Integration of Stent Screw-Assisted Internal Fixation Into Posterior Fixations for High-Grade Thoracolumbar Spine Compression Fractures (SAIF-Rod).

Background
Stent screw-assisted internal fixation (SAIF) has been shown to be a valid minimally invasive alternative in the treatment of high-grade osteoporotic and neoplastic fractures presenting with burst morphology, extreme collapse and kyphosis, extensive osteolysis, large pseudoarthrotic clefts, and pedicle or middle column involvement. However, the presence of local deformity and/or posterior tension band injury (as for osteoporotic fracture [OF] 4 and OF 5 fractures, according to the AO Spine-DGOU OF Classification) ideally requires a posterior fixation in addition to an armed kyphoplasty. For these cases, we have built upon our previous work that associates a posterior fixation with a SAIF by actually integrating the SAIF into the posterior fixation construct (SAIF-Rod).Objective
To describe the procedural steps and discuss the mechanical advantages of the novel technique called SAIF-Rod and present the results of our initial case series.Methods
After vertebral body stent expansion within the index vertebra, augmentable screws from the same set as the posterior fixation are introduced via K-wire exchange into the stent lumen. Kyphoplasty augmentation is performed through these screws. A posterior fixation performed above and below the index vertebra is connected to the screws at the index level. Rod-bending and compression maneuvers are used to address residual deformity that could not be corrected through the SAIF alone.Results
A total of 21 patients (13 men) with a mean age of 76 years (interquartile range [IQR] 65-80) and with neoplastic (19%), traumatic (10%), and osteoporotic (71%) thoracolumbar fractures were treated with SAIF-Rod at our institution. Demographic and surgical data for a minimum follow-up of 12 months were presented. No major early or delayed complications (Clavien-Dindo grades 4 or 5) occurred. Mean intraoperative blood loss (150 mL, IQR 100-400), operating time (318 minutes, IQR 263-346), and length of stay at the hospital (7 days, IQR 5-11) were recorded.Conclusion
In selected cases, SAIF-Rod represents a minimally invasive surgical alternative for the treatment of high-grade osteoporotic, traumatic, and neoplastic fractures, usually accompanied by deformity.