Principles involved in the use of an external fixation for management of open fractures.pptx

this powerpoint discusses the principles involved in the management of an open fracture from clinical assessment, diagnosis, principles of management etc

1. Principles involved in the use of an external fixator for an open tibial/fibular fracture Makafui S. C-J. K. D

2. Outline Introduction Types of external fixators Indications for external fixators Factors for stability Precautionary measures Use safe corridors to avoid neurovascular bundle injury Avoid the crest of the tibia Avoid growth plates and joints Use of external fixators in open tibial/fibular fractures Proximal fractures Diaphyseal fractures Distal fractures complications 08/07/2024 6:58 pm makafui s. c-j. k. d 2

3. introduction External fixation is a surgical treatment used to stabilize bone or soft tissue by applying external hardware at a distance from the zone of injury while providing unobstructed access to the zone of injury. The injury could involve the bone or joint or soft tissue disease or a combination of the above. A good working anatomy of the injured limb is important 08/07/2024 6:58 pm makafui s. c-j. k. d 3

4. Types of external fixators Linear/simple Ring hybrid 08/07/2024 6:58 pm makafui s. c-j. k. d 4

5. Components Pins or wires Bars/rods Clamps 08/07/2024 6:58 pm makafui s. c-j. k. d 5

6. Pins and Wires Half-pins/ transfixion pins Self-tapping/non-self-tapping Coated/non-coated : pin-bone interface and extraction torque, reduce risk of infection Constant diameter/conical threads 08/07/2024 6:58 pm makafui s. c-j. k. d 6

7. Pins and Wires Different sizes and designs: Pin bending strength (bending stiffness) is increased to the 4 th power of increase in its radius. To avoid creating a stress riser the pin should not exceed 1/3 diameter of the bone Pins with smaller core diameter have increased pullout strength but reduced bending strength 08/07/2024 6:58 pm makafui s. c-j. k. d 7

8. The weakest point of a pin is the thread-shank junction which forms a large stress riser Sinking the shank into the proximal cortex improves the stiffness up to two times 08/07/2024 6:58 pm makafui s. c-j. k. d 8

9. Bars/Rods Materials: Stainless steel/aluminum alloy/carbon fibre . An ideal bar: stiff, lightweight and radiolucent Design Simple rod Articulated Telescoping Principle increased diameter = increased stiffness/strength Stacked (2 parallel bars) = increased stiffness 08/07/2024 6:58 pm makafui s. c-j. k. d 9

10. Ring Fixators Components: Tensioned thin wires olive or straight Wire and half pin clamps Rings Rods Motors and hinges 08/07/2024 6:58 pm makafui s. c-j. k. d 10

11. 08/07/2024 6:58 pm makafui s. c-j. k. d 11

12. Frame Types Uniplanar Unilateral ( monolateral ) Bilateral Pin transfixes extremity Biplanar Unilateral ( monolateral ) Bilateral Circular (Ring Fixator) May use Half-pins and/or transfixion wires Hybrid Combines rings with planar frames monolateral uniplanar monolateral biplanar 08/07/2024 6:58 pm makafui s. c-j. k. d 12

13. Frame Types Standard frame Joint spanning frame: Nonarticulated Articulated frame Distraction or Correction frame 08/07/2024 6:58 pm makafui s. c-j. k. d 13

14. Method to manipulate ex-fix to increase stability Increase Decrease Diameter of pins Number of pins used Pin spread Number of planes pins are placed Diameter of rods Number of rods Pin-to-fracture distance Bone-to-rod distance 08/07/2024 6:58 pm makafui s. c-j. k. d 14

15. Pre-operative Considerations Trauma: ATLS protocol ; save life first! Age, size, premorbid condition, socio-economic circumstances, cause, severity and extent of injuries. Multi-disciplinary approach Get appropriate X-rays and other imaging modalities where necessary Justify the use of external fixator 08/07/2024 6:58 pm makafui s. c-j. k. d 15

16. Pre-op Determine the best device and in what configuration Consider surgical approaches and skills required Assemble the device and ensure they are functional before they are sterilized Determine if the ex-fix is for damage control or definitive management Get informed consent 08/07/2024 6:58 pm makafui s. c-j. k. d 16

17. Intra - Op Anaesthesia and antibiotics Use of tourniquet Prep and drape to have access to the proximal and distal joints Intra-op wound assessment Wound extension and wound debridement Thorough irrigation Image intensifier 08/07/2024 6:58 pm makafui s. c-j. k. d 17

18. Intra-op Fracture reduction: Reverse the mechanism of injury, direct visual reduction and ligamentotaxis Pin siting: Consider the safe corridors and method of wound cover Avoid siting pins through open wounds Pre-drill, use drill sleeve and depth gauge Use the appropriate drill bits and pins 08/07/2024 6:58 pm makafui s. c-j. k. d 18

19. Intra-op Drill Sharp drill bits for pilot hole Ensure the pin threads are inside the bone Avoid the epiphysis and physeal plate in children Ensure the far cortex is engaged Ensure good pin spread Reduce the distance between the bone and longitudinal bar 08/07/2024 6:58 pm makafui s. c-j. k. d 19

20. Intra-op More than one bar may be used Erect a second half-frame at an angle to the first The pins and bars should be aligned in the bending axis of the bone. Ensure the desired effect of the frame is achieved: compression, neutralization or distraction 08/07/2024 6:58 pm makafui s. c-j. k. d 20

21. Intra-op Assess the proximal and distal joints and ensure they are free Intra-op radiographs Achieve bone cover Remove tourniquet and achieve hemostasis Bulk dressing is advocated 08/07/2024 6:58 pm makafui s. c-j. k. d 21

22. Periarticular injuries Joint-spanning frame Knee joint spanning ext -fix Ankle joint spanning ext -fix 08/07/2024 6:58 pm makafui s. c-j. k. d 22

23. Post-op Antibiotics Elevate the limb Avoid unnecessary wound exposure on the ward Range of motion exercises Pin site care Ambulation (Non/partial/full weight bearing) 08/07/2024 6:58 pm makafui s. c-j. k. d 23

24. Complications Pin track infection Neurovascular injury Muscle and tendon impalement Frame or pin/wire failure pseudoaneurysm Delayed union Compartment syndrome Re-fracture Limitation of future alternatives 08/07/2024 6:58 pm makafui s. c-j. k. d 24

25. Pin-tract Infection Most common complication 0 – 14.2% incidence Manage appropriately 08/07/2024 6:58 pm makafui s. c-j. k. d 25

26. Pin-track Infection Prevention: Proper pin/wire insertion technique: Subcutaneous bone borders Away from zone of injury Adequate skin incision Use drill sleeve to prevent soft tissue injury during insertion Sharp drill bits and irrigation to prevent thermal necrosis Manual pin insertion (Figures from: Rockwood and Green, Fractures in Adults, 4 th ed, Lippincott-Raven, 1996) 08/07/2024 6:58 pm makafui s. c-j. k. d 26

27. Follow-up General patient assessment Limb assessment Assessment of stability of the construct 08/07/2024 6:58 pm makafui s. c-j. k. d 27

28. Removal of external fixator Depends on the indication: 1. For temporary use: 2 – 3 weeks 2. For definitive fracture treatment: exuberant callus formation in 10 weeks in stable fixation 3. Bone transport: corticotomy , distraction and consolidation 08/07/2024 6:58 pm makafui s. c-j. k. d 28

29. Rasmussen’s functional score system RATING PAIN WALKING CAPACITY RANGE OF MOTION CLINICAL SIGNS STABILITY EXCELLENT No Normal Normal No swelling Normal GOOD Minimal Walking outdoor for at least 1 hour 75% of normal Swelling + Minimal FAIR Ocassional Pain Walking outdoor for 15 min >50% of normal Swelling ++ Instability in flexion POOR Pain at Rest Walking indoor only 50% of normal or less Swelling +++ Instability in flexion and extension 08/07/2024 6:58 pm makafui s. c-j. k. d 29

30. Future Trends Pin coatings: (hydroxyapatite, silver, chlorhexidine ) Reduce infection Reduce pin loosening Optimization of dynamization for fracture healing Increasing ease of use Reduced cost 08/07/2024 6:58 pm makafui s. c-j. k. d 30

31. Conclusion External fixators have multiple applications Justify the use of ex-fix and choose the construct suitable for the application The risk:benefit ratio of added stability should be assessed with each external fixator. Appropriate use can lead to excellent results Recognize and correct complications early 08/07/2024 6:58 pm makafui s. c-j. k. d 31