Probability of Occult Ankle Fracture Based on Radiograph-Measured Swelling
Location
LSUHSC Center for Advanced Learning and Simulation (CALS)
Document Type
Presentation
Start Date
22-6-2024 10:30 AM
End Date
22-6-2024 11:25 AM
Publication Date
2024-06-22
Description
Introduction: Several children every year present to the emergency department (ED) with a traumatic ankle injury. It is our experience that about 1/2 of these patients have X-rays not showing a fracture. About 1/4 of those patients with a “normal” X-ray subsequently reveal a fracture on follow-up X-ray a few weeks later. Clinically, patients are assessed on initial ED visit as to weight bearing or nonweight bearing on the injured ankle. If non-weight bearing, physicians often likely presume an occult fracture and will cast the patient. Traditionally, ankle swelling has not been used clinically to predict occult fractures. We set out to compare the likelihood of an occult fracture using swelling, weightbearings status, and the combination of both. Methods: The study was a retrospective chart review. After obtaining IRB approval (#5179), using Children’s Hospital New Orleans data base, ED presentations for suspected lateral malleolus injury were pulled from a 1-year span (2021-2022). Soft tissue ankle swelling measurements were measured, as well as whether the patient was weight bearing or non-weight bearing. Fisher’s Exact test was used to calculate the sensitivity and specificity of each parameter. A computer model (Exact Logistic Regression) used both clinical parameters as well as just ankle swelling to predict probability of an occult fracture. Results: 61 children presented with ankle injury, of which 32 had negative initial x-rays. Of these 32, 8 (25%) had an occult fracture on follow-up X-ray. Non-weight bearing had sensitivity (75%) and specificity (58%) for occult fracture detection (p = 0.220), and for ankle swelling (p < 0.0001) with sensitivity and specificity variable based on ankle mm. Discussion: From this small retrospective study, it appears that X-ray measurement of ankle swelling is highly predictive of an occult ankle fracture. The addition of patient weight bearing / non-weight bearing may add to its predictive power; however, our sample size was not large enough to determine its statistical significance. Significance/Clinical relevance: Current practice uses weight-bearing status to predict occult fractures, often leading to unnecessary casting; our study demonstrates the significance of ankle swelling and should be utilized more often in a clinical setting to predict occult fractures
Recommended Citation
Kerut, Christian, "Probability of Occult Ankle Fracture Based on Radiograph-Measured Swelling" (2024). Dept. of Orthopaedics: Robert D. D’Ambrosia Lectureship & Research Day. 10.
https://digitalscholar.lsuhsc.edu/ortho_rd/2024/presentation2/10
Probability of Occult Ankle Fracture Based on Radiograph-Measured Swelling
LSUHSC Center for Advanced Learning and Simulation (CALS)
Introduction: Several children every year present to the emergency department (ED) with a traumatic ankle injury. It is our experience that about 1/2 of these patients have X-rays not showing a fracture. About 1/4 of those patients with a “normal” X-ray subsequently reveal a fracture on follow-up X-ray a few weeks later. Clinically, patients are assessed on initial ED visit as to weight bearing or nonweight bearing on the injured ankle. If non-weight bearing, physicians often likely presume an occult fracture and will cast the patient. Traditionally, ankle swelling has not been used clinically to predict occult fractures. We set out to compare the likelihood of an occult fracture using swelling, weightbearings status, and the combination of both. Methods: The study was a retrospective chart review. After obtaining IRB approval (#5179), using Children’s Hospital New Orleans data base, ED presentations for suspected lateral malleolus injury were pulled from a 1-year span (2021-2022). Soft tissue ankle swelling measurements were measured, as well as whether the patient was weight bearing or non-weight bearing. Fisher’s Exact test was used to calculate the sensitivity and specificity of each parameter. A computer model (Exact Logistic Regression) used both clinical parameters as well as just ankle swelling to predict probability of an occult fracture. Results: 61 children presented with ankle injury, of which 32 had negative initial x-rays. Of these 32, 8 (25%) had an occult fracture on follow-up X-ray. Non-weight bearing had sensitivity (75%) and specificity (58%) for occult fracture detection (p = 0.220), and for ankle swelling (p < 0.0001) with sensitivity and specificity variable based on ankle mm. Discussion: From this small retrospective study, it appears that X-ray measurement of ankle swelling is highly predictive of an occult ankle fracture. The addition of patient weight bearing / non-weight bearing may add to its predictive power; however, our sample size was not large enough to determine its statistical significance. Significance/Clinical relevance: Current practice uses weight-bearing status to predict occult fractures, often leading to unnecessary casting; our study demonstrates the significance of ankle swelling and should be utilized more often in a clinical setting to predict occult fractures