Rotatable Cable Plug for Orthopedic Bone Fixation
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Solution Overview
Problem
Existing bone fixation systems using surgical cables often experience shear stresses and strains due to cables being coupled at 90° to the bone's longitudinal axis, leading to bone plate shifting, as they lack the ability to orient cables at angles other than 90°, thereby inadequately addressing stress distribution.
Innovation Solution
A cable plug system comprising a cable retaining member with rotatable receiving members and a fastening member, allowing the surgical cable to be oriented at various angles relative to the bone's longitudinal axis without inducing torque stresses on the bone plate, utilizing a stopper member to secure the cable retaining member to the fastening member.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the surgical cable is coupled to the bone plate at 90° from the longitudinal axis of the bone, then the cable can be securely fixed using conventional adapters and fixation screws, but shear stresses and strains occur in the surgical cable causing the bone plate to shift relative to the bone
Solution Approach 1:
The cable retaining member is made rotatable relative to the fastening member, allowing the system to dynamically adjust to cable tension forces rather than being fixed at a single angle. This rotational freedom eliminates shear stresses by allowing the cable to self-align perpendicular to the bone surface while the retaining member rotates to accommodate the optimal orientation.
2Ease of operation
If fixation screws are used to couple the cable to the bone plate, then the cable can be secured at a fixed position, but the system cannot orient the surgical cable at angles less than 90° from the longitudinal axis of the bone
Solution Approach 1:
The rotatable cable retaining member provides dynamic positioning capability, allowing the cable to be oriented at multiple angles relative to the bone's longitudinal axis. The retaining member can rotate to accommodate cables oriented at angles less than 90°, while still maintaining secure fixation through the fastening member.
3Strength
If the cable is wrapped around the bone and bone plate, then the cable can provide fixation, but the cable tends to move from its coupled position with respect to the bone plate under applied forces
Solution Approach 1:
The rotatable retaining member allows the cable to maintain optimal positioning under load by rotating to accommodate force vectors, while the fastening member prevents migration along the longitudinal axis of the bone plate. This combination provides both stability and adaptability to varying force conditions.
Solution Approach 2:
The fixation system is divided into two functional components: the fastening member that prevents longitudinal migration and the rotatable retaining member that accommodates angular variations. This segmentation allows each component to specialize in preventing specific types of cable movement.
Data Source
AI summary
Disclosed herein are cable plugs for securing surgical cable to a bone plate. The cable plugs each have a cable retaining member and a fastening member. The cable retaining members each have a receiving portion adapted to receive a portion of the surgical cable therein. The cable retaining members are first coupled to the fastening members prior to securing the cable plug to the bone plate. The cable retaining member may rotate with respect to the fastening member about 270° along a longitudinal axis of the cable plug when the cable retaining member is coupled to the fastening member. When securing the surgical cable to the bone plate, the cable retaining member is rotated about the longitudinal axis of the cable plug until an axis of the receiving portion is parallel to an axis of the surgical cable. The surgical cable is then placed within the receiving portion, tightened, and crimped to secure the bone plate to the bone.