Medical-AI trial: can ChatGPT classify acetabular (pelvic) fractures? compared with orthopedic residents (multimodal LLM, 184 cases) (NCT07673991)

1Acetabular fractures are a complex call

The acetabulum is the socket part of the pelvis at the hip joint, and fractures there have complex shapes for which accurate classification is essential to plan surgery. The widely used Letournel-Judet system requires reading how fracture lines run across radiographs from several angles and demands expertise.

This study examines whether a multimodal large language model (LLM) that can also handle images, ChatGPT-4o, can be used for that task.

2Tested on 184 pelvic trauma cases

Per the registry summary, the study retrospectively analyzes standard radiographs (anteroposterior, iliac oblique, and obturator oblique, the Judet views) from 184 patients with pelvic injuries, and compares the ChatGPT-4o classification against the independent assessments of two fourth-year orthopedic residents and a reference standard set by an experienced trauma surgeon using multiplanar CT and intraoperative findings.

A systematic radiographic checklist is used to assess whether the AI can identify key anatomical landmarks (fracture lines, columns, walls) and integrate them into a final fracture pattern. The primary endpoint is the diagnostic accuracy of the ChatGPT-4o classification.

3Measured against two standards

The study compares the classification by ChatGPT-4o against two different references. Each measures something different.

Acetabular fractures are complex in form, and the widely used Letournel-Judet classification requires reading the course of fracture lines across radiographs in several projections, which takes experience. A systematic radiographic checklist is used to assess whether the AI can identify the key anatomical landmarks and integrate them into a final fracture pattern, across 184 pelvic trauma cases analysed retrospectively.