Tightrope Fixation for Syndesmosis Diastasis – What’s the Evidence?

Mark Porte, MDUniversity of Toronto

Case• 39 YO active female • External rotation injury to right lower extremity

– Fall with leg caught under her• Unable to weight bear post injury• On exam:• Pain at syndesmosis. • +ve squeeze test, +ve external rotation test

Presenting Xrays

Post Operative Films – 3 Months

Follow-up – 3 Months• Rehab Protocol

– Splinted 0-2 weeks– Aircast 2-6 weeks

• NWB ROM exercises– Progressive WBAT at 6 weeks– At last f/u good ROM (details not documented)– Pain free weight bearing– Progressing back to regular activities

Tightrope – Theoretical Advantages

• Preserve physiologic motion?• Reduce hardware pain?• Eliminate need for second surgery?• Earlier return to motion/activity?

Evidence? 4 Case Series• Walking a tightrope: Our experience in the treatment of traumatic

ankle syndesmosis rupture– D. McMurray, B. Hornung, B. Venkateswaran, Z. Ati

• Treatment of syndesmotic disruptions with the Arthrex Tightrope: A report of 25 cases– Cottom JM, Hyer CE, Philbin TM, Berlet GC

• Outcome and complications of treatment of ankle diastasis with tightrope fixation– HJS Willmott, B. Singh, LA David

• Treatment of syndesmosis disruptions with TightRope fixation– JC Coetzee, P Ebeling

• 8 cadavers, 3 groups– Intact ligaments– Syndesmosis repaired with screw

– Syndesmosis repaired with tightrope• Construct cycled under submaximal loads• Syndesmotic gap less after loading (p=0.0004) in screw group compared to control and

tightrope• Increased coronal (p=0.0002) and sagital (p=0.005) plane motion after cycling in

tightrope group compared to control• Decreased coronal (p=0.00014) and sagital (p=0.0000012) plane motion after cycling in

tightrope group compared to control • Study conclusions: Tightrope construct more closely mimicked physiologic syndesmotic

motion

Klitzman R, Zhao H, Zhang LQ, Strohmeyer G, Vora A. Suture-button versus screw fixation of the syndesmosis: a biomechanical analysis. Foot Ankle Int 2010 Jan;1(1):69-74

• Prospective; sequential patients• 16 patients• All with associated fractures• Mean follow-up 5.5 months• Mean time to weight bearing 6 weeks• No re-displacement• 3 hardware removal (2 infection, 1 soft tissue irritation)

D. McMurray, B. Hornung, B. Venkateswaran, Z. Ati. Walking a tightrope: Our experience in the treatment of traumatic ankle syndesmosis rupture. Injury Extra 2008;39:182.

• Retrospective review of 25 cases over 2y. Single Hospital• Mean follow-up 10.8 months• 21 using single tightrope, 4 using double tight rope• Associated ankle fractures treated according to AO principles• Mean time to weight bearing 5.5wks• No evidence of re-displacement of syndesmosis • No cases of hardware removal• “Considered a good option”

Cottom JM, Hyer CE, Philbin TM, Berlet GC. Treatment of syndesmotic disruptions with the Arthrex Tightrope: a report of 25 cases. Foot Ankle Int 2008 Aug;29(8)773-80.

• Retrospective review, single hospital• 6 cases met inclusion criterion• 5 cases associated with ankle fracture• Mean follow-up 6 months• Mean time to weight bearing 6 weeks• No evidence of re-displacement • 2 cases of hardware removal secondary to soft tissue irritation

Willmott HJS, Singh B, David LA. Outcome and complications of treatment of ankle diastasis with tightrope fixation. Int J Care Injured 2009;40:1204-5.

• Ongoing RCT• Average follow-up 18.5 months• 8 patients per group• AOFAS (Ankle an hindfoot score) 94 vs 88• No evidence of syndesmotic loosening• 1 tightrope removal for soft tissue irritation• Trend toward increased ROM in tightrope group however screw not routinely

removed

Coetzee JC, Ebeling P. Treatment of syndesmosis disruptions with TightRope fixation. Techniques in Foot and Ankle Surgery. 2008;7(3):196-202.

Conclusions• Limited literature

• Appears to be a safe option

– No published evidence for re-displacement

• May necessitate tightrope removal (0-33%)

• Better range of motion compared to intact in situ screw in biomechanical testing

Conclusions• Preserve physiologic motion?

– Compared with intact syndesmosis screw. Most likely• Reduce hardware pain?

– Maybe?• Eliminate need for second surgery?

– Maybe?• Earlier return to motion/activity?

– Doesn’t seem to be

Clinical Exam – The Classics 2. Squeeze test

3. External rotation test4. Fibular translation

1. syndesmotic pain

• Length of tenderness measured from tip of lateral malleolus correlates with time to return to sport in sprains with no diastasis

Tenderness LengthIn the absence of diastasis

Nussbaum et al (2001)

Tenderness LengthIn the absence of diastasis

Days Lost = 5 + [0.93xTL(cm)] +/- 3.7 Nussbaum et al (2001)

• Retrospective review of 106 cases• 76 underwent formal testing (mean f/u 23 mo) • Outcomes: Lower Extremity Measure (LEM) and Olerud Molander score (OM)• Decreased functional outcome in patients with intact syndesmosis screws.

(LEM, p=0.01; OM, p=0.04)• No functional difference between broken, loose or removed syndesmosis

screws

Manjoo A, Sanders DW, Tieszer C, MacLeod MD. Functional and radiographic results of patients with syndesmotic screw fixation: implications for screw removal. J Orthop Trauma. 2010 Jan;24(1):2-6.