Ottawa knee rule (Stiell 1995)
Ottawa knee rule (Stiell 1995). Knee x-ray is indicated when any of: age 55 or older, bone tenderness at the fibular head, isolated patellar tenderness (caller-applied), inability to flex to 90 degrees, or inability to bear weight both immediately after injury and in the emergency department (four steps). One weight-bearing failure alone is not enough. Not a diagnosis of fracture, not the Ottawa ankle or foot rule, and not the Pittsburgh knee rule. magent does not examine the knee.
Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.
Endpoint
POST https://api.magentlab.com/api/calc/ottawa_knee
| Category | Everything else |
|---|---|
| Provider host | api.magentlab.com |
| Networks | eip155:8453 |
| Payment schemes | exact |
| Self-reported calls, 30 days | 0 from 0 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-09-28 | valid payment request | 402 | $0.007 | 267 ms |
Example input (from the provider)
{
"body": {
"items": [
{
"age": 40,
"fibular_head_tenderness": false,
"flexion_less_than_90": false,
"isolated_patellar_tenderness": false,
"unable_to_bear_weight_immediately": false,
"unable_to_bear_weight_in_ed": false
},
{
"age": 40,
"fibular_head_tenderness": false,
"flexion_less_than_90": false,
"isolated_patellar_tenderness": false,
"unable_to_bear_weight_immediately": false,
"unable_to_bear_weight_in_ed": false
}
]
},
"method": "POST",
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"additionalProperties": false,
"properties": {
"items": {
"items": {
"properties": {
"age": {
"description": "Age in years (18-120). Age \u226555 meets this criterion; 54 does not.",
"type": "integer"
},
"fibular_head_tenderness": {
"description": "Bone tenderness at the head of the fibula. true or false.",
"type": "boolean"
},
"flexion_less_than_90": {
"description": "Inability to flex the knee to 90 degrees. true or false.",
"type": "boolean"
},
"isolated_patellar_tenderness": {
"description": "Isolated patellar tenderness as assigned by the caller. true or false. magent does not infer isolation from other flags.",
"type": "boolean"
},
"unable_to_bear_weight_immediately": {
"description": "Unable to bear weight immediately after injury (four steps). true or false. Counts only when also unable in the emergency department.",
"type": "boolean"
},
"unable_to_bear_weight_in_ed": {
"description": "Unable to bear weight in the emergency department (four steps). true or false. Counts only when also unable immediately after injury.",
"type": "boolean"
}
},
"required": [
"age",
"fibular_head_tenderness",
"isolated_patellar_tenderness",
"flexion_less_than_90",
"unable_to_bear_weight_immediately",
"unable_to_bear_weight_in_ed"
],
"type": "object"
},
"maxItems": 25,
"minItems": 1,
"type": "array"
}
},
"required": [
"items"
],
"type": "object"
},
"headers": {
"additionalProperties": {
"type": "string"
},
"type": "object"
},
"method": {
"const": "POST",
"type": "string"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}