Fracture Fixation Plate Cover Sheath Design
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Solution Overview
Problem
Existing surgical implants for metaphyseal fractures in long bones lack design attributes that allow for proper anatomical alignment, minimal soft-tissue disruption, and variable sturdy support, leading to incomplete fracture reduction and increased risk of complications like non-unions and reduced range of motion.
Innovation Solution
A fracture fixation plate with a cover sheath that includes a head element with a neck portion, through holes, and a plate element with slots, allowing for angled bone screw insertion and a sheath that covers fastener heads to inhibit movement, providing flexible alignment and stabilization of bone fragments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If threaded head screws and/or threaded head pegs are used to secure displaced bone fragments, then fracture fixation is achieved, but the surgeon is restricted to pre-set angular orientations and cannot adequately secure loose bone fragments or restore anatomical alignment
Solution Approach 1:
The head element is designed with a spherical configuration that allows bone screws and pegs to be inserted at variable angles and orientations. The spherical head enables dynamic adjustment during surgery, allowing the surgeon to optimize the angular orientation of fixation elements to match the specific anatomical requirements of each fracture pattern, thereby achieving both adaptability and precision.
Solution Approach 2:
The invention changes the fixed geometric parameters of traditional threaded heads to a spherical geometry with variable orientation parameters. This allows the insertion angles and directions of bone screws and pegs to be adjusted within a range defined by the spherical head's geometry, providing the surgeon with flexibility to achieve optimal anatomical alignment for different fracture configurations.
2Reliability
If threaded head design for screws and pegs is used, then fracture fixation is achieved, but the surgeon cannot draw or lag the bone fragments close to the implant, resulting in gaps that decrease stabilization and increase complication risks
Solution Approach 1:
The fixation system is segmented into distinct functional components: the spherical head element that provides compression and drawing capability, and the bone screws/pegs that provide angular flexibility. This segmentation allows the spherical head to specifically perform the bone fragment drawing function while the threaded elements provide secure fixation, thereby achieving both compression capability and reliable stabilization.
Solution Approach 2:
The spherical head element acts as an intermediary between the bone fragments and the threaded fixation elements. It receives the bone screws and pegs and translates their fixing action into compressive force that draws the bone fragments together, enabling effective fracture reduction and stabilization without the limitations of direct threaded head contact.
3Reliability
If exposed heads of fixation pegs and screws are used, then fracture fixation is achieved, but the potential for tendonitis, tendon rupture and other soft-tissue impingement complications is increased
Solution Approach 1:
The spherical heads of the bone screws and pegs are nested within a covering structure that is integrated with the implant body. This nested configuration protects the fixation element heads from direct contact with surrounding soft tissues, eliminating the risk of tendonitis and tendon rupture while maintaining the security of fracture fixation through the underlying threaded engagement.
Solution Approach 2:
A protective covering structure serves as an intermediary between the fixation element heads and the surrounding soft tissues. This intermediary layer prevents direct mechanical interaction that could cause tendon impingement or rupture, while allowing the fixation elements to maintain their secure engagement with the bone through the spherical head design.
Data Source
AI summary
A fracture fixation plate with cover sheath having a head element that is rigidly connected to a plate element in an upwardly angled direction. The head element is anatomically shaped and includes medial and lateral sheath recesses wherein non-threaded bone screw holes and a threaded sheath screw hole are located. Cylindrical head bone screws are inserted through the sheath recess and oriented at set angles allowing for bone fragment fixation and fracture reduction. Medial and lateral sheath elements are placed within the boundaries of their respective sheath recesses and are secured with a sheath screw. The sheath elements contact the heads of the inserted bone screws restricting and maintaining their implanted positions. Alternative sheath elements with outreaching medial, lateral and distal fragment capture flanges may also be utilized. The plate element includes at least one longitudinal slot with several bone screw holes for use with pivotable spherical headed bone screws.