AAOS Trauma Techniques Course

1. AAOS Trauma Techniques Course Mitchell Goldflies

2. Talus Fractures • High energy trauma • Mvc (abrupt deceleration) • Fall from height • 20% open fxs • 25% associated with medial malleolus fxs

3. Injury Classification • Neck (>50%) • Body (7-38%) • Head (10%) • Lateral process • Transchondral/dome fxs • OCD (Medial/lateral)

4. Hawkin’s Classification of Talar Neck Fxs • I-nondisplaced vertical • II-body displaced in relation to the subtalar or ankle joint • III-body displaced in relation to both the subtalar and ankle joint • IV-body and head displaced in relation to the talonavicular complex

5. The Talus is Special • Hyaline cartliage covers 60% of surface • Relies heavily on direct bloody suplly • Only muscular/tendinous insertion is the extensor digitorum brevis • Vulnerable because it relies on direct blood supply

6. Blood Supply • Direct • Posterior tibial artery • Branches to the body via the post ankle capsule, deep deltoid and artery to tarsal canal (supplies central 2/3 of body)

7. Blood Supply • Direct • Tibialis Anterior • Major supply to the talar neck and head via the dorsal surface • Sends branch to the tarsal canal which connects to the posterior tibial artery branch

8. Blood Supply • Indirect • Capsular and ligamentous attactments • ST, TN • Bifurcate, cervical, ninterosseous

9. Imaging • Ankle mortise, AP and lateral foot, modified AP foot (Canale view to see neck-maximal PF with foot everted 15 degrees) • Broden and Anthsen views of post and middle facets-center beam on sinus tarsi and angle up, cassette post to hindfoot, int or ext rotate foot @ 45 degrees

10. Treatment Options • Surgical

11. Nonoperative Guidelines • If truly nondisplaced and anatomic (unusual circumstances), slc for 6-8 weeks • Less than 2mm displacement and 5 degrees of malalignment is acceptable

12. Surgical Timing • No correlation between timing of surgery and development of osteonecrosis (vallier et al JBJS 2004) • Surgeon survey: treatment after 8 hours acceptable to 60%; treatment after 24 hours acceptable to 46% (Patel FAI 2005)

13. How do we fix these fxs? • Approaches (medial and/or lateral) • Intraop reduction/txn with dislocation • Bone graft with medial communication • Instruments/equipment • Fixation-stainless steel vs titanium • Timing

14. Fixation • Strength of fixation not a determinant of outcome (if stable) as anatomic fx reduction and extent of blood supply remaining (Higgins FAI 1999)

15. Body versus Neck • Neck Fx: anterior to the lateral talar process and tarsal tunnel (extra articular) • Body Fx: posterior to the above (intra articular) • Significance: increased morbidity, arthrosis, concurrent dislocatoin with body fx

16. Talar Body fxs • More than 25% of talar injuries • Greater incidence of poor outcomes • More likely to require medial malleolar osteotomy for exposure

17. Additional Fixation • Avoidance of varus malunion with miniplate and screw fixation often accompanying longitudinal screw fixation (Fleuriau Chateau et al JOT 2002)

18. Postop Care • Immoblization-ex or cast • Weight bearing status • Hawkin’s sign • Rehab • Salvage • AVN detection

19. Hawkin’s Sign • Subchondral luecencies in the talar dome on plain radiographs 6-8 weeks after injury • Implies preservation of the main blood supply • Absence of sign does not confirm osteonecrosis

20. Talar Neck Fx Outcome • Type I: 0-13% avn • Type II: 20-75% avn *disputed with MR study (claims <25% avn) • Type III: 75-100% avn* disputed with Mr study (claims 50-100%)

21. Talar Neck Fx Outcome • No prospective studies • Nonuion rate • Delayed union <10%

22. Talar Neck Fx Outcome • Union rate >90% • Varus Malunion up to 50% • Leads to rigid midfoot, breakdown, and reciprocal arthrosis with compensatory forefoot pronation

23. Other Complications • Long term (Vallier et al JBJS 2003) • Posttraumatic arthritis 54 % • Ostenonecrosis 49% (associated with fx communication and open injury)

24. Imaging • Plain radiographs correlate well with MR scans typifying signal changes in greater than 50% of the body (Thordarson FAI 1996) • High quality scans obtained in the presence of titanium screws

25. Imaging Recommendations • MRI- between 8-12 weeks postop/injury in all Hawkins II and in Hawkins II with suggestive plain films; f/u MR in 6 months for Hawkins II • May protect wt bearing longer and predict collapse

26. Talar Head Fxs • Fewer tan 10% of all talar fx • Instability ensues when the fracture fragment exceeds 50% of the articular surface • Usually associated with lateral column injury of subtalar dislocation

27. Salvage

28. Subtalar Fx/Dislocation • Associated with head fractures • May see lateral process fx • Check CT scan

29. Lateral Process Fx • Type I – simple, two part fx • Type II- comminuted fx • Type III- chip fx of anterior-inferior process • Types I and III – generally nonoperative if nondisplaced

30. Lateral Process Fx • Type II or Types I and III displaced more than 2mm treated surgically • If fragment > 1cm, ORIF • If fragment <1 cm or if comminuted, excise

31. Miscellaneous Fx • OCD/dome shearing fx • Posterior process fx • Posterolateral: Shepherd fx (larger process) • Postermodedial: Cedell fx • Both generally treated conservatively with late excision for pain

32. Talar Extrusion • Wipe it off and pit it back???