Risk Factors of Cage Subsidence in Patients Received Minimally Invasive Transforaminal Lumbar Interbody Fusion

Abstract

Study Design. A retrospective cohort study. Objective. To determine the risk factors of cage subsidence in patients undergoing minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) and its correlation with patient-reported outcomes. Summary of Background Data. Cage subsidence is among the cage-related complications after TLIF and may lead to poor outcomes. Few studies have addressed the incidence of cage subsidence in MI-TLIF. Methods. This retrospective study of a prospectively collected database was conducted from October 2015 to October 2017. All patients received MI-TLIF with a minimum of 2-year follow-up. All levels were separated into the cage subsidence (CS group) and no cage subsidence (non-CS group) groups. Cage subsidence was evaluated using lateral radiographs and defined as more than 2 mm migration of the cage into the endplate of adjacent vertebral body. Patient demographics, perioperative details, and radiographic parameters were recorded. Cage-related parameters were cage height, cage insertion level, and cage position. Cage position was recorded using central point ration (CPR). Patient-reported outcome was analyzed using the Oswestry Disability Index (ODI) questionnaire and Visual Analog Scale (VAS) preoperatively and at 2 years postoperatively. Results. Ninety-three patients (126 levels) were included. Mean age was 66.5 years with an average follow-up of 36.9 months. Overall incidence of cage subsidence was 34.1%. The CS group had significantly higher body mass index, less bone mineral density (BMD), shorter disc height, and higher CPR than the non-CS group. BMD, disc height, and CPR were significantly negatively correlated with depth of cage subsidence. ODI improvement was significantly lesser in the CS group than in the non-CS group. Fusion rate and complications were unrelated to cage subsidence. Conclusion. The BMD, disc height, and cage position were the most significant risk factors that were negatively correlated with depth of cage subsidence. Placing a TLIF cage anteriorly if possible may reduce the risk of cage subsidence. Level of Evidence: 3

Comparison between intervertebral oblique lumbar interbody fusion and transforaminal lumbar interbody fusion: a multicenter study

“…Postoperative intervertebral height was found to remain significantly higher in OLIF until the final evaluation. Endplate subsidence has been reported to be 30–70% for TLIF 14 – 18 and 11–30% for OLIF 19 – 22 , According to a biomechanical study by Lu et al 10 , as the surface area of the OLIF cage is much larger than that of the TLIF cage, the stresses on the vertebral endplates and cancellous bone are distributed and less susceptible to subsidence. Lin et al 4 also reported a higher cage subsidence rate in minimally invasive (MI) TLIF than in OLIF because the OLIF cage is placed at the strongest point on both ends of the vertebral endplate, whereas the TLIF cage is mostly placed near the center of the vertebral endplate.…”

Clinical and radiographic outcomes of hybrid graft in patients with Modic changes undergoing transforaminal lumbar interbody fusion

“…Cage subsidence (CS) is one of the complications that results in gradual loss of disc height (DH) and segmental lordosis (SL). Previous studies have suggested that CS is associated with osteoporosis, excessive distraction of the intervertebral space, and damage to the endplate [7][8][9][10]. Modic changes (MCs) in the lumbar endplate and subendplate bones on magnetic resonance imaging (MRI) images are classified into three types: MCs-1 is considered as the inflammatory phase or edema phase; MCs-2 is considered as the fatty phase or yellow marrow phase; MCs-3 is considered as the osteosclerosis phase.…”

A Finite Element Analysis of the Effects of Different Internal Fixation Strategies and Cage Implantation Methods on the Biomechanics of the Lumbar Spine

“…Modern intervertebral fusion is mostly achieved by implanting an intervertebral fusion Cage (Cage). As a permanent implant in the human body, Cage plays an important role in promoting intervertebral bony fusion and maintaining early biomechanical stability [22]. At rst, clinicians used two Cages to implant the intervertebral space [23].…”