: An orthopaedic response to challenges faced by regional referral centres during a national cyber-attack
2022, Surgeon
Citation Excerpt :
The success of many Orthopaedic procedures is contingent on careful preoperative planning.9 Templating of prosthetic components using preoperative radiographs is a safe and accurate method15 of assessing component sizes16,17 for joint arthroplasty. Templating can aid preoperative planning such that component sizes can be predicted with a greater degree of accuracy, which is beneficial in cases where sizes with reduced availability are required.9
A national ransomware attack on the Irish Health Service Executive left the Healthcare system bereft of access to IT systems, electronic patient records, and the national imaging system. Widespread disruption to internal and external referral pathways, and both trauma and elective Orthopaedic services occurred as a result. The purpose of this paper to discuss the challenges faced by Regional trauma units and adjustments made to overcome these.
Issues occurring as a result of the IT cybersecurity attack were discussed at regional level. Local and specialist centre adaptations were collated to identify effective modifications to established practice in the wake of the IT attack.
The main areas affecting Orthopaedic regional practice were identified, including internal referrals, interhospital referrals to both regional and specialist centres, outpatient clinics, and elective practice. Strategies to overcome these were collated and shared between regional centres, including the use of secure messaging systems to safely transmit relevant clinical information between services, use of radiological hard copies, and integration of imaging resources to the outpatient department to expedite clinical review.
The national cyberattack necessitated rapid adaptations to overcome the challenges faced as a result of reduced clinical and radiological access. While the recent cyberattack highlights the vulnerability of electronic systems, and the need for vigilance including staff training on cybersecurity; Changes implemented by regional centres also illustrate the potential for further development and expansion of current clinical practices.
Digital templating in hip hemiarthroplasty: Is it possible to accurately predict femoral head size from magnification alone?
2022, Journal of Clinical Orthopaedics and Trauma
Templating is an integral part of pre-operative planning in elective hip arthroplasty to achieve favourable long-term outcomes, but its applications in trauma surgery remain limited. When templating from radiographs without a calibration marker, there is always an element of magnification which must be accounted for. Our aim was to establish our institute-specific magnification and to determine whether using this to predict femoral head size in hemiarthroplasty was more accurate than using set magnifications previously reported in the literature.
Fifty consecutive patients who underwent hip hemiarthroplasty were retrospectively identified, their pre-operative radiographs reviewed and femoral head measured with templating software. Intra- and inter-observer reliability analyses were performed. Using this value, and two set values of 15% and 21% magnification, we attempted to predict femoral head sizes of our original cohort. The results were compared using paired t-test to ascertain if there was any significant difference in accuracy.
We established our institute-specific magnification as 17%. Inter- and intra-observer reliability were excellent. However, using this magnification we were only able to correctly predict to within ± one femoral head size in 49% of patients. There was no significant difference in accuracy comparing our institute-specific magnification with other magnifications from the literature.
We would not recommend using magnification factor in digital templating software as this could potentially lead to errors in predicting final femoral head size in hip hemiarthroplasty and adversely affect patient outcomes.
Demographic Data Reliably Predicts Total Hip Arthroplasty Component Size
2022, Journal of Arthroplasty
Preoperative radiographic templating for total hip arthroplasty (THA) has been shown to be inaccurate, although essential for streamlining operating room efficiency. Although demographic data have shown to predict total knee arthroplasty component sizes, the unique contour and design among femoral stem implants have limited a similar application for hip arthroplasty. The purpose of this study was to determine whether demographic data may predict cementless THA size independent of the stem design.
A consecutive series of 1,653 index cementless metaphyseal-fitting THAs were reviewed between 2007 and 2019. This included 12 unique femoral component designs, 6 acetabular component designs, 60 femur size-design combinations, and 23 acetabular size-design combinations. Implanted component sizes and patient demographic data were collected, including gender, height, weight, laterality, age, race, and ethnicity. Multivariate linear regressions were formulated to predict implanted femur and acetabular component sizes from the demographic data.
There was a significant linear correlation between gender, implant model, age, height, and weight for femur (R² = 0.778; P < .001) and acetabular (R² = 0.491; P < .001) sizes. Calculated femur and acetabular component sizes averaged within 0.97 and 0.95 sizes of those implants, respectively. Femur and acetabular sizes were predicted within 1 size 79.1% and 78.2% and within 2 sizes 94.3% and 94.6% of the time, respectively.
Multivariate regression models were created based on specific demographics data to predict femur and acetabular component sizes. The model allows for simplified preoperative planning and potential cost savings implementation. A free phone application named EasyTJA was constructed for ease of implementation.
Accuracy of Preoperative Templating in Total Hip Arthroplasty With Special Focus on Stem Morphology: A Randomized Comparison Between Common Digital and Three-Dimensional Planning Using Biplanar Radiographs
2021, Journal of Arthroplasty
Accurate preoperative planning is a key component of successful total hip arthroplasty (THA). The purpose of the present study was to compare the accuracy and reliability of three-dimensional (hipEOS) and common digital two-dimensional (TraumaCad) templating with special focus on stem morphology.
51 patients undergoing THA were randomized to two groups. Preoperative planning was performed on 23 patients with hipEOS (3D) and on 28 patients with TraumaCad (2D) planning software. Planning results were compared with the implanted component size. Inter- and intraobserver reliability as well as planning accuracy of both planning methods with special focus on straight and short stem design were recorded.
Intraobserver reliability of both planning methods was good for component planning (ICC_2,1: 0.835-0.967). Interobserver ICC_2,1 for stem and cup planning were higher for 3D templating (3D ICC_2,1: 0.906-0.918 vs. 2D ICC_2,1: 0.835-0.843). Total stem and cup size predictions were within 2 sizes for 3D and within 3 sizes for 2D planning. Comparing short stem planning accuracy of both planning methods, absolute difference between implanted and planned component size was significantly lower in 3D planning (P = .029). There was no significant difference in straight stem (P = .935) and cup (P = .954) planning accuracy.
Our findings suggest that 3D templating with hipEOS software has a good overall reliability and may have a better planning accuracy of short stem prostheses than digital templating with TraumaCad software. Assuming that the number of implanted short stem prostheses will further increase in coming years, a more precise planning with 3D technique can contribute to improve surgery outcome.

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: No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article. No funds were received in support of this study.

: Investigation performed at the Department of Orthopedic Surgery, Lahey Clinic Medical Center, Burlington, Mass.

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Original ArticleA Comparison of Acetate vs Digital Templating for Preoperative Planning of Total Hip Arthroplasty: Is Digital Templating Accurate and Safe?

Abstract

Section snippets

Materials and Methods

Results

Discussion

J Arthroplasty

J Arthroplasty

J Arthroplasty

Preoperative planning for primary total hip arthroplasty

J Am Acad Orthop Surg

Preoperative templating and biomechanics in total hip arthroplasty

Orthopedics

Comparison of preoperative templating with postoperative assessment in cementless total hip arthroplasty

Acta Orthop Scand

Original Article
A Comparison of Acetate vs Digital Templating for Preoperative Planning of Total Hip Arthroplasty: Is Digital Templating Accurate and Safe?