Introduction: The safety and use of growing rods for curve correction and maintenance in the growing spine population has been established in published reports. While auto‐fusion has been reported, the prevalence and sequelae are not known. The purpose of this paper is: to identify the rate of auto‐fusion in the growing spine with the use of growing rods and to quantify how much correction can be attained with definitive instrumented fusion after long‐term treatment with growing rods.
Methods: Nine skeletally immature children with scoliosis were identified who had been treated using growing rods. A retrospective review of the medical records and radiographs was conducted. The following data were collected: complications, pre‐ and postoperative Cobb angles at time of initial surgery (growing rod placement,) pre‐ and postoperative Cobb angles at time of final surgery (growing rod removal and definitive fusion), total spine length as measured from T1‐S1, % correction since initiation of treatment and at definitive fusion, total number of surgeries, and number of patients found to have auto‐fusion at the time of device removal.
Results: The rate of auto‐fusion in children treated with growing rods was 89%. The average percent of the Cobb angle correction obtained at definitive fusion was 44%. On average, seven osteotomies per patient were required at the time of definitive fusion due to auto‐fusion.
Conclusion: Although growing rods do show moderate efficacy in the control of deformity within the growing spine, they also have adverse effects on the spine. Immature spines treated with a growing rod have high rates of unintended auto‐fusion which can possibly lead to difficult and only moderate correction at the time of definitive fusion.
Significance: Growing rods have been previously described as a fusionless device. However, we have demonstrated that fusion does occur and that subsequent definitive surgery is more difficult and deformity correction may be diminished.