Neurological injury, pseudoarthrosis and progressive deformity are just some of the risks associated with the surgical management of high grade spondylolisthesis in young patients. A presentation chronicling fourteen years of experience treating the condition with a progressive reduction technique has shown to safely offer good functional and radiological outcomes.
Presented at the International Society for the Advancement of Spinal Surgery (ISASS; 6-8 April, Las Vegas, USA), the retrospective analysis was intended to address the controversy surrounding in situ fusion vs. reduction, and the use of closed postural reduction techniques vs. open reduction instrumentation. An ideal technique, the presentation noted, would promote motion with minimal segments fused, would sustainably resolve symptoms and restore near-normal balance to the sagittal vertical axis.
The researchers followed 27 patients with spondyloptosis (17), grade four spondylolisthesis (7) or grade three spondylolisthesis (3) who underwent a reduction technique at the Apollo Hospital (Chennai, India) between 1998 and 2012. This technique involved “positioning the hips in extension with traction, pedicle screw fixation, correction of lumbosacral kyphosis with a specific distraction manoeuvre, wide decompression, and gradual reduction of the deformity and maintenance of reduction with interbody fusion” all in a single staged posterior approach surgery.
The procedures were assessed by clinical and radiological measures. Follow-up took place at one, three and six months, and annually after the first year. All patients’ spondylolisthesis was reduced to at least grade two, with solid fusion present at six months in all cases. A mean postoperative slip angle improvement of 42 degrees was noted (45-3 degrees), as was a mean sacral slope improvement of 22 degrees (13-35 degrees). Significant improvements visual analogue scale and modified Oswestry Disability Index scores were observed with good functional outcomes reported in all but one patient. The poor outcome was due to a deep infection which required implant removal. One revision surgery was required due to screw misplacement on the third day after surgery. This study also showed 4 cases of concomitant scoliosis which had spontaneous correction after reduction of spondylolisthesis.
The researchers found that their reduction technique, whilst technically challenging, was safe. It offered generally good results, which had been reproduced over almost a decade and a half in young patients with high grade spondylolisthesis.
Pramod Sudarshan, the presenting author of the paper won the Charles D Ray award for the best clinical paper at ISASS. The study will also be published in the International Journal of Spine Surgery (IJSS).
Spinal News International spoke to Sajan Hegde, the lead author of the study.
What do you think is most important about this study?
The key to a successful outcome in high grade sponsylolisthesis is to obtain perfect screw placement in L5 and bicortical purchase in the sacrum. Correction of lumbosacral kyphosis with gradual reduction and interbody reconstruction with compression at L5S1 helps to further improve the lordosis and maintain the sagittal balance.
What implications does your study hold?
We feel our study addresses the controversies surrounding the management of high grade listhesis and proves the point that a single staged posterior alone surgery is successful in getting a good outcome.
We ourselves improved with our technique over the years, with better instrumentation making it feasible for a monosegmental fixation. With a better understanding of the pathobiomechanics of the high grade listhesis, the technique may further evolve and be technically less demanding.
Most centres, particularly in the west believe they need to include sacroiliac fixation after reduction. With an inherent poor gluteal musculature in these children, such implants can lead to severe discomfort. Also, in a growing child we feel that fixing across a normal joint is unwarranted.