Prevalence of segmental wire breakage using Cotrel-Dubousset instrumentation in the management of idiopathic scoliosis

Study Design. This is a retrospective radiographic and medical record analysis of 77 patients. Objectives. To determine whether there is an increased prevalence of segmental sublaminar wire breakage associated with the knurled (diamond) pattern machined onto the Cotrel-Dubousset rod as opposed to a smooth rod. Summary of Background Data. Segmental fixation of vertebral segments with sublaminar wires is a common surgical technique, and the use of sublaminar wires with a knurled Cotrel-Dubousset rod theoretically could cause premature wire breakage. Methods. Sixty-six patients with idiopathic scoliosis had the Cotrel-Dubousset (knurled rod) system and comprised the study group, and the Texas Scottish Rite Hospital system (smooth rod) was placed in 14 patients, who served as a control group. Serial radiographs after 3, 6, 12, and 24 months were reviewed. All patients had augmentation of their scoliosis constructs with 16-gauge sublaminar wires in the lumbar spine. Minimum follow-up period was 24 months. Results. No wire breakage was noted in any patient. Conclusions. There is no increased likelihood that the knurled rod pattern will cause wire breakage, provided a solid fusion is obtained.