Obtain three-view radiographs of the right foot immediately to evaluate for metatarsal fractures and rule out Lisfranc injury
This 73-year-old woman with acute twisting injury causing severe forefoot pain requires plain radiography as the initial imaging study, specifically anteroposterior (AP), lateral, and oblique views of the foot. 1
Clinical Reasoning
The presentation of severe pain localized to the ball of the foot (metatarsal heads) and toes following a twisting mechanism raises concern for:
- Metatarsal fractures (most likely given the mechanism and location)
- Lisfranc injury (midfoot injury that can occur with twisting)
- Toe fractures
- Plantar plate injuries
Why Radiographs Are Indicated
While the Ottawa Foot Rules are highly sensitive (99%) for detecting foot fractures, trauma to the distal forefoot (metatarsal heads and toes) is not directly addressed by the Ottawa rules 1. When a fracture is suspected in this region, radiographs should be obtained regardless of Ottawa criteria 1.
Radiographs are the mainstay of initial imaging in acute foot trauma with a standard three-view study (AP, oblique, and lateral) 1. This approach has 99% sensitivity for detecting foot fractures 1.
Critical Consideration: Lisfranc Injury
Given the twisting mechanism, you must actively evaluate for Lisfranc injury, which is frequently overlooked 2. Key steps:
- If clinically feasible, obtain weight-bearing AP views in addition to standard three views 1
- Weight-bearing radiographs are superior because non-weight-bearing films are unreliable for detecting subtle Lisfranc injuries 1
- Look specifically for widening at the tarsometatarsal joint 2
- Consider bilateral AP views to compare alignment with the uninjured side 1
Initial Management Pending Imaging
- Immobilize the foot in a posterior splint or walking boot
- Non-weight-bearing or protected weight-bearing until fracture is ruled out
- Ice, elevation, and analgesia (NSAIDs or acetaminophen)
- Avoid opioids as first-line given her age and fall risk
If Radiographs Are Normal But High Clinical Suspicion Persists
If initial radiographs are normal or equivocal but you strongly suspect:
- Lisfranc injury: Consider MRI or CT as next step 1
- Occult metatarsal fracture: Consider MRI or CT 1
- Plantar plate tear: MRI has 87% sensitivity, ultrasound 96% sensitivity 1
Common Pitfall to Avoid
Do not dismiss this as a simple sprain. Twisting injuries in elderly patients can cause significant fractures, and missed Lisfranc injuries lead to chronic pain, arthritis, and disability 2. The severe pain with walking and localized tenderness to multiple metatarsal heads strongly suggests bony injury requiring imaging confirmation.
Age-Specific Consideration
At 73 years old, this patient may have underlying osteoporosis, increasing fracture risk even with seemingly minor trauma. Ensure adequate immobilization and non-weight-bearing status until fractures are definitively excluded.