Inverted Concave Humeral Surface Shoulder Prosthesis

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

In total shoulder prostheses, the interference between the humeral prosthetic component and the scapula limits the range of adductive movement and can cause pain or prosthesis dislodgment due to poor quality cancellous bone in the humeral metaphysis, leading to gradual subsidence of interpositional implants.

Innovation Solution

A method of forming a shoulder prosthesis by resecting an end portion of the humerus to create a concave articular surface, which is articulated with a convex articular surface of an implant secured to the glenoid, using a reinforcing structure or bone graft material to enhance metaphyseal support and prevent subsidence.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a conventional total shoulder prosthesis is used with a humeral component, then the shoulder joint can be replaced, but the lower portion of the humeral prosthetic component strikes the scapula during adductive movement, limiting the range of motion and causing pain

Engineering Contradiction:

Improverange of adductive movementVSAvoidinterference between humeral component and scapula

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent removes the interfering lower portion of the humeral metaphysis that causes impingement with the scapula. By resecting the distal part of the humeral metaphysis, the harmful interference is eliminated while preserving the functional articular surface for shoulder movement.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent inverts the conventional prosthesis configuration by creating a concave articular surface in the humerus instead of using a conventional convex humeral component. This inverted geometry allows the humeral component to articulate with the glenoid without interfering with the scapula during adduction.

Inventive Principle:

Principle #13The other way round (Inversion)

2Reliability

If the cancellous bone in the humeral metaphysis is of poor quality, then the bone may lead to gradual subsidence of the interpositional implant, but using a reinforcing structure or bone graft material can prevent subsidence

Engineering Contradiction:

Improvestability of interpositional implantVSAvoidquality of cancellous bone

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent applies bone graft material or reinforcing structures beforehand to prepare the humeral metaphysis before implanting the interpositional implant. This pre-reinforcement prevents future subsidence by compensating for the poor quality of the cancellous bone in advance.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The patent uses composite construction by combining bone graft material with the patient's own cancellous bone, or using reinforcing structures made of different materials (such as metal or ceramic) to create a composite support structure that prevents implant subsidence.

Inventive Principle:

Principle #40Composite materials

Data Source

PatentUS11547572B2Intra-articular joint replacement

Publication Date: 2023.01.10 TORNIER SA SAINT ISMIER

AI summary

A method of forming a shoulder prosthesis includes resecting an end portion of a humerus to form a resected end of the humerus and a resected portion separated from the humerus, the resected portion having an outer convex surface and an inner surface. The inner surface of the resected portion is processed to include a concave articular surface. The outer convex surface of the resected portion is implanted in the resected end of the humerus. An implant having a convex articular surface is secured to a glenoid. The concave articular surface of the resected portion is articulated with the convex articular surface of the implant.