Pin Positioning Block for Dynamic Ligament Balancing

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Solution Overview

Problem

Current endoprosthetic surgery for knee joint replacement lacks standardization and objective measurement of soft tissue tension, leading to potential misalignment and discomfort for patients, resulting in unsatisfactory outcomes and increased healthcare costs.

Innovation Solution

A surgical pin positioning block and ligament balancing tool that measures and records soft tissue tension before and after implantation, providing a platform-independent solution for objective adjustment and standardization of tendon tension, enabling precise reproduction of natural kinematics and muscle tension states.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional endoprosthetic surgery is performed without standardized measurement tools, then surgical procedure can be completed, but soft tissue tension cannot be objectively measured and adjusted, leading to patient discomfort and unsatisfactory outcomes

Engineering Contradiction:
Improvesoft tissue tension measurementVSAvoidsurgical instrumentation
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The pin positioning block integrates multiple functions: it serves as both a drilling guide for pin placement and a measurement device for soft tissue tension assessment. The block contains internal reference features and measurement mechanisms nested within its structure, allowing simultaneous positioning and measurement capabilities without requiring separate instruments.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The pin positioning block acts as an intermediary device between the surgeon and the complex measurement task. It provides a standardized interface that translates soft tissue tension into measurable pin insertion forces, mediating between the biological tissue and the measurement system while maintaining surgical workflow.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If soft tissue tension is not objectively measured during surgery, then surgical procedure is simpler, but implant alignment and tendon tension cannot be standardized, resulting in patient pain and potential need for revision surgery

Engineering Contradiction:
Improveimplant alignment and tendon tension standardizationVSAvoidsurgical procedure simplicity
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The pin positioning block is designed with pre-established reference features and measurement scales that enable standardized tension assessment before final implant placement. The block provides pre-calibrated measurement capabilities that guide the surgeon in achieving correct soft tissue tension prior to committing to the final implant position.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The device enables measurement and adjustment of soft tissue tension parameters through standardized force application and measurement. By quantifying tension forces and providing feedback, the system allows dynamic adjustment of soft tissue parameters to achieve optimal alignment and tension standards.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If standardized measurement and adjustment of soft tissue tension is implemented, then patient outcomes and satisfaction improve, but surgical time and measurement/adjustment process increase

Engineering Contradiction:
Improvesurgical outcome consistencyVSAvoidsurgical procedure time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The pin positioning block is designed to be self-contained with all necessary measurement and positioning features integrated into a single device. The block provides self-evident measurement readings and self-correcting positioning features that reduce the need for additional measurement steps and decision-making time during surgery.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3742970B1Dynamic ligament balancing system with pin positioning block
Publication Date: 2022.03.16 MEDFIT BERATUNGS UND BETGES M B H
  • EP3742970B1 patent drawingFigure 1
  • EP3742970B1 patent drawingFigure 2
  • EP3742970B1 patent drawingFigure 3

AI summary

A surgical pin positioning block comprising a top portion comprising a pin position dial including one or more pin hole guides, the pin position dial setting angular pin positions of the one or more pin hole guides, wherein the one or more pin hole guides includes an orifice for drilling of pin holes, one or more dial position notches that secures the pin position dial in a given angular pin position, one or more sliding members coupled with one or more receptacles of a bottom portion, the bottom portion comprising the one or more receptacles, an adapter including one or more prongs that attach to a prosthetic inlay device, and a locking mechanism for securing the one or more sliding members in the one or more receptacles.