Clinical Prediction Rules

Question 1

Ottawa Knee Rule

Answer 1

Radiograph of the knee should be obtained after acute injury ONLY for patients who meet one or more of the following criteria:
Age >55 years
Isolated tenderness of patellar
Tenderness at the head of the fibula
inability to flex the knee to 90 degrees
Inability to WB both immediately and in the ED for 4 steps

100% Sn, 49% Sp

Question 2

NEXUS criteria

Answer 2

1. No midline tenderness
2. No focal neurological deficit
3. Normal alertness
4. No intoxication
5. No painful distracting injury

If all 5 items are met, imaging is not required.

Question 3

Canadian C-Spine Rule

Answer 3

1. Any high-risk factor that mandates radiograph?
   - Age > 65 or Dangerous mechanism or Paresthesia in extremities
2. Any low-risk factor that allows safe assessment of ROM?
   - Simple rear-ended MVA or
   - Sitting position in ED or
   - Ambulatory at any time or
   - Delayed onset of neck pain or
   - Absence of midline C spine tenderness
3. Able to actively rotate neck?
   - 45 degrees left and right

Question 4

Ottawa ankle rules

Answer 4

Ottawa ankle rules
Plain radiographs of the ankle are only indicated for patients who have pain in the malleolar zone AND
have bone tenderness at the posterior edge or tip of the lateral or medial malleolus
OR
Are unable to weight bear both immediately following injury and for 4 steps in the ED

Plain radiographs of the foot are only indicated for patients who have pain in the midfoot zone AND
have bone tenderness at the base of the fifth metatarsal or at the navicular
OR
are unable to weight bear both immediately after the injury and for 4 steps in the ED

Question 5

Well’s Criteria for DVT

Answer 5

1. Active cancer
2. Bed rest > 3days or major surgery within 12 weeks
3. Calf swelling >3cm compared to other leg (10cm distal to tibial tuberosity)
4. Collateral superficial veins
5. Entire leg swollen
6. Localised tenderness along the DVS
7. Pitting edema, confined to symptomatic leg
8. Paralysis, paresis, or recent plaster immobilisation of the lower extremity
9. Previous DVT
10. Alternative diagnosis to DVT likely (-2)

Score of 1-2=moderate risk, score > 3 DVT likely