OBJECTIVE: To observe the behavior of the expansive screw in patients with poor bone quality, its safety, the technique, conduct and complications: percentage of loosening, breaks, pull-outs and pseudoarthrosis. METHODS: Prospective multicenter study analyzing the patient’s risk factors, VAS, surgery time, blood loss, location of the screws and complications due to the implant at the time of discharge, and at 3, 12 and 24 months. RESULTS: 99% of the patients did not have any permanent complications related to the implant; there was only one case of unresolved radiculopathy. In 95% of the implants, the screws were placed without complications; in 5% percent of cases there were complications related to poor placement or expansion of the screw, which were resolved with the surgery. Mean intervention time per level: 56 minutes; average intervention time, 2 hours and 35 min. Average bleeding per level that received intervention, 211cc. There were three cases of "pull-out". VAS evolved favorably and significantly, with average reduction greater than four points. The study will continue until age five, these being the preliminary results. CONCLUSIONS: This type of expansive screw provides a new anchoring system for patients with poor bone quality; it is safe and effective, easy to insert, and provides less exposure to X-ray, and in case of removal of the screw, it leaves the way free for a new surgery.
Arthrodesis; Spine; Bone screws; Postoperative complications; Osteoporosis
