Is a weight-bearing X-ray (X-ray taken while the patient is bearing weight) acceptable for diagnosing a suspected fracture in the foot?

Weight-Bearing X-rays for Suspected Foot Fractures

Weight-bearing X-rays are not only acceptable but actually preferred over non-weight-bearing films for suspected foot fractures, as they detect dynamic abnormalities such as joint malalignment, subluxation, and fracture displacement that may be missed on non-weight-bearing images. 1, 2

Standard Imaging Protocol

The American College of Radiology recommends obtaining standard three-view radiographs (anteroposterior, medial oblique, and lateral projections) performed weight-bearing as the initial imaging modality for suspected foot fractures. 1, 2, 3

Why Weight-Bearing is Superior

• Weight-bearing radiographs provide functional information about how the fracture behaves under physiologic load, revealing instability or displacement that only manifests when the foot is loaded 1, 2
• Dynamic abnormalities including hardware loosening, joint malalignment, subluxation, and implant displacement are often not apparent on non-weight-bearing films 2
• For Lisfranc injuries specifically, weight-bearing views are essential as non-weight-bearing images are unreliable for detecting subtle injuries 3
• Standard three-view radiographic studies have 99% sensitivity for detecting foot fractures 4

When Non-Weight-Bearing is Acceptable

Non-weight-bearing radiographs are an acceptable alternative only when the patient cannot bear weight due to pain, limited mobility, or when there is risk of further displacement of joints and/or bones. 1, 2

Important Caveats

• The American College of Radiology specifically advises against relying solely on non-weight-bearing films when assessing fracture stability or alignment, as this can miss clinically significant displacement that only manifests under physiologic load 2
• For Lisfranc injuries, relying solely on non-weight-bearing radiographs can lead to missed diagnoses 3
• In patients with neuropathy (such as diabetic Charcot foot), special attention is required as they may be able to bear weight despite fractures 3

Clinical Application Algorithm

1. First-line imaging: Obtain weight-bearing three-view radiographs (AP, medial oblique, lateral) if patient can tolerate 1, 2, 3

2. If weight-bearing not feasible: Obtain non-weight-bearing films, but recognize their limitations in detecting dynamic instability 1, 2

3. Consider bilateral comparison views: Helpful for detecting subtle malalignment, particularly in midfoot injuries where anatomic relationships are complex 2, 3

4. If radiographs normal but clinical suspicion high: Proceed to advanced imaging (CT for osseous detail, MRI for ligamentous injury) 3

Specific Fracture Considerations

Lisfranc Injuries

• Weight-bearing radiographs are the cornerstone of diagnosis, with attention to diastasis between first and second metatarsal bases and the "fleck" sign 3
• A study comparing weight-bearing radiographs to CT found that when initial weight-bearing radiographs were positive, 54% of subsequent CT scans were equivocal or negative, suggesting weight-bearing films are highly reliable 5
• Bilateral imaging with both feet on anteroposterior radiographs helps detect subtle malalignment when compared to the uninjured side 3

Ankle Fractures (Weber B/SER Types)

• Weight-bearing radiographs reliably predict normal ankle congruence and stability in Weber B fractures 6
• However, research shows that weight-bearing radiographs may not show significant medial clear space widening even with complete deltoid ligament disruption, as the talus often centers itself underneath the tibia with weight-bearing 7, 8
• This represents a limitation where weight-bearing films may underestimate instability in certain ankle fracture patterns 7, 8

Charcot Neuroarthropathy

• Weight-bearing radiographs are preferred to detect dynamic abnormalities in diabetic patients with suspected Charcot foot 1
• Immediate immobilization should be employed while awaiting imaging if weight-bearing is not feasible 1

Common Pitfalls to Avoid

• Do not assume non-weight-bearing films provide equivalent information - they systematically underestimate dynamic instability 2, 3
• Ensure consistent positioning between serial studies - inconsistent cassette-side positioning or weight-bearing status can obscure subtle hardware migration or fracture displacement 2
• Do not delay immobilization in high-risk patients - if weight-bearing films cannot be obtained immediately in suspected Charcot or unstable fractures, immobilize first and image later 1