Spondylolisthesis refers to the anterior translation of a vertebra on the subadjacent endplate. The most common type, isthmic spondylolisthesis, is produced by bilateral pars interarticularis defects. This occurs most often in the L5 vertebral body, allowing subluxation of L5 on the sacrum. High-grade slips are almost invariably symptomatic and usually progress in the skeletally immature. In turn, a considerable body of literature is dedicated to operative management of pediatric manifestations. As spinal fixation has evolved over the past decades, however, so too have the accepted surgical guidelines.
In this article, we provide an account of our recent surgical experience with high-grade spondylolisthesis in pediatric and young adult patients. Briefly, we favor a single all-posterior operation consisting of wide-decompression, discectomy with or without sacral dome osteotomy, postural reduction, and posterior fusion with pedicle screw instrumentation. Our practice has evolved to incorporate partial reduction and moved away from both in situ fusion and complete, anatomic reduction due to lower fusion rate and higher associated neurologic complication rate, respectively. Modern pedicle screw instrumentation, fusion techniques, and neuromonitoring have enabled us to achieve better outcomes with these surgical maneuvers.
In the presence of poor bone stock or spinal rigidity, we employ a number of alternative surgical strategies to correct the deformity. These options include adding levels of fixation, interbody fusion, transsacral screws, correcting the slip angle alone, and vertebrectomy. Regardless of the chosen strategy, the risk of complications when dealing with high-grade spondylolisthesis cannot be understated. These are some of the most challenging deformities faced by spine surgeons. Anatomic expertise, surgical skill, and meticulous preoperative planning are all mandatory to achieve desirable outcomes.