Direct reduction of high-grade lumbosacral spondylolisthesis with anterior cantilever technique - surgical technique note and preliminary results

Abstract

Backgrounds Surgical reduction for high-grade spondylolisthesis is beneficial for restoring sagittal balance and improving the biomechanical environment for arthrodesis. Compared to posterior total laminectomy and long instrumentation, anterior lumbar inter-body fusion (ALIF) is less invasive and has the biomechanical advantage of restoring the original disk height and increasing lumbar lordosis, thus improving sagittal balance. However, the application of ALIF is still limited in treating low-grade spondylolisthesis. In this study, we developed a new technique termed anterior cantilever procedure to directly reduce the slippage of high-grade lumbosacral spondylolisthesis. The purpose of our study was to investigate the surgical outcomes of the anterior cantilever procedure followed by ALIF and posterior mono-segment instrumented fixation in high-grade spondylolisthesis. Methods All patients with high-grade spondylolisthesis who underwent anterior cantilever procedure followed by anterior lumbar inter-body fusion (ALIF) and posterior mono-segment instrumented fixation between November 2006 and July 2017 were enrolled in our study. The slip percentage, Dubousset’s lumbosacral angle, pelvic tilt, sacral slope, pelvic incidence, and sagittal alignment were measured pre-operatively and postoperatively at the last follow-up. Surgery time, blood loss, complications, and hospital stay were also collected and analysed. Results A total of 11 consecutive patients with high-grade spondylolisthesis patients were included and analysed. All of the high-grade spondylolisthesis in our series occurred at the L5-S1 level. The median age was 37 years, and the median follow-up duration was 36 months. The average slip reduction was 30% (60 to 30%, P < 0.01), and the average correction of Dubousset’s lumbosacral angle was 13.8° (84.1° to 97.9°, P < 0.01). The median intra-operative blood loss was 300 mL. All patients attained improved sagittal balance after the operation and achieved solid fusion within 9 months after surgery. No incidences of implant failure, permanent neurological deficit, or pseudarthrosis were recorded at the last follow-up. Conclusions Anterior cantilever procedure followed by ALIF and posterior mono-segment instrumented fixation is a valid procedure for treating high-grade spondylolisthesis. It achieved a high fusion rate, partially reduced slippage, and significantly improved lumbosacral angle, while minimizing common complications, such as pseudarthrosis, nerve traction injury, excessive soft tissue dissection, and blood loss in posterior reduction procedures. However, posterior instrumentation is still required to the structural stability in the ALIF procedure. Level of evidence IV

Reduction of spondylolisthesis and restoration of lumbar lordosis after anterior lumbar interbody fusion (ALIF)

“…This is similar to blood loss values reported in the literature. Tu et al (2021), for example, found a mean blood loss of 300ml, and Teng et al (2017) report a mean blood loss of 200-300ml, which, however, can increase drastically in the case of vascular injury (4,22). Blood loss associated with venous vessel injury ranged from 250ml to 10,000ml in our sample.…”

“…Most studies investigating the reduction of spondylolisthesis after ALIF have relatively low sample size numbers, with case numbers between 5 and 65 participants (3-5, 11, 13, 14, 17) and most studies having fewer than 30 participants (4,5,11,14,17). With 96 cases, we present, to our knowledge, one of the most extensive single-center studies investigating this topic.…”

“…Our ndings are similar to the reductions reported in the literature. In 2020, Kalani et al reported a mean reduction of spondylolisthesis by 58.7% in combined procedures with anterior fusion and dorsal instrumentation (11) 2013) report a mean spondylolisthesis reduction of 30% (3,4). In a meta-analysis of 2019, Cho et al ( 12) compared anterior and posterior approaches for spondylolisthesis treatment.…”

Vertebral Slip Morphology in Dysplastic Spondylolisthesis as a Criterion for the Choice of the L5/S1 Support (ALIF, PLIF, Fibular Graft) in Surgical Treatment

“…Lamartina [1] presents satisfactory short-te outcomes with the reduction in the deformity using the PLIF technique wit interbody fusion. In the case of smaller slips, good results were achieved by tion of posterior reduction and anterior interbody fusion using the ALIF techn new technique presented in the literature describes a combination of appro posterior mono-segmental stabilization and anterior direct reduction in the sli anterior cantilever procedure [32]. The authors achieved a high fusion rate reduction in the slip, and improved the anatomy of the LS junction.…”

Reduction of spondylolisthesis and restoration of lumbar lordosis after anterior lumbar interbody fusion (ALIF)

“…ALIF can be used in cases of isthmic spondylolisthesis as well as degenerative spondylolisthesis. While some authors routinely use ALIF alone for spondylolisthesis cases [ 2 , 3 ], others combine it with dorsal instrumentation for these patient groups [ 4 ]. Dorsal instrumentation also provides better long-term fusion rates [ 5 ].…”