# Patient specific instrumentation for open Latarjet procedure. Technique, accuracy, and short-term outcome. A prospective case series

## TL;DR

This study introduces a new surgical technique using 3D-printed guides to improve accuracy in a shoulder stabilization procedure.

## Contribution

A patient-specific instrumentation technique using 3D-printed guides is proposed for the Latarjet procedure.

## Key findings

- Median mediolateral displacement of grafts was 0.01 mm medially compared to digital plans.
- All grafts showed healing within six weeks post-surgery.
- One screw was malpositioned in a single case despite guide modifications.

## Abstract

The Latarjet procedure is a common technique to address anteroinferior shoulder instability. However, inadequate positioning of the coracoid bone graft may lead to persistent instability or early arthritis, with complication rates described up to 15% in open procedures. Adequate bone-block positioning tailored to patients’ scapular morphology may reduce these complications. This study aims to optimize the Patient-Specific Instrumentation (PSI) Latarjet procedure by detailing the technique and assessing the accuracy of graft positioning through a comparison of the digitally planned and actual surgical outcomes. It is hypothesized that patient-specific, 3D-printed guides will enhance coracoid graft accuracy in the open Latarjet procedure.

Between January and May 2024, 5 patients underwent the open PSI Latarjet procedure. Using computer aided design software, the procedure was digitally planned, followed by the design and production of PSI drill guides utilized in a standard double screw technique. Patients were immobilized for three weeks with radiological evaluations at 6 weeks postoperatively.

All patients were included in the analysis. Compared to digitally planning, the median mediolateral displacement was 0.01 mm medially (range 1.8 mm medially-1.7 mm laterally), and the median craniocaudal displacement was 0.97 mm caudally (range 5.16 mm caudally-5.58 mm cranially), from what was digitally planned. Modifications to the PSI guides were made over time to improve accuracy, though one screw was malpositioned in a single case. However, all grafts showed evidence of graft healing within 6 weeks.

The open PSI Latarjet procedure is safe and reliable, showing accurate graft positioning at six weeks postsurgery. We believe that 3D printing marks a significant advancement for surgeons, allowing a shift from conventional instruments to innovative, customized solutions.