Objective
This study aims to compare the risk of subsequent surgery following surgical treatment of clinical adjacent-segment pathology (CASP) after lumbar fusion, specifically evaluating decompression alone versus decompression with extension of the fusion.
Methods
Using the Swespine registry, we included patients who had surgical treatment for CASP following index lumbar fusion surgery, 1997–2019. The cohort was divided according to CASP treatment: decompression alone or decompression with extended fusion. A comparison of subsequent surgeries was made with Kaplan-Meier analysis and Cox regressions adjusted for potential confounders (age, sex, body mass index, smoking status, number of operated levels at CASP surgery, number of fused levels at index fusion surgery, and diagnosis for CASP surgery).
Results
A total of 2,521 patients were included, 1,176 (47%) in the decompression-group and 1,345 (53%) in the extended fusion group and the mean follow-up was 6.1±4.4 years. Mean age at CASP surgery was 61 years and 1,588 (63%) were females. The median time to subsequent surgery was 1.7 years (range, 0.9–3.7 years). Kaplan-Meier–estimated probability of subsequent surgeries at 5 years was 18% (95% confidence interval [CI], 15%–20%) for the decompression-group and 25% (95% CI, 22%–27%) for the extended fusion group. The hazard ratio was 1.26 (95% CI, 1.02–1.56; p=0.032) for those with extended fusion.
Conclusion
Extension of fusion for CASP was associated with significantly higher risk of subsequent surgery, but causality should be interpreted with caution as radiographic information on instability, deformity, or foraminal stenosis could not be verified.

Objective
Combined with different configuration types of syringomyelia, to analyze the correlation between syrinx resolution and changes in cervical sagittal alignment following Foramen magnum and Magendie dredging (FMMD) for syringomyelia associated with Chiari I malformation (CM-I), and to further explore the respective relationship with clinical outcome.
Methods
A consecutive series of 127 patients with CM-I and syringomyelia who underwent FMMD in our center met the inclusion criteria of this study. Their clinical records and radiologic data were retrospectively reviewed. The Japanese Orthopedic Association (JOA) scoring system and the Chicago Chiari Outcome Scale (CCOS) were used to evaluate the surgical efficacy. The phenotypes of syringomyelia and the clinical characteristics of the patients were analyzed according to grouping by cervical curvature at baseline.
Results
The preoperative straight or kyphotic cervical alignment is more common in the moniliform syrinx. After surgery, the syrinx resolution and cervical sagittal realignment in the moniliform group are more obvious, and the corresponding prognosis is relatively better. Spearman correlation analysis showed that the ΔS/C ratio (the change ratio of syrinx/cord) was positively correlated with the CCOS (p = 0.001, r = 0.897) and ΔC2–7A (the change of lower cervical angle) (p = 0.002, r = 0.560). There was also a correlation between the ΔJOA score (the change rate of the JOA score) and ΔC2–7A (p = 0.012, r = 0.467).
Conclusion
After decompression surgery, syrinx resolution may coexist with the changes in the subaxial lordosis angle, especially for syrinx in moniliform type, and the relationship between syrinx resolution and cervical sagittal realignment might be valuable for evaluating the surgical outcome.