Rod Fracture After Apparently Solid Radiographic Fusion in Adult Spinal Deformity Patients.


Rod fracture occurs with delayed fusion or pseudarthrosis after adult spinal deformity (ASD) surgery. Rod fracture after apparent radiographic fusion has not been previously investigated.Patients with ASD in a multicenter database were assessed for radiographic fusion by a committee of 3 spinal deformity surgeons. Fusions were rated as bilaterally fused (A), unilaterally fused (B), partially fused (C), or not fused (D). Patients with grade A or B fusion and 2-year follow-up were included. Patients with radiographic fusion were evaluated for subsequent rod fracture. Adjusted analyses were conducted with multiple logistic regression, using backwards-variable selection to a threshold of P < 0.2, to assess for associated factors.Of 402 patients with radiographically apparent solid fusion, 9.5% (38) subsequently suffered a broken rod. On multivariate analysis, greater rates of rod fracture were seen among patients of age group 60-69 years (vs. 18-49), body mass index 30-34 and 35+ (vs. <25), stainless-steel rods (vs. titanium), patients with rods ≤5.5 mm (vs. 6.35 mm), and patients with Charlson score 0 (vs. 3+). Of the 38 patients with rod fractures, 18 (47.4%) presented with worsened pain, and 8 (21.1%) required revision at minimum 2-year follow-up.Rod fracture occurred in 9.5% of patients with apparently solid radiographic fusion after ASD surgery. Advanced age, obesity, small diameter rods (5.5 mm), osteotomy, and lower comorbidity burden were significantly associated with rod fracture. Nearly one-half of these patients noted worsening pain, and 21.1% required revision surgery. Instrumentation failure may occur and may be symptomatic even in the setting of apparent fusion on plain radiographs.





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Publication Info

Daniels, Alan H, J Mason DePasse, Wesley Durand, D Kojo Hamilton, Peter Passias, Han Jo Kim, Themistocles Protopsaltis, Daniel BC Reid, et al. (2018). Rod Fracture After Apparently Solid Radiographic Fusion in Adult Spinal Deformity Patients. World neurosurgery, 117. pp. e530–e537. 10.1016/j.wneu.2018.06.071 Retrieved from

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Peter Passias

Instructor in the Department of Orthopaedic Surgery

Christopher Ignatius Shaffrey

Professor of Orthopaedic Surgery

I have more than 25 years of experience treating patients of all ages with spinal disorders. I have had an interest in the management of spinal disorders since starting my medical education. I performed residencies in both orthopaedic surgery and neurosurgery to gain a comprehensive understanding of the entire range of spinal disorders. My goal has been to find innovative ways to manage the range of spinal conditions, straightforward to complex. I have a focus on managing patients with complex spinal disorders. My patient evaluation and management philosophy is to provide engaged, compassionate care that focuses on providing the simplest and least aggressive treatment option for a particular condition. In many cases, non-operative treatment options exist to improve a patient’s symptoms. I have been actively engaged in clinical research to find the best ways to manage spinal disorders in order to achieve better results with fewer complications.

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