Metatarsal Arthroplasty Implants With Guided Broaching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current surgical interventions for hallux rigidus and arthritis of the first metatarsophalangeal joint, such as decompression, partial joint resection, fusion, and joint replacement, involve risks and drawbacks, necessitating improved implants and methods for metatarsal arthroplasty.
Innovation Solution
Development of metatarsal arthroplasty implants and instruments, including sizing templates, repositioning guides, reamers, step drills, broach tools, and trial devices, which facilitate minimal bone removal and enhanced bone fixation, using a broach tool with a slap hammer and retention features for precise implant placement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional surgical interventions (decompression, partial joint resection, fusion, joint replacement) are used for hallux rigidus, then the joint condition can be treated, but surgical risks and complications increase
Solution Approach 1:
The patent extracts and removes only the necessary portion of bone (osteophytes) through the broach tool, avoiding extensive bone resection or fusion. The broach tool selectively removes bone spurs while preserving healthy bone tissue, thereby treating the joint condition with minimal surgical intervention and reduced complications.
Solution Approach 2:
Instead of replacing the entire joint or fusing bones, the patent inverts the approach by using the broach tool to create precise bone contours that directly receive and secure the implant. The broach tool prepares the bone bed by removing material and creating engaging surfaces, allowing the implant to be anchored in the natural bone structure rather than requiring joint replacement or fusion.
2Ease of operation
If extensive bone removal is performed during arthroplasty preparation, then implant placement is facilitated, but bone fixation strength is reduced
Solution Approach 1:
The broach tool is segmented into multiple cutting elements arranged along its length, allowing sequential removal of bone material at different depths and angles. This segmentation enables precise contouring of the bone bed to match the implant geometry while preserving surrounding healthy bone, thereby facilitating implant placement without compromising fixation strength.
Solution Approach 2:
The broach tool applies localized cutting action only where bone removal is needed to receive the implant. The cutting elements are positioned to remove bone spurs and create engaging surfaces specifically at the implant interface, while leaving the surrounding bone structure intact. This local quality approach ensures easy implant placement while maintaining strong bone fixation.
3Strength
If precise implant placement is achieved through minimal bone removal, then bone fixation is enhanced, but surgical precision requirements increase
Solution Approach 1:
The broach tool serves as an intermediary between the surgeon and the bone-implant interface. It translates the surgeon's positioning into precise bone contouring and implant reception preparation. The broach tool's guided cutting elements automatically create the correct bone geometry, reducing the precision burden on the surgeon while ensuring optimal implant placement and bone fixation.
Solution Approach 2:
The broach tool performs preliminary preparation of the bone bed before implant insertion. By pre-contouring the bone surface and creating engaging features through broaching, the tool ensures that the implant will seat correctly and achieve strong fixation. This preliminary action reduces the precision requirements during the actual implant placement step.
4Productivity
If traditional instruments are used for bone preparation, then surgical procedures can be performed, but bone removal is excessive
Solution Approach 1:
The broach tool changes the parameters of bone removal by using controlled mechanical broaching action instead of traditional reaming or drilling. The cutting elements are designed to remove bone material in a controlled manner, changing from extensive removal to minimal, precise removal. This parameter change maintains surgical efficiency while significantly reducing bone loss.
Solution Approach 2:
The broach tool discards only the necessary bone material (osteophytes and excess bone) that interferes with implant placement, while recovering and preserving the majority of the native bone structure. The selective removal approach ensures that healthy bone tissue is maintained for optimal implant fixation, minimizing bone loss while maintaining procedural efficiency.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system enables precise and minimally invasive preparation of the metatarsal bone for implantation, reducing complications and improving surgical outcomes by allowing for enhanced bone fixation and efficient implant placement.
Implementation Method 1
The removal strike surface of the strike plate may be configured to receive and transmit a removal impact force from the slap hammer to remove the cutting form from the metatarsal bone
Implementation Method 2
The insertion strike surface of the strike plate may be configured to receive and transmit an insertion impact force to drive the cutting form into the metatarsal bone and prepare the metatarsal bone to receive the metatarsal arthroplasty implant
Data Source
AI summary
Implants, systems, instruments, methods, and kits for metatarsophalangeal joint arthroplasty may include metatarsal arthroplasty implants, repositioning guides, broach tools, inserter tools, and sterilizable packaging configured to facilitate metatarsal arthroplasty surgical procedures. The metatarsal arthroplasty implants may generally include an articular member having a convex articular surface, a concave bone-facing surface opposite the convex articular surface, and at least one side surface intermediate the convex articular surface and the concave bone-facing surface, as well as a central shaft sized for insertion into a metatarsal bone having a central shaft longitudinal axis, a central shaft proximal end coupled to the concave bone-facing surface of the articular member, and a central shaft distal end extending away from the concave bone-facing surface of the articular member along the central shaft longitudinal axis.