1. Session VIII Fixation Devices Casts are stress sharing Pins, screws, Steinman pins and Kirschner wires when used alone provide partial immobilization and are stress sharing. Compression screws and plates are stress shielding or bearing. External fixation is stress sharing –No metal at fx site: distal and proximal –Avoids excessive soft tissue dissection –Potential loss of joint motion due to penetration of multiple tissues –Applicable to any long bone fx

2. Casts are stress sharing

3. Intramedullary rod with locking screws- stress sharing

4. Tibial nail unlocked (L) and statically locked (R) are stress sharing

5. K wires are stress sharing

7. Screws: Note threads and flutes Cortical Screw: May-depending on type- require tapping of threads into cortex. Small flutes, designed for solid cortical bone. Can be used for fixation of bone to bone or hardware to bone. Will not create compression without over-drilling near cortex. Cancellous screw: self tapping. Large flutes for gripping softer spongy bone. Usually used for bone to bone fixation. Will create compression. May be used to attach hardware.

9. Cortical Screw Self-tapping flutes on this example.

10. Cancellous Screw Note the larger flutes

11. Comparision of cancellous and cortical screws.

12. Fixation plates. Many types available. These are malleable and are hand-bent to fit bone contour. Note oval screw holes. Eccentric placement of screw within hole allows compression of fracture fragments.

13. Screws combined with plates are stress bearing.

15. Dynamic Compression Plate

16. Kirschner Wires and Steinman Pins K-wires are smaller, come in smooth or threaded, usually in 3 sizes:.035,.045, and.062. Steinman pins are larger.

17. Steinman Pins Kirschner Wires Thicker Usually Threaded Thinner.035.045.062 Threaded or plain

18. Cerclage Wires and Staples

19. Stainless Steel Monofilament Wire

20. SS Wire in Cerclage

21. AP View Cerclage

22. K-wires used for small bone fixation. The hooked portion protrudes through the skin allowing “easy” removal.

23. Lateral View, same wrist

24. Medullary Rod. Here a femoral rod.

25. Note locked rod fixation to prevent rotation, and “pistoning” of rod.

27. Canulated Screw K-wire used as guide for larger screw: less bone loss if error occurs and second placement attempt is required.

28. Canulated Screw: where you really don’t want to lose too much bone while getting the screw just right. What was the pre-op Dx?

29. Try this one for practice.

30. Practice film #2. Dynamic hip screw