Dystrophic Lumbar Kyphoscoliosis Associated with Giant Dural Ectasia in a 19-Year-Old Patient with Neurofibromatosis Type 1. Case Report

SN Comprehensive Clinical Medicine https://doi.org/10.1007/s42399-020-00458-y SURGERY Dystrophic Lumbar Kyphoscoliosis Associated with Giant Dural Ectasia in a 19-Year-Old Patient with Neurofibromatosis Type 1. Case Report Nicolas Plais 1 2 3 3 3 & Peter H. Connolly & Renaud Lafage & Debra Jacobs & Virginie Lafage & Frank Schwab 3 Accepted: 13 August 2020 # Springer Nature Switzerland AG 2020 Abstract Dystrophic curves in neurofibromatosis type I (NF-1) are refractory to conservative treatment. The association with dural ectasia is a rare entity with a high risk of spine dislocation that often requires complex surgical treatment. We present the case of a 19-year-old woman diagnosed with NF-1 and a lumbar scoliosis associated with giant dural ectasia. She was complaining of pain and progressive collapse of her spine. Complementary exams revealed an extended lumbar dural ectasia with scalloping erosion of the anterior and posterior column of the spine as well as missing pedicles at L3, L4, and L5. Due to the severity of the spinal deformity and progressive collapse, surgery was undertaken. The patient underwent a two-stage surgery with an anterior and a posterior approach. Five interbody titanium mesh cages were inserted at the lumbar disc levels from S1 to L1 and a posterior instrumentation was placed to reduce the kyphosis and stabilize the spine. Iliac bone graft, allograft, BMP (bone morphogenetic protein), and two fibular grafts were placed to ensure fusion. The lumbar kyphosis was reduced and the spine was stabilized. The patient had excellent outcome at 28 months follow-up with complete resolution of symptoms. Dystrophic deformities with kyphoscoliosis and giant dural ectasia in NF-1 require reduction of the kyphosis, stabilization of the spine with and anterior and posterior approach, and the use of both autologous and allogenic bone graft to achieve a solid fusion. It’s necessary to avoid any injury of the dural sac during the procedure. Keywords Dural ectasia . Tarlov cyst . Neurofibromatosis type 1 . Kyphoscoliosis . Dystrophic spinal deformity . Anterior and posterior approach Level of evidence: 5 Key Points • Dystrophic curves in Neurofibromatosis type 1 are refractory to conservative treatment. • The association with dural ectasia is a rare entity with a high risk of spine dislocation that often requires complex surgical treatment. • These complex deformities require the reduction of the kyphosis, the stabilization of the spine with an anterior and posterior approach and the use of both autologous and allogenic bone graft to achieve a solid fusion. This article is part of the Topical Collection Surgery * Nicolas Plais 1 Departement of Orthopaedic Surgery, Hospital Universitario San Cecilio, Paseo del Agua, 15, Parque del Cubillas, 18220 Albolote, Granada, Spain 2 Vascular Surgery Service, New York-Presbyterian Hospital/Weill Cornell Medical Center, New York, NY, USA 3 Department of Orthopedic Surgery, Hospital for Special Surgery, New York, NY, USA SN Compr. Clin. Med. Orthopedic disorders and more specifically, spinal abnormalities are the most common clinical presentation of NF-1. Ten percent of NF-1 patients present with spinal deformities [2]. Spinal curves have been classified [3] as non-dystrophic (similar to idiopathic scoliosis) versus dystrophic (with or without kyphosis). Dystrophic deformities present specific features [3]: vertebral scalloping, vertebral wedging, dysplastic pedicles, rib penciling, transverse process spindling, paravertebral tissue mass, severe apical vertebral rotation, intervertebral foraminal enlargement, or adjacent soft tissue neurofibromas. Dural ectasia is a circumferential dilatation of the dural sac and is commonly associated with Marfan syndrome (90%) [4, 5]. It has also been reported in NF-1 (10%). Its etiology has been related to collagen weakness, fibroblast dysfunction, or increased dural pulsation [5–7]. It is more frequent in the lumbosacral region where the pressure of the CSF is greater. In this area, vertebral scalloping and thinning pedicles can potentially destabilize the spine. As the spinal canal is increased, it is however rarely associated with neurologic dysfunction. Case Presentation Fig. 1 Long-standing X-rays Introduction The neurofibromatosis type 1 (NF-1) or Van Recklinghausen disease is one of the most common autosomal dominant disorders (prevalence 1/3.000) [1]. It is due to a defect of the NF1 gene on the long arm of the chromosome 17. We report the case of a 19-year-old female diagnosed with NF-1 who presented with complaints of intermittent back pain in the last 3 years and progressive collapse of her spine. She required 2 h of traction by day to maintain her alignment, alleviate pain, and support standing position. On examination, she presented with cafe au lait spots, stiffness with forward flexion of the lumbar spine as well as extension, left lumbar asymmetry, and a completely normal neurological examination. On complementary exams, long-standing X-rays evidenced the presence of a pathologic lumbar scoliosis (Fig. 1). The MRI demonstrated an extended dural ectasia at Fig. 2 Magnetic resonance imaging—progression of the dural ectasia between 2014 and 2017 SN Compr. Clin. Med. Fig. 3 Recent magnetic resonance imaging that evidences bone scalloping, pedicle destruction, and the giant dural ectasia in the lumbosacral spine Fig. 4 CT scan—3D reconstruction of the lumbar kyphoscoliosis Fig. 5 Preoperative planning SN Compr. Clin. Med. Fig. 6 Posterior instrumentation and the two fibular grafts placed into direct apposition onto the posterior elements the lumber region that eroded the anterior column. Comparison between MRI obtained 3 years earlier revealed marked severity of the progression (Figs. 2 and 3). The CT scan confirmed the scalloping and bone destruction at the lumbar level. Pedicles were missing at the L3, L4, and L5 as well part of the posterior column (Fig. 4). The patient was diagnosed of progressive dystrophic lumbar kyphoscoliosis and dural ectasia. Due to the severity of the spinal deformity, pain, the progressive collapse of the spine, and the presence of dysplastic lesions, surgical treatment was recommended and planned (Fig. 5). A two-stage surgery was undertaken: the first stage was anterior with a left-sided paramedian thoracoabdominal approach. Discectomies of L5-S1, L4-5, L3-4, L2-3, and L1-2-disc space were performed. To increase fusion rate, an interbody titanium mesh cage packed with bone morphogenetic protein (BMP) and allograft was then placed at each of the levels. Immediately after, segmental pedicle screws from T5 to T11, bicortical screws at S1, and double iliac screws were inserted on each side by a posterior approach. Sublaminar tethers were placed at three levels to augment anchorage through the posterior arc. Kyphosis was reduced, and iliac bone graft, allograft, BMP, as well as two fibular grafts were placed into direct appos (...truncated)