Could the Type of Allograft Used for Anterior Cervical Discectomy and Fusion Affect Surgical Outcome? A Comparison Between Cortical Ring Allograft and Cortico-Cancellous Allograft
Bibliographic record
Abstract
Background: Allograft is predominantly used interbody spacers for anterior cervical discectomy and fusion (ACDF).The corticocancellous allograft has weaker mechanical strength as it is an artificial composite of the cancellous and cortical parts.Additionally, whether utilizing a firmer allograft, such as the cortical ring, leads to better outcomes is unclear.Therefore, we aimed to compare the surgical outcomes of cortical ring and cortico-cancellous allografts in ACDF.Methods: Patients who underwent ACDF using allograft and were followed up for > 1 year were retrospectively reviewed.Patient characteristics, including fusion rates (assessed by interspinous motion [ISM], intra-graft bone bridging, and extra-graft bone bridging), subsidence, allograft complications (e.g., allograft fracture and resorption), and patient-reported outcome measures (neck pain visual analog scale [VAS], arm pain VAS, and neck disability index), were assessed.Patients were divided into 2 groups based on the allograft used: cortical ring and cortico-cancellous allograft groups.Subgroup analysis was subsequently conducted in singleand multi-level operation groups.Results: A total of 227 patients were included.Of them, 134 (59.0%) and 93 (41.0%) underwent ACDF using cortical ring and corticocancellous allograft, respectively.In single-level operations, the cortico-cancellous allograft significantly frequented allograft resorption (24 / 66, 36.4%)than the cortical ring allograft (1 / 28, 3.7%) (p = 0.001).The cortico-cancellous allograft group demonstrated significantly greater subsidence.However, the fusion rates did not significantly differ between the 2 groups.In multi-level operations, the cortico-cancellous allograft (5 / 27, 18.5%) resulted in a significantly higher fracture rate than the cortical ring allograft (5 / 105, 4.7%) (p = 0.030).The fusion rate at 1-year postoperative assessed using ISM (63.2% vs. 55.5%) and intra-graft bone bridging (66.7% vs. 40.7%)was higher in the cortical ring group; however, the difference was not significant.The patient-reported outcomes at 1-year postoperative did not demonstrate significant intergroup differences both in single-and multi-level operations.Conclusions: Allograft resorption or fracture occurs more frequently with cortico-cancellous than cortical ring allografts.Despite the frequent occurrence of allograft-related complications with cortico-cancellous allografts, the fusion rate was not significantly affected.Due to the higher rate of allograft resorption or fractures and greater subsidence with cortico-cancellous allografts, cortical ring allografts might yield more stable results in ACDF.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.003 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.002 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".