EOS IN TOTAL HIP AND KNEE REPLACEMENT
EOS scanning is a sophisticated low dose imaging technology that uses dual X-Ray tubes to scan the spine, lower limbs or the full body in a natural upright resting position to create detailed, high resolution 2D and 3D images that allow accurate measurement of a wide range of biometric measurements. These include scoliosis angle (Cobb Angle), pelvic tilt, precise leg length measurement, and specific biometric measurements of the hip and knee to assess alignment and anatomy to assist pre-operative assessment and planning for joint replacement surgery, as well as post operative followup to measure outcomes and monitor stability over time.
Pre-operative EOS scanning of the hip and knee enables the technology to map out and precisely measure spine, knee and hip anatomy, including measurements of femoral and acetabular version and torsion which may influence surgical planning for arthroplasty.
The scan is a quick, low dose procedure taking around 10 seconds, and has the added benefit of producing no image magnification (ie – a 1:1 image ratio), an age-old problem inherent to conventional X-Ray imaging which limits the calibration and precision of measurements due to the variable image magnification in plain X-Rays.
EOS Parameters for Biometric Assessment, and Peri-Operative Workup for THR & TKR
Femoro-Acetabular Anatomy :
- Femoral head diameter
- Femoral Version
- Acetabular Version
- Femoral Torsion
- Acetabular Torsion
Pelvic Alignment :
- Pelvic obliquity (lateral tilt)
- Pelvic axial rotation (cranio-caudal 3D rotational view of pelvic rotational angle)
- Pelvic incidence (forward pelvic tilt angle)
- Sacral slope (sacral tilt angle relative to crests)
- Anterior Pelvic inclination
Acetabular Cup Parameters (relative to standing pelvic plane) :
- Acetabular Cup Inclination
- Acetabular Cup Anteversion
Leg Lengths and Alignment :
- Femur Length
- Tibial Length
- Functional Leg Length
- Anatomical Length
- Valgus/Varus at Knee
- Flexion/Extension at rest
THR Parameters :
- Femoral Offset Implant
- Neck-Shaft Angle of Femoral component of prosthesis
- Ante-torsion of Femoral Stem
Our EOS scanner and specialised software empowers orthopaedic and spinal surgeons with new insights into surgical planning, and supports more seamless surgical workflows, while helping to optimise surgical outcomes.
For post-op patients, EOS provides a simple low dose technique to monitor post-op outcomes and progress over time.
I’m always happy to discuss individual cases with referring clinicians – if you’re a medical practitioner seeking an opinion on which imaging-guided pain management measures may be most appropriate and beneficial in an individual clinical situation, please feel free to contact me directly.
Dr Angus Watts
MBBS, FRANZCR