High-grade spondyloretrolisthesis in a 12-year-old girl with neurofibromatosis type 1

Abstract

Neurofibromatosis (NF) type 1 is characterized by several skin, endocrine, central nervous system and musculoskeletal manifestations, spine deformities being the most common, affecting up to 64% of patients. Thoracic kyphoscoliosis is the most common deformity observed; however, high-grade spondylolisthesis and dural defects such as dural ectasia can also be found. The aim of this study is to describe a case of high-grade spondyloretrolisthesis in an NF-1 patient, associated with dural ectasia and extensive lumbar laminectomies, and to discuss our management and review the current literature on this controversial topic. A 12-year-old girl with NF-1 who had undergone extensive lumbar laminectomies in an outside facility presented to our emergency department complaining of back pain and lower limbs upper motor neuron symptoms. Image studies showed a high-grade lumbar spondyloretrolisthesis associated with dural ectasia. The first step of treatment was spine immobilization using a Boston brace. An anterior approach was used, and an L2 corporectomy was performed, using a Moss type cage between L1 and L3 with an instrumented arthrodesis and autologous bone graft for stabilization purposes. The second step planned was a posterior approach for arthrodesis and instrumentation, but after an extensive discussion with the parents and the patient, the parents did not agree to the procedure planned for the patient. A brace was used for 1 year while rehabilitation was performed. At the 1-year follow-up, there was a 70° kyphosis at the thoracolumbar junction but it was clinically stable, with an acceptable sagittal balance. Dural ectasia is not a common finding in children with NF-1; however, it should be identified as its presence may predispose to spine instability and as a consequence the development of a high-grade spondyloretrolisthesis. Even though a few cases have been reported, we believe that it is important to consider the option of a double approach to achieve a better correction in both planes and a good outcome. If an extensive laminectomy is involved, it is mandatory to perform a posterior fusion and instrumentation.