Published online Jun 30, 2016.
https://doi.org/10.4184/jkss.2016.23.2.100
Risk Factors of Cage Subsidence after Posterior Lumbar Interbody Fusion
Abstract
Study Design
Retrospective study.
Objectives
The purpose of this study was to evaluate risk factors for subsidence after posterior lumbar interbody fusion (PLIF).
Summary of Literature Review
Body mass index (BMI), bone mineral density (BMD), cage characteristics (titanium or poly-ether-ether-ketone (PEEK)) and degree of disc distraction are risk factors for cage subsidence after PLIF.
Materials and Methods
From January 2010 to January 2015, a total of 69 patients (93 segments) who were diagnosed with degenerative lumbar spine disease at the current authors' institution and underwent follow-up for at least 1 year were included in this retrospective study. Data on all factors related to cage subsidence were taken into consideration. The degree of association for each of the factors was determined through the calculation of odds ratios (ORs) with a 95% confidence interval. Logistic regression analyses were performed. The P-value that represented statistical significance was set below 0.05.
Results
There were no significant associations between fused segment level and cage subsidence (p=0.588), nor were there any significant associations between the kind of cage (titanium or PEEK) and cage subsidence (p=0.371). Using logistic regression, the factors with a P-value below the 0.20 level in univariate analyses were included in the multivariate analyses. In multivariate analyses, diabetes mellitus (DM) (p=0.029, OR, 4.524), osteoporosis (p=0.026, OR, 6.046), and degree of disc distraction (p=0.010, OR, 1.446) had significant associations with cage subsidence. In addition, there were significant associations between cage subsidence and instrument failure (p=0.008, OR, 8.235).
Conclusions
DM and osteoporosis, which may affect bony structures, have significant associations with cage subsidence after PLIF. Cage insertion with excessive disc distraction during surgery may also affect cage subsidence after PLIF.
Fig. 1
Measurement of preoperative and postoperative disc height in the lumbar lateral view (A: anterior disc height, B: posterior disc height, C: sagittal diameter of the vertebral body measured between the midpoints of the anterior and posterior surfaces).
Table 1
Demographic and clinical data of the patients (N=93 segments)
Table 2
Cage subsidence following the inserted level
Table 3
Subsidence and clinical outcomes
Table 4
Strengths of associations between cage subsidence and various factors in the univariate and multivariate analyses
This Work (RPP-2015-023) was Supported by a fund of the Research Promotion Program, Gyeongsang National University, 2015.
References
-
Oh KW, Lee JH, Lee JH, et al. The Correlation Between Cage Subsidence, Bone Mineral Density, and Clinical Results in Posterior Lumbar Interbody Fusion. J Spinal Disord Tech. 2015 Aug 18;[Epub ahead of print].
-
-
Steffee AD, Sitkowski DJ. Posterior lumbar interbody fusion and plates. Clin Orthop Relat Res 1988;227:99–102.
-
-
Steffen T, Tsantrizos A, Fruth I, et al. Cages: designs and concepts. Eur Spine J 2000;9 Suppl:S89–S94.
-
-
Borm W, Seitz K. Use of cervical stand-alone cages. Eur Spine J 2004;13:474–475.
-
-
Tokuhashi Y, Ajiro Y, Umezawa N. Subsidence of metal interbody cage after posterior lumbar interbody fusion with pedicle screw fixation. Orthopedics 2010;34:226–227.
-