Radiographic Evaluation of Congenital and Acquired Foot Deformities Tibial-Calcaneal Angle

         

Purpose

Characterization of congenital and acquired foot deformities on radiographs

Tag(s)

bilateral foot, foot, x-rays, radiographs, congenital foot, pes, feet, tibio-calcaneal angle, weight-bearing

Panel

Pediatric

Define-AI ID

20010014

Originator

Pediatrics Panel
Lead Viet Le & Alex Towbin

Panel Chair

Steven Blumer

Panel Reviewers

Pediatric Panel

License

Creative Commons 4.0
Status Public Comment
RadElement Set RDES204
                     

Clinical Implementation


Value Proposition


Multiple angles and measurements can be used to evaluate abnormal development of the foot, but the task of obtaining these can be cumbersome and time-intensive. An automated method for obtaining a series of angle measurements and bony relationships, which can eventually be used to characterize foot deformities, should improve the radiologists’ workflow.

For our use case(s), we will first focus on automating the measurement of a series of different angles and bony associations on foot radiographs, which can then be compiled to determine the presence vs. absence of a foot deformity. If present, our hope is for the algorithm to further diagnose/characterize the specific foot deformity. Ultimately, this may be expanded to include additional modalities, such as CT.

For this particular use case, we will limit our evaluation to measuring the tibial-calcaneal angle, which can be used to determine the midfoot/hindfoot alignment on lateral view, particularly for evaluation of clubfoot (talipes equinovarus). Additional use cases include the the AP talo-calcaneal and lateral talo-calcaneal angles, intermetatarsal angle, talo-1st metatarsal angle, 1st metatarsophalangeal angle, Meary’s angle, talonavicular axis and calcaneal pitch.

Narrative(s)


3 year-old female presents to the pediatrician with abnormal gait and in-toeing. Bilateral, weight-bearing 3-view foot radiographs are obtained for evaluation of foot deformities.

6 month-old male presents for contractures/abnormal positioning of the feet. Bilateral, 3-view foot radiographs with simulated weight-bearing are obtained for evaluation of foot deformities.

Workflow Description

Radiographs of the foot/feet are ordered, obtained, sent to PACS and the algorithm is triggered.


The algorithm delivers the following outputs: tibial-calcaneal angle, and normal vs. increased/decreased angle

Considerations for Dataset Development


Procedures

X-ray, Foot

Radiograph, Foot

Gender

Male, Female

Age (years)

0-18

Views

Lateral

Technique

Weight-bearing or Simulated weight-bearing, Erect

Anatomy

Foot

Confounders

Cast, Splint, Brace, Non-weight-bearing, Supine

Technical Specifications


Input

 

DICOM Study

Procedure

X-ray, Foot Radiograph

Views

Lateral

Data Type

DICOM

Modality

X-ray

Body Region

Lower Extremity

Anatomic Focus

Foot


Primary Outputs

 

Tibial-calcaneal Angle   

RadElement ID

RDE1340 

Definition

The intersection between the anatomic axis of the tibia and the plantar surface of the calcaneus on weight-bearing lateral foot radiograph.

Data Type

Numeric

Value Set

0-180

Units

Degrees


Secondary Outputs 

 

Normal vs. Decreased vs. Increased Tibial-calcaneal Angle       

RadElement ID

RDE1341 

Definition

Normal range for the tibial-calcaneal angle is 60 to 90 degrees, depending on age.

Data Type

Categorical

Value Set

  • normal (60-90)

  • decreased (<60), calcaneus

  • increased (>90), equinus

Units

N/A

Future Development Ideas


As mentioned in the Value Proposition, future development ideas include

  • Additional angle measurements

  • Bony relationships in the foot

  • Diagnosis of foot deformities if present (“diagnostic use cases”)

  • Improvement from prior studies if comparisons are available

  • Extrapolation to another imaging modality, such as CT

  • Comparison with prior studies and documentation of change over time.