Incidence and risk factors of posterior cage migration following decompression and instrumented fusion for degenerative lumbar disorders

Abstract

The aim of this study was to explore the incidence and risk factors for posterior cage migration (PCM) following decompression and instrumented fusion for degenerative lumbar disorders, and hope to provide references in decision making and surgical planning for spine surgeons.By retrieving the medical records from January 2011 to December 2015, 286 patients were retrospectively reviewed. According to the occurrence of PCM, patients were divided into 2 groups: PCM group and non-PCM (N-PCM). To investigate risk values for PCM, 3 categorized factors were analyzed statistically: patient characteristics: age, sex, body mass index, bone mineral density, duration of disease, diagnosis, comorbidity, smoke; surgical variables: surgery time, blood loss, surgical strategy, cage morphology, cage size, surgical segment, fusion number, source of bone graft, surgeon experience; radiographic parameters: preoperative lumbar lordosis, correction of lumbar lordosis, preoperative lumbar mobility, preoperative intervertebral height, change of intervertebral height, Modic changes, paraspinal muscle degeneration.PCM was detected in 18 of 286 patients (6.3%) at follow-up. There was no statistically significant difference between the 2 groups in patient characteristics, except diagnosis, as lumbar spondylolisthesis was more prevalent in PCM group than that in N-PCM group. There was no difference between the 2 groups in surgical variables, except cage size and surgeon experience, as size of cage was smaller in PCM group than that in N-PCM group, and the surgeons with less experience (less than 3 years) were more prevalent in PCM group than that in N-PCM group. There was no statistically significant difference between 2 groups in radiographic parameters. Logistic regression model revealed that less than 3 years of surgeons’ experience, small cage size, and lumbar spondylolisthesis were independently associated with PCM.For patients with lumbar spondylolisthesis, they should be fully informed about the risk of PCM before operation. While for spinal surgeons, large cage should be preferred, and careful manipulation should be adopted, especially for new learners with less than 3-year experience of fusion surgery.

Cage positioning as a risk factor for posterior cage migration following transforaminal lumbar interbody fusion – an analysis of 953 cases

“…The prevalence of PCM was 2.52%, and one fourth of the patients (6 of 24) received revision surgery due to severe symptoms. The incidence was compatible to prior studies that reported the prevalence of PCM after TLIF or PLIF ranging from 1.17 to 14.7%, and occurred within 7 months after operation [3, 4, 6, 10]. Most cases of PCM occurred in the early postoperative period before achieving solid fusion.…”

“…The authors failed to demonstrate the relationship between PCM and posteriorly located cages, possibly due to the small sample size. This current study had more patients compared to Aoki et al (24 patients versus 4 patients) and other existing literatures [3, 4, 6–8, 10]. Because the cages used in this study were all radiolucent, it was difficult to define cage margins by radiograph as Aoki et al did.…”

“…To our knowledge, few clinical studies have researched the relation of cage positioning and PCM. Prior published reports indicated several risk factors for PCM following posterolateral interbody fusion (PLIF) and TLIF, including undersized cages, unilateral pedicle screw fixation, end disc fusion, bullet-type cages, pear-shaped discs, surgeon experience, and high preoperative disc height [3, 4, 6–10]. The impact of cage position on PCM has yet to be identified.…”

Standalone oblique lateral interbody fusion vs. combined with percutaneous pedicle screw in spondylolisthesis

“…Nevertheless, other authors reported similar results. Li et al [20] and Lee et al [21] showed that lower BMD could result in cage migration. Pan et al [22] and Lee et al [23] reported that BMI of patients with cage retropulsion was higher than that in those without.…”

Assessment of the association between paraspinal muscle degeneration and quality of life in patients with degenerative lumbar scoliosis

“…Decreased PVM CSA is a risk factor for post-operative pedicle screw loosening (46). One study reported the correlation between pre-operative PVM degeneration and cage displacement after fusion (47). Reduced PVM strength and an increased pre-operative FIA may lead to proximal junctional kyphosis (48).…”