New Minimally Invasive Method for Treating Posterior Pelvic Ring Fractures: Biomechanical Validation and Clinical Application of Sacroiliac Joint Locking Plate

Objective: Considering the high incidence and complexity of unstable posterior pelvic ring fractures, and the need for less invasive and more effective treatment options, this study aims to introduce a novel minimally invasive, safe, and simple internal fixation method for the treatment of unstable posterior pelvic ring fractures using the sacroiliac joint locking plate (SJP) system, and to provide biomechanical validation and clinical evaluation of this method.

Methods: Biomechanical research was conducted using standard pelvic bone models from Synbone, Switzerland, to create Denis II zone unstable posterior pelvic ring fracture models, and to assess the stability of the SJP under different loads compared with traditional fixation methods. A retrospective clinical study analyzed the clinical efficacy of SJP treatment in 62 patients (mean age of 51.7 ± 11.9 years and male-to-female ratio of 42/20) treated at our hospital from October 2016 to January 2023.

Results: Biomechanical tests showed that at a maximum load of 300 N, the displacement values for the SJP (3.361 ± 0.246 mm) and two iliosacral (IS) screws (3.325 ± 0.335 mm) were significantly lower than those for a single IS screw (4.281 ± 0.399 mm) and tension band plate (TBP) (4.678 ± 0.534 mm). In the stiffness test of the compression-separation experiment, the average stiffness of the SJP (92.09 ± 1.17 N/mm) was higher than that of a single IS screw (80.06 ± 2.57 N/mm) and TBP (71.67 ± 1.12 N/mm) (p < 0.05 for both), but lower than that of two IS screws (104.94 ± 1.16 N/mm) (p < 0.05). Clinically, postoperative pain scores decreased to 1.9 ± 0.9 after SJP surgery, which was a significant reduction compared with the preoperative score of 9.1 ± 1.1. Functional prognosis scores improved from 36.1 ± 11.5 preoperatively to 88.4 ± 14.2, showing a marked improvement. The postoperative Majeed scores for the patients were 87.4 ± 8.1, and the incidence of complications was low, with only one case reported so far.

Conclusion: The SJP demonstrates robust stability in biomechanical experiments, making it highly advantageous for clinical applications and widespread adoption. It offers several benefits, including straightforward surgical operation, minimal risk of vascular and neural injury, low surgical requirements, and eliminates the need for fluoroscopy. These advantages contribute to its remarkable clinical efficacy and potential for extensive utilization.