Key Findings to Evaluate in a Patient with Right Ankle Pain After Slipping
When evaluating a patient with right ankle pain after a slip, you should focus on the Ottawa Ankle Rules criteria and assess for specific signs of ligament injury, fracture, and other soft tissue damage to determine severity and appropriate management. 1, 2
Initial Assessment
- Determine the mechanism of injury (typically an inversion injury in plantar-flexed position for lateral ankle sprains) and assess timing of injury and history of previous ankle sprains, which is a common risk factor for new injuries 2
- Evaluate for urgent signs requiring immediate attention: high level of pain, rapid onset of swelling, coldness/numbness in the injured foot, inability to bear weight, or complicating conditions (e.g., diabetes) 1, 2
- The ability to walk again within 48 hours after trauma is an auspicious sign and indicates a good prognosis 1
Ottawa Ankle Rules Assessment
- Apply the Ottawa Ankle Rules to determine if radiography is necessary 1
- X-ray diagnostics is only indicated if there is:
- Pain in the malleoli or midfoot, combined with one of the following:
- Palpation pain on the dorsal side of one or both malleoli
- Palpation pain at the base of the fifth metatarsal bone
- Palpation pain of the navicular bone
- Inability to walk at least four steps 1
- The Ottawa Ankle Rules have high sensitivity (99.7%) for detecting fractures, missing fractures in only 0.3% of patients 1
Physical Examination
- Look for key findings associated with more severe (grade III) sprains: swelling, hematoma, pain on palpation, and positive anterior drawer test 1, 2
- When all four of these findings are present, 96% of patients have a lateral ligament rupture 1
- Perform the anterior drawer test to detect excessive anterior displacement of the talus, indicating anterior talofibular ligament tear 1, 2
- Conduct a crossed-leg test to detect high ankle (syndesmotic) sprains - pain in the syndesmosis area when pressure is applied to the medial side of the knee 1, 2
- Pay special attention to the area inferior to the lateral malleolus in patients with appropriate clinical setting to exclude a "snowboarder's fracture" (lateral talar process fracture) which may be misdiagnosed as a lateral ankle sprain 1
Specific Areas to Evaluate
- Assess for tenderness over the anterior talofibular ligament, calcaneofibular ligament, and deltoid ligament 1, 2
- Evaluate for tenderness over the syndesmosis (high ankle sprain) 1, 2
- Check for tenderness over the base of the fifth metatarsal and navicular bone (potential fracture sites) 1
- Assess for tenderness over the peroneal tendons and Achilles tendon 1, 2
- Examine for ankle joint effusion, which may indicate intra-articular pathology 1
Important Caveats
- Reexamination 3-5 days after injury is important in distinguishing partial tears from frank ligament ruptures, as excessive swelling and pain can limit examination up to 48 hours after injury 1
- Delayed physical examination (5 days after injury) has been shown to be more accurate than examination within 48 hours, with specificity of 84% and sensitivity of 96% for ligament injuries 3
- In patients with diabetic neuropathy or neurologic compromise where application of the Ottawa Ankle Rules is not possible, ankle radiographs should be considered as the initial imaging study regardless of symptoms 1
- Pay attention to potential deficits in proprioception, static and dynamic balance, which may persist even a year after ankle sprain and predispose to recurrent injury 4
Imaging Considerations
- If Ottawa Ankle Rules are positive, radiography is the first-line imaging modality 1
- If radiographs are normal but symptoms persist, MRI may be appropriate to evaluate for ligament, tendon, or osteochondral injuries 1
- For suspected syndesmotic injuries, MRI is recommended for verification 2
- CT may be appropriate for further evaluation if radiographs demonstrate fracture or potential osteochondral injury 1, 2