# Clinical and Radiological Outcomes of C1–C2 Fixation: 3D-Printed Template vs. Free-Hand Technique

## TL;DR

This study compares 3D-printed templates and free-hand techniques for C1–C2 spine surgery, finding that the 3D method reduces operation and fluoroscopy times.

## Contribution

The study introduces 3D-printed templates as a faster and cost-effective alternative to traditional free-hand techniques in C1–C2 fixation.

## Key findings

- 3D-printed templates reduced operative and fluoroscopy times significantly compared to free-hand techniques.
- Screw accuracy was high in both groups, with 95% accuracy in the 3D-printed group and 93.1% in the free-hand group.

## Abstract

Objectives: The Goel–Harms technique provides rapid stabilization and high fusion rates for atlantoaxial instability but carries a risk of neurovascular injury during lateral mass and pedicle screw insertion. Recently, 3D printing has emerged as a cost-effective and increasingly accessible tool in various surgical fields. This study aimed to compare the clinical and radiological outcomes of C1–C2 fixation using a 3D-printed template versus the free-hand technique. Methods: This retrospective cohort study included patients who underwent C1–C2 fixation with the Goel–Harms technique at two tertiary neurosurgical centers between 2021 and 2023. Operative, radiological, and functional outcomes were reviewed in 21 patients who were operated using either a patient-specific 3D-printed template applied intraoperatively (Group 1; n = 10) or the free-hand technique (Group 2; n = 11). Postoperative screw accuracy was assessed using the Gertzbein–Robbins classification. Results: A total of 84 screws were placed (Group 1: 40; Group 2: 44). In Group 1, 38 of 40 screws (95%) were accurately placed, compared with 41 of 44 screws (93.1%) in Group 2. The mean fluoroscopy and operative times were significantly shorter in Group 1 than in Group 2 (21.90 ± 4.33 s vs. 27.09 ± 13.48 s, p = 0.012; 126.60 ± 28.70 min vs. 171.36 ± 40.44 min, p = 0.010, respectively). Conclusions: The 3D-printed template technique significantly reduced operative and fluoroscopy times compared with the free-hand technique. Three-dimensional printing offers a cost-effective alternative to conventional navigation systems by eliminating their time-consuming preoperative setup in the operating room.