Rod fracture after long construct fusion for spinal deformity: clinical and radiographic risk factors

• Published in: Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association 2013-11, Vol.18 (6), p.926-931
• Main Authors: Akazawa, Tsutomu, Kotani, Toshiaki, Sakuma, Tsuyoshi, Nemoto, Tetsuharu, Minami, Shohei
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aged; Analysis of Variance; Child; Cohort Studies; Female; Humans; Incidence; Internal Fixators - adverse effects; Logistic Models; Male; Medicine; Medicine & Public Health; Middle Aged; Original Article; Orthopedics; Prosthesis Failure; Radiography; Retrospective Studies; Rheumatology; Risk Assessment; Scoliosis - diagnostic imaging; Scoliosis - surgery; Severity of Illness Index; Spinal Fusion - adverse effects; Spinal Fusion - instrumentation; Spinal Fusion - methods; Statistics, Nonparametric; Time Factors; Young Adult
• ISSN: 0949-2658; 1436-2023
• DOI: 10.1007/s00776-013-0464-4

No reports have been published on detailed risk factors for rod fracture after spinal deformity correction and fusion. The purpose of this study was to analyze clinical and radiographic risk factors of rod fracture after long construct fusion for spinal deformity. The survey subjects were 155 cases who were diagnosed with spinal deformity and underwent correction and fusion surgery with long construct instrumentation (>3 levels, average 10.3 levels) between July 2004 and June 2010. The subjects comprised 32 males and 123 females with a mean age of 19.0 (range 8–78)years. The mean Cobb angle was 61.0±16.1° preoperatively and 25.7±16.9° postoperatively. Univariate analysis and logistic regression analysis were performed. Rod fracture occurred in 8 of 155 cases (5.2%). The mean period from surgery to rod fracture was 18.1months (range 2–37). The level of fracture ranged from the thoracolumbar junction to the lumbosacral vertebrae. Six patients had fracture near the fused lower end and two patients had fracture at the thoracolumbar junction. Univariate analysis revealed that non-ambulatory status, preoperative kyphosis, small-diameter rods, multiple surgery, and use of iliac screws were significant risk factors for rod fracture. Sex, obesity, severity of preoperative scoliosis, and rod material were not significant risk factors. Logistic regression analysis revealed that use of iliac screws (odds ratio: 81.9, 95% confidence interval: 7.2–935.0, p