Accurate measurements of joint angles and bone lengths are essential for evaluating conditions, guiding diagnoses, determining treatment plans, surgical strategies, and fixation methods in orthopaedics. Traditionally, most physicians rely on manual techniques—using permanent markers, rulers, and goniometers—to measure on X-rays or CT scans. This process is not only time-consuming but also inconsistent across operators.
As clinical demand for precision increases and AI technologies evolve, efficient and accurate automatic measurement systems are poised to transform orthopaedic workflows.
Limitations of Traditional Manual Measurements
1. Full Spine Measurements
Cobb Angle (for scoliosis):
On an AP view X-ray, identify the upper and lower end vertebrae. Draw lines along their respective endplates and measure the intersecting angle or perpendiculars, i.e., Cobb's angle.
Time: 3–5 minutes (experienced physician)
Vertebral Rotation Angle (Nash-Moe Method):
Graded based on pedicle displacement on AP view X-rays.
Time: 2–3 minutes per vertebra.
Axial CT Rotation Measurements:
Assess pedicle–rib angle or vertebral–spinous process angle.
Time: 5–10 minutes for full spine (requires multi-slice reconstruction).
Total Time (Combined):
X-ray only: 5–8 minutes
X-ray + CT: 8–15 minutes
2. Full Lower Limb Measurements
Functional Lower Limb Length:
Distance from femoral head center to ankle joint center on erect position radiology.
Time: 1–2 minutes (Bilateral comparison)
Mechanical Axis Deviation (MAD):
Vertical distance from the knee joint center to the line connecting the femoral head center and ankle joint center.
Time: 2–3 minutes (Magnification calibration required )
Hip–Knee–Ankle Angle (HKA):
Angle between mechanical axes of femur and tibia.
Time: 3–4 minutes (Precise joint center identification required)
3. Knee Joint Measurements
Femorotibial Angle (FTA):
To evaluate Genu Varum (bow legs or knock knees).
On erect position radiology, draw the femoral mechanical axis (from the center of the femoral head to the knee joint) and the tibial mechanical axis (from the center of the knee joint to the ankle joint). Measure the lateral angle between these two axes.
Time: 2–3 minutes
Femoral Torsion Angle:
CT-based angle between femoral neck axis and the posterior tangent line of the femoral condyle (transverse position + 3D reconstruction required).
Time: 5–8 minutes per side
Joint Line Convergence Angle (JLCA):
Tangent angle between tibial and femoral joint lines.
Time: 1–2 minutes
4. Hip Joint Measurements
Pelvic Incidence (PI):
Angle between sacral endplate perpendicular and sacro-femoral line.
Time: 2–3 minutes
Sacral Slope (SS):
Angle between S1 superior endplate and a horizontal reference line.
Time: 1–2 minutes
Pelvic Tilt (PT):
Angle between vertical and sacro-femoral line (or via PT = PI – SS).
Time: 1 minute
5. Foot & Ankle Measurements
Pitch Angle:
Based on a lateral X-ray, draw a line along the inferior cortex of the calcaneus and a horizontal reference line. The angle between them is the Pitch angle.
Time: 1–2 minutes
Meary’s Angle:
On lateral X-rays, draw one line through the center of the talus and another through the first metatarsal. The angle between them is Meary’s angle.
Time: 2–3 minutes
Automatic Measurement System: Precision Meets Efficiency
- World’s first system supporting automated full spine, lower limb, and single part measurements
- Covers nearly 200 measurement parameters
- Generates structured reports in just 15 seconds
- Provides Median sagittal section and torsional data of joints under weight-bearing conditions
- Uses independent coordinate systems for each limb to reflect true deformities
- Supports 3D printing of scanned anatomical models for use in brace design, surgical planning, and clinical education
1. Full Spine Automatic Measurement
Time: 15 seconds
Parameters: 20 automated measurements
Capable of full spine and pelvic assessment, including 3D Cobb angle, vertebral rotation, pelvic tilt, and sagittal vertical axis (SVA) offsets. Exports full skeletal and surface 3D-printable files.
2. Full Lower Limb Automatic Measurement
Time: 15 seconds
Parameters: 77 automated measurements
Supports full lower limb analysis, including functional leg length, femoral and tibial torsion, MAD, HKA, JLCA, mLDFA, etc.
Exports full lower extremity skeletal and body surface 3D print files.
3. Knee Joint Automatic Measurement
Time: 15 seconds
Parameters: 17 automated measurements
Supports MPR-based 3D reconstruction and AI evaluation of parameters such as medial/lateral joint space width, JLCA, joint gap heat map, intercondylar notch width/height, and notch width index.
4. Hip Joint Automatic Measurement
Time: 15 seconds
Parameters: 11 automated measurements
Provides MPR-based 3D reconstruction with AI measurement of pelvic incidence (PI), sacral slope (SS), pelvic tilt (PT), pelvic obliquity, and axial pelvic rotation.
5. Foot & Ankle Automatic Measurement
Time: 15 seconds
Parameters: 35 automated measurements
Supports Pitch angle, Meary angle, Böhler’s angle, Preiser’s angle, Langré’s angle, etc., with 3D-printable models for clinical use.
WR-3D Automatic Measurement: Powering the Future of Orthopedics
Fast: Only 15 seconds to generate a structured report
Accurate: Deep learning algorithms with minimal error
Comprehensive: Covers nearly 200 measurement parameters
Consistent: Eliminates operator-dependent variability
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