Medial Discoid Meniscus in Children: A Multicenter Case Series of Clinical Features and Operative Results
Bibliographic record
Abstract
Background: The discoid medial meniscus is a rare congenital anomaly of the knee. The literature is limited to small case series. Purpose/Hypothesis: Our purpose is to report the clinical manifestations and operative treatments of discoid medial menisci in children from multiple centers in North America. We hypothesized that symptoms and signs, arthroscopic findings, surgical treatments, and outcomes are similar to those for symptomatic discoid lateral menisci. Study Design: Case series; Level of evidence, 4. Methods: A retrospective review identified patients with a diagnosed discoid medial meniscus confirmed at surgery across 8 children’s hospitals between January 2000 and June 2021. The literature on discoid lateral menisci was reviewed and summarized for comparison. Results: A total of 21 patients (9 female, 12 male) with 22 discoid medial menisci were identified. The mean ± SD age at the time of diagnosis was 12.8 ± 3.8 years. The most common symptoms and signs were locking and/or clunking, present in 12 of 22 knees (55%), similar to that reported in patients with discoid lateral menisci. Twelve discoid medial menisci were complete (55%); 8, incomplete (36%); and 2, indeterminate (9%). Tears were present in 13 knees, most commonly horizontal cleavage (54%). Five discoid medial menisci were unstable (23%): 3 for posterior tears and 2 for rim insufficiency. All 22 knees underwent arthroscopic saucerization, and of the 13 torn menisci, 7 (54%) were repaired. The median follow-up was 24 months (range, 2-82 months). Four knees underwent reoperation. All knees that required reoperation had undergone repair for a posteriorly located tear. There was a significant association between operative repair and need for reoperation ( P = .0048). High rates of peripheral instability were also noted in case series of patients with discoid lateral menisci. Conclusion: Patient presentations and treatments for those with discoid medial menisci were similar to those reported for patients with discoid lateral menisci. Knees with discoid medial menisci also demonstrated instability attributed to peripheral insufficiency and posterior tears. Tears were present in over half of knees with discoid medial menisci, and reoperation was more common in knees that underwent repair of tears than those without repair.
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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 | 0.003 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.001 | 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".