Planification préopératoire d’une PTH : cette partie essentielle de la procédure doit-elle être nécessairement réalisée par le chirurgien orthopédiste ? Est-elle influencée par le design de l’implant ? Une étude prospective à propos de 200 arthroplasties totales de hanche.

Background
Currently, patients who undergo total hip arthroplasty want a complete restoration of their hip function and not only pain relief. Templating in THA is essential for accurately predicting the optimal size of the implants required. It also reduces the risk of potential complications.
Aim
To check the reproducibility of our preoperative planning, to compare the accuracy of templating between orthopedic surgeon (OS), orthopedic resident (OR) and data manager (DM), to determine the learning curve between the different planners and to evaluate the effect of body mass index impact on digital templating for THA.
Materials and methods
The software used for templating was IMPAX-Orthopaedic-Tools. A calibration marker (28-mm ball) was used for calibration. All the anteroposterior pelvis radiographs were planned by three participants (OS, OR, DM).
Results
We systematically collected the precisely planned size measurements as well as the variation by 1 or 2 sizes of prostheses. At +/- 1 size, we did not find any significant difference between the participants with respectively 94%, 96% and 93% concordance for the cup, 88%, 90% and 90% for the stem and 85%, 84% and 83% for the neck.
Conclusions
Our preoperative templating was accurate in predicting the required implant size and results were similar to those available in the literature. We did not find any difference between the planners and we were unable to objectivate a learning curve period. We conclude that this essential part of the planning procedure can be performed by the surgeon himself or an orthopedic resident or data manager who has anatomical knowledge if the surgeon is unable to perform templating himself.