We analysed 100 patients following anterior cervical discectomy and fusion with interbody stabilisation with PEEK cages. Radiographs obtained preoperatively and during the 12-month follow-up were compared to track changes in overall and local cervical lordosis and disk space height. Subsidence was defined as cage migration ≥ 3 mm into the adjacent endplates. Mean change in operated disk space height was 1.13 ± 1.33 mm. Subsidence was detected in 10.23% of the operated spaces. Mean change in overall cervical lordosis was 1.31 ± 5.71 degrees, and mean change in local lordosis was 0.19 ± 4.71 degrees. Change in overall cervical lordosis correlated with change in local lordosis (r = 0.61, p < 0.01). The greatest changes in lordosis and disk space height were noted immediately post-surgery. Baseline values were approximated gradually over time, but the post-operative values at 12 months were still higher than baseline. Disk space height change did not correlate with changes in patient-reported pain intensity at baseline (VAS 0) vs. at 12 months post-operatively (VAS 12) (r = 0.12, p < 0.05) or changes in the Neck Disability Index (NDI) at baseline (NDI 0) vs. at 12 months post-operatively (NDI 12) (r = -0.02, p = 0.05). Changes in overall cervical lordosis did not directly influence treatment outcomes assessed by comparing VAS 0 vs. VAS 12 (r = 0.13, p = 0.24) or NDI 0 vs. NDI 12 (r = -0.0005, p = 0.96). Surgical outcomes depend primarily on adequate decompression of the spinal cord and nerve roots. Post-operative radiological changes did not directly influence patients' pain level or quality of life.
Keywords: Cage subsidence; Cervical alignment; Clinical and radiological outcome; Disc height; Stand-alone PEEK cage.
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