Do the positioning variables of the cage contribute to adjacent facet joint degeneration? Radiological and clinical analysis following intervertebral fusion

Fuping Li; Xinhua Zhan; Xin Xi; Zhili Zeng; Bin Ma; Ning Xie; Rui Zhu; Tsung-Yuan Tsai; Guoan Li; Yan Yu; Liming Cheng

doi:10.21037/atm-20-7718

Do the positioning variables of the cage contribute to adjacent facet joint degeneration? Radiological and clinical analysis following intervertebral fusion

Ann Transl Med. 2021 May;9(9):776. doi: 10.21037/atm-20-7718.

Authors

Fuping Li^{1

2

3}, Xinhua Zhan^{4

5}, Xin Xi^{1

2}, Zhili Zeng^{1

2}, Bin Ma^{1

2}, Ning Xie^{1

2}, Rui Zhu², Tsung-Yuan Tsai⁶, Guoan Li⁷, Yan Yu^{1

2}, Liming Cheng^{1

2}

Affiliations

¹ Department of Spine Surgery, Tongji Hospital, Tongji University School of Medicine, Shanghai, China.
² Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration, Ministry of Education, Tongji Hospital, Tongji University School of Medicine, Shanghai, China.
³ Department of Spine Surgery, Shanghai Fourth People's Hospital Affiliated to Tongji University School of Medicine, Shanghai, China.
⁴ Jiading Branch of Shanghai General Hospital, Shanghai, China.
⁵ Department of Orthopedics, Jiangqiao Hospital, Shanghai, China.
⁶ School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China.
⁷ Orthopedic Bioengineering Research Center, Department of Orthopedic Surgery, Newton-Wellesley, Hospital/Harvard Medical School, Wellesley, MA, USA.

Abstract

Background: Compared to other risk factors, adjacent facet joint degeneration (AFD) is the main contributor to adjacent segment disease (ASD). The interbody cage may be a potential indirect risk of AFD. This study investigated the correlations among the lumbar sagittal balance parameters, the inter-body cage's intraoperative positioning variables, and adjacent facet joint degeneration following the transforaminal lumbar interbody fusion (TLIF) technique.

Methods: Patients who accepted single-level TLIF for symptomatic lumbar degenerative disease and were followed up for at least six months were enrolled in this study. According to the inclusive and exclusive criteria, 93 patients were included (44 males and 49 females). X-ray and computed tomography (CT) images were obtained before and six months after surgery. The vertebral contour and the center of the marker mass in the cage were calculated using a geometric algorithm. Orthopedic surgeons measured the disc height, lordosis angle, and facet joint degeneration. Patient-reported outcomes, including the Oswestry Disability Index (ODI) and the visual analog scale (VAS), were used to assess the clinical outcomes. The Student's t-test, Wilcoxon rank-sum test, and Chi-square test were used for the statistical analyses.

Results: The average age was 53.7 years old (range, 27-84 years). The average functional disability outcome assessed by the ODI was 61.2, and the average back and leg pain assessed by the VAS was 6.2 and 6.9, respectively. The patients were categorized into a normal group and an abnormal (AFD) group according to whether the facet joint degeneration was aggravated. The abnormal group had a higher back pain VAS score (P=0.031) and lower sagittal vertical position (P=0.027). The other parameters were similar at baseline (P>0.05). The cage's sagittal vertical position decreased significantly with AFD aggravation (OR, 0.737; 95% CI, 0.561-0.969).

Conclusions: In patients with AFD aggravation, the preoperative VAS and postoperative ODI scores were significantly higher. The cage position parameters were related to AFD. A lower cage center was associated with a greater incidence of AFD.

Keywords: Adjacent segment disease (ASD); adjacent facet joint degeneration (AFD); interbody cage; transforaminal lumbar interbody fusion.