g12 bone grafts & subs
TRANSCRIPT
![Page 1: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/1.jpg)
Bone Grafting and Bone Graft Substitutes
James Krieg, MD
![Page 2: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/2.jpg)
• “Bone graft material is any implanted material that, alone or in combination with other materials, promotes a bone healing response by providing osteogenic, osteoconductive, or osteoinductive activity to a local site.”
– Muschler and Lane
![Page 3: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/3.jpg)
Functions of Bone Graft• osteoconduction
– provides matrix for bone growth• osteoinduction
– growth factors encourage mesencymal cells to differentiate into osteoblastic lineages
• osteogenesis– transplanted osteoblasts and periosteal cells
directly produce bone• structural support
![Page 4: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/4.jpg)
Types of Bone Grafts
• autogenous bone• allograft bone• osteoconductive synthetics• osteoinductive agents• composites
![Page 5: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/5.jpg)
Autogenous Bone Graft
– “gold standard”• most effective graft material
– limitations• limited supply• donor site morbidity
![Page 6: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/6.jpg)
Types of Bone Grafts• Cancellous
– biologically conducive to bone formation• hydroxyapatite and collagen form osteoconductive
frame• osteogenic potential of stromal cells• together with adjacent blood clot, growth factors are
provided, providing osteoinduction– bone morphogenic proteins (BMP)– transforming growth factor-beta
![Page 7: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/7.jpg)
Types of Bone Grafts
• Cancellous– little initial structural support– can gain support quickly as bone is formed
![Page 8: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/8.jpg)
Types of Bone Grafts• Cortical
– less biologically active than cancellous bone• less porous, less surface area, less cellular matrix• Prologed time to revascularizarion
– more structural support• can be used to span defects
• Vascularized cortical– more structural support due to early
incorporation– also osteogenic, osteoinductive
• Transported periosteum
![Page 9: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/9.jpg)
Types of Bone Grafts
• Bone marrow– aspirated– Osteogenic
• osteoprogenitor cells exist in a 1:50,000 ratio to nucleated cells in marrow aspirate
– can be used in combination with an osteoconductive matrix
![Page 10: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/10.jpg)
Bone Graft Substitutes
• Allograft bone– can be cancellous or cortical– plentiful supply– good osteoconductive properties– limited osteoinductive properties– good structural support
![Page 11: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/11.jpg)
Bone Graft Substitutes
• Allograft bone– fresh
• highly antigenic• limited time to test for immunogenicity or diseases• use limited to joint resurfacing
![Page 12: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/12.jpg)
Bone Graft Substitutes
• Allograft bone– fresh frozen
• less antigenic• time to test for diseases
– strictly regulated by FDA
• preserves biomechanical properties– good for structural grafts
![Page 13: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/13.jpg)
Bone Graft Substitutes
• Allograft bone– freeze-dried
• even less antigenic• time to test for diseases
– strictly regulated by FDA
• can be stored at room temperature up to 5 years• mechanical properties degrade• osteoinductive properties slightly preserved
![Page 14: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/14.jpg)
Bone Graft Substitutes
• Ceramics– osteoconductive matrix– mostly hydroxyapatite (HA) , tricalcium
phosphate (TCP)– come in many forms
• porous implants• nonporous dense implants• granular particles
![Page 15: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/15.jpg)
Bone Graft Substitutes
• Ceramics– resorption rates vary widely
• dependant on composition– trade off between rapid resorption (TCP) and structural
support (HA)» combinations of the two often help in this trade-off
• also dependant on porosity, geometry
![Page 16: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/16.jpg)
Bone Graft Substitutes
• Ceramics– resist compression well
• HA more resistant than TCP– brittle
• poor resistance to tension, bending, torque– must protect load bearing until incorporated
![Page 17: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/17.jpg)
Bone Graft Substitutes
• Ceramics– can be used as bone graft extenders– useful for large defects, but need to protect load
bearing until incorporated• can be a lengthy process
– not useful for nonunions where biological activity is needed
![Page 18: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/18.jpg)
Bone Graft Substitutes
• Osteoconductive cement– e.g Norian SRS – provide immediate stability and long term bone
ingrowth– resorption rates can be very slow
![Page 19: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/19.jpg)
Bone Graft Substitutes
• Osteoinductive proteins– bone morphogenic proteins
• BMP-2, BMP-4, BMP-7 (OP-1)• preclinical trials show bone formation in response to
these proteins– other osteotrophic cytokines
• TGF-beta, FGF-2, PDGF, EGF, IGF-1, IGF-11, LMP, and others
![Page 20: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/20.jpg)
Bone Graft Substitutes
• Osteoinductive proteins– BMP bone morphogenetic protein– EGF endothelial growth factor– FGF fibroblast growth factor– IGF insulinlike growth factor– PDGFplatelet derived growth factor– TGF transforming growth factor– LMP LIM-mineralizing protein
![Page 21: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/21.jpg)
Bone Graft Substitutes
• Osteoinductive proteins– delivery directly into graft site– Remaining questions regarding use
• What combination of factors to use?• How to deliver them in appropriate carriers?• How long will they remain biologically active?• Can they cause overactivity? e.g. osteosarcoma
![Page 22: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/22.jpg)
Bone Graft Substitutes
• Osteoinductive proteins– demineralized bone matrix (DBM)
• acid extraction of bone• noncollagenous proteins, bone growth factors, and
collagen• generally poor strength, but can be osteoconductive
and osteoinductive• must be sterilized to prevent disease transmission
![Page 23: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/23.jpg)
Bone Graft Substitutes
• Osteoinductive proteins– can their production be promoted in
mesencymal cells at the desired site?• Genetic therapy
– requires vectors (currently viral vectors exist)– regulation can be a real concern to prevent
overstimulation
![Page 24: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/24.jpg)
Composite Grafts
• Combinations of several techniques and materials can be utilized to take advantage of the strengths of each.
![Page 25: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/25.jpg)
Indications for Bone Graft
• provide structure– metaphyseal impaction
– 27 y.o male with lateral split/depression tibial plateau fracture. Note posterolateral depression.
![Page 26: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/26.jpg)
Indications for Bone Graft
• provide structure– metaphyseal impaction
– ORIF with allograft cancellous bone chips for graft of depressed area.
![Page 27: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/27.jpg)
Indications for Bone Graft
• provide structure– metaphyseal impaction
– 4 months s/p surgery and the graft is well incorporated.
![Page 28: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/28.jpg)
Indications for Bone Graft
• provide structure– metaphyseal impaction– segmental defect
– 29 y.o male with defect s/p IMN Type IIIB open tibia fracture. Gentamicin PMMA beads were used as spacers and removed.
![Page 29: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/29.jpg)
Indications for Bone Graft
• provide structure– metaphyseal impaction– segmental defect
– s/p bone grafting with iliac crest autograft.
![Page 30: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/30.jpg)
Indications for Bone Graft
• provide structure– metaphyseal impaction– segmental defect
– 14 months after injury, the fracture is healed and the nail removed.
![Page 31: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/31.jpg)
Indications for Bone Graft
• provide structure– metaphyseal impaction– segmental defect
• stimulate healing– nonunions
– 26 y.o. woman with established atrophic nonunion of the clavicle.
![Page 32: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/32.jpg)
Indications for Bone Graft
• provide structure– metaphyseal impaction– segmental defect
• stimulate healing– nonunions
– Plating with cancellous iliac crest autograft.
![Page 33: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/33.jpg)
Indications for Bone Graft
• provide structure– metaphyseal impaction– segmental defect
• stimulate healing– nonunions
– 6 months after surgery she is asymptomatic.
![Page 34: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/34.jpg)
Indications for Bone Graft
• provide structure– metaphyseal impaction– segmental defect
• stimulate healing– nonunions– arthrodesis
– Failed subtalar arthrodesis
![Page 35: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/35.jpg)
Indications for Bone Graft
• provide structure– metaphyseal impaction– segmental defect
• stimulate healing– nonunions– arthrodesis
– Repeat fusion with autogenous iliac crest.
![Page 36: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/36.jpg)
Indications for Bone Graft
• provide structure– metaphyseal impaction– segmental defect
• stimulate healing– nonunions– arthrodesis
– 6 months after surgery, fused successfully
![Page 37: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/37.jpg)
Graft Incorporation• hematoma formation
– release of cytokines and growth factors
![Page 38: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/38.jpg)
Graft Incorporation• hematoma formation
– release of cytokines and growth factors• inflammation
– development of fibrovascular tissue
![Page 39: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/39.jpg)
Graft Incorporation• hematoma formation
– release of cytokines and growth factors• inflammation
– development of fibrovascular tissue• vascular ingrowth
– often extending Haversian canals
![Page 40: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/40.jpg)
Graft Incorporation• hematoma formation
– release of cytokines and growth factors• inflammation
– development of fibrovascular tissue• vascular ingrowth
– often extending Haversian canals • focal osteoclastic resorption of graft
![Page 41: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/41.jpg)
Graft Incorporation• hematoma formation
– release of cytokines and growth factors• inflammation
– development of fibrovascular tissue• vascular ingrowth
– often extending Haversian canals • focal osteoclastic resorption of graft• intramembranous and/or endochondral bone
formation on graft surfaces
![Page 42: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/42.jpg)
Graft Incorporation
• Cancellous bone interface between graft and host bone.
![Page 43: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/43.jpg)
Graft Incorporation
• Cortical allograft strut graft placed next to cortex of host. After 4 years of incorporation.
![Page 44: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/44.jpg)
Graft Incorporation
• Hydroxyapatitematerial after partialincorporation. Graftwas placed one yearago.
![Page 45: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/45.jpg)
Autograft Harvest
• cancellous– iliac crest (most common)
• anterior- taken from gluteus medius pillar• posterior- taken from posterior ilium near SI joint
– metaphyseal bone• often taken near site of implant
– greater trochanter, distal femur, proximal or distal tibia, calcaneus, olecranon, distal radius, proximal humerus
![Page 46: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/46.jpg)
Autograft Harvest
• cancellous– technique
• cortical window made to harvest cancellous graft• can be done with trephine instrument
– drill sleeves– commercially available trephines or “harvesters”– can be percutaneus procedure
![Page 47: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/47.jpg)
Autograft Harvest
• cortical – fibula common donor
• avoid distal fibula to protect ankle function• preserve head to keep LCL, hamstrings intact
– iliac crest• can be harvested in shape to fill defect
![Page 48: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/48.jpg)
Developments: Present and Future
• graft delivery– implants to support structures and supply graft
• spine cages, etc.
– Osteoconductive cements• provide immediate support, promise of resorption
and replacement by native structure
![Page 49: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/49.jpg)
Developments: Present and Future
• bioactive proteins– use is well supported in animal studies
• BMP, DBM, TGF all proven in vivo– questions remain regarding optimal mix and
delivery of proteins
![Page 50: G12 bone grafts & subs](https://reader035.vdocuments.mx/reader035/viewer/2022081421/58ed51f21a28ab266c8b4617/html5/thumbnails/50.jpg)
Developments: Present and Future
• gene therapy– promises to allow pleuripotential mesenchymal
cells to be “turned on” and “turned off” to regulate bone growth by host production of bioactive proteins
– delivery systems a challenge• currently only vectors are viruses, better ones sought
Return to General Index