Use of Dynamic Spinal Instruments (Dynesys) in Adult Spinal Deformities According to Silva-Lenke and Berjano-Lamartina Classifications

BACKGROUND

Adult spinal deformities (ASD) present complex challenges in spine surgery. The diverse nature of these deformities requires a comprehensive understanding of their classification and treatment options. Traditional approaches, such as fusion and rigid stabilization are associated with complications, including screw loosening, breakage, proximal junctional kyphosis (PJK), and pseudoarthrosis. Dynamic stabilization techniques have emerged as promising alternatives, to reduce these complications and preserve spinal motion.

OBJECTIVE

This study investigated the effectiveness of dynamic stabilization using the Dynesys system in the surgical treatment of adult degenerative spinal deformities, with a particular emphasis on their classification.

METHODS

ASDs were classified according to the Berjano-Lamartina (BL) and Silva-Lenke (SL) classifications. We analyzed the efficacy of the Dynesys system in enhancing sagittal balance, radiological parameters, and clinical outcomes in this context.

RESULTS

Dynamic stabilization of patients with ASDs using the Dynesys system significantly improved the visual analog scale and Oswestry Disability Index scores and decreased the complication rates. Patients with BL types 2, 3, and 4 experienced a significant improvement in sagittal balance followed by sagittal vertical axis measurements (p = 0.045, p = 0.015, and p < 0.0001, respectively).

CONCLUSION

The SL and BL classifications, which were originally developed for rigid spinal stabilization, can be applied in dynamic stabilization. Furthermore, dynamic stabilization using the Dynesys system can be used as an alternative to rigid stabilization in SL levels 2 and 3, and BL types 1, 2, and 3, and in some patients with type 4 ASDs.

High Infection Rates in Patients with Long-Segment Dynesys System

BACKGROUND

Infection follow-up in patients stabilized with the Dynesys system. Infection rates were determined in patients who had ≥5 segments stabilized with the Dynesys system.

METHODS

Eighty-three patients with various etiologies were stabilized with the Dynesys system. Long-level stabilization patients were separated from the main group as a result of their high rates of infection.

RESULTS

Long-level stabilizations were performed in 8 of 83 patients. Five patients were determined to have infections including 4 deep infections and 1 superficial infection. In patients with deep infections, 3 of them exhibited chronic infections that lasted for approximately 2 years and the system was removed. A deep infection in 1 patient and a superficial infection in 1 patient were diagnosed after 1 month. The early-diagnosed deep infection patient was treated with wound irrigation and antibiotics. The system was not removed, and the wound was closed with daily dressing after 45 days. One superficial infection patient was only treated with daily dressing, and the infection healed within 2 weeks. The infectious agent was determined in 2 patients. Three patients in the chronic infection group underwent a surgical procedure to remove the system. Specific antibiotic treatments were administered to patients whose infectious agents were identified. The remaining patients were treated with wide-spectrum antibiotics.

CONCLUSIONS

We report that long-level stabilization with the Dynesys system results in a high infection rate.