Designing patient-specific solutions using biomodelling and 3D-printing for revision lumbar spine surgery
Despite the variety of “off-the-shelf” implants and instrumentation, outcomes following revision lumbosacral surgery are inconstant. Revision fusion surgery presents a unique set of patient-specific challenges that may not be adequately addressed using universal kits. This study aims to describe how patient-specific factors, surgeon requirements, and healthcare efficiencies were integrated to design and manufacture anatomically matched surgical tools and implants to complement a minimally invasive posterior approach for revision lumbar fusion surgery.
A 72-year-old woman presented with sciatica and a complex L5–S1 pseudoarthrosis 12 months after L2–S1 fixation surgery for symptomatic degenerative scoliosis. Patient computed tomography data were used to develop 1:1 scale biomodels of the bony lumbosacral spine for pre-operative planning, patient education, and intraoperative reference. The surgeon collaborated with engineers and developed a patient-specific 3D-printed titanium lumbosacral fixation implant secured by L2–L5, S2, and iliac screws. Sizes and trajectories for the S2 and iliac screws were simulated using biomodelling to develop a stereotactic 3D-printed drill guide. Self-docking 3D-printed nylon tubular retractors specific to patient tissue depth and bony anatomy at L5–S1 were developed for a minimally invasive transforaminal approach. The pre-selected screws were separately sourced, bundled with the patient-specific devices, and supplied as a kit to the hospital before surgery.
At 6-month follow-up, the patient reported resolution of symptoms. No evidence of implant dysfunction was observed on radiography.
Pre-operative planning combined with biomodelling and 3D printing is a viable process that enables surgical techniques, equipment, and implants to meet patient and surgeon-specific requirements for revision lumbar fusion surgery.
KeywordsBiomodelling Lumbosacral Patient specific Revision 3D printing
The authors would like to thank Dr Philip M. Lewis for providing academic support.
Compliance with ethical standards
Conflict of interest
Mark Owbridge is an employee at Anatomics Pty Ltd. Robert Thompson is an employee at Anatomics Pty Ltd. Paul D’Urso is a director and shareholder at Anatomics Pty Ltd and has received funding from Stryker Corporation, Epworth Healthcare, and Anatomics Pty Ltd.
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Ethical approval for this study was obtained from Epworth Healthcare Human Research Ethics and Research Governance Committees (HREC2017-254).
Human and animal rights
This article does not contain any studies with animals performed by any of the authors.
Informed consent for surgery was obtained from all individual participants included in the study.
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