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Athanasios Badekas M.D.
6,Kesarias str, 11527
Athens, Greece
Director of the Athineon Hospital,Foot and Ankle Disorders Dpt
President of the Greek Foot and Ankle Society
Council Member of EFAS (European Foot and Ankle Society)
Chairman of the EFAS Scientific Committee
Ankle Syndesmotic Joint
• Anterior Inferior Tibiofibular Ligament
• Posterior Inferior Tibiofibular Liament
• Interosseous Ligament
– Maximal Strain with External Rotation & Dorsiflexion
“High Ankle Sprain” =
Syndesmotic Injury
• Uncommon Injury
• Boytim AJSM 19:294 1991
– Only 18 syndesmotic injuries (vs 80 lateral ankle sprains) over 6 years in Minnesota Vikings
• Hopkinson Foot & Ankle 10:325 1990
– 15 Syndesmotic Injuries (vs 367 lateral ankle sprains) over 3.5 years in West Point Cadets
Mechanism of Injury
• No mechanism has produced an isolated syndesomosis sprain in the lab
• Most believe it is a combination of external rotation and dorsiflexion
• High energy injury - unusual below college level
Anatomy
• Anterior Tibiofibular Ligament - lies just proximal to the mortise over the syndesmosis
• Interosseous Ligament - Fibrous membrane between tibia and fibula extending far up into the leg
• Posterior Tibiofibular Ligament - Very strong. Acts as a labrum to the posterior talus.
Diagnosis - Physical Examination
• Taylor AJSM 20:146 1992
– Noted importance of tenderness over AITFL in diagnosis (Duke Football Players)
Physical Examination
• Squeeze Test
– Compress Fibula to Tibia above midpoint of leg
– Positive test is pain distally at the level of the syndesmosis
– 9 of 10 patients with positive a squeeze test developed heterotopic ossification of IO ligament
External Rotation Stress Test
• Foot and Ankle are externally rotated while knee is held flexed at 90 degrees
• Pain at syndesmosis is indicative of injury
Radiographic Evaluation
• Mortise View most useful
– Interosseous Clear Space < 6mm (1 cm above joint line)
– If any question, should be compared to contralateral extremity
• Medial Clear space widening (< 4mm)
• Avulsion Fx in syndesmosis (Unusual)
• Frank diastasis - rare. Look for Maisoneuve Fracture
Stress Radiography
• Dorsiflexion & External Rotation of ankle with foot at neutral and knee at 90
• Best results with intra articular block for comfort
• Flouroscopic examination allows for direct observation of widening
• Single stress view will document widening (+/-)
Other Studies...
• MRI Scan - will show disruption of anatomic structures
• Bone Scan - Will show increased uptake of isotope at diastasis
• Arthrogram - leakage of dye proximally above plafond
• Ultrasound - Mostly in Europe
Treatment
• Key to succesful treatment is early detection
• High level of suspicion required to make diagnosis
• Remember… High energy injury + unusual mechanism
Acute Classification
Clanton & Schon 1993
in Mann’s Surgery of the Foot & Ankle
Type 1 - Sprain without Diastasis
Type 2 - Latent Diastasis
Type 3 - Frank Diastasis
a. Subluxation without fracture
b. Plastic Deformation of the fibula
c. Displacement of Talus into the mortise
Treatment -
Grade 1 - Clinical signs of sprain
with no diastasis
• Non-Weight Bearing in SLC X 3 Weeks, then WB in SLC or Boot Walker X 3 Weeks.
– Out of Walker for Active DF & PF
– Graduate ankle rehab after 6 weeks
Treatment
Grade 2 - Widening of Syndesmosis on Stress Radiographs
• Depends on stability:
• Stable Injury :
– NWB in SLC (vs LLC !!!) X 4-8 Weeks
– Rehab & Ween out of boot walker over next 2-4 weeks
• Unstable Injury :
– Fixation with Syndesmotic Screw
– WB in SLC @ 6 Weeks
– Screw Removal at 12 Weeks
Treatment
Grade 3 : Gross Disruption of Syndesmosis
• Reduction and Fixation of Syndesmosis with Cortical Screws
• NWB in SLC X 6 Weeks
• Screw Removal at 12 Weeks
– Important to Check Syndesmosis stability at time of screw removal (ie. flouroscope) to verify healing. If still unstable… Replace screw!
Return to Play
• Grade 1 : Usually 5 - 7 Weeks
• Grade 2 with Cast Treatment:
– Minimum of 8 Weeks. More usual 12 Weeks.
• Grade 2 & 3 with Operative Treatment:
– Athletics in 5 - 6 months
Complications…
• Most common is failure to recognize injury… if left untreated, requires much more extensive surgery than acute.
• Technical Problems in Treatment
• Late Problems of Treatment
Technical Problems
• Failure to Reduce Syndesmosis
– Must verify flouroscopically during case
• Failure to Reduce Medial Clear Space
– Deltoid Ligament or Posterior Tibial Tendon can be caught in medial ankle
• Incorrect application of hardware
– “Lagging” syndesmosis together
– Application of screw with ankle in plantarflexion
Late Problems
• Screw Failure
– Avoid by hardware removal before return to full activities (3 - 6 months)
– Retrieval of broken screw in tibia can be problematic depending on how the hardware was placed
– Some advocate use of bioabsorbable screw fixation
• Strength of hardware
• Sterile abscess
Late Problems
• Heterotopic Ossification of Syndesmosis
– Hopkinson Foot & Ankle 10:325 1990
• 9/10 on long term evaluation - all asymptomatic
– Veltri Foot & Ankle 16:285 1995
• Report of 2 cases of symptomatic HO requiring resection in collegiate and professional Football
• Synostosis of Fibula to Tibia
– Very Rare, but reported
– May occur with stress fracture
– requires surgical excision if symptomatic, but may recur
Tibiofibular Instability
• Chronic pain over AITFL
• Worsens with exercise. Twisting & cutting.
• May be associated with ankle instability
• Associated with unrecognized syndesmosis injury in ankle fractures
Radiographic Examination
• X-Rays may be normal
• MRI can show rupture of AITFL, Edema of Ligament or interosseus membrane, Interposed tissue in syndesmosis
• External Stress X-Ray may be positive
Chronic Sprains : Physical Examination
• Pain with external rotation stress testing
• Tender over AITFL
• New Test : Syndesmosis Stability Test
Amendola & Frost : Presented at AAOS 3/3/01
- Leg wrapped tightly with tape 6 – 10 cm above ankle.
- Patient asked to jump on one leg or twist attempting to reproduce symptoms
- If taping relieves symptoms, operative stabilization may be indicated.
Amenodola & Frost : Diagnosis & Treatment of Syndesmosis Sprains of the Ankle.
• 14 Patients with isolated injury to syndesmosis injury
• Normal Radiographs
• Positive Stress Test
• 12/14 improved with stabilization
• NWB 8 Weeks, Screw Removal 10 Weeks
Unrecognized Injury with Fracture
• AITFL in some cases originates below ankle
• Unrecognized injury may lead to chronic pain and instability of ankle
• Assess Fibular Length/Rotation.
– Most common deformity is shortened & externally rotated
– Beware of plastic deformation of the fibula in young patients
Sneden & Shea : Diastasis with low distal fibula fractures. CORR 1/01
• Reported 2 patients with syndesmosis diastasis following Weber B ankle fractures
• Anatomic study 1/18 (6%) AITFL originates below tibiotalar joint
Harper : Delayed Reconstruction of the Tibiofibular Syndesmosis. Foot & Ankle 1/01
• 6 Patients with chronic tibiofibular diastasis
• All treated with debridement of syndesmosis & screw reduction. 1 with tibiofibular arthrodesis.
• 5/6 Good results. No Fibular malrotation or shortening noted
Conclusions
• Detection of syndesmosis injury require a high level of suspicion.
• Radiographs are often normal.
• Dorsiflexion & External Rotation + High Energy!
• Repeat physical examination is key to diagnosis
• Stable injuries require cast immobilzation
• Unstable injuries require operative fixation
• Interosseous HO is common and may be symptomatic
• Chronic instability treated with open debridement of syndesmosis, repair AITFL & Screw Fixation
Bibliography
-Amendola A: Controversies in diagnosis and management of syndesmosis injuries of the Ankle. Foot & Ankle 1992;13 44-50
-Boytim MJ, Fischer DA, Neumann L: Syndesmotic ankle sprains. Am J Sports Med 1991; 19 294-298
-Clanton To; Schon LC: Athletic injuries to the soft tissues of the foot and ankle, in Mann RA, Coughlin MJ: Surgery of the Foot & Ankle, ed 6. St Louis, MO, CV Mosby, 1993,vol 2, pp 1095-1224
-Conlin FD, Johnson PG., Sinning JE Jr: Theetiologyand repair of rotatory ankle instability. Foot & Ankle 1989; 10:152-155
-Diamond JE: Rehabilitation of ankle sprains. Clin Sports Med 1989;8:877-891
-Harper MC: Talar shift: The stabilizing role of the medial, lateral, and posterior ankle structures. Clin Orthop 1990;257:177-183
-Harper MC, Keller TS: A radiographic evaluation of tibiofibular syndesmosis. Foot & Ankle 1989; 10:156-160
-Hopkinson WJ, St Pierre P, Ryan JB, et al: Syndesmosis sprains of the ankle. Foot & Ankle 1990; 10:325-330
Karlsson J, Bergsten T, Peterson L, Zachrisson BE: Radiographic evaluation of ankle joint instability. Clin Orthop 226:169-173, 1988
Larsen, E.: Experimental instability of the ankle. Clin Orthop., 204:193-200, 1986
-Laurin CA, Fleming LL, Hamilton WG, et al: Symposium : ligamentous injuries about the ankle. Contemp. Orthop. 1992;25 81-100
-Sammarco GJ, Hockenbury RT: Biomechanics of the Foot & Ankle. Chapter 9, pp222-255. Basic Biomechanics of the Muscoloskeletal System 3rd edition Nordin M, Frankel VH, 2001.
-VanDijk CN. PhD Thesis on diagnostic strategies in patients with severe ankle sprain. Amsterdam, 1994
-Veltri: Report of two cases of symptomatic heterotopic ossification requiring resection in collegiate and professional Football. Foot & Ankle 1995; 16;285
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