IN WHICH PATIENTS IS IT POSSIBLE TO PERFORM STANDALONE LATERAL LUMBAR INTERBODY FUSION WITHOUT CAGE SUBSIDENCE?

Luis Marchi,Luiz Pimenta,Rodrigo Amaral,Joes Nogueira-Neto,Fernanda Fortti,Nitamar Abdala,Rubens Jensen,Etevaldo Coutinho,Leonardo Oliveira

doi:10.1590/s1808-185120161503162720

Abstract

ABSTRACT Objective: To identify the factors related to the non-occurrence of cage subsidence in standalone lateral lumbar interbody fusion procedures. Methods: Case-control study of single level standalone lateral lumbar interbody fusion (LLIF) including 86 cases. Patients without cage subsidence composed the control group (C), while those in the subsidence group (S) developed cage subsidence. Preoperative data were examined to create a risk score based on correlation factors with S group. The proven risk factors were part of an evaluation score. Results: Of the 86 cases included, 72 were in group C and 14 in group S. The following risk factors were more prevalent in group S compared to C group: spondylolisthesis (93% vs 18%; p<0.001); scoliosis (31% vs 12%; p=0.033); women (79% vs 38%; p=0.007); older patients (average 57.0 vs 68.4 years; p=0.001). These risk factors were used in a score (0-4) to evaluate the risk in each case. The patients with higher risk scores had greater subsidence (p<0.001). Scores ≥2 were predictive of subsidence with 92% sensitivity and 72% specificity. Conclusions: It was possible to correlate the degree of subsidence in standalone LLIF procedures using demographic (age and gender) and pathological (spondylolisthesis and scoliosis) data. With a score based on risk factors and considering any score <2, the probability of non-occurrence of subsidence following standalone LLIF (negative predictive value) was 98%.

Highlights

Lateral lumbar interbody fusion (LLIF) has evolved into an effective and less invasive treatment option adopted for different toracolumbar conditions.[1,2,3] Biomechanical features of lateral lumbar interbody fusion (LLIF) constructions provide better rigidity than other constructions.[4,5] It uses large diameter, hollow spacers that can engage the peripheral margins of the endplate, the design and positioning of which seems to be superior to others.[6]
It was possible to correlate the degree of subsidence in standalone LLIF procedures using demographic and pathological data
Of 719 cases treated with LLIF, 100 stand-alone LLIF cases were identified; 14 were excluded due lack of images, and 86 cases were eligible for analysis (86 levels)

Summary

Introduction

Lateral lumbar interbody fusion (LLIF) has evolved into an effective and less invasive treatment option adopted for different toracolumbar conditions.[1,2,3] Biomechanical features of LLIF constructions provide better rigidity than other constructions.[4,5] It uses large diameter, hollow spacers that can engage the peripheral margins of the endplate, the design and positioning of which seems to be superior to others.[6] In conventional lumbar fusion techniques, the interbody cage is always supplemented by internal fixation. In LLIF, the anterior and posterior longitudinal ligaments (ALL and PLL, respectively) are preserved. For this reason, a stand-alone construction can provide good stabilization, comparable to a TLIF supplemented with pedicle screws.[4] Good results and complications from non-supplemented LLIF have been reported;[7,8,9,10,11] the ideal indication is not clear

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Conclusion