CT Lesion Model-Based Structural Allografts: Custom Fabrication and Clinical Experience

Abstract

Background: Patients requiring knee and hip revision arthroplasty often present with difficult anatomical situations that limit options for surgery. Customised mega-implants may be one of few remaining treatment options. However, extensive damage to residual bone stock may also be present, and in such cases even customised prosthetics may be difficult to implant. Small quantities of lost bone can be replaced with standard allografts or autologous bone. Larger defects may require structural macro-allografts, sometimes in combination with implants (allograft-prosthesis composites). Methods: Herein, we describe a process for manufacturing lesionspecific large structural allografts according to a 3D, fullscale, lithographically generated defect model. These macroallografts deliver the volume and the mechanical stability necessary for certain complex revisions. They are patient- and implant-matched, negate some requirements for additional implants and biomaterials and save time in the operating theatre by eliminating the requirement for intra-operative sizing and shaping of standard allografts. Conclusion: While a robust data set from long-term follow-up of patients receiving customised macro-allografts is not yet available, initial clinical experience and results suggest that lesion-matched macro-allografts can be an important component of revision joint surgery.

Bone Regeneration Based on Tissue Engineering Conceptions — A 21st Century Perspective

“…Additive manufacturing enables the fabrication of highly structured scaffolds to optimise properties highly relevant in bone tissue engineering (osteoconductivity, osteoinductivity, osteogenicity, vascularisation, mechanical and chemical properties) on a micro- and nanometre scale. Using high-resolution medical images of bone pathologies (acquired via CT, μCT, MRI, ultrasound, 3D digital photogrammy and other techniques) ( 168 ), we are not only be able to fabricate patient-specific instrumentation ( 235–237 ), patient-specific conventional implants ( 238–242 ) or allografts ( 243 ), but also to realise custom-made tissue engineering constructs (TEC) tailored specifically to the needs of each individual patient and the desired clinical application ( 168 , 174 , 244 ). We therefore predict that the commencing area of Regenerative Medicine 3.0 will hold a significant leap forward in terms of Personalised Medicine.…”

Factors associated with self-assessed increase in tobacco consumption among over-indebted individuals in Germany: a cross-sectional study

“…In comparison, smoking prevalence in the general German population is considerably lower (34%) and even the subpopulation with the highest tendency to smoke (40- to 59-year-old men of low socio-economic status) are significantly less likely to smoke (54.8%) than over-indebted individuals [22]. The findings suggest that smoking is particularly prevalent among over-indebted individuals.…”

Reconstruction for Massive Proximal Tibial Bone Defects Using Patient‐Customized Three‐Dimensional‐Printed Metaphyseal Cones in Revision Total Knee Arthroplasty

“…High friction from the porous surface also provides immediate fixation. A simplified procedure with a shortened operating time is another advantage, particularly when massive bone defects are involved 13 . However, few studies have focused on the utilization of patient‐customized 3D‐printed cones are less reported in RTKA with massive bone defects.…”