Spine surgery at the wrong level is an undesirable event and unique pitfall in spine surgery. It is detrimental to the relationship between the patient and the surgeon and typically results in profound medical and legal consequences. It falls under the wrong-site surgery sentinel events reporting system. This error is most frequently observed in lumbosacral spine. Several risk factors are implicated; however, anatomical variations of the lumbosacral spine are a major risk factor. The aim of this article was to provide a detailed description of these high-risk anatomical variations, including transitional vertebrae, lumbar ribs, butterfly vertebrae, hemivertebra, block/fused vertebrae, and spinal dysraphism. A literature review was performed in the database PubMed to obtain all relative English-only articles concerning these anatomical variations and their implication in the development of lumbosacral spine surgery at the wrong level. We also described patient characteristics that can lead to lumbosacral surgery at the wrong level such as tumors, infection, previous lumbosacral surgery, obesity, and osteoporosis. Certain techniques to prevent such incorrect surgery were explained. Lumbosacral spine anatomical variations are surgically significant. Awareness of their existence may provide better pre-operative planning and surgical intervention, leading to avoidance of incorrect-level surgery and potentially better clinical outcomes. In addition, collaboration with radiologists and careful examination of patient’s anatomy and characteristics should be exercised, especially in difficult cases.
