Ten-day below-knee cast,
does it really help with Improved ankle function at three months versus double-layer tubular compression bandage?
research showsThe grade is C with 50 points. CAST randomized 584 participants across four groups, including 142 to cast and 144 to tubular bandage. At 12 weeks, adjusted FAOS differences were +8.7 points for sport (95% CI 1.6-15.7) and +8.7 for ankle-related quality of life (2.4-15.0), but the report's standardized effects were 0.35 and 0.36. With no validated between-group threshold, the conventional 0.5 boundary classifies these as smaller than moderate.
ads claimA cast physically immobilizes the ankle. That fact is separate from better patient-reported function, and CAST found only small, temporary gains.
Useful facts when choosing a product
- The cast was applied 2-3 days after emergency attendance, after swelling began to settle, and remained for 10 days.
- Twenty-three of 142 cast-assigned participants did not receive the allocated cast, but analysis retained randomized assignment.
- Across all four groups, two cellulitis cases, three DVTs, and two pulmonary emboli were reported; complete arm-specific totals were not provided.
Chamgap Semantic Classification Code
Candidate index · review held
UNK.below-knee-cast.UNK.ankle-function-at.improve.UNKUnknown > below-knee cast > Unknown > ankle function at > Improvement claim > Unknown
An automated migration candidate, not an issued permanent code; exact claim scope remains under review. This machine-generated migration candidate helps retrieval but is not a permanent assignment. The original verdict ID and URL remain authoritative.
What the research actually shows
CAST centrally randomized 584 participants in eight UK emergency departments and used analyses adjusted for sex, age, and baseline score. The Lancet article and HTA monograph report the same CAST trial and are not two replications. Verdicts 1770, 1847, and 2276 concern therapeutic ultrasound, topical diclofenac, and ice respectively, not casting.
Why this is classified as C (50)
A single publicly funded trial found statistically significant but small standardized three-month functional effects, with 18% missing questionnaire data, giving C with 50 points.
Counterpoint. This applies to severe, non-weight-bearing sprains without fracture, not mild sprains, fracture, or chronic instability.
Rejudgment record. Cross-check applied — Cross-checked adjusted between-group estimates, standardized effect sizes, missing-data analyses in the CAST HTA monograph, and the ISRCTN record
| Endpoint | P | Symptom or function itself is the target - including patient reports and performance tests |
| Replication | R1 | Single confirmatory trial |
| Independence | I2 | Decisive evidence is publicly or non-profit funded |
| Effect size | E~ | Statistically positive but below the threshold |
Stored derived and displayed grades match; this is not a current recalculation or validity check (C).
Sub-claim grades by effect
This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.
| Effect (sub-claim) | Grade | Basis |
|---|---|---|
| A 10-day cast improves three-month ankle function | C | Some FAOS differences were significant, but standardized effects were 0.35-0.36. |
| A 10-day cast remains superior at nine months | D | No significant nine-month differences remained. |
Cross-check — AI research and Codex final gate
Evidence Table
| Study | Design | Sample | Funding | Endpoint | Result | Weight |
|---|---|---|---|---|---|---|
| Lamb SE et al.; Collaborative Ankle Support Trial (CAST Group). 2009 CAST | Four-arm pragmatic randomized trial in eight emergency departments with blinded outcome handling | 584 randomized; 142 cast and 144 tubular bandage; 82% response at 12 weeks | NHS Health Technology Assessment Programme | Twelve-week FAOS pain, activities of daily living, sport, and quality of life | Adjusted cast-versus-bandage differences: pain +5.1 (0.3-10.0), ADL +3.5 (0.4-6.6), sport +8.7 (1.6-15.7; effect size 0.35), quality of life +8.7 (2.4-15.0; 0.36) | Pivotal single publicly funded trial |
| Cooke MW et al.; CAST trial group. 2009 HTA | Full monograph of the same CAST trial | Same 584 participants | NHS HTA | CAST clinical and cost-effectiveness outcomes | Reported central allocation, randomized-group analysis, multiple-imputation sensitivity analysis, and standardized effect sizes | Detailed methods and tables, not a replication |
Receipt — 2 References
All 2 cited sources were verified for existence at the original page (as of 2026-08-14).
Final verification and publication gate: Codex · Evidence date: 2026-08-14 · Corrections: none
Cite this verdict
[Chamgap] Ten-day below-knee cast x three-month function after severe ankle sprain — Evidence Grade C·50. 2 cited sources checked. Source: https://chamgap.com/en/verdicts/joint-bone/ten-day-below-knee-cast-severe-ankle-sprain-three-month-function/ · CC BY 4.0CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.
What this document does and does not do
Chamgap is an information source. It reports what research has and has not confirmed; it does not tell readers what to take or buy. That decision belongs to readers and, when needed, medical or legal professionals. This verdict reflects literature available up to the search date and may change as new research appears. Nothing here is medical advice.