Anterior Decompression of L5 Nerve Root for Far-Out Syndrome Due to Anterolateral Vertebral Osteophyte Formation: 2 Case Reports and Literature Review

<sec><title>Background</title> Far-out syndrome is considered a rare spinal disorder characterized by L5 radiculopathy due to extraforaminal stenosis at the lumbosacral junction. Despite advancements in surgical techniques, managing far-out syndrome remains a significant challenge owing to the complex anatomical variations usually associated with the condition. This article reports 2 cases of far-out syndrome resulting from anterolateral vertebral osteophyte formation that underwent anterior decompression. A comprehensive review of the literature is also provided. </sec><sec><title>Case Presentation</title> A 51-year-old man and a 72-year-old woman presented with progressive leg pain and neurogenic claudication associated with hypesthesia over the left L5 dermatome. Radiological findings in both patients revealed entrapment of the L5 nerve root by anterolateral vertebral osteophytes at the anterior exit zone of the foramen. One patient presented with Castellvi Type IV lumbosacral transitional vertebra, and the other patient showed spontaneous facet joint fusion at adjacent segments. </sec><sec><title>Case Management</title> We performed anterior-extraperitoneal osteophytectomy using an ultrasonic bone dissector to decompress the extraforaminal stenosis, which resulted in successful resolution of the symptoms and improved neurological status. Both patients remained asymptomatic at the 1-year follow-up. </sec><sec><title>Conclusions</title> Extraforaminal stenosis at the lumbosacral junction due to anterolateral vertebral osteophytes usually occurs in patients with anatomical abnormalities such as lumbosacral transitional vertebra and adjacent segment fusion. Anterior decompression via extraperitoneal approach is an effective and safe treatment option for far-out syndrome, offering a viable alternative to the conventional posterior approach. </sec><sec><title>Level of Evidence</title> 5. </sec>