- Patient history and physical examination are as accurate as imaging for diagnosing acute ankle and knee injuries.
- Apply the Ottawa Ankle Rules or Ottawa Knee Rules to rule out fracture.
- Only consider imaging if the results will change your management of the injury
- Conservative management is based on RICE and no HARM in the first days after injury.
- If physical examination is limited because of pain and swelling, provide conservative management and re-evaluate 4 days after injury for ankle sprains (lateral ligament) and 1–2 weeks after injury for ACL tears.
- Consider referral to an orthopedic specialist if symptoms persist, despite conservative management.
MedicineWise News: Diagnosing knee pain in middle-aged patients
Knee pain is common in middle-aged patients, and brings them to your surgery often. But is it an acute injury or older damage? In almost all cases a diagnosis can be made without advanced imaging techniques such as MRI.
NPS MedicineWise videos: physical examination of acute ankle and knee injuries
- Meniscal tears
- Anterior cruciate ligament (ACL) tears
- Ankle sprains (lateral ligament)
CPD options for knee and ankle imaging
Consolidate your knowledge about knee and ankle injuries and imaging, brush up on current guidelines and practices and earn CPD points through our learning activities.
- We are no longer taking bookings for educational visits on this topic
- Online case study: Diagnostic imaging in acute ankle and knee injuries
In my practice: Dr Andrew Rees on diagnosing ankle and knee injuries
Since the early 2000s the number of ankle ultrasounds and knee MRI referrals has been rising in primary care. GPs can turn the tide by improving their knowledge and building confidence in their diagnostic and management skills.
Clinical snapshot: Help remembering the Ottawa Ankle Rules
The Ottawa Ankle Rules (OAR) are a highly sensitive, validated tool for deciding whether to order an X-ray for an acute ankle injury.
The 44-55-66-PM mnemonic might help you remember them.
A single-blind RCT of 206 participants (96 medical students and 94 hospital residents) gave one group the mnemonic and a control group the standard version of the OAR.
At 3 weeks both groups had improved their memory of the OAR, after 5–9 months the mnemonic group had better recall.
The Ottawa Ankle Rules (OAR): 44-55-66-PM
Patients need an X-ray only if:
4 Unable to do 4 steps immediately AND
4 Unable to do 4 steps in the emergency department
5 Has pain at the base of the 5th metatarsal
5 Has pain at the 5caphoid (navicular)
6 Tenderness in 6 cm posterior edge of lateral malleolus
6 Tenderness in 6 cm posterior edge of medial malleolus