0.66°
Mean absolute error in flexion
Nine-point bench comparison against a reference protractor.
All nine points were within ±2°.
EVIDENCE & DEVELOPMENT
The evidence behind the next phase.
The clinical rationale, preliminary OrthoEdge findings, and the work ahead to establish performance and decision utility.
ORTHOEDGE FINDINGS
An early engineering foundation.
Preliminary bench characterization and cadaveric feasibility studies provide the starting point for formal validation.
35/35
Observations within ±1 mm
Optical displacement measurements compared with reference distances under clean-target bench conditions.
Preliminary bench characterizationIn-tissue
capture
Range of motion, shuck & modeled boundary
Two cadaveric hips assessed across two sequential feasibility sessions.
Preliminary cadaveric feasibilityStudy scope and limitations
These small feasibility studies do not establish clinical safety or effectiveness, broad compatibility, or the decision and efficiency benefits of guided next-trial comparisons.
Bench conditions
The angular result covers flexion at nine test points against a reference protractor. The optical result covers 35 observations under clean-target bench conditions. Accuracy across other motions, tissue conditions, and repeated builds remains to be established.
Cadaveric assessment
Two sequential sessions explored integrated ROM, shuck, and modeled boundary capture. Shuck measured distance, not pull force. The reference workflow assumes relative pelvic stability; contact detection has not been independently validated.
092026
PRESENTED AT THE HIP SOCIETY · STOCKHOLM
Cadaveric Feasibility of a
Sensorized Trial Femoral Head
Ryan Nunley, MD
Sources: OrthoEdge preliminary engineering characterization, October 2026; “Cadaveric Feasibility of a Sensorized Trial Femoral Head,” Ryan Nunley, MD, The Hip Society, September 2026.
PUBLISHED CLINICAL RESEARCH
Why investigate functional trialing?
Independent clinical research informs the rationale for functional trialing. These studies did not evaluate OrthoEdge.
ABDEL ET AL. · 2016
Component position and dislocation
Among 9,784 primary total hip arthroplasties (THAs), 206 hips dislocated. Of those, 120 (58%) had cups within the traditional Lewinnek safe zone. The 58% describes the dislocated hips, not the risk of dislocation within that zone.
Read the study · Clinical Orthopaedics and Related Research , opens in a new tabTANINO ET AL. · 2018
Intraoperative motion and subsequent instability
In a study of 185 hips with 32 mm femoral heads, Tanino and colleagues found an association between internal rotation during intraoperative stability testing and subsequent dislocation.
All procedures were performed by one surgeon. The study-derived angle cutoffs are not universal safety thresholds or validated OrthoEdge decision rules.
Read the study · BMC Musculoskeletal Disorders , opens in a new tabWOERNER ET AL. · 2016
The limits of visual estimation
In 60 patients undergoing minimally invasive THA, four experienced surgeons estimated hip motion visually. Differences from navigation measurements varied by movement and were sometimes substantial.
Read the study · Archives of Orthopaedic and Trauma Surgery , opens in a new tabFRASER ET AL. · 2025
Quantifying the shuck assessment
Fraser and colleagues described the conventional shuck test as subjective and investigated quantitative assessment during robotic-assisted THA. Their work adds context for studying measurements during this familiar maneuver.
Read the study · Hip International , opens in a new tabTHE DEVELOPMENT PATH
From feasibility to formal validation.
The next phase focuses on a repeatable product and the evidence needed for its intended use.
- 01DEMONSTRATED
Integrated prototype
Working hardware, firmware, and software, supported by initial bench and cadaver testing.
- 02CURRENT FOCUS
Repeatable product design
Refine the device and reference workflow, improve performance in tissue, and prepare the design for manufacturing.
- 03PLANNED
Verification & regulatory work
Verify measurement performance, evaluate construct comparison and the guided workflow, and prepare for regulatory review.
- 04FUTURE
Clinical & economic validation
Evaluate the value of the measurements in surgical decision-making, their fit within the workflow, and their economic impact.
Measurement and construct comparison
Further work will assess reference repeatability, performance in tissue, agreement with independently observed contact, and the ability to distinguish trial constructs.
Guidance and workflow
Studies must establish whether next-trial comparisons help surgeons make decisions. Evaluation also needs to address compatibility, setup, training, interpretation, and the effect on trialing time and iteration.
Patent applications filed. Product development and regulatory planning underway.
Discuss the evidence.
For study context or a discussion of the next evaluation phase. Explore research collaborations.