Personalized 3D printing-assisted preoperative simulation surgery improves surgery outcomes and function recovery for complex tibial plateau fractures: a retrospective cohort study

Technical Summary: Personalized 3D Printing-Assisted Preoperative Simulation for Complex Tibial Plateau Fractures

Problem Statement
Complex tibial plateau fractures, specifically Schatzker types V and VI, present significant therapeutic challenges due to their intricate anatomical structures, high rates of displacement, and frequent involvement of the articular surface, metaphysis, and ligamentous complexes. Conventional surgical management relies heavily on two-dimensional imaging (X-rays) and three-dimensional CT scans viewed on screens. Surgeons must mentally reconstruct fracture morphology to plan reduction and fixation, a process prone to subjectivity. This reliance on mental visualization often leads to inaccurate reduction, prolonged operative times, increased intraoperative fluoroscopy usage, higher blood loss, and a substantial risk of postoperative complications, including joint stiffness, fixation failure, and post-traumatic arthritis. Up to 32.3% of patients treated with conventional open reduction and internal fixation (ORIF) may experience malreduction, contributing to long-term functional deficits.

Methodology
This retrospective cohort study analyzed 49 patients with complex tibial plateau fractures treated between June 2022 and June 2025 at Shaoguan First People's Hospital. Patients were divided into two groups:

1. 3D Printing Group (n=22): Received personalized 3D-printed models combined with preoperative surgical simulation.
2. Conventional Group (n=27): Received standard surgical treatment based on preoperative imaging without physical models.

Technical Workflow for the 3D Printing Group:

• Data Acquisition: Thin-slice (1 mm) CT scans of the proximal tibia were performed.
• Model Reconstruction: DICOM data were imported into Mimics 25.0 software for threshold segmentation, region growing, and mask editing to reconstruct a 3D model of the proximal tibia. Major fracture fragments were identified, and preliminary reduction simulations were conducted to design plate placement and screw trajectories.
• Fabrication: The model was converted to STL and G-code formats, then printed at a 1:1 scale using an industrial-grade 3D printer and polylactic acid (PLA) material.
• Preoperative Simulation: Surgeons performed simulated surgery on the physical model. This included reducing fragments, temporarily fixing them with Kirschner wires, and pre-contouring locking plates to match the reduced bone surface. Screw length, diameter, and trajectory were meticulously planned.
• Surgical Execution: Pre-contoured plates and pre-planned screws were sterilized for direct intraoperative use. The physical model was brought into the operating room as a reference guide. The surgical approach and reduction techniques remained consistent with the conventional group.

Key Contributions and Findings
The study compared intraoperative parameters, postoperative complications, and functional outcomes (Range of Motion [ROM], Rasmussen scores, and Hospital for Special Surgery [HSS] scores) between the two groups.

• Intraoperative Efficiency: The 3D printing group demonstrated statistically significant improvements in:

  • Operative Time: Reduced from 140.82 ± 16.15 min (conventional) to 110.27 ± 12.92 min.
  • Blood Loss: Reduced from 200.36 ± 21.66 mL to 140.28 ± 19.42 mL.
  • Fluoroscopy Usage: Reduced from 16.51 ± 2.63 exposures to 8.55 ± 3.12 exposures.
  • Complication Rate: Significantly lower in the 3D group (9.09%) compared to the conventional group (33.3%).

• Functional Recovery:

  • Short-term (3 months): No statistically significant differences were observed in ROM, Rasmussen scores, or HSS scores between the groups.
  • Long-term (6 and 12 months): The 3D printing group exhibited significantly superior outcomes. At one year, the 3D group achieved a mean ROM of 122.72° ± 4.23° and an HSS score of 90.55 ± 3.54, compared to 116.57° ± 3.73° and 87.63 ± 5.50 in the conventional group.
  • Rasmussen Scores: At one year, 100% of patients in the 3D group achieved "excellent" or "good" outcomes, compared to 92.59% in the conventional group.

• Specific Complications: The conventional group experienced higher rates of tension blisters, skin necrosis, wound dehiscence, and signs of post-traumatic osteoarthritis. No fixation failures were observed in either group.

Significance and Claims
The authors claim that the integration of personalized 3D-printed models with preoperative simulation significantly enhances the precision of fracture reduction and the predictability of surgical planning. By providing a tactile, 1:1 physical representation of the fracture, the technology allows surgeons to:

1. Visualize complex fracture morphology and displacement directions more intuitively than virtual images allow.
2. Pre-determine the optimal surgical approach, reduction sequence, and fixation strategy.
3. Pre-contour plates and plan screw trajectories, eliminating time-consuming intraoperative adjustments.
4. Reduce surgical trauma, operative time, and radiation exposure.

Ultimately, the study concludes that this approach leads to better anatomical restoration of the articular surface, which is critical for preventing post-traumatic arthritis and improving long-term functional recovery. The authors suggest that as the technology matures and costs decrease, 3D printing-assisted surgery could become a standard component of the treatment protocol for complex tibial plateau fractures.

Limitations
The authors acknowledge the study's limitations, including its retrospective nature, the relatively small sample size, and the lack of biomechanical analysis regarding fixation stability. They note that group allocation biases may exist and call for larger, multi-center prospective studies to further validate these findings.