Automated Leg Length Discrepancy Assessment on Radiographs

Purpose

Quantify the lower extremity limb lengths on standing radiographs

Tag(s)

Limb length, leg length, discrepancy, lower extremity

Panel

Musculoskeletal Panel

Define-AI ID

19050029

Originator

David Sandman
Lead David Sandman

Panel Chair

Jay Patti

Panel Reviewers

Musculoskeletal Panel

License

Creative Commons 4.0 

Status Public Commenting
RadElement Set RDES102
                               

Clinical Implementation


Value Proposition


Leg or lower extremity limb length discrepancy is a correctable problem affecting the pediatric and adult populations. Several methods of measuring the lower extremities have been described, each of which is prone to both intra-reader and inter-reader variability and can be a tedious task to complete. Automated measurements of the lower extremities can provide an accurate and reproducible measuring technique and result.

Narrative(s)


65 year old male with severe medial compartment osteoarthritis of the left knee. Total knee arthroplasty is planned, goals of which include attaining limb length equality and physiologic alignment. Weightbearing long-leg/lower extremity radiographs is ordered as part of the preoperative work-up. An algorithm measures the lower extremity lengths, auto-populating the data when a radiologist or other clinician reviews the study.

Workflow Description


Images obtained from the radiography unit are sent to PACS and the AI engine. The images are analyzed by AI. Coordinates of areas of interest are assessed using a measuring tool. Annotated measurements are saved as an image along with a summary of the measurement data set.


Considerations for Dataset Development



Procedures(s)

{ lower extremity limb length radiographs, long-leg radiographs}

View(s)

{ Upright/standing-radiographs}

Sex at Birth

{Male,Female}

Age

[0,90]

Technical Specifications


Inputs

 

DICOM Study

Procedure

Long-leg study, weight-bearing lower extremity

Views

AP views

Data Type

DICOM

Modality

Radiograph

Body Region

Lower Extremity

Anatomic Focus

Hip, thigh, knee, leg, ankle



 

Primary Outputs

 

Bilateral Lower Extremity Length


RadElement ID

RDE636

Definition

distance from top of femoral head to mid tibial plafond

Data Type

Numeric

Value Set

N/A

Units

Centimeters

 

 

Bilateral Lower Extremity Length Coordinates


RadElement ID

RDE637

Definition

Line from top of femoral head to mid tibial plafond

Data Type

Coordinates

Value Set

N/A

Units

N/A

 

 

Bilateral Femur Length


RadElement ID

RDE638

Definition

Distance from top of femoral head to medial condyle articular surface

Data Type

Numeric

Value Set

N/A

Units

Centimeters

 

Bilateral Tibia Length


RadElement ID

RDE639

Definition

Distance from top of tibial intercondylar eminence to the mid tibial plafond

Data Type

Numeric

Value Set

N/A

Units

Centimeters

 

Bilateral Bone Length

 


RadElement ID

RDE640

Definition

Femur length + tibia length

Data Type

Numeric

Value Set

N/A

Units

Centimeters