JAAOS - 2026-09-15 - Journal Article
Relationship Between Preoperative Pfirrmann Grading and Adjacent Segment Degeneration After Anterior Cervical Diskectomy and Fusion.
Dalton JF, Oris RJ, Mathew J, McCurdy MA, Alexander T, Lin RT, Ng M, Lee Y, Narayanan R, Henry TW, Lee Y, Kothari P, Sarikonda A, Dean E, Cha R, Kazantsev M, Mangan JJ, Rihn JA, Cha TD, Kurd MF, Canseco JA, Hilibrand AS, Vaccaro AR, Kepler CK, Schroeder GD
Topics
Key Takeaway
High preoperative Pfirrmann grade (III–IV) at adjacent segments independently predicts a 0.16 decrease in postoperative-to-preoperative disk height ratio and 3.9× greater odds of worse disk height score at 1–2 years after ACDF, though 5-year revision rates for ASD were equivalent between groups.
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Summary
This study asked whether preoperative adjacent segment disk health, graded by modified Pfirrmann classification, predicts radiographic ASD after ACDF. Fifty-six patients with 114 adjacent levels were stratified into low (grades I–II) versus high (grades III–IV) degeneration groups and assessed with a validated radiographic scoring system at 1–2 years. High Pfirrmann grade independently predicted decreased disk height ratio (estimate −0.16, p=0.025) and worse disk height score (OR 3.9, p=0.030), but 5-year revision rates for symptomatic ASD were similar between groups.
Key Limitation
The 5-year revision rate comparison is underpowered given only 56 patients, making it impossible to determine whether the observed radiographic degeneration differences translate into clinically meaningful differences in symptomatic ASD requiring reoperation.
Original Abstract
INTRODUCTION
To evaluate the association between preoperative adjacent segment disk health, evaluated by the Pfirrmann classification, and adjacent segment disease (ASD) risk.
METHODS
Patients who underwent anterior cervical decompression and fusion (2013 to 2020) with available preoperative magnetic resonance imaging and 2 years of radiographic follow-up were retrospectively identified. Patients with prior cervical surgery or malignancy/infection/trauma were excluded. Preoperative adjacent disk degeneration was evaluated with modified Pfirrmann classification (grades I to IV) and substratified as low (grades I to II) or high (grades III to IV). Radiographic degeneration 2 years postoperatively was assessed through a published radiograph scoring system based on disk height, osteophyte formation, and vertebral sclerosis. Statistical analyses were conducted to compare demographic, surgical, and radiographic outcomes between low and high degeneration groups.
RESULTS
Fifty-six patients (15 with high Pfirrmann degeneration at both levels, 21 with one high level, and 20 with no high levels) and a total of 114 levels (51 with high and 63 with low Pfirrmann degeneration) were included. Age, male sex, Charlson comorbidity index, and construct length all increased consistently from patients with neither adjacent level having high degeneration to one level to both levels ( P < 0.05). Linear regression showed that high preoperative adjacent Pfirrmann grade was independently predictive of decreased postoperative to preoperative adjacent disk height ratio (estimate: -0.16, P = 0.025) at 2 years postoperatively. Similarly, ordinal logistic regression showed that high preoperative adjacent Pfirrmann grade was independently predictive of more severe postoperative disk height score at 1 year (odds ratio: 3.9, P = 0.030). Both regression models included age, sex, Charlson comorbidity index, number of levels fused, indication for surgery (radiculopathy and myelopathy), and smoking status. The revision rate for ASD was similar between groups at 5 years.
CONCLUSION
High preoperative Pfirrmann grade at the disk level adjacent to anterior cervical decompression and fusion is predictive of worse adjacent segment degeneration, specifically decreased disk height at 2 years postoperatively. However, revision for ASD was similar at 5 years postoperatively.