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Study Design: Retrospective study.Objective: To determine whether postoperative pseudarthrosis can be predicted from specific preoperative radiograph measurements.Summary Of Background Data: Various factors reportedly influence the occurrence of pseudarthrosis after anterior cervical discectomy and fusion (ACDF). However, to our knowledge, there are no reports on the relationships between preoperative radiographic parameters and pseudarthrosis.Methods: We analyzed 84 consecutive patients (45 males, 39 females, mean age, 58.9 ± 11.2 yrs) who underwent ACDF. In all patients, allografts filled with local chip bone were inserted after discectomy and anterior plating was performed. On preoperative plain radiographs, we analyzed C2-C7 sagittal vertical axis, T1 sagittal slope, segmental motion, global cervical motion, and location of fusion segments. Pseudarthrosis was diagnosed as interspinous motion >1 mm with superjacent interspinous motion ≥4 mm on magnified dynamic lateral radiographs. Multivariate logistic regression was used to analyze the risk factors for pseudarthrosis and the receiver operating characteristic (ROC) curve was used to define a cutoff value.Results: One hundred and twenty-five segments from 84 patients were included. The pseudarthrosis rate was 29% based on number of patients (24/84) and 20% based on number of segments (25/125). Multilevel surgery and segments at the lowest levels showed higher pseudarthrosis rates (P = 0.01). Per multivariate logistic regression analysis, greater preoperative segmental motion, greater preoperative T1 sagittal slope, and C6-7 segments were associated with a higher risk of pseudarthrosis (all P < 0.05). A segmental motion cutoff value of 12° demonstrated pseudarthrosis with sensitivity of 87%, specificity of 84%, and area under the curve of 0.899, indicating moderate accuracy.Conclusion: Greater preoperative segmental motion, greater preoperative T1 sagittal slope, and lower fusion levels could be risk factors for pseudarthrosis following ACDF. Preoperative segmental motion >12° is likely to be an important indicator of the development of pseudarthrosis.Level Of Evidence: 3. [ABSTRACT FROM AUTHOR]

[Purpose] This study assessed the reliability and validity of an ultrasound-based imaging method for measuring the interspinous process distance in the lumbar spine using two different index points. [Subjects and Methods] Ten healthy males were recruited. Five physical therapy students participated in this study as examiners. The L2-L3 interspinous distance was measured from the caudal end of the L2 spinous process to the cranial end of the L3 spinous process (E-E measurement) and from the top of the L2 spinous process to the top of the L3 spinous process (T-T measurement). Intraclass correlation coefficients were calculated to estimate the relative reliability. Validity was assessed using a model resembling the living human body. [Results] The reliability study showed no difference in intra-rater reliability between the two measurements. However, the E-E measurement showed higher inter-rater reliability than the T-T measurement (Intraclass correlation coefficients: 0.914 vs. 0.725). Moreover, the E-E measurement method had good validity (Intraclass correlation coefficients: 0.999 and 95% confidence interval for minimal detectable change: 0.29 mm). [Conclusion] These results demonstrate the high reliability and validity of ultrasound-based imaging in the quantitative assessment of lumbar interspinous process distance. Of the two methods, the E-E measurement method is recommended.