Angled Tibial Implant Base Locking for Patella Clearance
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Solution Overview
Problem
Conventional tibial implant systems in knee arthroplasty face challenges during minimally invasive surgery (MIS) due to obstruction from the patient's patella during insertion and locking of the tibial insert, as the insertion typically occurs along the medial-lateral midline.
Innovation Solution
The tibial implant and insert are designed with angled engagement structures, allowing the tibial insert to be inserted from the medial side, avoiding the patella, with a guide member and undercut structure facilitating secure locking along an angled engagement vector, enabling insertion and locking without obstructing the patella.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the tibial insert is inserted along the medial-lateral midline, then the insertion path is straightforward and alignment is simple, but the patella obstructs the insertion and locking process
Solution Approach 1:
The patent changes the insertion direction from a straight medial-lateral midline approach to an angled approach coming from the medial side. The guide member extends at an angle relative to the medial-lateral midline, allowing the tibial insert to be inserted from a different spatial dimension/vector, thereby avoiding the patellar obstruction while maintaining proper alignment and locking
2Manufacturing precision
If a guide member is added to facilitate angled insertion, then the insertion precision is improved, but the device complexity increases
Solution Approach 1:
The guide member is integrated directly into the tibial base structure, merging the guidance function with the existing base design. The guide member forms part of the locking structure assembly, combining multiple functions (guidance, alignment, and locking) into a unified structure rather than adding a separate complex guidance mechanism
Solution Approach 2:
The guide member acts as an intermediary element that facilitates the angled insertion path. It provides a physical guide that directs the tibial insert along the correct angular trajectory during insertion, enabling precise alignment without requiring complex active control systems or multiple separate components
Data Source
AI summary
An orthopedic prosthesis includes a tibial implant and a tibial insert. The tibial implant includes an upper surface, a medial side, a lateral side and a first locking structure provided on the upper surface where the medial side and the lateral side of the tibial implant are defined by a medial-lateral midline. The tibial insert includes a second locking structure provided on its bottom surface. The first and second locking structures are configured for engaging each other along an engagement direction vector when the tibial insert is inserted into the tibial base towards the posterior side. The engagement direction vector is angled away from the medial-lateral midline of the tibial implant towards the medial side of the tibial implant by a predetermine angle.