Customized implants for bone replacement

Abstract

The present invention relates to customized implants for bone replacement that are prepared from poly(ether ketone ketone) or PEKK, and to a computer-based imaging and rapid prototyping (RP)-based manufacturing method for the design and manufacture of these customized implants. The PEKK customized implants made using rapid prototyping demonstrate biomechanical properties similar (if not identical) to that of natural bone even when prepared without the use of processing aids such as carbon black and aluminum powder.

Description

TECHNICAL FIELD[0001]The present invention generally relates to customized implants for bone replacement that are prepared from poly(ether ketone ketone) or PEKK, and to a computer-based imaging and rapid prototyping (RP)-based manufacturing method for the design and manufacture of these customized implants.BACKGROUND AND SUMMARY OF THE INVENTION[0002]Bone is composed of two kinds of tissue, exterior tissue which is dense in texture (compact tissue) and interior tissue that consists of slender fibers and lamellae that together form a lattice-type structure (cancellous tissue). Damage or loss of bone can result from trauma, congenital anomaly, pathologic conditions (e.g., rheumatoid arthritis, scleroderma, acromegaly and Gauchers disease), and surgical procedures.[0003]In conventional treatment of bone defects, bone-derived or synthetic biomaterials are used to restore form and function. These biomaterials are preferably in the form of porous implant structures having interconnected ...

AI Technical Summary

Benefits of technology

[0006]Regardless of the manufacturing route, the resulting implant may then be subjected to one or more post-processing steps, which include modifying the implant to include pre-tab holes and other features that aid in rigid affixation.

[0011]By way of the present invention, it has been discovered that poly (ether ketone ketone) or PEKK may be used to make customized implants for bone replacement using rapid prototyping. PEKK offers the benefit of lower solidification rates, and in some embodiments, may also offer the added benefit of considerably lower processing temperatures.

Problems solved by technology

Damage or loss of bone can result from trauma, congenital anomaly, pathologic conditions (e.g., rheumatoid arthritis, scleroderma, acromegaly and Gauchers disease), and surgical procedures.

Unfortunately, PEEK processing temperatures are quite high.

In addition, less than favorable compressive residual stress profiles have been observed in these customized PEEK scaffolds, attributed to the relatively high solidification rates demonstrated by PEEK materials.

Moreover, achieving and maintaining homogeneity in PEEK-HAP powder blends is difficult, with a lack of homogeneity causing the formation of HAP particle clusters in the powder blend.

Localized heating of these HAP particle clusters have been found to result in the partial degradation of PEEK and / or the formation of microscale thermal stresses in the resulting scaffold.