Contoured Acetabular Cup Rim for Hip Joint Range of Motion
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Solution Overview
Problem
Conventional prosthetic femoral joints have limited angular movement and misalignment issues due to their flat peripheral rim, causing discomfort and pain by interfering with muscles and tissues.
Innovation Solution
A prosthetic acetabular cup with a contoured outer peripheral rim that mimics the natural shape of the acetabulum, providing a greater range of motion and aiding correct alignment, made from materials like polyurethane or polyethylene, and potentially including metal and/or synthetic plastics, with optional markings for surgical alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional flat peripheral rim is used in the prosthetic cup, then the manufacturing is simpler, but the range of angular movement is limited and misalignment occurs
Solution Approach 1:
The peripheral rim is transformed from a flat plane to a contoured shape that mimics the natural acetabulum geometry. The rim features varying heights at different locations (pubis, ischium, ilium regions) creating a three-dimensional contoured surface that enables greater angular movement while maintaining anatomical compatibility
Solution Approach 2:
Different portions of the peripheral rim are given different heights and contours to match specific anatomical regions of the natural acetabulum. The rim is not uniformly shaped but has localized variations in elevation corresponding to the pubis, ischium, and ilium areas, allowing optimized movement in each region
2Reliability
If the cup is made slightly larger to ensure coverage, then the stability improves, but the rim may project outside the acetabulum causing pain and interference with muscles
Solution Approach 1:
The contoured peripheral rim follows the natural curvature and boundaries of the acetabulum, ensuring that the cup remains within anatomical limits while providing stable coverage. The varying rim heights create a profile that conforms to the acetabular socket without protruding into surrounding muscle tissue
Solution Approach 2:
The peripheral rim is designed to copy or mimic the natural contours of the acetabulum as found in healthy anatomy. By replicating the natural bone geometry, the prosthetic cup achieves proper positioning and stability while avoiding interference with adjacent soft tissues and muscles
3Manufacturing precision
If the cup is made to match the contoured natural acetabulum shape, then the alignment precision improves, but the manufacturing complexity increases
Solution Approach 1:
The contoured rim geometry provides inherent alignment cues that guide the surgeon in positioning the cup correctly within the acetabulum. The varying heights at different rim locations correspond to anatomical landmarks, serving as built-in alignment references that improve positioning precision during implantation
Data Source
AI summary
An acetabular prosthesis having an outer member for engaging the acetabulum. The outer member has a part-spherical bearing surface terminating in a distal rim. The rim has a contour such that the portion thereof to be located between the ischium and the pubis extends distally further from an equator of the bearing surface than the contour to be implanted between the pubis and the illium and between the ischium and the illium.