Clinical Outcomes of Multiple Osteochondral Allograft Transplantation of the Knee: An Analysis of Snowman Technique and Multifocal Lesions
Bibliographic record
Abstract
Objectives: To report the clinical outcomes of snowman technique osteochondral allograft transplantation (OCA) and clinical outcomes of multifocal OCA. Methods: Consecutive patients who underwent either a primary snowman OCA or multifocal (i.e. bipolar patellofemoral, patellofemoral and a condyle or bicondylar) with a minimum 2-year follow-up by a single surgeon from 4/2003 to 4/2015 were isolated. Failure was defined as revision OCA, conversion to arthroplasty, or gross appearance of graft degeneration on 2 nd look arthroscopy. Results: Twenty-six patients (28 knees) were isolated with 22 patients (24 knees; 85.7%) having 2-year clinical follow-up. Nine of 11 patients (81.8%) who underwent isolated condylar snowman allografts met inclusion criteria at mean follow-up of 7.4±3.6 years, while 13 additional patients (15 knees; 88.2%) underwent multifocal OCA at mean follow-up of 6.4±3.9 years. All 9 patients who received isolated snowman OCA were to the medial femoral condyle. Reoperations were common with 44.4% (N=4) of the snowman group and 20% of multifocal OCA (N=3) undergoing at least 1 reoperation. There were 3 failures (33.3%) in the snowman technique group at a mean 7.7±5.5 years and 1 failure in the multifocal OCA group at 4.5 years. All 4 failures underwent TKA. Patients who underwent multifocal OCA demonstrated significant improvements in the International Knee Documentation Committee score, Knee Injury and Osteoarthritis subscores, Western Ontario and McMaster Universities Osteoarthritis Index subscores, and the Short-Form-12 physical component (P <0.05 for all). Patients who underwent snowman OCA demonstrated significant improvement in KOOS pain subscore and WOMAC overall scores (P<0.05 for both) Table 1]. Conclusion: While in a small cohort, patients who underwent snowman OCA had a high rate of reoperation (44.4%) and a high rate of failure (33.3%). Comparatively, patients who underwent multifocal OCA had reoperation and graft survival rates comparable to published literature for focal OCA. [Table: see text]
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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 source (direct Gemma or distilled Codex), 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".