Patient-Mounted Surgical Support With Polyaxial Anchor Control
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Solution Overview
Problem
Existing surgical access devices inadequately support surgical instruments, often moving relative to the patient or impeding access during procedures like spinal fusion, particularly when modular pedicle screws are used.
Innovation Solution
A patient-mounted surgical support instrument that couples to an implanted anchor, providing an adjustable and selectively lockable platform for securing surgical instruments and retractors, with features like a drag force mechanism to control polyaxial movement and a retractor assembly for tissue manipulation, allowing secure access to surgical sites.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If devices are anchored to a surgical table or external structure, then support stability is improved, but patient movement relative to the operating table causes device movement and impedes surgical access
Solution Approach 1:
The patent introduces an intermediary coupling mechanism that connects the surgical device to the patient's anatomy through implanted anchors rather than to external structures. This intermediary connection (the anchor-elongate body interface with drag force mechanism) allows the device to move with the patient while maintaining stable relative positioning, resolving the contradiction between stability and ease of operation.
2Ease of manufacture
If receiver heads with extension posts are implanted before intervertebral disc work, then pedicle screw implantation is facilitated, but access to the intervertebral disc space is blocked
Solution Approach 1:
The patent extracts the problematic extension post from the initial implant configuration. By implanting only the lower-profile anchor without the extension post or receiver head initially, the surgical path remains clear for disc work. The receiver head and extension post are added later after the disc space has been accessed and prepared, thus taking out the obstruction at the critical time when access is needed.
Solution Approach 2:
The patent applies preliminary action by implanting the anchor in advance before the receiver head and extension post. This allows the anchor to be in place to guide subsequent pedicle screw implantation, while the bulky receiver head components are deferred until after disc space access is required, optimizing the sequence of operations.
3Ease of manufacture
If guidewires are inserted for pedicle screws, then screw implantation is enabled, but surgical access is impeded by requiring bending of guidewires away from the intervertebral space
Solution Approach 1:
The patent uses preliminary action by implanting the anchor before inserting the guidewires. The anchor serves as a pre-established reference point that simplifies subsequent guidewire placement, eliminating the need to bend guidewires away from the disc space. The anchor is positioned first to enable accurate screw implantation while maintaining clear access during the intermediate steps.
4Ease of operation
If modular pedicle screws with lower-profile anchors are used, then access to intervertebral disc is improved, but device support and stability are reduced
Solution Approach 1:
The patent introduces an intermediary support structure (the elongate body coupled to the anchor) that provides the necessary stability without requiring a bulky receiver head at the implant site. This intermediary element transfers and distributes forces, maintaining device stability while allowing the anchor itself to remain low-profile and non-obstructive to disc space access.
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 instrument stabilizes surgical instruments relative to the patient, minimizing movement and interference, enhancing access and reducing the footprint of surgical equipment, especially in orthopedic and neurologic procedures.
Implementation Method 1
a lock configured to exert a drag force on the head of the anchor to control polyaxial movement of the instrument relative to the anchor
Data Source
Figure 1
Figure 2A~2B
Figure 3A~3B
AI summary
Surgical support instruments are described herein that can couple to, e.g., an implanted anchor and provide a platform for coupling other surgical implements thereto. In one embodiment, an instrument can include an elongate body having opposed projections extending laterally from a distal portion thereof that can at least partially surround a shank of an implantable anchor such that a longitudinal axis of the elongate body is laterally offset from a longitudinal axis of the anchor. The instrument can further include a lock configured to exert a drag force on a head of the anchor to control polyaxial movement of the instrument relative to the anchor. Further, a proximal portion of the elongate body can be configured to receive a retractor assembly including a plurality of tissue manipulating implements and selectively lock the retractor assembly at any of a plurality of positions along a length of the elongate body.