ASTM F1378-00 Standard Specification for Shoulder Prostheses

The standard “ASTM F1378-00 Standard specification for shoulder prostheses” developed by the American Society for Testing and Materials (ASTM) describes the requirements for shoulder prostheses for total or hemiarthroplasty used to provide functional articulation using glenoid and humeral components. Devices for special applications are not covered by this standard. However, modular prostheses are covered by this standard.

For the purposes of this standard, the following terms and definitions apply:

• The collar refers to the flange where the neck and body meet.
• The glenoid component refers to the prosthetic portion of the scapula that partially or completely replaces the glenoid fossa and articulates with the natural humeral head or a prosthetic replacement.
• The head refers to the carrier element that provides articulation with the glenoid.
• The humeral component is the prosthetic portion that partially or completely replaces the proximal humerus or humeral head and articulates with the native glenoid fossa or a prosthetic replacement.
• Keels (or pins) refer to single or multiple projections that fuse with the spaces created in the glenoid fossa to resist translation or rotation, or both, of the glenoid component.
• The neck refers to the segment that connects the head and body.
• The stem refers to the segment designed to be inserted into the medullary canal of the humerus.

In the ASTM F1378-00 standard, the classification is made as follows:

• Constrained: A constrained joint prosthesis is used for joint replacement and resists displacement of the prosthesis in more than one anatomic plane and consists of a single, flexible, cross-joint component or multiple components connected or in close proximity to each other.
• Semi-constrained: A semi-constrained joint prosthesis is used for partial or total joint replacement and limits translation and rotation of the prosthesis in one or more planes through the geometry of the articular surfaces. It has no attachments across the joint.
• Unconstrained: An unconstrained joint prosthesis is used for partial or total joint replacement and minimally restricts the movement of the prosthesis in one or more planes. Its components have no connection across the joint.

The choice of materials is understood as a necessary but not sufficient guarantee of the functionality of the device made of them. All devices complying with this standard are manufactured from materials having sufficient mechanical strength and durability, corrosion resistance and biocompatibility.

In terms of mechanical strength, various components of shoulder prostheses have been successfully manufactured from materials defined in the following standards. However, not all of these materials may possess sufficient mechanical strength for critically high-stress components (ASTM F75-18, ASTM F90-23, ASTM F136-13, ASTM F138-19, ASTM F562-02, ASTM F563-00, ASTM F603-12, ASTM F648-21, ASTM F745-00, ASTM F799-19, ASTM F1108-22, and ASTM F1537-20).

For corrosion resistance, materials with limited or no history of successful use for orthopedic implant application must be determined to exhibit corrosion resistance equal to or better than one of the materials listed in the standard when tested in accordance with ASTM F746-04.

For biocompatibility, materials with limited or no history of successful use for orthopedic implant application must be determined to exhibit acceptable biological response equal to or better than one of the materials listed in the standard when tested in accordance with ASTM F748-16 and ASTM F981-23 standards.

It is important to understand the wear performance of articulating surfaces. Any new or different material should not exceed the wear rates of the material pair specified in the standard when tested under physiological conditions. The current standard wear pair is cobalt-648 chromium-21 molybdenum alloy (ASTM F28-6) versus ultra-high molecular weight polyethylene (ASTM F75-23), both of which have prosthetic-quality surface coatings that comply with the standard.

In terms of range of motion of the shoulder prosthesis before implantation, flexion should be at least 90 degrees, abduction at least 90 degrees, internal rotation at least 90 degrees, external rotation at least 45 degrees, and extension at least 45 degrees. Porous metal coatings are tested in accordance with ASTM F1044-5 (shear strength) and ASTM F1147-05 (tensile strength) standards.

All modular implants must be tested in accordance with ASTM F1829-16, and all prosthetic glenoid components must be tested in accordance with ASTM F2028-17.

Implant testing should reflect current clinical failures and potential failure modes specific to the implant. These tests may include subluxation, glenoid loosening, insert separation from a metal strut, and humeral head separation.

Among the numerous testing, measurement, analysis and evaluation studies that our organization has carried out for businesses in various sectors, it also provides testing services defined in the "ASTM F1378-00 Standard specification for shoulder prostheses" standard with its trained and expert staff and advanced technological equipment.