Treatment of L5-S1 spondyloptosis with stand-alone anterior lumbar interbody fusion in a patient with neurofibromatosis

Background: Neurofibromatosis type 1 (NF1) is a multisystem disorder that causes multiple tumor formations throughout the nervous system. Common spinal dysplasias seen with NF1, such as dural ectasia (DE), often undergo modulation and predispose these patients to spondylolisthesis, making surgical treatment challenging.Case Description: A patient with NF1 presented with a 12-year-history of back and left lower extremity radicular pain. Lumbar spine magnetic resonance imaging revealed developmental anomalies with severe DE and associated scalloping of the L4-S1 vertebral bodies and severe L5-S1 Meyerding grade 4 spondylolisthesis. During surgery, post-positioning x-rays demonstrated a grade 5 spondyloptosis. The patient underwent an L5-S1 stand-alone anterior lumbar interbody fusion (ALIF). The final construct was an ALIF cage with one screw into S1, without an anterior plate. By 3-months post-operative, there was complete resolution of preoperative symptoms and at 2 year follow-up the patient was asymptomatic with stable hardware and solid bony fusion. To the authors' knowledge, this is the first report of spondyloptosis treated with a stand-alone ALIF in a patient with NF1 and severe DE.