Introduction: The number of surgeries for fusion on the lumbar spine is steadily increasing. Despite the fact that most of these operations have a high degree of success, there remains a fairly high risk of pseudoarthrosis and adjacent segment disease. New technologies and materials allow maintaining some mobility in fixed segments. The use of TiNi as a material for the rods can significantly decrease the rate of complications.

Methods: 114 patients underwent surgical treatment using TiNi rods between 2010 and 2012. Control group – 97 patients underwent surgical treatment using Ti rods. All patients were divided into six groups depending on the level of intervention. Radiographs, CT, MRI and clinical outcomes were examined preoperatively, at 6, 12, 24 and 42 months.

Results: The mean patient age was 53 years. Minimum follow - up period was 9.5 years. Statistically better results (p˂ 0.05) were shown 10 years after surgery in all groups with nitinol rods. One of the main evaluation criteria in our study was the extent of preserved mobility of the spine segments fixed with nitinol rods. In all patient groups where nitinol rods were used for stabilization, mobility was present at all times throughout the observation. An important evaluation criterion was the distribution of complications associated with the implant. Thus, in the group of patients with Nitinol rods, there were statistically fewer pseudoarthroses, adjacent segment disease and implant instability. At the same time, these patients have a significantly higher risk of rod fracture (p˂ 0.05).

Conclusions Nitinol rods allow to preserve mobility in the motion segment 10 years after surgery. The application of this method will reduce the number of complications typical for rigid fixation. The main indications are fixation of 1-2 levels without fixation of the L5-S1 segment and fixation of only the L5-S1 segment