Modular Bone Anchor Assemblies for Spinal Fixation

Solution Overview

Problem

In orthopedic surgery, particularly in spinal procedures, there is a challenge in maintaining spatial anatomical awareness and direct visualization due to the disruptive nature of bone anchor assemblies and their instrumentation, which can obscure the local anatomy and require larger working channels, limiting the effectiveness of less-invasive surgical techniques.

Innovation Solution

A modular bone anchor assembly design that allows for a smaller footprint during insertion, enabling improved visualization and anatomical awareness, with various modular head types and instruments for driving, attaching, and removing components, along with features for fixation, distraction, and derotation, facilitating easier surgical procedures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a complete bone anchor assembly with head is inserted, then the fixation function is provided, but the footprint is large which obscures visualization and disrupts spatial anatomical awareness

Engineering Contradiction:

Improvefixation functionVSAvoidfootprint

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The bone anchor assembly is divided into separate components: a bone anchor portion that is inserted first, and a head portion that is attached later. This segmentation allows the bone anchor to be inserted with a smaller footprint, improving visualization during insertion, while the head can be attached subsequently to provide the complete fixation function.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The bone anchor portion is inserted and positioned in the bone before the head portion is attached. This preliminary action allows the surgeon to establish the anchor in the bone with minimal disruption to the surrounding anatomy and better visualization, then complete the assembly with the head attachment in a later step.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If a complete bone anchor assembly with head is inserted, then the fixation function is provided, but the instrumentation required for insertion is complex and requires larger working channels

Engineering Contradiction:

Improvefixation functionVSAvoidinstrumentation complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The instrumentation is segmented into separate functions: a driver for inserting the bone anchor portion, and separate instruments for attaching and removing the head portion. This reduces the complexity of any single instrument and allows for smaller working channels since the insertion instrumentation does not need to accommodate the complete assembly with head.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The head attachment and removal functions are extracted as separate operations with dedicated instruments. This extraction simplifies the insertion instrumentation by removing the need for complex mechanisms to handle the complete assembly, thereby reducing working channel requirements.

Inventive Principle:

Principle #2Taking out (Extraction)

3Difficulty of detecting and measuring

If the bone anchor is inserted without the head, then visualization and anatomical awareness are improved, but the fixation function is not complete

Engineering Contradiction:

ImprovevisualizationVSAvoidfixation function

Core Design Contradiction:

Difficulty of detecting and measuringVSReliability

Solution Approach 1:

The bone anchor portion is inserted and positioned in the bone before the head portion is attached. This preliminary action allows the surgeon to establish the anchor in the bone with minimal disruption to the surrounding anatomy and better visualization, then complete the assembly with the head attachment in a later step.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The bone anchor assembly is divided into separate components: a bone anchor portion that is inserted first, and a head portion that is attached later. This segmentation allows the bone anchor to be inserted with a smaller footprint, improving visualization during insertion, while the head can be attached subsequently to provide the complete fixation function.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS10463402B2Bone anchor assemblies and related instrumentation

Publication Date: 2019.11.05 MEDOS INT SARL

AI summary

Bone anchor assemblies and related instrumentation are disclosed herein. In some embodiments, a modular bone anchor assembly allows for a bone anchor to be driven into bone and a head or receiver member to be attached thereto at some later point in time. The bone anchor can have a smaller footprint than the complete assembly, which can improve visualization and anatomical spatial awareness during insertion of the bone anchor and during other surgical steps performed prior to attaching the head or receiver member to the bone anchor. A variety of modular head types are disclosed, as are various instruments for driving a bone anchor, attaching a head to a bone anchor, removing a head from a bone anchor, and making a unilateral attachment to a head of a bone anchor assembly. Drive interfaces for driving a bone anchor are disclosed, as are features that allow a bone anchor to act as a fixation point for soft tissue retraction, disc space distraction, derotation, and the like.