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Relative extramedullary stability
- 1. AOTrauma Principles Course Relativestability: extramedullary techniques Christopher Finkemeier, US
- 2. Objectives • Identify whatfracture patterns are best suited for relatively stable fixation techniques • Identify two common extramedullary techniques for obtaining relative stability • Identify several fundamental features of bridge plating • Understand several surgical techniques unique to bridge plating
- 3. Relative stability—review • Appliedload to fracture exceeds the preload • Small amount of motion between fragments leads to callus formation and “indirect bone healing” • Healing occurs if the interfragmental strain remains below the critical strain level for the repair tissue • The more fragments present, the less strain between fragments and the less rigid the construct requirement
- 4. Ideal fracture patternsfor “relatively stable” fixation methods • Multifragmentary diaphyseal fractures • Multifragmentary metaphyseal fractures • Not amenable to anatomical reduction and absolute stability
- 5. Extramedullary techniques • Externalfixation • Plate fixation: - Bridge plating - “Internal fixator”
- 6. Aim of technique •To preserve the vascularity of the fracture site and fracture fragments • To provide sufficient stabilization to promote union
- 7. External fixation • Externalfixator may be used as provisional or definitive management of fracture • Provisional fixators are used mainly to treat the soft tissues • Definitive fixators treat both bone and soft tissues
- 8. Relative stability: externalfixator
- 9. Relative Stability: externalfixator
- 10. Current trend inexternal fixation • Provisional external fixation
- 11. Provisional external fixation— eg,femoral fractures IMN (intramedullary nail) 4 days later Unstable multitrauma patient Immediate provisional external fixator “Damage Control”
- 12. High-energy mechanism with severe depression Provisionalexternal fixation—eg, tibial plateau fractures Provisional external fixator restores length and alignment Definitive ORIF (open reduction and internal fixation) when soft tissues ready Articular segment remains depressed
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- 14. Relative stability: plates •Extraperiosteal exposure of bone • Indirect reduction to achieve anatomic alignment • Implants that minimize bone necrosis • Longer plates • Judicious use of screws with balanced fixation • Infrequent bone grafting
- 15. Epiperiosteal exposure ofbone • Fractures disrupt the normal blood supply to bone (predominantly intramedullary via nutrient artery)
- 16. Epiperiosteal exposure ofbone • After fracture the surrounding soft tissues provide an • extraosseous blood supply • Proliferation of periosteal osteoblasts occur when vessels • grow from the musculature to the periosteum
- 17. Epiperiosteal exposure ofbone • Damage to the periosteum: • Escape of hematoma • Diffusion of pluripotent mesenchymal cells • Necrosis at the fracture site
- 18. Indirect reduction toachieve anatomical alignment Ligamentotaxis Length Rotation axis
- 19. Indirect reduction toachieve anatomical alignment (slide 1 of 2)
- 20. Indirect reduction toachieve anatomical alignment (slide 2 of 2)
- 21. Implants that minimizebone necrosis Limited contact dynamic compression plate LC-DCP Less invasive stabilization system LISS
- 23. Fewer screws/longer plates •Longer plates improve the construct by increasing the lever arm of the plate • Longer plates require fewer screws to achieve optimal fixation (near fracture and farthest from fracture) • The strain on longer plates is reduced as is the strain on the screws • Fewer screws minimize damage to the bone • A tensioned plate without lag screws acts as an elastic but rigid spring
- 24. = Gotzen et al,1983 Mini—max fixation
- 26. Bone grafting isunnecessary Rozbruch et al, 1998 • Incidence of primary bone grafting femoral • Shaft fractures: 16% to 4% Krettek et al, 1997 • 92% union in proximal and distal femur fractures without bone grafting Kregor et al, 1999 • 97% union rate (Type A and C supracondylar femoral fractures) without bone grafting
- 27. Planning and reductiontechnique in fracture surgery • Fracture configuration • Implant templates • Plan fixation construct • Step-by-step operative plan (open vs MIPO)
- 28. Surgical technique • Equipment •Radiolucent OR table • Image intensifier
- 29. Surgical technique • Externalfixator or femoral distractor (2) • Sterile towels (to make bumps if needed)
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- 31. Surgical technique Reduction instruments:pointed clamps, lamina spreader, dental pick
- 32. Surgical technique Minimize useof clamps that disrupt soft tissues and blood supply Lohman worst Locking Lane Verbrugge Weber tenaculum least
- 33. Surgical technique • Anatomicalreduction • Anatomical reduction of articular surfaces
- 34. Surgical technique • Indirectreduction • Restore length, axial alignment, rotation
- 35. Surgical technique • Exposure •Open, periosteal preserving
- 36. Surgical technique • Exposure •Percutaneous
- 37. Surgical technique Placement ofhardware Plates Submuscular Subcutaneus Extraperiosteal Screws Near and far +/- percutaneus Blanced
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- 42. Postoperatively 2 weeks4 months
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- 46. Summary—relative stability using extramedullarytechniques (plating) • Extraperiosteal exposure of bone • Indirect reduction to achieve anatomical alignment • Implants that minimize bone necrosis • Longer plates • Judicious use of screws with balanced fixation • Infrequent bone grafting