Offset Arm Drill Guide for Acetabular Tunnel Placement
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Solution Overview
Problem
The challenge in hip arthroscopy is accurately drilling bone tunnels in the acetabulum without causing a blow-out of the acetabular cartilage, due to the limitations of existing drill guides in navigating the complex anatomy and high-angle arthroscopic trajectories, leading to difficulties in mentally projecting a straight drill path with accuracy.
Innovation Solution
A drill guide with a flexible or pivotable offset arm, which can bend, flex, or pivot within a single plane, allowing for a safer and more accurate placement of bone tunnels by engaging the articular surface of the acetabulum, and featuring a depth stop and obturator for protection and precise alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a straight drill guide is used with high-angle arthroscopic trajectories, then the surgical approach is simpler, but the accuracy of drill path projection is insufficient leading to potential cartilage blow-out
Solution Approach 1:
The patent introduces an offset arm that creates a perpendicular dimension to the shaft, allowing the drill guide to project the drill path onto the articular surface in a different dimensional plane. This offset geometry transforms the high-angle trajectory problem into an accurate surface projection, enabling precise drill hole placement without direct mental projection through the bone.
Solution Approach 2:
The offset arm acts as an intermediary element between the shaft and the articular surface. It physically bridges the gap between the high-angle arthroscopic trajectory and the cartilage surface, providing a mechanical reference that eliminates the need for accurate mental projection while maintaining surgical simplicity.
2Ease of operation
If brute force is used to force the drill guide into the correct trajectory, then the device can be positioned, but the risk of cartilage blow-out increases due to inaccurate trajectory control
Solution Approach 1:
The patent replaces the brute-force mechanical positioning method with a geometry-based positioning system. The offset arm's fixed perpendicular relationship to the shaft creates a predetermined safe trajectory that naturally prevents cartilage blow-out, eliminating the need for forceful insertion and manual trajectory adjustment.
3Reliability
If a curved drill guide is used to minimize blow-out, then the drill can enter at a safer angle, but lens distortion with wide-angled arthroscope makes trajectory visualization difficult
Solution Approach 1:
The patent uses visual marking features (analogous to color changes) on the offset arm to indicate the correct positioning and drill trajectory. These visual cues allow the surgeon to accurately determine the drill path despite lens distortion from the wide-angled arthroscope, maintaining both safety and visual clarity.
Data Source
AI summary
The present invention relates to a drill guide for use in drilling an acetabular tunnel. The drill guide comprises a cannulated shaft having a handle towards a proximal end, and an offset arm towards a distal end. The arm is flexible or pivotable and has a distal tip for engaging the articular surface of the acetabulum, and is offset from a projected path of the shaft cannulation.