Design Concepts of Polycarbonate-Based Intervertebral Lumbar Cages: Finite Element Analysis and Compression Testing

Abstract

This work explores the viability of 3D printed intervertebral lumbar cages based on biocompatible polycarbonate (PC-ISO® material). Several design concepts are proposed for the generation of patient-specific intervertebral lumbar cages. The 3D printed material achieved compressive yield strength of 55 MPa under a specific combination of manufacturing parameters. The literature recommends a reference load of 4,000 N for design of intervertebral lumbar cages. Under compression testing conditions, the proposed design concepts withstand between 7,500 and 10,000 N of load before showing yielding. Although some stress concentration regions were found during analysis, the overall viability of the proposed design concepts was validated.

A UK-based pilot study of current surgical practice and implant preferences in lumbar fusion surgery

“…This approach has shown great popularity in orthopedics over the past 5 years, however, its applicability to spinal fusion surgery has only recently been explored. [ 52 , 53 ] The feasibility of designing and manufacturing of anatomical-shaped fusion cages using 3D printing technology has been shown. [ 52 , 54 ] However, clinically relevant studies in this area still need to be explored.…”

Systematic review of 3D printing in spinal surgery: the current state of play

“…As 3DP technology continues to become cheaper, faster and more accurate, its use in the setting of spinal surgery is likely to become routine, and in a greater number of procedures (1)(2)(3)(4)6,42,44,65). Lower cost desktop 3D printers for everyday use could soon be a reality, aiding real-time model and implant creation for more personalised surgical care (46,48).…”

“…Lower cost desktop 3D printers for everyday use could soon be a reality, aiding real-time model and implant creation for more personalised surgical care (46,48). A greater range of materials is also expected to open new avenues, with improved biocompatibility, osseointegration, biodegradability and load-bearing properties just some of the expected benefits (3,4,48,65). However, the greatest step forward is anticipated to be bioprinting, where cells, growth factors and biomaterial are used to create living tissue.…”

Structure–property relationships for 3D-printed PEEK intervertebral lumbar cages produced using fused filament fabrication

“…Spinal surgery is one of the therapeutic areas in which there has been early interest in AM. Additive manufacturing techniques, including fused filament fabrication (FFF) and selective laser sintering (SLS), have been successfully used to manufacture spinal implants 7, 8 , including spinal cages 9–11 .…”

“…Figueroa et al 11 manufactured spinal cages via FFF with Acrylonitrile Butadiene Styrene (ABS) and polycarbonate (PC). Cavazos et al 9 also investigated the viability of several design concepts in 3D printed intervertebral lumbar cages based on PC. Previous studies investigated design concepts for lumbar cages to establish technical feasibility of FFF with PC and ABS.…”