1/27/2016. Background. Background. Seth R. Yarboro University of Virginia January 29, Distal tibio fibular joint

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1 Seth R. Yarboro January 29, 2015 Background Distal tibio fibular joint maintains ankle stability while allowing motion Dorsiflexion/external rotation mechanism Poor alignment ankle arthritis Background Ligamentous or with fracture Up to 45% of SER IV ankle fractures (Tornetta JOT 2012) 1

2 Background Ligamentous or with fracture Up to 45% of SER IV ankle fractures (Tornetta JOT 2012) Anatomy Ligamentous stability Bony congruity (concavity of incisura) Morphology Elgafy, Skeletal Radiology

3 Clinical evaluation Mechanism usually external rotation and/or hyperdorsiflexion SER PER Maisonneuve Clinical evaluation PE Squeeze test 20% may be missed on exam (Beumer 2002) Static imaging Standing radiographs A. Distal tib fib overlap B. Distal tib fib clear space C. Medial clear space May image contralateral side 3

4 Dynamic evaluation External rotation or gravity stress views Intraoperative stress views Cotton test or Hook test 100N threshold suggested (Stoffel JBJS 2009) Described with both lateral force, as well as anterior/posterior force Dorsiflexion / external rotation stress Intraoperative stress views Cotton test or Hook test Manual external rotation 4

5 Malreduction rate up to 52% (Gardner FAI 2006) Negative effect on 2yr outcome (Sagi JOT 2012) 16% malreduction if open reduction or direct visualization vs 52% (Miller FAI 2009) All posterior malleolar fractures fixed, regardless of size If no fracture, fibula visualized between anterior/posterior tubercles What do we mean by open? Open reduction of anterior or posterior tubercle in setting of fracture Open debridement/reduction of syndesmosis instead of indirect reduction 5

6 Stability from PITFL Superior stability after fixing posterior mal (PITFL) compared to screw fixation (Gardner CORR 2006, Miller CORR 2010) Threshold to fix fracture 25% rule? (Macko JBJS 1991) 6

7 What if no fracture? Over the front of the fibula only OR Expose anterior and posterior to fibula Absolute indications to open Incarcerated fragment blocking reduction Chronic subluxation with fibrosis of syndesmosis 7

8 Relative indications to open Flat incisura that results in mobile fibula Inadequate ability to evaluate reduction with fluoroscopy If you don t open Get the clamp and screw angle correct Goal: Neutral anatomic axis Limitations? 8

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10 Opening to confirm reduction may not be enough, but is a helpful adjunct. Healthy dose of skepticism required What we don t know yet How much displacement is clinically significant? What size fragment requires ORIF? Conclusions Have a low threshold to open Direct reduction of fractures in incisura decreases malreduction rate Either anterior or anterior/posterior exposure acceptable if no fracture Opening syndesmosis does not ensure appropriate reduction. 10

11 References Beumer A, Swierstra BA, Mulder PG. Clinical diagnosis of syndesmotic ankle instability: evaluation of stress tests behind the curtains. Acta Orthop Scand Dec;73(6): Gardner MJ, Demetrakopoulos D, Briggs SM, Helfet DL, Lorich DG: Malreduction of the tibiofibular syndesmosis in ankle fractures. Foot Ankle Int 2006;27(10): Sagi HC, Shah AR, Sanders RW: The functional consequence of syndesmotic joint malreduction at a minimum 2 year follow up. J Orthop Trauma 2012;26(7): Miller AN, Carroll EA, Parker RJ, Boraiah S, Helfet DL, Lorich DG: Direct visualization for syndesmotic stabilization of ankle fractures. Foot Ankle Int 2009;30 (5): Gardner MJ, Brodsky A, Briggs SM, Nielson JH, Lorich DG: Fixation of posterior malleolar fractures provides greater syndesmotic stability. Clin Orthop Relat Res 2006;447: Macko VW. The Joint Contact Area of the Ankle. JBJS 1991; 73: Elgafy H, Semaan HB, Blessinger B, Wassef A, Ebraheim NA. Computed tomography of normal distal tibiofibular syndesmosis. Skeletal Radiol. 2010;39(6): Miller AN, Carroll EA, Parker RJ, Helfet DL, Lorich DG. Posterior Malleolar Stabilization of Syndesmotic Injuries is Equivalent to Screw Fixation. CORR. 2010; 468: