Early postoperative changes predict long-term cervical kyphosis after laminoplasty: A retrospective radiographic study

Postoperative loss of cervical lordosis is a common outcome following laminoplasty, with kyphotic changes often appearing shortly after surgery. We hypothesized that radiographic findings as early as one week postoperatively could help predict long-term kyphotic progression. To explore this, we analyzed associations between preoperative and postoperative radiographic parameters up to one year following surgery. This retrospective study included 113 patients who underwent cervical laminoplasty for compressive myelopathy. Collected preoperative data included age, number of operated levels, C2–7 Cobb angle, C2–7 cervical sagittal vertical axis (cSVA), T1 slope, and modified Japanese Orthopaedic Association (mJOA) score. Radiographic evaluations were conducted preoperatively and at 1 week, 1 month, 6 months, and 1 year postoperatively. Changes in alignment (ΔC2–7 and ΔcSVA) were calculated at both 1 week and 1 year. Patients were grouped based on kyphotic progression, and intergroup comparisons of radiographic changes were made. ΔC2–7 at 1 week strongly correlated with ΔC2–7 at 1 year (r = 0.522, p < 0.0001), and a similar correlation was found for ΔcSVA (r = 0.541, p < 0.0001). The progression group exhibited a greater early decrease in C2–7 Cobb angle (−8.65°) and a larger increase in cSVA at 1 week postoperatively compared to the non-progression group. Patients exhibiting early postoperative kyphotic changes within the first week after laminoplasty are more likely to develop significant kyphosis by one year. Early imaging may serve as a valuable indicator of long-term sagittal alignment outcomes.