Periprosthetic Bone Plates with Variable-Angle Implant Avoidance
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Solution Overview
Problem
Periprosthetic fractures surrounding previous surgically implanted orthopedic implants pose unique fixation challenges due to interference from the existing implants, osteoporosis, and bone defects, limiting treatment options and complicating surgical stabilization.
Innovation Solution
Design of bone fixation plates with variable angled fastener openings and locking screw openings, allowing for securement across fractures adjacent to previous implants, and featuring contoured ends and undercuts to accommodate patient anatomy, enhancing flexibility and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional bone fixation plate is used for periprosthetic fractures, then the plate can provide basic fracture stabilization, but the previous surgically implanted orthopedic device interferes with plate placement and screw fixation
Solution Approach 1:
The bone fixation plate is designed with distinct functional zones: a head portion with hook members for engaging the trochanter, a shaft portion with variable angle screw holes for cortical bone fixation, and a contoured body that navigates around the prosthetic stem. This segmentation allows each zone to address specific anatomical and surgical challenges independently.
Solution Approach 2:
The plate design incorporates variable angle screw holes that allow screws to be directed at different angles to avoid the prosthetic stem while still securing the plate to the bone. The contoured body acts as an intermediary structure that bridges the gap between the proximal fracture site and the distal fixation points, navigating around the obstructive stem.
2Adaptability or versatility
If standard fixation techniques are used, then simple fracture patterns can be treated, but periprosthetic fractures with osteoporosis and bone defects have limited treatment options
Solution Approach 1:
The plate incorporates variable angle screw holes that allow the surgeon to adjust screw insertion angles dynamically based on bone quality, fracture pattern, and prosthetic position. The hook members provide dynamic engagement with the trochanter, allowing for both stable and flexible fixation modes depending on the surgical requirements.
Solution Approach 2:
Different regions of the plate have specialized features: the head portion has hook members for trochanteric engagement in osteoporotic bone, the shaft has variable angle holes for adapting to different bone densities and fracture patterns, and the contoured body provides localized stress distribution. This local quality optimization allows the plate to address specific challenges in different anatomical zones.
3Adaptability or versatility
If the bone fixation plate has multiple openings for screws, then securement options increase, but stress risers may occur at the ends of the plate
Solution Approach 1:
The plate features a contoured, curved body that follows the natural anatomy of the proximal femur. This curvature distributes mechanical stresses more evenly along the plate length and prevents stress concentration at the ends. The smooth transitions and rounded contours reduce stress risers compared to straight, angular plate designs.
Data Source
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AI summary
Periprosthetic bone fixation plates are disclosed including, for example, periprosthetic proximal femur plate, periprosthetic distal femur plate, periprosthetic humerus plate, periprosthetic ring plate, and periprosthetic troch plate. In use, the periprosthetic bone fixation plates are arranged and configured for use in periprosthetic fractures. That is, the periprosthetic plates include one or more features to facilitate positioning and securement of the bone fixation plate to a patients bone that previously received a surgically implanted orthopedic device or implant such as, for example, an intramedullary nail, a hip prosthesis, a knee prosthesis, etc. In use, the one or more features are designed and configured to facilitate avoidance of the previous surgically implanted orthopedic device or implant. In addition, the periprosthetic bone fixation plates are arranged and configured to facilitate plating of a longer working length as compared to existing bone fixation plates (e.g., plating from, for example, femoral condyle to greater trochanter).