Flexible Fixation Devices for the Ankle Syndesmosis Michael J. Coughlin, M.D.
Anatomy • AITFL • PITFL • Interosseous ligament
Anterior and posterior
Stability • Goal: restore ankle joint contact mechanics! – Ramey and Hamilton(1976) • 42% reduction tibio-talar contact pressure with one millimeter of lateral talar displacement – Yablon(1977) • Residual lateral mal displacement results in poor outcomes
Type C • Successful fixation requires restoring length and rotation to the fibula. • Exact reduction of the fibula into the fibular notch (incisura fibularis) guarantees a normal ankle mortise. Even small degrees of mal-reduction may lead to DJD
Other times…. • Stable syndesmotic injury without diastasis generally does well nonoperatively – Nussbaum AJSM 2001 • If unsure, stress examination – Standing external rotation stress – Manual stress – Gravity stress
Diagnosis: Gravity versus Manual stress exam • Both effective • Gravity requires tech education • Manual requires physician time and radiation • Medial swelling, echymosis, Tenderness, all unreliable (Schock 2007) Michelson et al. CORR 387: 178-82, 2001.
Defining syndesmosis reduction • High anatomic variability • Traditional radiographs difficult
Cotton test • Once the fibula is fixed, intraoperative stress of the fibula can help determine if the syndesmosis is unstable
Another key point- The posterior malleolus • Garner FAI 2006 – 70% of stability restored after posterior malleolus ORIF versus 40% with single syndesmotic screw • Miller 2010 – Post malleolus ORIF equal to syndesmotic ORIF
Why syndesmosis screws suck
Why syndesmosis screws suck • 1. Need to be removed – “No surgeon ever looked good taking out hardware.” – Most normal people don’t like surgery • More surgical/anesthetic risks • Limited weightbearing • More postop visits • Higher cost to society
Why syndesmosis screws suck 2 nd surgery for removal Screw Operating Room 30 min: $3,000* = $380 Drill: $80-$100 Sterile drapes, gloves, and Screw: $50-$100 fluoroscopy: $200 Sterilization for set: $180 Sterilization for screw removal: $180 = $3,380 * Jo ur nal o f Clinic al Ane sthe sia (2010), 22,233-236 $3,760 Total
Why syndesmosis screws suck • 2. Screws break! – Don’t forget the broken screw removal set – Leave the screws prominent – Surgeons really don’t look good digging out their broken hardware!
Why syndesmosis screws suck Painful Loose Heterotopic Broken Diastasis broken screw ossification screw screw
Why syndesmosis screws suck • 3. How do you know your syndesmosis is reduced???
Why syndesmosis screws suck • 3. How do you know your syndesmosis is reduced??? • Gardner showed in FAI 2006 that 52% (13/25) patients had malreduction of the syndesmosis on CT imaging after ORIF using screws. • Might as well flip a coin! • “Better to be lucky than good!”
How can we do better? • Gardner (2006) 52% syndesmosis mal-reduciton rate on CT
Recent attention on perioperative CT • Sagi 2012 – 27/68 (39% malreduction) on post-op CT – At 2 year follow-up, those who were malreduced did worse – Recommend bilateral post-op CT and open visualization!!!! • not at my hospital!!!
Why flexible syndesmosis fixation rocks
Why flexible syndesmosis fixation rocks • 1. The distal tib-fib joint is a joint – Flexible syndesmotic fixation allows for natural motion of the distal tibiofibular joint • Normal function requires articular congruity – All three are integrally related » Tibia-talus articulation » Fibula-talus articulation » Tibia-fibula articulation
Location • 2.0 cm above joint line Less widening compared to 3.5cm McBryde FAI 1997
Why flexible syndesmosis fixation rocks • 2. No reoperation – Does not require hardware removal – Complications are low – Cottom FAS 2006 showed that in 8-10 months postop • Screws were removed in 68% of patients • No Tightrope devices were removed • Tightrope avoided late diastasis of the distal tibiofibular joint where following screw removal diastasis occurred
Why flexible syndesmosis fixation rocks • 3. More forgiving distal syndesmosis reduction
Why flexible syndesmosis fixation rocks • 4. More forgiving distal syndesmosis reduction • Naqvi in AJSM 2012 demonstrated a 22% malreduction rate on CT imaging of syndesmosis injuries fixed with screws compared with 0% with Tightrope fixation – They also showed that late diastasis occurred with screw fixation and did not occur using Tightrope
PRE-DISSECTION- SCREW FIXATION-BUTTON FIXATION
Why flexible syndesmosis fixation rocks • 5. Flexible syndesmotic fixation is stronger – 2012 Arthrex R&D • 4.5 mm stainless steel screw failed after 11844 cycles • Tightrope didn’t fail – They gave up after 27000 cycles!
Pt. #89-left • 18 yr old all- state linebacker • High ankle sprain on left as junior • No fibula fracture
Pt. #89 • Broke screws 4 months post op
Pt- #89 left • Hardware removal and placement of tightrope
JS-right • Senior, second game, high ankle sprain on right • No fibula fracture
Final follow-up One year Two extra surgeries (hardware removal x@, and redo- Cost $13,000)
Why flexible syndesmosis fixation rocks • 2015: A Prospective Randomized Multicentric Trial Comparing a Static Implant to a Dynamic Implant in the Surgical Treatment of Acute Ankle Syndesmosis Rupture Mélissa Laflamme, MD1 ; Etienne L. Belzile, MD1 ; Luc • Bédard, MD1 ; Michel van den Bekerom, MD2 ; Mark Glazebrook, MD3 ; Stéphane Pelet, MD, PhD1 ; 1 CHU de Québec, Quebec City, Quebec, Canada; 2 Spaarne Ziekenhuis - Locatie Hoofddorp, Hoofddorp, The Netherlands; 3 Dalhousie University, Halifax, Nova Scotia, Canada
Why flexible syndesmosis fixation rocks • In Dr. Glazebrook’s prospective randomized mulitcenter study: – Higher Olerud-Molander score at 3, 6 and 12 months – Higher AOFAS scores at 3, 6, and 12 months – Greater plantarflexion at all time points with flexible fixation – Flexible fixation also: • Lower implant failure • Less reoperation (6% vs 33%) • No loss of reduction (0% vs 11%)
Why flexible syndesmosis fixation rocks • The article concludes: – “Dynamic fixation of acute ankle syndesmosis rupture with the TightRope gives better functional outcomes at short and intermediate terms. The implant offers adequate syndesmosis stabilization without breakage or loss of reduction and reoperation rate is significantly lower than with the conventional screw fixation.”
Final advice- Proximal fracture with inadequate reduction. (see medial widening)
ORIF prox. fracture, screw and/or tightrope
Thank you!
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