Implementation of a semiautomatic method to design patient-specific instruments for corrective osteotomy of the radius

G Caiti*, J G G Dobbe, A C Y Loenen, M Beerens, S D Strackee, G J Strijkers, G J Streekstra

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


PURPOSE: 3D-printed patient-specific instruments (PSIs), such as surgical guides and implants, show great promise for accurate navigation in surgical correction of post-traumatic deformities of the distal radius. However, existing costs of computer-aided design and manufacturing process prevent everyday surgical use. In this paper, we propose an innovative semiautomatic methodology to streamline the PSIs design.

METHODS: The new method was implemented as an extension of our existing 3D planning software. It facilitates the design of a regular and smooth implant and a companion guide starting from a user-selected surface on the affected bone. We evaluated the software by designing PSIs starting from preoperative virtual 3D plans of five patients previously treated at our institute for corrective osteotomy. We repeated the design for the same cases also with commercially available software, with and without dedicated customization. We measured design time and tracked user activity during the design process of implants, guides and subsequent modifications.

RESULTS: All the designed shapes were considered valid. Median design times ([Formula: see text]) were reduced for implants (([Formula: see text]) = 2.2 min) and guides (([Formula: see text]) = 1.0 min) compared to the standard (([Formula: see text]) = 13 min and ([Formula: see text]) = 8 min) and the partially customized (([Formula: see text]) = 6.5 min and ([Formula: see text]) = 6.0 min) commercially available alternatives. Mouse and keyboard activities were reduced (median count of strokes and clicks during implant design (([Formula: see text]) = 53, and guide design (([Formula: see text]) = 27) compared to using standard software (([Formula: see text]) = 559 and ([Formula: see text]) = 380) and customized commercial software (([Formula: see text]) = 217 and ([Formula: see text]) = 180).

CONCLUSION: Our software solution efficiently streamlines the design of PSIs for distal radius malunion. It represents a first step in making 3D-printed PSIs technology more accessible.

Original languageEnglish
Pages (from-to)829-840
Number of pages12
JournalInternational Journal of Computer Assisted Radiology and Surgery
Issue number5
Early online date10 Dec 2018
Publication statusPublished - May 2019


  • Patient-specific instruments
  • Distal radius malunion
  • Computer-aided design
  • Semiautomatic design

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