Digital Templating for Total Knee Arthroplasty (TKA)
Prepared byDr. Kayahan KARAYTUG
Overview
Preoperative digital templating in total knee arthroplasty (TKA) aims to estimate implant size and assist surgical planning. Unlike THA, its influence on postoperative biomechanics and clinical outcomes remains limited.
Purpose of TKA Templating
Digital templating in TKA is primarily used to:
Estimate femoral and tibial component size
Anticipate bone resections
Support implant inventory planning
Accuracy of Digital Templating in TKA
Studies demonstrate that digital templating:
Predicts implant size within ±1 size in most cases
Rarely predicts the exact final implant size
Does not reliably predict postoperative alignment
Clinical Impact
Current evidence shows no consistent association between templating accuracy and:
As such, digital templating does not appear to directly influence functional outcomes in TKA.
Limitations
Variable sizing accuracy
Additional cost related to software licensing and training
Increased preoperative planning time
Limited impact on clinical results
Alternative Predictive Methods
Demographic-based prediction models using:
Patient height
Weight
Sex
Age
have demonstrated equal or superior accuracy in estimating component size compared with digital templating, while being faster and more cost-effective.
Practical Role of TKA Templating
The primary benefit of digital templating in TKA lies in:
Logistical preparation
Implant inventory management
Surgical workflow optimization
rather than direct improvement in patient outcomes.
Key Clinical Pearls
TKA templating is a planning aid, not a determinant of outcome
Alignment and function depend more on surgical technique than templating
Demographic models may replace templating for routine sizing
References:
Chau R, et al. Preoperative templating in total knee arthroplasty: How accurate is it? J Arthroplasty. 2009;24(5):681–687.
Issa K, et al. Reliability of digital templating in predicting implant size in total knee arthroplasty. J Knee Surg. 2013;26(5):351–355.
Sershon RA, et al. Does preoperative templating improve outcomes in total knee arthroplasty? J Arthroplasty. 2016;31(9):1986–1990.
Schotanus MGM, et al. No difference in implant size prediction between digital templating and anthropometric data in TKA. Knee Surg Sports Traumatol Arthrosc. 2017;25(11):3483–3490.
Nunley RM, et al. Do patient demographics predict component size in total knee arthroplasty? Clin Orthop Relat Res. 2012;470(1):182–189.
Hitt K, et al. Anthropometric measurements of the human knee: Correlation with implant sizing. J Bone Joint Surg Am. 2003;85(1):115–122.
