Emergency · LIVE

Pittsburgh knee rule (Seaberg 1994)

Pittsburgh knee

Apply the Seaberg 1994 Pittsburgh knee rule: a knee radiograph is indicated after fall or blunt trauma if the patient cannot walk four weight-bearing steps or is younger than 12 or older than 50.

LIVE $0.005 USDC GET /api/calc/pittsburgh_knee

Markdown: /docs/pittsburgh-knee.md · Canonical: https://magentlab.com/docs/pittsburgh-knee

Not a medical device. Not a diagnosis, dose, or listing recommendation.

What it computes

Apply the Seaberg 1994 Pittsburgh knee rule: a knee radiograph is indicated after fall or blunt trauma if the patient cannot walk four weight-bearing steps or is younger than 12 or older than 50.

When to use

When an agent needs the published Pittsburgh knee radiography rule and must not apply the Ottawa knee rule or invent a different age cutoff.

When not to use

• Not a diagnosis of fracture. magent does not examine the knee.
• Without fall or blunt trauma the rule does not indicate a film.
• Age 12 and age 50 do not meet the age limb (younger than 12 or older than 50). This is not the Ottawa knee rule (Stiell 1995).

Formula

Knee x-ray indicated iff blunt_trauma_or_fall and (unable_to_walk_four_steps or age < 12 or age > 50)

Citation

Title

Clinical decision rule for knee radiographs

Authors

Seaberg DC, Jackson R

Source

Am J Emerg Med. 1994;12(5):541-543

DOI

10.1016/0735-6757(94)90274-7

Worked example

Also searched as

• Pittsburgh knee rules
• Pittsburgh knee rule
• Seaberg knee
• knee radiograph rule
• blunt trauma knee x-ray
• Pittsburgh vs Ottawa knee

Try

Opens the live endpoint. Unpaid browser requests show the paywall; agents should send Accept: application/json.

/api/calc/pittsburgh_knee?age=30&blunt_trauma_or_fall=true&unable_to_walk_four_steps=false

Full URL: https://api.magentlab.com/api/calc/pittsburgh_knee?age=30&blunt_trauma_or_fall=true&unable_to_walk_four_steps=false

Call

Expect HTTP 402 until you retry with PAYMENT-SIGNATURE. Incomplete query params return HTTP 400 before any quote or charge.

curl -i -H "Accept: application/json" "https://api.magentlab.com/api/calc/pittsburgh_knee?age=30&blunt_trauma_or_fall=true&unable_to_walk_four_steps=false"

Parameters

Bulk (POST)

POST the same path with a JSON items array. The first item is the GET unit; each additional item is $0.002. Invalid items return HTTP 400 before settlement.

POST /api/calc/pittsburgh_knee Max 25 unit_amount + extra_item_amount * (n - 1) extra $0.002 PREVIEW

• 1 to 25 items. Each item uses the same keys as the GET query parameters.
• POST of 1 item costs the same as GET. Lists longer than 25: chunk into multiple POSTs. Extra items still execute; do not pad dummy rows.
• The first invalid item fails the whole request (index in the 400 JSON). You are not charged.
• HTTP 200 is {count, path, items}. Each items[i] is the GET 200 body for that row.
• Catalog misses (empty matches, found=false) stay paid 200s inside that slot.
• x402 resource URL is this path plus n and body_sha256. Browsers that prefer text/html get the same paywall as GET; Pay retries POST with the same items.

Example request (fixture)

{
  "items": [
    {
      "age": "30",
      "blunt_trauma_or_fall": "true",
      "unable_to_walk_four_steps": "false"
    },
    {
      "age": "30",
      "blunt_trauma_or_fall": "true",
      "unable_to_walk_four_steps": "false"
    }
  ]
}

Open bulk paywall →

Opens a two-item fixture on the API host. Unpaid browsers get the same MetaMask paywall as GET; Pay retries POST with those items.

Example 200 (fixture)

{
  "count": 2,
  "path": "/api/calc/pittsburgh_knee",
  "items": [
    {
      "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
      "citation": {
        "authors": "Seaberg DC, Jackson R",
        "doi": "10.1016/0735-6757(94)90274-7",
        "id": "seaberg-1994",
        "source": "Am J Emerg Med. 1994;12(5):541-543",
        "title": "Clinical decision rule for knee radiographs"
      },
      "formula": "pittsburgh_knee",
      "formula_expression": "Knee x-ray indicated iff blunt_trauma_or_fall and (unable_to_walk_four_steps or age < 12 or age > 50)",
      "age_years": 30,
      "criteria": [
        {
          "factor": "blunt_trauma_or_fall",
          "met": true
        },
        {
          "factor": "unable_to_walk_four_steps",
          "met": false
        },
        {
          "value": 30,
          "factor": "age_lt_12",
          "met": false
        },
        {
          "value": 30,
          "factor": "age_gt_50",
          "met": false
        }
      ],
      "xray_indicated": false,
      "blunt_trauma_or_fall": true,
      "unable_to_walk_four_steps": false
    },
    {
      "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
      "citation": {
        "authors": "Seaberg DC, Jackson R",
        "doi": "10.1016/0735-6757(94)90274-7",
        "id": "seaberg-1994",
        "source": "Am J Emerg Med. 1994;12(5):541-543",
        "title": "Clinical decision rule for knee radiographs"
      },
      "formula": "pittsburgh_knee",
      "formula_expression": "Knee x-ray indicated iff blunt_trauma_or_fall and (unable_to_walk_four_steps or age < 12 or age > 50)",
      "age_years": 30,
      "criteria": [
        {
          "factor": "blunt_trauma_or_fall",
          "met": true
        },
        {
          "factor": "unable_to_walk_four_steps",
          "met": false
        },
        {
          "value": 30,
          "factor": "age_lt_12",
          "met": false
        },
        {
          "value": 30,
          "factor": "age_gt_50",
          "met": false
        }
      ],
      "xray_indicated": false,
      "blunt_trauma_or_fall": true,
      "unable_to_walk_four_steps": false
    }
  ]
}

Response

Example JSON

Machine form of the same example. Frozen fixture. Not a live lookup.

{
  "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
  "citation": {
    "authors": "Seaberg DC, Jackson R",
    "doi": "10.1016/0735-6757(94)90274-7",
    "id": "seaberg-1994",
    "source": "Am J Emerg Med. 1994;12(5):541-543",
    "title": "Clinical decision rule for knee radiographs"
  },
  "formula": "pittsburgh_knee",
  "formula_expression": "Knee x-ray indicated iff blunt_trauma_or_fall and (unable_to_walk_four_steps or age < 12 or age > 50)",
  "age_years": 30,
  "criteria": [
    {
      "factor": "blunt_trauma_or_fall",
      "met": true
    },
    {
      "factor": "unable_to_walk_four_steps",
      "met": false
    },
    {
      "value": 30,
      "factor": "age_lt_12",
      "met": false
    },
    {
      "value": 30,
      "factor": "age_gt_50",
      "met": false
    }
  ],
  "xray_indicated": false,
  "blunt_trauma_or_fall": true,
  "unable_to_walk_four_steps": false
}

Client errors (HTTP 400)

Invalid params return 400 without charge. Shared HTTP 402 and 503 meanings: Payments.

Related tools

• Ottawa knee rule — Apply the Stiell 1995 Ottawa knee rule and return whether a knee x-ray series is indicated from age and caller-assigned bone tenderness, flexion, and weight-bearing findings.
• Ottawa ankle rule — Apply the Stiell 1992 Ottawa ankle rule and return whether an ankle x-ray series is indicated from caller-assigned malleolar pain, malleolar bone tenderness, and inability to bear weight.

Payment

Unpaid requests return HTTP 402 even if query parameters or POST items are missing or invalid, so CDP and agents can index the path. After a PAYMENT-SIGNATURE, invalid params return HTTP 400 JSON before settlement. magent does not charge. Fix the params, then request a new 402 quote for that complete URL. Catalog misses (empty matches, found=false) are valid paid 200s. Unpaid valid requests return HTTP 402 with a base64 PAYMENT-REQUIRED header. HTTP 503 is not a new quote: retry the same PAYMENT-SIGNATURE. Full handshake and shared payment errors: Payments. Stdio MCP: /docs/mcp.

Guarantees

• HTTP 402 is unpaid, including a missing query. After PAYMENT-SIGNATURE, invalid parameters return HTTP 400 before settlement. You are not charged.
• exact: settlement finishes before the tool (paymentFlow upfront). batch-settlement: verify/deposit before the tool; chargedCumulativeAmount commits after HTTP 2xx. Uncertain or failed settlement fails closed (HTTP 503). Retry the same PAYMENT-SIGNATURE.
• HTTP 402 is unpaid only. Do not sign a second authorization because of a 503.
• Execution is timeout-bounded and concurrency-capped.
• Calculator inputs are stored encrypted for allowlisted operators (Magent Console). They are not in public logs, SSH lookups, catalog, or rollups. Request logs store path without query.