Abstract
OBJECTIVE: To explore the effectiveness of mirrored three-dimensional (3D) printing technology in the treatment of hyperextension-type bicondylar tibial plateau fractures. METHODS: Retrospective analysis was performed on the clinical data of 11 patients with hyperextension-type bicondylar tibial plateau fractures treated using mirrored 3D printing technology between January 2021 and June 2024. There were 7 males and 4 females, aged 31-67 years (mean, 47.6 years). According to the three-column classification theory of the tibial plateau, all were three-column fractures. Among them, there were 3 cases of pure hyperextension-type injury, 6 cases of hyperextension-varus-type injury, and 2 cases of hyperextension-valgus-type injury. The preoperative tibial plateau posterior slope angle ranged from -10.7° to 2.1° (mean, -3.8°). Postoperatively, fracture healing and complications were observed. Reduction quality was assessed using the Rasmussen radiographic scoring system for the tibial plateau. Knee joint function was evaluated using the Hospital for Special Surgery (HSS) knee score. At last follow-up, the tibial plateau posterior slope angle and knee range of motion (ROM) were measured and compared with the contralateral healthy knee. For patients with long-term follow-up (follow-up time ≥2 years), signs of post-traumatic arthritis were observed on weight-bearing anteroposterior and lateral knee X-ray films and assessed using the Kellgren-Lawrence grading criteria. RESULTS: All surgeries completed successfully. During the perioperative period, 3 patients developed intermuscular venous thrombosis in the affected limb and 1 patient developed posterior tibial vein thrombosis; these resolved after fluid therapy and anticoagulation. All 11 patients were followed up 18-26 months (mean, 22.6 months). There was no postoperative complications such as incision infection, compartment syndrome, neurovascular injury, implant failure, or fracture redisplacement. One patient with a repaired posterolateral complex injury still had knee instability and underwent secondary posterolateral complex reconstruction at 7 months postoperatively, after which knee stability was restored. All fractures healed within 9-16 weeks (mean, 12.2 weeks). At last follow-up, imaging showed good reduction of the tibial plateau fracture, normal joint congruity, and no significant joint surface irregularity. The Rasmussen score for the affected side was 11-18 (mean, 16.2), with excellent results in 8 cases, good in 2 cases, and fair in 1 case, yielding an excellent-good rate of 90.9%. The posterior slope angle of the affected side was (7.7±1.5)°, showing no significant difference compared to the healthy side (8.1±1.4)° ( t=-1.450, P=0.178). The HSS knee score was 80-98 (mean, 89.1), with excellent results in 9 cases and good in 2 cases, resulting in an excellent-good rate of 100%. Knee ROM was (130.4±3.5)°, showing no significant difference compared to the healthy side (131.8±3.4)° ( t=-1.399, P=0.192). Five patients were followed up over 2 years. According to the Kellgren-Lawrence grading criteria, 4 cases were grade 0 and 1 case was grade 1, with no moderate or severe osteoarthritis. CONCLUSION: Through preoperative planning and surgical simulation, mirrored 3D printing technology can accurately restore the posterior slope angle and articular surface of hyperextension-type tibial plateau fractures, resulting in satisfactory recovery of knee joint function.