High grade isthmic spondylolisthesis – A case series illustrating three different operative instrumented fusion techniques

Adult isthmic spondylolisthesis most commonly occurs at the L5-S1 level. In adults a high-grade slip degree is rare comprising less than 1% of cases. Progressive axial lumbar backache characterizes the early stage of the disease which over time commonly complicates with the development of a super-imposed L5 radiculopathy. These are difficult cases to manage and the attending spinal surgeon must have an understanding of several different surgical options. These options include conservative treatment in those who are mildly symptomatic, decompression alone with its inherent tendency to facilitate further slip, decompression and fusion without instrumentation, decompression and fusion with instrumentation, and if so the extent of the construct both cranially and caudally. Another important consideration is whether, or not, reduction is necessary or whether fusion in situ will suffice. Regarding the surgical approach some surgeons regard an anterior approach, to perform an anterior release, as necessary if reduction is to be achieved. Others consider nerve root decompression and posterior spinal fusion in situ as the technique of choice. Others advocate a combined anterior and posterior surgical approach. We report a case series of three adult female patients with high grade isthmic spondylolisthesis complicated by L5 nerve root compression. Each patient was successfully managed with a different instrumented fusion technique. Our case series serves to highlight several of the specific surgical nuances pertaining to the management of high-grade isthmic spondylolisthesis and as such is valuable to the attending spinal surgeon who may infrequently encounter patient with the high-grade form of this disease.