Acetabular Cup Targeting for Standing-Seated Pelvic Mobility
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Solution Overview
Problem
Current methods for planning and executing total hip replacement surgeries rely heavily on the frontal plane, which may not accurately account for individual patient biomechanics, particularly pelvic tilt and mobility, leading to suboptimal acetabular cup placement and potential implant failure.
Innovation Solution
The use of sagittal parameters such as Anteinclination (AI) and Sacroacetabular Angle (SAA) to individually target and track the acetabular cup, leveraging digital platforms and navigation systems for precise placement based on patient-specific measurements from X-rays, CT scans, and MRI scans, incorporating pelvic incidence, sacral slope, and femoral version to ensure optimal positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the frontal plane (Lewinnek safe zone) is used to plan and assess acetabular cup position, then the methodology is simple and widely adopted, but it does not accurately account for individual patient biomechanics such as pelvic tilt and mobility
Solution Approach 1:
The patent transitions from traditional frontal plane (2D) assessment to incorporate sagittal plane parameters (adding a dimensional perspective). By measuring anteinclination and sacroacetabular angle in the sagittal plane alongside frontal plane parameters, the system captures three-dimensional acetabular cup positioning that accounts for pelvic tilt and mobility, thereby improving measurement precision without overwhelming complexity
Solution Approach 2:
The patent introduces new measurement parameters (anteinclination and sacroacetabular angle) to complement traditional frontal plane parameters. These additional parameters enable customization of acetabular cup positioning based on individual patient biomechanics including pelvic tilt and mobility, transforming the standardized approach into a personalized one while maintaining systematic methodology
2Reliability
If static tilt adjustment in supine position is performed, then the procedure is straightforward, but it fails to account for dynamic pelvic mobility between standing and seated positions
Solution Approach 1:
The patent moves from static tilt adjustment performed in supine position to a dynamic approach that measures and accounts for pelvic mobility between standing and seated positions. By capturing the range of motion and functional pelvic behavior, the system determines acetabular cup positioning that remains reliable across multiple functional positions, thereby reducing implant failure while incorporating dynamic assessment
Solution Approach 2:
The patent performs preoperative measurement of sagittal plane parameters (anteinclination and sacroacetabular angle) in both standing and seated positions to establish individualized target values before surgery. This preliminary characterization of pelvic mobility enables the surgical team to plan acetabular cup positioning that anticipates functional movement, improving reliability without requiring complex intraoperative adjustments
3Manufacturing precision
If individualized targeting based on sagittal parameters is implemented, then placement accuracy is improved, but the complexity of preoperative planning and intraoperative guidance increases
Solution Approach 1:
The patent creates a digital representation (virtual model) of the patient's unique spinopelvic-femoral geometry based on preoperative imaging and measurements. This virtual model includes individualized sagittal plane parameters and serves as a template for planning acetabular cup positioning. During surgery, navigation systems reference this pre-created digital copy to guide precise placement, achieving high precision while managing complexity through virtual rather than purely physical planning tools
Data Source
AI summary
The disclosure provides example methods and non-transitory computer-readable mediums for acetabular cup placement. An example method includes a processor (a) determining for a first patient a sagittal acetabular cup position in the form of a standing AI, a seated AI and a SAA based on (i) a standing SS relative to a normative SS, (ii) a dSS between a standing position and an upright seated position, (iii) a femoral version corresponding to a femoral version outlier position, and (iv) a PFA to correspond to a PFA outlier position in a standing position or an upright seated position, (b) determining a coronal acetabular cup position in the form of a supine coronal anteversion and at least one of a supine or a standing coronal inclination based on the sagittal acetabular cup position, and (c) determining a post-operative standing AI and a post-operative seated AI based on the coronal acetabular cup position.