The Use of Intralaminar Screws in Patients With Spinal Deformity

Abstract

Study Design:Retrospective study.Objective:To demonstrate that intralaminar screws (ILS) can be used as supplements in spinal deformity surgery in the thoracic and lumbar levels in pediatric and adult patients.Summary of Background Data:Rigid posterior fixation of the spine is generally accomplished using pedicle screws, hooks, or wires. ILSs are useful tools when other spinal fixation techniques have failed or the bony anatomy precludes hook or screw placement.Materials and Methods:All spinal deformity patients (primary/revision) operated between 2007 and 2011 were retrospectively reviewed. The patients with ILS were included in the study. The anteroposterior and lateral standing x-rays were evaluated in terms of preoperative and postoperative coronal and sagittal deformities. The number and level of ILS, intraoperative complications, and postoperative complications were noted.Results:There were 20 patients (12 male and 8 female). The mean age was 21.75 years. The mean follow-up period was 17.4 months. Fifty-seven ILS were inserted. Seventeen screws were used in the uppermost to lowermost levels. Forty screws were used in the middle. There was 1 lamina fracture and screw pull out (1.75%). There were 3 canal violations (corrected intraoperative) and 2 instrument prominences which required implant removal. The mean preoperative/postoperative cobb angles were 78.5 degrees/27.8 degrees and the mean preoperative/postoperative kyphosis angles were 57.2 degrees/32.5 degrees, respectively. The loss of correction was 1.2 degrees. There were no neurological deficits and no instrument failures.Conclusions:ILS are safe and effective when used in deformity correction. However, biomechanical studies and randomized controlled trials are needed to conclude whether ILS will be considered a first-line technique, or will remain a technique for salvage situations.