Ankle Syndesmosis
Normal Anatomy
· Distal tibiofibular syndesmosis made up of several ligaments
o Anterior tibiofibular ligament
o Posterior tibiofibular ligament
o Transverse tibiofibular ligament
o Interosseous tibiofibular ligament
· Strongest connection between tibia and fibular is by the interosseous tibiofibular ligament
· During dorsiflexion the fibula moves laterally and posteriorly
· During plantarflexion the fibula moves medially and anteriorly
· From plantarflexion to dorsiflexion the distance between the medial and lateral malleolus increases
· The syndesmotic ligaments restrict lateral movement of the fibula
Pathology
· External rotation of the foot causes disruption of the anterior syndesmotic ligaments
· Disruption to the syndesmotic ligaments can increase fibula lateral movement and therefore lead to instability
· Large external rotation force and increased fibula movement can lead to complete tibiofibular diastasis (separation)
· Diastasis usually occurs in combination with medial and sometimes lateral malleolus fractures
Mechanism of Injury
Traumatic
· Forced external rotation of the foot
o Rapidly pivoting internally with the foot planted in an externally rotated position
o Valgus force to a planted foot in a tackle
o Direct blow to the lateral aspect of the heel
· Forced Dorsiflexion
Classification
· Multiple classification systems based on clinical findings, MRI
· Porter Clinical Grades
Grade 1
· Injury to anterior deltoid ligament
· Injury to distal interosseous ligament
· Nil tear of proximal syndesmosis or deep deltoid ligament
· Stable
Grade 2
· Disruption of anterior and deep deltoid ligaments
· Tear in syndesmosis
· Unstable Ankle with normal alignment on radiographs
Grade 3
· Complete disruption of deltoid, anterior and syndesmotic ligaments
· Proximal fibula fracture (Maisonneuve fracture)
· Unstable clinical and on radiographs
Associated Pathologies
· Deltoid ligament sprains
· Weber Type B Fracture
o Lateral malleolus fracture level with the talar dome
· Weber Type C Fracture
o Lateral malleolus fracture above the ankle joint
· Maisonneuve fractures
o Spiral fracture of the proximal third of the fibula
· Osteochondral Lesions
Examination
Subjective
· Pain above ankle joint line
· Traumatic history of forced external rotation
· Pain with pivoting internally with a planted foot
· Pain with “pushing off” during gait or running
· History of sports requiring a boot that fixes the ankle such as skiing or hockey
Objective
· Swelling anterior medial ankle joint
· Painful Dorsiflexion
· Painful External rotation of the foot
· Tenderness over distal anterior tibiofibular ligament
· Tenderness along the interosseous membrane
Special Tests
· Passive dorsiflexion
· Squeeze test
· External Rotation Stress Test
· Crossed Leg Test
· Cotton Stress Test
· Fibular Translation
Further Investigations
· X-ray
· CT
· MRI
Management
· Prolonged recovery time
· Surgery not always considered if a fracture is present
o Weber Type C Fracture is unstable and usually operated on
o Weber Type B Fracture maybe stable or unstable
· Conservative management considered where injury is stable
· If symptoms persist longer than 6 months surgery is considered
Conservative
· Period of immobilisation if fracture is present
· (Williams and Allen 2010) for a detailed rehabilitation programme
· Reduce pain and inflammation
o Immobilisation
o NSAID’s
o Ice
o Massage
· Restore Normal Range of Movement
o Ankle
§ Massage
§ Joint mobilisation
§ Joint manipulation
· Restore Normal Muscle Activation
o Evertors
o Invertors
o Plantarflexors
o Dorsiflexors
o Intrinsic Foot Muscles
· Restore Dynamic Stability
o Proprioceptive Training
· Sport Specific Training
Plan B
· Dependent on instability and fracture sites
o Arthroscopic debridement
o Screw fixation
o Arthrodesis (joint fusion)
References
(Bloemers and Bakker 2006, Williams and Allen 2010, McCollum, van den Bekerom et al. 2013, Sman, Hiller et al. 2013, Magan, Golano et al. 2014, Miller and Skalak 2014, Porter, Jaggers et al. 2014, Van Heest and Lafferty 2014)
Bloemers, F. W. and F. C. Bakker (2006). "Acute Ankle Syndesmosis Injury In Athletes." European Journal of Trauma 32(4): 350-356.
Magan, A., P. Golano, N. Maffulli and V. Khanduja (2014). "Evaluation and management of injuries of the tibiofibular syndesmosis." Br Med Bull 111(1): 101-115.
McCollum, G. A., M. P. van den Bekerom, G. M. Kerkhoffs, J. D. Calder and C. N. van Dijk (2013). "Syndesmosis and deltoid ligament injuries in the athlete." Knee Surg Sports Traumatol Arthrosc 21(6): 1328-1337.
Miller, T. L. and T. Skalak (2014). "Evaluation and treatment recommendations for acute injuries to the ankle syndesmosis without associated fracture." Sports Med 44(2): 179-188.
Porter, D. A., R. R. Jaggers, A. F. Barnes and A. M. Rund (2014). "Optimal management of ankle syndesmosis injuries." Open Access J Sports Med 5: 173-182.
Sman, A. D., C. E. Hiller and K. M. Refshauge (2013). "Diagnostic accuracy of clinical tests for diagnosis of ankle syndesmosis injury: a systematic review." Br J Sports Med 47(10): 620-628.
Van Heest, T. J. and P. M. Lafferty (2014). "Injuries to the Ankle Syndesmosis." The Journal of Bone & Joint Surgery 96(7): 603-613.
Williams, G. N. and E. J. Allen (2010). "Rehabilitation of Syndesmotic (High) Ankle Sprains." Sports Health: A Multidisciplinary Approach 2(6): 460-470.
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